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SpaceX Vehicles and Missions => SpaceX Starship Program => Topic started by: Chris Bergin on 01/28/2019 02:12 am

Title: Developing the BFS - Phase 1 - StarHopper - Discussion - THREAD 3
Post by: Chris Bergin on 01/28/2019 02:12 am
Thread 3 for the discussion of Starship Hopper. Keeping BFH just for housekeeping and some familiarity. Starting it now as Thread 2 is huge and could use a new thread and there's going to be some major milestones coming in the life of this Thread 3!

Resources:

Discussion Thread 1:
https://forum.nasaspaceflight.com/index.php?topic=47022.0

Discussion Thread 2:
https://forum.nasaspaceflight.com/index.php?topic=47113.0

UPDATES ONLY Thread:
https://forum.nasaspaceflight.com/index.php?topic=47120.0

L2 SpaceX Boca Chica Photos/Videos Update Thread (now a new standalone thread out of L2 SpaceX Pads and Facilities due to the surge in content with different views of the ongoing work):
https://forum.nasaspaceflight.com/index.php?topic=47107.0

---

Remember the rules. Civil at all time. Make sure you post is useful. Want to crack a joke about shiny things, use the party thread. Be on topic. Start a new thread if you want to discuss splinter topics. Now, I'll let you get on with your business ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: guckyfan on 01/28/2019 04:15 am
https://forum.nasaspaceflight.com/index.php?topic=47113.msg1905773#msg1905773

@Norm38

Quote
Just getting caught up. The tank section with the dome top suddenly looks flight worthy for short hops. Just like the old Grasshopper.
Without the windstorm I would have flown it combined. But why wait?
I’d do every sub 100ft hop as is.

Elon gave a repair time of ~2 weeks, probably shorter than the time to build the pad and finish the hopper. They may change their plans and abandon the fairing, however.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JonathanD on 01/28/2019 04:20 am
More importantly, they don't have the engines yet.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 01/28/2019 04:49 am
https://forum.nasaspaceflight.com/index.php?topic=47113.msg1905773#msg1905773

@Norm38

Quote
Just getting caught up. The tank section with the dome top suddenly looks flight worthy for short hops. Just like the old Grasshopper.
Without the windstorm I would have flown it combined. But why wait?
I’d do every sub 100ft hop as is.

Elon gave a repair time of ~2 weeks, probably shorter than the time to build the pad and finish the hopper. They may change their plans and abandon the fairing, however.
I don't think he said they'll repair the fairing, but rather the hopper as a while.  Given how fast it was to build it, I'd expect a new fairing to be built...

But as people are pointing out, there's no rush.  They can even do it on the pad and assemble it there.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OneSpeed on 01/28/2019 08:57 am
Quote from: su27k link=topic=47113.msg1905446#msg1905446
Upper manhole center is about 1.2m from the top edge, if this hole is indeed at the mid point of the LOX tank that gives LOX tank height at 2.4m, dome height is ~2.6m, dome volume is about 80m^3, total LOX tank volume is 311m^3, which is 355t of LOX.

Mixture ratio is 3.6, so methane mass would be ~99t, which gives methane tank height ~3.7m, total hopper height is 12m, so distance between lowest point of the methane tank to lower edge of the hopper is 12 - 2.4 - 3.7 - 2.6 = 3.3m

Total propellant load is 454t, still seems high, since first prod Raptor may not reach 200t thrust. Maybe they'll just let it thrust for a while on the pad until T/W is high enough for liftoff, I think Soyuz uses this method.

Perhaps we should also subtract the volume of the triangular support structure inside the LOX tank?

I measure them as 1mØ tubes, giving a volume of about cos(30°) * 8.875 * 3 * Π * 0.5^2 = 18m^3 for a total of 311 - 18 = 293m^3. As well, LOX ullage is typically about 6%, so the actual volume of LOX might only be 293 * 0.94 = 275m^3. I'm not sure how cryogenic the propellant will be for the StarHopper, but assuming a density of 1,141 kg/m^3, that would be 275 * 1.141 = 314t of LOX. For a LOX:CH4 mass ratio of 3.6, that would be 314 / 3.6 = 87t of CH4, for a total of 314 + 87 = 401t of propellant. Even if the StarHopper is on the heavy side, say 100t dry, 3 Raptors at 200t thrust would give an initial T/W of 600/501 = 1.2.

I'm not sure of the likely ullage requirement for liquid methane, but guessing 5%, and density of 424kg/m^3, the volume would be 87 * 1.05 / 0.424 = 215.5 m^3, which would correspond to an additional 3.5m for the methane tank. In cross section it might look something like this:
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Zephyrox on 01/28/2019 09:49 am
Quote from: su27k link=topic=47113.msg1905446#msg1905446
Upper manhole center is about 1.2m from the top edge, if this hole is indeed at the mid point of the LOX tank that gives LOX tank height at 2.4m, dome height is ~2.6m, dome volume is about 80m^3, total LOX tank volume is 311m^3, which is 355t of LOX.

Mixture ratio is 3.6, so methane mass would be ~99t, which gives methane tank height ~3.7m, total hopper height is 12m, so distance between lowest point of the methane tank to lower edge of the hopper is 12 - 2.4 - 3.7 - 2.6 = 3.3m

Total propellant load is 454t, still seems high, since first prod Raptor may not reach 200t thrust. Maybe they'll just let it thrust for a while on the pad until T/W is high enough for liftoff, I think Soyuz uses this method.

Perhaps we should also subtract the volume of the triangular support structure inside the LOX tank?

I measure them as 1mØ tubes, giving a volume of about cos(30°) * 8.875 * 3 * Π * 0.5^2 = 18m^3 for a total of 311 - 18 = 293m^3. As well, LOX ullage is typically about 6%, so the actual volume of LOX might only be 293 * 0.94 = 275m^3. I'm not sure how cryogenic the propellant will be for the StarHopper, but assuming a density of 1,141 kg/m^3, that would be 275 * 1.141 = 314t of LOX. For a LOX:CH4 mass ratio of 3.6, that would be 314 / 3.6 = 87t of CH4, for a total of 314 + 87 = 401t of propellant. Even if the StarHopper is on the heavy side, say 100t dry, 3 Raptors at 200t thrust would give an initial T/W of 600/501 = 1.2.

I'm not sure of the likely ullage requirement for liquid methane, but guessing 5%, and density of 424kg/m^3, the volume would be 87 * 1.05 / 0.424 = 215.5 m^3, which would correspond to an additional 3.5m for the methane tank. In cross section it might look something like this:

Can someone please explain to a frenetic kerballer how the Center of mass on that thing isn't going to make it do a u turn once in the air?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Crispy on 01/28/2019 10:01 am
Can someone please explain to a frenetic kerballer how the Center of mass on that thing isn't going to make it do a u turn once in the air?
It'll be dynamically unstable, just like any VTVL rocket, but the engine control is good enough to keep it balanced (unlike the Auto mode in Kerbal!)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Semmel on 01/28/2019 10:52 am
Can someone please explain to a frenetic kerballer how the Center of mass on that thing isn't going to make it do a u turn once in the air?

Many people here guess that the tinfoil hat is purely cosmetic. I challenge them for the exact reason you give. I think (speculation!) the tinfoil hat is as large as it is to make the hopper aerodynamically stable on the way down. The current design would have a strong tendency to head dive into the ground, active control or not. With the large hat though, the aero forces should right it up, o at least make the margin for errors much larger. I have no way o proving that though.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 01/28/2019 10:59 am
Can someone please explain to a frenetic kerballer how the Center of mass on that thing isn't going to make it do a u turn once in the air?

Many people here guess that the tinfoil hat is purely cosmetic. I challenge them for the exact reason you give. I think (speculation!) the tinfoil hat is as large as it is to make the hopper aerodynamically stable on the way down. The current design would have a strong tendency to head dive into the ground, active control or not. With the large hat though, the aero forces should right it up, o at least make the margin for errors much larger. I have no way o proving that though.
Yes, its affect aerodynamic on the way up and down, good point in that it will increase stability by moving center of drag up. it also make the hopper more like the final version aerodynamically giving better test data.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 01/28/2019 11:04 am
RE: the cylinders at the base of the hopper
there's no real way to tell what's in them, but the labels on them are green which I believe indicates inert gasses. Since they're all clustered together they're probably all homogeneous. Depending on the process they're using, the cylinders could be full of Argon, an Argon/CO2 mix, or maybe even some helium, although I doubt that.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 01/28/2019 03:44 pm
The brown cylinders are Argon, the bluish green cylinders are oxygen. The cylinder cap doesn't always indicate anything but in this case do appear to be color matched to the cylinders. It also appears that there is one yellow or dirty yellow bottle there and that is normally breathable air. That is about all I can make out.

Thanks for the great site! This is my first post, but I have been following it closely from the beginning of the hopper construction. Nice to "meet" you all! :D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: georgegassaway on 01/28/2019 04:54 pm
Regarding BocaChicaGal's recent images of scaffolding going up around BFH:
https://forum.nasaspaceflight.com/index.php?topic=47120.msg1905755#msg1905755

Reminded me of Little Joe-I:

(https://cdn.dvidshub.net/media/thumbs/photos/1210/738560/1000w_q95.jpg)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Rei on 01/28/2019 05:42 pm
Very reminiscent.  I expect to soon start seeing lots of pictures of welders out there on the scaffolding turning those tacks into proper welds.  ;)

You know, despite the wind disaster, I have a strong suspicion that something like this ("shipyard"-style construction) is going to end up how the final Super Heavy and Starship are built, rather than in pristine factory conditions.

Musk has a habit of doing things like this: trying some cheap, improvised approach for testing reasons or as a temporary cost savings measure, and then deciding that he likes it so much that it becomes the way forward from there on. For example, at Tesla they built GA4 (General Assembly 4) in a tent in order to get their production rates up on a very limited budget and tight schedule. Much of the line was built out of scrap they had lying around - for example, the conveyor belt that moves the cars was actually a scrapped parts conveyor (since the motor wasn't powerful enough to move whole cars, they simply jacked it up on one end so that gravity assisted it). It turned out that GA4 outperformed their fancy automated GA3 line on both labour cost and QA testing metrics.  Because it was a long tent, trucks just pulled up beside each workstation on the outside of the tent and unloaded the parts straight to the workstation, rather than into a central depot from which they had to to transport parts. Tesla now plans to make future GA lines follow this principle.

If Musk likes how quickly they can put together the hopper like this, and it manages to perform, I fully expect this sort of "shipyard assembly" to be the way Starship and Super Heavy get built as well.  Sure, it can complicate some things (LOX for example doesn't play nice with organic contaminants, you have potential corrosion problems, etc). But if they design for dealing with this... and it's a cheap, fast way to build...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 01/28/2019 06:31 pm
Hopper is a test-bed anomaly hack. Not some new way forward for building the largest, most complex spaceship ever. There is no chance that an SS designed for Crewed Lunar and/or Mars missions will be constructed outside, exposed to the elements for the many months, years it will take to build.

...imo.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 01/28/2019 06:39 pm
Hopper is a test-bed anomaly hack. Not some new way forward for building the largest, most complex spaceship ever. There is no chance that an SS designed for Crewed Lunar and/or Mars missions will be constructed outside, exposed to the elements for the many months, years it will take to build.

...imo.

Or maybe not.

...imo
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 01/28/2019 07:17 pm
This may be nothing but it caught my eye this morning.  ;D

LOX pipe??

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47120.0;attach=1541672;image)

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Rei on 01/28/2019 08:27 pm
I really don't think corrosion is going to be an issue. Starship should be able to sit outside for centuries without corrosion.  The only concerns would be any exposed junctions between dissimilar metals.

Alumium is ostensibly also quite inert, but it's really prone to galvanic corrosion. And when in contact with a dissimilar metal, it's almost always the alumium which corrodes, not the other metal. Doesn't like salt, either; it ruins the protective oxide layer.

I really see no issues with the tankage (incl bulkheads) and fairing being built first out in the open - however long it takes - just like a ship. Once it's weathertight, with a closable opening for lowering hardware into the rocket - the rest of the work can be done from the inside or underneath. Again, very similar to building a ship. The only thing I see that requires a particular caution (apart from *cough* proper anchoring) is that they'd need to clean the LOX tank well (methane isn't particularly sensitive to contaminants).

I just don't see SpaceX making a new VAB.  Or engineering it to lay on its side during construction.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 01/28/2019 08:43 pm
Hopper is a test-bed anomaly hack. Not some new way forward for building the largest, most complex spaceship ever. There is no chance that an SS designed for Crewed Lunar and/or Mars missions will be constructed outside, exposed to the elements for the many months, years it will take to build.

...imo.

Why? Every house, office block etc was built open to the elements until the roof is put on and they can be pretty complicated. As long as the crafts shell is water proof, the work inside can be as compicated as you want. It's already indoors....

Need the bottom kept dry? Attached a tent around the bottom. You can have covered passageways to small buildings where parts are kept.

I'd make proper one in two parts, just like this. That way you don't need to have lifts up the the top outside the craft.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: b.lorenz on 01/28/2019 08:47 pm
Hopper is a test-bed anomaly hack. Not some new way forward for building the largest, most complex spaceship ever. There is no chance that an SS designed for Crewed Lunar and/or Mars missions will be constructed outside, exposed to the elements for the many months, years it will take to build.

...imo.

Or maybe not.

...imo

My guess is that the competing needs for fast and cheap construction vs. clean and controlled environment will meet in the middle.
I can imagine that this would be a closed space, but more akin in its atmosphere to a sci-fi shipyard-- with sparks flying and cranes tossing around hull segments-- than the clean room environment present day deep space vehicles are usually assembled. (After all, Starship would be  a deep space vehicle, that is also half a launch vehicle and also a crewed ship)

I can also imagine, that this 'spaceshipyard' could unite the responsibilites of a factory assembling rocket stages (tanks, piping, wiring, mating engines) and those functions of the integration facility that are not meant to be performed on the pad (inspection, SS-SH mating). So they would ingest low-level components (test-fired raptors, electronics boxes, wires, hull panels) and put out a finished spaceship.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 01/28/2019 10:39 pm
Perhaps they are going to enclose the sprung structure? Caught this load at the main gate this morning.

I might be wrong, but this looks like 2 rollgates on the truck. If they close up the sprung structure, they would have a wind-protected, debris protected area to do some work in. Unfortunately it would also stop us from looking.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 01/28/2019 11:02 pm
I really don't think corrosion is going to be an issue. Starship should be able to sit outside for centuries without corrosion.  The only concerns would be any exposed junctions between dissimilar metals.

Centuries?  ::) I don't think SpaceX will be able to cash the checks your are writing on their behalf. This is the real world, not a world of perfect materials.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Rocket Science on 01/28/2019 11:06 pm
The brown cylinders are Argon, the bluish green cylinders are oxygen. The cylinder cap doesn't always indicate anything but in this case do appear to be color matched to the cylinders. It also appears that there is one yellow or dirty yellow bottle there and that is normally breathable air. That is about all I can make out.

Thanks for the great site! This is my first post, but I have been following it closely from the beginning of the hopper construction. Nice to "meet" you all! :D
Welcome to the forum! :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CraigLieb on 01/29/2019 12:53 am
In a previous job, a small task was setting up OSHA compliant storage areas for compressed gas cylinders both oxidizers and types of other flammable compressed gasses. Here is a link to a nice summary of the rules.

 https://www.aps.anl.gov/files/APS-Uploads/Safety-and-Training/Safety/Experiment-Safety/Hazard-Classes/Compressed-Gas-Cylinder-Storage-Guidelines.pdf

Generally, oxidizers have to be at least 20 feet away from other flammable gasses (like propane) and sorted into empty and full separate sections. Exceptions are if you separate them by a wall with certain characteristics.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 01/29/2019 01:30 am
This may be nothing but it caught my eye this morning.  ;D

LOX pipe??

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47120.0;attach=1541672;image)

Interesting that this particular part seems much more refined than the tank pieces, and they took care of supporting it instead of just laying it on the ground, I wonder why this part needs more precision than the rest?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 01/29/2019 01:43 am
Very reminiscent.  I expect to soon start seeing lots of pictures of welders out there on the scaffolding turning those tacks into proper welds.  ;)

You know, despite the wind disaster, I have a strong suspicion that something like this ("shipyard"-style construction) is going to end up how the final Super Heavy and Starship are built, rather than in pristine factory conditions.

<snip>

If Musk likes how quickly they can put together the hopper like this, and it manages to perform, I fully expect this sort of "shipyard assembly" to be the way Starship and Super Heavy get built as well.  Sure, it can complicate some things (LOX for example doesn't play nice with organic contaminants, you have potential corrosion problems, etc). But if they design for dealing with this... and it's a cheap, fast way to build...

I think the main difficulty of building production level Super Heavy and Starship outside is the tooling. It's ok for prototype to be welded by some welder outside, but presumably for production they'll want to use something like FSW which requires big tooling, and I don't think you'll want your tooling being exposed to weather all the time.

Another concern is wind, it seems that they'll need to stop work whenever wind speed exceeds safety limit, I don't know how often this happens, but this seems to be a productivity killer that you don't want on production lines.

So while I agree that they'll build future prototypes outside (including the prototype orbital Starship and first Super Heavy), I think they'll eventually want a factory. Although when exactly that'll happen depends on a lot of factors (how good the outside work is, their cashflow situation, design maturation, etc).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 01/29/2019 01:46 am
The brown cylinders are Argon, the bluish green cylinders are oxygen. The cylinder cap doesn't always indicate anything but in this case do appear to be color matched to the cylinders. It also appears that there is one yellow or dirty yellow bottle there and that is normally breathable air. That is about all I can make out.
I really can't see why they'd need an oxygen bottle, which is why I didn't suggest it. You can't cut stainless with a fuel-oxy torch. Unless it's for pre- and post- heating welds which is a reasonable suggeestion and now I've convinced myself. Now we just need to find where they're storing the propane/MAP/methane/acetylene.

Interesting that this particular part seems much more refined than the tank pieces, and they took care of supporting it instead of just laying it on the ground, I wonder why this part needs more precision than the rest?
those are pipe stands, you need to use them when you're cutting/welding/prepping pipe to keep them out of the dirt
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 01/29/2019 02:10 am
When fitting seams and forming assorted pieces of heavy gauge material, either carbon steel or stainless steel, a rosebud heating tip is often used to heat a section of metal to red heat to soften it and make it ductile for bending. Heavy gauge stainless is particularly tough stuff. The heating tip would burn either acetylene or propane with oxygen.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Restless on 01/29/2019 04:43 am
I really don't think corrosion is going to be an issue. Starship should be able to sit outside for centuries without corrosion.  The only concerns would be any exposed junctions between dissimilar metals.

Alumium is ostensibly also quite inert, but it's really prone to galvanic corrosion. And when in contact with a dissimilar metal, it's almost always the alumium which corrodes, not the other metal. Doesn't like salt, either; it ruins the protective oxide layer.

I really see no issues with the tankage (incl bulkheads) and fairing being built first out in the open - however long it takes - just like a ship. Once it's weathertight, with a closable opening for lowering hardware into the rocket - the rest of the work can be done from the inside or underneath. Again, very similar to building a ship. The only thing I see that requires a particular caution (apart from *cough* proper anchoring) is that they'd need to clean the LOX tank well (methane isn't particularly sensitive to contaminants).

I just don't see SpaceX making a new VAB.  Or engineering it to lay on its side during construction.

300 series stainless steels are susceptible to chloride stress corrosion/cracking. During much of the year there is a stiff onshore breeze at Boca which will carry particles of salt inland. At a minimum, SH and SS  will need to be protected from this.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Stan-1967 on 01/29/2019 05:42 am
I really don't think corrosion is going to be an issue. Starship should be able to sit outside for centuries without corrosion.  The only concerns would be any exposed junctions between dissimilar metals.

Centuries?  ::) I don't think SpaceX will be able to cash the checks your are writing on their behalf. This is the real world, not a world of perfect materials.

I would point out that both MER rovers & now Curiosity have found iron meteorites on the surface of Mars that have very specular surfaces that were free from iron oxides ( rust)  How long do you think these blobs of metal have been sitting on the Martial surface?  Longer than a few centuries would be my guess.  The composition needs just a bit of nickel to give it a surface oxide resistant to rusting.  Add in some Cr & it gets even more favorable.

I do electrochemistry for a living, & have thought quite a bit about corrosion mechanisms on Mars, as well as using the the available salts & metals in ISRU schemes.   Corrosion requires an anode, cathode, & an electrolyte for ion mobility.  Mars just has very poor ability to provide that last component, i.e the electrolyte.  Surface salts may also be dessicated due to the low pressure, & there is little to no mechanism for atmospheric condensation to sustain a galvanic cell in mid equatorial to equatorial latitudes.  The polar areas of Mars do have ice sublimation & condensation occurring, and corrosion can at least happen in those conditions, albeit very slowly as the low temperature slows the process down. 

From standpoint of BFS ship design, I would worry more about the interior of the ship than the exterior.  The habitable pressurized sections will be most vulnerable, as human sweat, oils, waste etc., all will enable corrosion cells. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Stan-1967 on 01/29/2019 06:15 am
I would also add that while I don't see corrosion of SH on Mars to be a problem, that is not the case for storing BFS outdoors on Earth, & most especially any coastal location.  Corrosion will find a way to do its thing, & very active measures will be needed.  Still should not be a show stopper, aircraft operations have good practices to inhibit corrosion.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bynaus on 01/29/2019 06:59 am
I would point out that both MER rovers & now Curiosity have found iron meteorites on the surface of Mars that have very specular surfaces that were free from iron oxides ( rust)  How long do you think these blobs of metal have been sitting on the Martial surface?  Longer than a few centuries would be my guess.  The composition needs just a bit of nickel to give it a surface oxide resistant to rusting.  Add in some Cr & it gets even more favorable.

Actually the surface residence ages of the meteorites the MER rovers found has been estimated to be on the order of a billion years (Bland & Smith, 2000 Icarus (http://adsabs.harvard.edu/abs/2000Icar..144...21B)). Most of them are iron meteorites or (iron-rich) pallasites, and in both cases the iron does contain a significant amount (~5-15%) of Ni and some trace amounts (<1%) of Cr.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 01/29/2019 07:26 am
I really don't think corrosion is going to be an issue. Starship should be able to sit outside for centuries without corrosion.  The only concerns would be any exposed junctions between dissimilar metals.

Centuries?  ::) I don't think SpaceX will be able to cash the checks your are writing on their behalf. This is the real world, not a world of perfect materials.

I would point out that both MER rovers &amp; now Curiosity have found iron meteorites on the surface of Mars that have very specular surfaces that were free from iron oxides ( rust)  How long do you think these blobs of metal have been sitting on the Martial surface?  Longer than a few centuries would be my guess.  The composition needs just a bit of nickel to give it a surface oxide resistant to rusting.  Add in some Cr &amp; it gets even more favorable.

I do electrochemistry for a living, &amp; have thought quite a bit about corrosion mechanisms on Mars, as well as using the the available salts &amp; metals in ISRU schemes.   Corrosion requires an anode, cathode, &amp; an electrolyte for ion mobility.  Mars just has very poor ability to provide that last component, i.e the electrolyte.
[snip]

I’m not worried about Mars exposure. Earth exposure is another thing. The idea that a stainless steel starship could sit out exposed to a Earths atmosphere for centuries is preposterous. Do you as a chemist disagree?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: strato1 on 01/29/2019 08:03 am
It looks like they may be enclosing the sprung structure prior to nose cone disassembly in order to hide it from view.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: zodiacchris on 01/29/2019 08:39 am
I’d rather think they enclose it to keep it out of the wind, for once they start chopping and changing they’ll have a lot of thin sheet fluttering around in the breeze...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 01/29/2019 09:07 am
It looks like they may be enclosing the sprung structure prior to nose cone disassembly in order to hide it from view.

Or they expect the actual engines. These would would require some protection from prying eyes because of ITAR.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cheapchips on 01/29/2019 09:22 am
It looks like they may be enclosing the sprung structure prior to nose cone disassembly in order to hide it from view.

Or they expect the actual engines. These would would require some protection from prying eyes because of ITAR.

They shouldn't really be taking them apart.  A rocket engine from the outside is hardly sharing military secrets.  At a recent event Blue pretty much let people go up at touch a BE4.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Jet Black on 01/29/2019 10:06 am
It looks like they may be enclosing the sprung structure prior to nose cone disassembly in order to hide it from view.

Or they expect the actual engines. These would would require some protection from prying eyes because of ITAR.

They should really be taking them apart.  A rocket engine from the outside is hardly sharing military secrets.  At a recent event Blue pretty much let people go up at touch a BE4.

iirc, the ITAR bit is usually the pintle injector, which is why they have a bung in the nozzle to hide them.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Rei on 01/29/2019 11:06 am
I really don't think corrosion is going to be an issue. Starship should be able to sit outside for centuries without corrosion.  The only concerns would be any exposed junctions between dissimilar metals.

Centuries?  ::) I don't think SpaceX will be able to cash the checks your are writing on their behalf. This is the real world, not a world of perfect materials.

You may not believe that stainless steel lifespans exposed to the elements are centuries or longer, but that's the reality.

https://www.bssa.org.uk/topics.php?article=51

The estimated time to penetrate 1mm of 316 stainless in marine environments is 260 years; in semi-industrial environments, 525 years; and in rural areas, 1200 years.

The 10000-year lifespan Clock of the Long Now is made primarily out of 316 stainless.

Corrosion will simply not be an issue.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Rei on 01/29/2019 11:17 am
I think the main difficulty of building production level Super Heavy and Starship outside is the tooling. It's ok for prototype to be welded by some welder outside, but presumably for production they'll want to use something like FSW

Who friction-stir welds stainless?  I'm not even sure that's possible to do in a practical manner; the tool has to be a lot harder and more durable than the material you're welding, or it's going to wear out very quickly.

Giant pressuretight steel tanks are welded all the time outdoors.  Nothing radical about that at all.

As for your wind concern, do you see shipbuilders building giant VABs around their ships for that reason?  Suspensions due to severe weather rare enough as to not come close to justifying the cost.  And once the structure is weathertight, you can work inside without weather concerns.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: guckyfan on 01/29/2019 12:23 pm
Corrosion will simply not be an issue.

I hope that is true. After all the point to point flights will be from marine platforms for noise reasons.

I wonder about another issue. I have heard about corrosion from atomic oxygen in space, even at ISS altitudes. I wonder what that would do to the mirror finish of the surface? Or is this a matter of exposure over many years?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Robotbeat on 01/29/2019 12:27 pm
It looks like they may be enclosing the sprung structure prior to nose cone disassembly in order to hide it from view.

Or they expect the actual engines. These would would require some protection from prying eyes because of ITAR.
I wonder about that. There are lots of engines just exposed directly to the public (sometimes even cut in half so you can see inside) in museums and rocket gardens all over the country, some of which are designs better suited to development into ICBMs than Raptor.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 01/29/2019 01:08 pm
Corrosion will simply not be an issue.

I hope that is true. After all the point to point flights will be from marine platforms for noise reasons.

I wonder about another issue. I have heard about corrosion from atomic oxygen in space, even at ISS altitudes. I wonder what that would do to the mirror finish of the surface? Or is this a matter of exposure over many years?
All stainless steel surfaces will be covered in a layer of oxide, so that should help. This is one of many things that will be tested during the orbital re-entry of the prototype.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 01/29/2019 03:10 pm
Are they enclosing the spring structure, or just screening the camera-facing end of it? If they fitted out both ends in the manner the 'front' currently is, the collapsed nosecone would be stuck in there forever unless the structure was disassembled again.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 01/29/2019 03:19 pm
Dunno, might have some very high doors. But the structure is made to be assembled and disassembley quickly, so should not be a problem if you have to take a wall down to get the fairing out again.

( Oh, and if the initial BFR architecture is still in use in centuries, and not replaced by something more advanced, Elon will rotate in his grave and haunt the slackers resting on his laurels. The effective lifetime of a Starship is unlikely to depend on oxidization of all things. More likely on flight cycles. )
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 01/29/2019 03:26 pm
(Oh, and if the initial BFR architecture is still in use in centuries...)

Talking in a hyperbolic nature to show that oxidation will not be a problem for the time it takes to construct, move, and launch the Starship.

But I agree that Musk would roll over in his grave.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 01/29/2019 03:45 pm
But I agree that Musk would roll over in his grave.
Why? I see no reason why they shouldn't reuse them in storage roles once their service life is up, they're still whopping big sturdy stainless steel structures.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: strato1 on 01/29/2019 03:54 pm
They are doing the same thing they did in Fremont when they needed to keep cameras out.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 01/29/2019 03:55 pm
I look forward to the day that a first flight STARTS with re-entry and a subsequent landing rather than finishes with it. (ships built in orbit that then land)... but that's a long way off.

The idea of building spaceships using ship building techniques or at least airliner techniques is very compelling. I think we will see a meet in the middle approach.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Stan-1967 on 01/29/2019 04:36 pm

I’m not worried about Mars exposure. Earth exposure is another thing. The idea that a stainless steel starship could sit out exposed to a Earths atmosphere for centuries is preposterous. Do you as a chemist disagree?

I agree that corrosion during earth exposure is an issue that BFS will have to deal with, & it is not a trivial consideration.  It will be an important design consideration.  Do a quick Google of "Abandoned DeLoreans" for how I think a BFS left outdoors will look after a few decades. 

 I will also note that I know for certainty that SpaceX has consulted with people in electrochemical industries like mine for various solutions. ( not necessarily corrosion related)  They have the resources & intelligence to mitigate all these concerns.  It is basic engineering to consider the corrosion failure modes a design creates.

 Stainless steel, while a great corrosion resistant material, is not impervious, especially 301/304 series with lower Ni/Cr content.  The point with corrosion is that is like the killer Terminator robots.  It never sleeps, it doesn't get tired, & it wont stop until it finds a way to kill your metal.    Furthermore, even it the stainless doesn't corrode, everything attached to it is likely to be anodic to it.  ( think hydraulics, fasteners, electronics, etc.)  The huge connected stainless skin is a cathodic current sink for lots of other little parts that are failure modes for the vehicle.

I'll add some observations about the Big Falcon Hopper construction from a corrosion perspective.  I do think this vehicle represents a "hack" to quickly fielding a test vehicle.  I do not think BFS should be built this way.  Here are some problems I saw regarding corrosion.

1.  Field welding ==>  heat affected zones will have variable composition in the grain structure of the metal.  This  is one mechanism how stainless can still fail at highly localized sites ( Cr, Fe, Ni precipitates) and propagate elsewhere.   Welding needs to be more controiled &  characterized.
2.  Welding in open environmental conditions ==> want to bet a dollar that dust, grime & salt of the surrounding Boca Chica area are now incorporated into the weld metallurgy?  Not a problem for BFH, but not advisable on future ships.  There is also dust & salt in the joints where the sheet metal is up against the stringers. 
3.  Polishing of the sheet metal ==>  what was the abrasive or buffing compound used?  How was it rinsed off/removed afterwards?  Want to bet that some of that abrasive is stuck/embedded into the 301 at a microscopic level?  Over time this will corrode out pits in the surface.   The buffing also looked like it took the cold rolled material with the surface scale still intact, welded it, then buffed it.  So that surface scale is now also part of the welds, as well as some impurities buffed into the bulk substrate.  For a production panel, I would do all this indoors & in a controlled environment, & I would chemically remove the scale, & carefully engineer how to polish the surface without producing micro defects.  This does not have to be costly, just well thought out.

Last thing.  I am not a chemist, but I work in the field of electrochemistry.  My education is in Mechanical Engineering, which included general chemistry ( some organic)  & a substantial amount of material science.  My work profession has exposed me to a multitude of industrial challenges involving corrosion protection, wear resistance, cosmetic appearance, & electrical performance of electrodeposited films.  The primary industries I dealt with range from aerospace, automotive, & currently electronics.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 01/29/2019 04:59 pm
3.  Polishing of the sheet metal
Did we see the sheet metal being polished? the base of the hopper was covered in a big shiny sticker and the newly flattened top of the hopper arrived shiny, neither has anything to do with being outside.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: acsawdey on 01/29/2019 05:08 pm
3.  Polishing of the sheet metal
Did we see the sheet metal being polished? the base of the hopper was covered in a big shiny sticker and the newly flattened top of the hopper arrived shiny, neither has anything to do with being outside.

They were polishing the outside of the bottom part at one point but gave up and applied the thin shiny stainless sheets.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RedLineTrain on 01/29/2019 05:28 pm
3.  Polishing of the sheet metal
Did we see the sheet metal being polished? the base of the hopper was covered in a big shiny sticker and the newly flattened top of the hopper arrived shiny, neither has anything to do with being outside.

They were polishing the outside of the bottom part at one point but gave up and applied the thin shiny stainless sheets.

Rather than "giving up," I interpreted that as something they were testing in the field.  Unknown whether the test was successful or not or what they learned otherwise.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RobLynn on 01/29/2019 05:30 pm
Who friction-stir welds stainless?  I'm not even sure that's possible to do in a practical manner; the tool has to be a lot harder and more durable than the material you're welding, or it's going to wear out very quickly.
I am dubious of this too, though it is possible in stainless steel using polycrystaline cubic boron nitride tools.  https://megastir.com/tools/ we are talking apples and oranges (aluminum and stainless steel), and issues that drive use of FSW in aluminum - poor strength of welds, do not affect stainless steel to the same degree.

If you want to use friction welding to do butt joints in thin stainless then ultrasonic is probably just as good and better/easier, but more likely they will just use TIG MIG or LAser welding in what is just about the easiest of all metals to weld.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 01/29/2019 05:35 pm
 Or, they were just cleaning up the surface because it was about to get several thousand spot welds, and they weren't the type who puts siding over crappy surfaces.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 01/29/2019 05:39 pm
 As for enclosing the tent, they probably finally figured out that working with large, extremely thin sheets of steel in a place where the wind never quits wasn't the brightest idea they'd ever had, in addition to needing an enclosed space for the real engines and systems.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: strato1 on 01/29/2019 06:36 pm
At least they finished the assembly first.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MizaruSpaceXNut on 01/29/2019 08:02 pm
I really don't think corrosion is going to be an issue. Starship should be able to sit outside for centuries without corrosion.  The only concerns would be any exposed junctions between dissimilar metals.

Centuries?  ::) I don't think SpaceX will be able to cash the checks your are writing on their behalf. This is the real world, not a world of perfect materials.

Horse shoes, nails, swords and pistols were still being found along Coronado's trail in New Mexico back in

the fifties! Depends on the climate. 478 years ago!

I would point out that both MER rovers &amp; now Curiosity have found iron meteorites on the surface of Mars that have very specular surfaces that were free from iron oxides ( rust)  How long do you think these blobs of metal have been sitting on the Martial surface?  Longer than a few centuries would be my guess.  The composition needs just a bit of nickel to give it a surface oxide resistant to rusting.  Add in some Cr &amp; it gets even more favorable.

I do electrochemistry for a living, &amp; have thought quite a bit about corrosion mechanisms on Mars, as well as using the the available salts &amp; metals in ISRU schemes.   Corrosion requires an anode, cathode, &amp; an electrolyte for ion mobility.  Mars just has very poor ability to provide that last component, i.e the electrolyte.
[snip]

I’m not worried about Mars exposure. Earth exposure is another thing. The idea that a stainless steel starship could sit out exposed to a Earths atmosphere for centuries is preposterous. Do you as a chemist disagree?

Iron horseshoes, nails, swords and pistols were still being found along Coronado's trail in New Mexico in the fifties? 478 years ago?

  It depends on the climate.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 01/29/2019 09:09 pm
In my original post:

https://forum.nasaspaceflight.com/index.php?topic=47301.msg1905903#msg1905903

When I wrote “…exposed to the elements for the many months, years it will take to build.” I wasn't referring to erosion.. I said "build" as in while they are actually constructing an operational class StarShip, they will not expose their workers, their tools, structures and sub-assemblies to an uncontrolled, open-air environment. They are building a vehicle to travel to another planet. There are no safe harbors, dry docks, no Home Depots around the corner or Blacksmiths in the castle courtyard.

There's a saying...Control the controllables. Once they launch and are out there, anything can happen. You better believe that while they can, they will control what they can. And the weather, heat, wind, dust, humidity, etc, etc...are things they can and will control to give themselves the very best chance at building a marvel for the times.

BUT...if they do build the actual StarShip out in the open and not inside an enclosure,  whether circus tent or a Pad 39A HIF type building, I will of course honorably admit that I was... factually challenged. :) Until then...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: gaballard on 01/29/2019 09:17 pm
Are they enclosing the spring structure, or just screening the camera-facing end of it? If they fitted out both ends in the manner the 'front' currently is, the collapsed nosecone would be stuck in there forever unless the structure was disassembled again.

It stays in there while it thinks about what it's done.

Seriously though, looking at the most recent pictures from the photos thread, it looks like the far end of the tent only has support poles on the left side. It's possible the right side will be open or fitted with a door of some kind. My guess is the structure is both to have some privacy away from the cameras, and to provide a quick shelter for the nose cone in case of future high winds.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 01/29/2019 09:36 pm
Are they enclosing the spring structure, or just screening the camera-facing end of it? If they fitted out both ends in the manner the 'front' currently is, the collapsed nosecone would be stuck in there forever unless the structure was disassembled again.

It stays in there while it thinks about what it's done.

Seriously though, looking at the most recent pictures from the photos thread, it looks like the far end of the tent only has support poles on the left side. It's possible the right side will be open or fitted with a door of some kind. My guess is the structure is both to have some privacy away from the cameras, and to provide a quick shelter for the nose cone in case of future high winds.
There are roller doors on the flatbed, as well as a human sized door frame.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SPadre on 01/29/2019 10:07 pm
Could someone please reveal the formula for determining at what height someone would begin to see Starship relative to their distance and elevation from the launch pad? My friends in Monterrey Mexico want to know at what altitude would they be able see it, according to their elevation? Thanks!!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 01/29/2019 10:18 pm
I did not run the numbers, but Wikipedia is your friend for such questions:
https://en.wikipedia.org/wiki/Horizon

Go down to the section Objects above the horizon that gives you the formula.

[Edit]
Or to make it short:

(https://upload.wikimedia.org/wikipedia/commons/5/5a/HorizonDistance.png)
[/edit]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Rei on 01/30/2019 11:02 am
Do a quick Google of "Abandoned DeLoreans" for how I think a BFS left outdoors will look after a few decades. 

I just did. No signs of corrosion in any of the pictures, so I'm not sure what your point was:

https://www.google.is/search?tbm=isch&source=hp&biw=1920&bih=1068&ei=V49RXI_AN_e61fAP3vqriA0&q=abandoned+delorean&oq=abandoned+delorean&gs_l=img.3..0j0i24l2.170.2070..2350...0.0..1.204.1598.15j1j1......1....1..gws-wiz-img.....0..0i8i30.erPJr0poIUQ#imgrc=pi_c4IW85s4YvM:

Some are covered in dirt and grime, so you can't see the metal clearly, but on the ones where you can see the metal, there's not a hint of corrosion on any of the pictures I've come across.  Clean them off and they'll look shiny and new.  Well, the stainless at least.

Did you bother to try the search before you asked us to? (this is snark. Don't be snarky. -Lar)

The simple fact is that stainless corrosion rates even in marine environments are tiny.  And even with galvanic corrosion, most metal junctions (say, stainless and alumium) would corrode the other metal, not the stainless - and the other metal would actually protect the stainless. As cited above for 316, the ambient corrosion rates are hundreds of years per millimeter in marine environments.

Quote
Stainless steel, while a great corrosion resistant material, is not impervious, especially 301/304 series with lower Ni/Cr content.  The point with corrosion is that is like the killer Terminator robots.  It never sleeps, it doesn't get tired, & it wont stop until it finds a way to kill your metal.    Furthermore, even it the stainless doesn't corrode, everything attached to it is likely to be anodic to it.  ( think hydraulics, fasteners, electronics, etc.)  The huge connected stainless skin is a cathodic current sink for lots of other little parts that are failure modes for the vehicle.

As I wrote. But that's irrelevant to the discussion. The discussion started out not on the topic of "whether completed Starships / Super Heavies sitting outside without maintenance would be flyable hundreds of years later", but rather whether you could build them like ships, first assembling an outer shell, and then working on the rest from the inside once it's weathertight. Aka, could the outer shell withstand months of sitting outside exposed to the weather.  And the answer is "absolutely, by many orders of magnitude over".

Quote
1.  Field welding ==>  heat affected zones will have variable composition in the grain structure of the metal.  This  is one mechanism how stainless can still fail at highly localized sites ( Cr, Fe, Ni precipitates) and propagate elsewhere.   Welding needs to be more controiled &  characterized.
2.  Welding in open environmental conditions ==> want to bet a dollar that dust, grime & salt of the surrounding Boca Chica area are now incorporated into the weld metallurgy?  Not a problem for BFH, but not advisable on future ships.  There is also dust & salt in the joints where the sheet metal is up against the stringers. 

What you're describing applies to literally every pressuretight steel structure that's ever been built outside in history, and that hasn't driven people to try to build everything indoors in tightly controlled conditions. You engineer tolerances and you inspect welds.

If giant steel structures designed for dealing with pressure and hostile chemical conditions had to be built in VABs, every refinery in the world would be surrounded by a refinery-sized VAB.  Oh, and by the way?  Most refineries are on the coast, aka exposed to salt air.

Quote
3.  Polishing of the sheet metal ==>  what was the abrasive or buffing compound used?  How was it rinsed off/removed afterwards?  Want to bet that some of that abrasive is stuck/embedded into the 301 at a microscopic level?  Over time this will corrode out pits in the surface

This is stainless sheet purchased straight from a supplier. The exact same situation would apply to every single project that uses it. Yet measured stainless sheet corrosion rates are tiny, polished or not.  Also, is it actually even abrasively polished at all?  Doesn't stainless most commonly use either one of A) electropolishing (for finished parts), or B) pinch-rolled after descaling (for 2B finish on sheet steel)? You sure it's going to use higher than a 2B finish (https://5.imimg.com/data5/YJ/MR/MY-10256531/304-2b-stainless-steel-sheet-500x500.jpg), but not use electropolishing either.... because?  Because if there actually were a problem with abrasives, they wouldn't use a 2B finish or electropolishing.... because?

Quote
My education is in Mechanical Engineering, which included general chemistry ( some organic)  & a substantial amount of material science

So this is not your field of expertise, but you still want to dispute industry data on the corrosion rates of stainless in marine environments. Duly noted.

Anyone here want to go see how polished stainless reacts to dirt and grime and even loose metal being ground against it under full submersive water exposure conditions, every several days for years on end?  Go look inside the drum of your washing machine.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 01/30/2019 01:10 pm
The outer skin could be made of 100% corrosion-proof unobtainalloy for all it matters during construction: final sealing up of the outer mould line is going to end up as one of the last production operation, not the first.
While an oceangoing ship* is large enough - and has large enough openings after structural completion - to move in most (though not all, engines will be 'dropped' into a partially completed vessel, and vessels cut apart if that engine ever needs to be removed) parts and equipment, SS is still pretty tiny in that respect. Looking at the Starhopper, it could not be completed with the entire upper portion in place, and even the tank section needed to wait for the tank internals (anti-slosh and plumbing) to be installed before the upper dome cap could be put in place, and even that had a hole left for further parts to be lowered though. Once you start adding in crew compartments (themselves inside an insulated pressure vessel, necessary due to the hot structure) it is not feasible to construct everything 'outside in'.

While protection of all the exposed internals against contamination during construction could be done by plopping a large tent over the top, it makes sense to use a 'traditional' warehouse construction simply because it gives you a nice place to put a gantry crane, rather than having to tear down and rebuild your tent to crane heavy pieces in from outside (and timing those operations to avoid rain/storms/etc). If you need to build a big load-bearing frame anyway, you may as well wrap your building skin around it.


* Counterexample: modern submarine construction (OK, technically, those are 'Boats' not Targets). Fellow large-ish pressure vessels wrapped around high density gubbins, and also built indoors rather than outdoors. Built as individual segments with those discrete segments mostly fitted out 'loose', then the segments slotted around any monolithic segment-spanning components (e.g. a reactor) and joined.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 01/30/2019 01:37 pm
Have they scaffolded the entire BFH or just the back side, bracketing the unfinished back leg. It looks to just be the back side to me.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 01/30/2019 01:40 pm
This is how I see the Starship being brought out from its assembly hangar.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 01/30/2019 01:45 pm
Have they scaffolded the entire BFH or just the back side, bracketing the unfinished back leg. It looks to just be the back side to me.
Yes, definitely looks the same to me, just the back side.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: berkie on 01/30/2019 01:54 pm

Quote
So this is not your field of expertise, but you still want to dispute industry data on the corrosion rates of stainless in marine environments. Duly noted.

Anyone here want to go see how polished stainless reacts to dirt and grime and even loose metal being ground against it under full submersive water exposure conditions, every several days for years on end?  Go look inside the drum of your washing machine.

As is often the case on the internet, i don't disagree with what you are saying in this post but how you are saying it. All of these points can be said in a framework of mutual respect and deeper understanding, not bravado.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 01/30/2019 01:59 pm
The outer skin could be made of 100% corrosion-proof unobtainalloy for all it matters during construction: final sealing up of the outer mould line is going to end up as one of the last production operation, not the first.
While an oceangoing ship* is large enough - and has large enough openings after structural completion - to move in most (though not all, engines will be 'dropped' into a partially completed vessel, and vessels cut apart if that engine ever needs to be removed) parts and equipment, SS is still pretty tiny in that respect. Looking at the Starhopper, it could not be completed with the entire upper portion in place, and even the tank section needed to wait for the tank internals (anti-slosh and plumbing) to be installed before the upper dome cap could be put in place, and even that had a hole left for further parts to be lowered though. Once you start adding in crew compartments (themselves inside an insulated pressure vessel, necessary due to the hot structure) it is not feasible to construct everything 'outside in'.

I disagree. Design it to be constructed outside in and that's what you get.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 01/30/2019 02:44 pm
Do a quick Google of "Abandoned DeLoreans" for how I think a BFS left outdoors will look after a few decades. 

I just did. No signs of corrosion in any of the pictures, so I'm not sure what your point was:

https://www.google.is/search?tbm=isch&source=hp&biw=1920&bih=1068&ei=V49RXI_AN_e61fAP3vqriA0&q=abandoned+delorean&oq=abandoned+delorean&gs_l=img.3..0j0i24l2.170.2070..2350...0.0..1.204.1598.15j1j1......1....1..gws-wiz-img.....0..0i8i30.erPJr0poIUQ#imgrc=pi_c4IW85s4YvM:

Some are covered in dirt and grime, so you can't see the metal clearly, but on the ones where you can see the metal, there's not a hint of corrosion on any of the pictures I've come across.  Clean them off and they'll look shiny and new.  Well, the stainless at least.

Did you bother to try the search before you asked us to?

I think you are misreading his statement. Stan is saying that he doesn't think earth exposure will be an issue for a couple decades, and offered up the deloreans as an exhibit. the original time scale mentioned was centuries.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AndrewSmith on 01/30/2019 02:44 pm
Anyone here want to go see how polished stainless reacts to dirt and grime and even loose metal being ground against it under full submersive water exposure conditions, every several days for years on end?  Go look inside the drum of your washing machine.

Your example is a 300-series stainless with an electro-polished and passivated finish, that experiences a hot water/detergent bath with every cycle.

Starship won't have the benefit of a full-immersion passivation process after welding, and will spend a significant part of its service life in a salt spray environment.  It may not be enough to compromise the structure, or even visibly rust/pit - but it has serious ramifications for the emissive properties of the heat shield. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 01/30/2019 02:44 pm
Have they scaffolded the entire BFH or just the back side, bracketing the unfinished back leg. It looks to just be the back side to me.
Just the two sides with the holes. The west side doesn't have any scaffolding. Doing all three sides at once would have made it hard to get scissors lifts and stuff in and out.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: abaddon on 01/30/2019 02:59 pm
Perhaps Starship construction techniques and environment would be better served in another thread.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 01/30/2019 03:00 pm

Quote
So this is not your field of expertise, but you still want to dispute industry data on the corrosion rates of stainless in marine environments. Duly noted.

Anyone here want to go see how polished stainless reacts to dirt and grime and even loose metal being ground against it under full submersive water exposure conditions, every several days for years on end?  Go look inside the drum of your washing machine.

As is often the case on the internet, i don't disagree with what you are saying in this post but how you are saying it. All of these points can be said in a framework of mutual respect and deeper understanding, not bravado.
(mod) I agree. We need to dial the snarkiness back. Normally I don't publicly single one person out... but repeated snarkiness will get me to do that.

Berkie, welcome to the forum, sorry that your first post had to be on this topic but thanks! Self moderation is always good.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Restless on 01/30/2019 04:09 pm
Anyone here want to go see how polished stainless reacts to dirt and grime and even loose metal being ground against it under full submersive water exposure conditions, every several days for years on end?  Go look inside the drum of your washing machine.

Your example is a 300-series stainless with an electro-polished and passivated finish, that experiences a hot water/detergent bath with every cycle.

Starship won't have the benefit of a full-immersion passivation process after welding, and will spend a significant part of its service life in a salt spray environment.  It may not be enough to compromise the structure, or even visibly rust/pit - but it has serious ramifications for the emissive properties of the heat shield.

There is voluminous literature, much available on the internet, that documents the susceptibility of austenitic stainless steels to chloride stress corrosion/cracking in marine environments. It is a problem that can be controlled, but it cannot be ignored.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DistantTemple on 01/30/2019 05:24 pm
A very minor but related experience with stainless steel. Yacht rigging is usually only considered safe and insurable for a limited period... I thought 10 years, as the strands at the terminal (end hardware) are known to crack in the marine environment, particularly where they are bent, gripped, or there is a natural crevice for buildup of salt, and dust etc. Conversely "old-fashioned" steel wire with a string core soaked in linseed oil, (and re-soaked occasionally) can continue to be used even after limited external evidence of broken strands. This is understood to be a known measurable loss of performance, whereas the stainless shows little sign of impending failure - at least without impossible or at least prohibitive inspection/scanning. And failure can be without warning.

I'm telling this from the POV of a yachtsman's common knowledge, ... but I haven't checked the details. Edit: I think some sailors pressure wash the terminals at least at lay-up, and whenever washing the boat to remove the supposedly risky build up of salt dirt and damp. The failure is a crack, not much of a loss of material.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: niwax on 01/30/2019 06:09 pm
A very minor but related experience with stainless steel. Yacht rigging is usually only considered safe and insurable for a limited period... I thought 10 years, as the strands at the terminal (end hardware) are known to crack in the marine environment, particularly where they are bent, gripped, or there is a natural crevice for buildup of salt, and dust etc. Conversely "old-fashioned" steel wire with a string core soaked in linseed oil, (and re-soaked occasionally) can continue to be used even after limited external evidence of broken strands. This is understood to be a known measurable loss of performance, whereas the stainless shows little sign of impending failure - at least without impossible or at least prohibitive inspection/scanning. And failure can be without warning.

I'm telling this from the POV of a yachtsman's common knowledge, ... but I haven't checked the details. Edit: I think some sailors pressure wash the terminals at least at lay-up, and whenever washing the boat to remove the supposedly risky build up of salt dirt and damp. The failure is a crack, not much of a loss of material.

Washing could be the key. Everyday Astronaut just did a video summarizing the changes to SH/SS where he highlighted that WD-40 was developed as a corrosion inhibitor and softener for Atlas.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jak Kennedy on 01/30/2019 06:14 pm
Anyone here want to go see how polished stainless reacts to dirt and grime and even loose metal being ground against it under full submersive water exposure conditions, every several days for years on end?  Go look inside the drum of your washing machine.

Having seeen rust form on so called stainless sold in C. America. ie sinks in just a few months and although I love the idea of forum members all sticking their heads in washing machines to check, a quick check shows typical drums are made from 430 grade so perhaps not relevant comparing to other grades.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Elmar Moelzer on 01/30/2019 06:25 pm
I think people are overestimating the corrosion issue. As an example. U-2540 ("Wilhelm Bauer") was scuttled by the Germans in May 1945. It was raised in June 1957 (more than 12 years later!) and then refurbished. Some of it had to be taken apart and sand blasted, but it was mostly in a good condition despite the fact that the entire inside had been flooded. It was in service until 1980 and is now a permanent display in the harbor of Bremen.
When it was raised, it did look pretty bad, but they were able to fully refurbish it with just some sandblasting and paint. Even many of the control panels and the electric motors were still usable. The diesel engines were replaced, not because they would not have been functional, but because they wanted to test newer engines for the German Type 201 design on this boat.
https://ww2.dsm.museum/DSA/DSA07_1984_153186_Roessler.pdf
Either way, I believe that any minor corrosion of the outer hull could be fixed with some light sand blasting, which would not take a lot of time.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Warby12 on 01/30/2019 08:41 pm
Hi, it's not the surface corrosion that is of concern with stainless steel. It's "crevice corrosion", in the joins and edges and hidden bits where oxygen cannot reach the surface and form the protective layer. Without the oxygen to create the protective oxide layer, it starts sneakily.

We live on a sailing boat and every important bit of stainless has been replaced as after a couple of decades it cannot be trusted. I've had plenty of S/S nuts shatter trying to remove components. It's true about stainless steel rigging for holding up masts too. Many insurance companies advise only 10 years in the tropics before replacement.

Having said all of that, composition of the stainless is critical, I'm 100% sure Spacex have this covered. It's all very well understood, which is again the reason they are using stainless, it's well understood :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JBF on 01/30/2019 09:15 pm
I don't understand why they are doing the side framing for the tent now.  Based on how those beams are spaced it doesn't look like the nose cone will fit through them even if it is re-rounded.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cheapchips on 01/30/2019 09:20 pm
I don't understand why they are doing the side framing for the tent now.  Based on how those beams are spaced it doesn't look like the nose cone will fit through them even if it is re-rounded.

If they have to dismantle it they probably want to hide their shame.  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Pallen on 01/30/2019 10:01 pm
That "flange" going upto the hole looks really thick and heavy. Post with pic:  https://forum.nasaspaceflight.com/index.php?topic=47120.msg1906549#msg1906549 (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1906549#msg1906549)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Stan-1967 on 01/30/2019 10:45 pm
Do a quick Google of "Abandoned DeLoreans" for how I think a BFS left outdoors will look after a few decades. 

I just did. No signs of corrosion in any of the pictures, so I'm not sure what your point was:

https://www.google.is/search?tbm=isch&source=hp&biw=1920&bih=1068&ei=V49RXI_AN_e61fAP3vqriA0&q=abandoned+delorean&oq=abandoned+delorean&gs_l=img.3..0j0i24l2.170.2070..2350...0.0..1.204.1598.15j1j1......1....1..gws-wiz-img.....0..0i8i30.erPJr0poIUQ#imgrc=pi_c4IW85s4YvM:

Some are covered in dirt and grime, so you can't see the metal clearly, but on the ones where you can see the metal, there's not a hint of corrosion on any of the pictures I've come across.  Clean them off and they'll look shiny and new.  Well, the stainless at least.

Did you bother to try the search before you asked us to?

I think you are misreading his statement. Stan is saying that he doesn't think earth exposure will be an issue for a couple decades, and offered up the deloreans as an exhibit. the original time scale mentioned was centuries.

If it was not clear in my post, while I do think stainless in a marine environment does have long term exposure issues, what I think REI focused on was the stainless only.   The BFS will be made of more than just stainless, so everything attached to it that is not stainless is a corrosion cell.  Look at the pictures again.  Look at the tire rims, hinges, brake calipers etc.  I'm not challenging that a DeLorean or a BFS left outside in a warm coastal environment may still have some pretty stainless steel visible after 10 years or even a hundred, I am challenging that stainless is some miracle material material that negates considering corrosion on the vehicle over time, & that the overall material properties will be unchanged over time.

As to the comments on being an expert, I am one, & I also don't worry that my expertise has limits, & I'm happy to acknowledge them.  What I wrote can be valid without me having a PhD.  I know more experts than myself who have degrees in degrees as wide ranging as chemE, civil E, material science, physics, chemistry etc., many of them doctorates, who would agree with part of all of what I have wrote.  Corrosion affects pretty much everything that is built at large scale, and the science of corrosion & its remediation in any given application isn't contained in any single degree someone earns. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kansan52 on 01/30/2019 11:13 pm
Thank you for the clarification. I did not understand that you meant other items than the stainless steel body. Your point on galvanic corrosion certainly comes out in the recap.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 01/30/2019 11:39 pm
We've seen a lot of stainless steel go by in the last 6 week or so.  Heavy plate, "tinfoil" stainless, leg tubes, internal bracing tubes, domes.  And they looked like typical stainless steel.  But what are we to read into the brownish perimeter plates of the cap dome?  Is that brown tinge the result of heating with a torch during the forming operation?  Or.... Or...?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 01/31/2019 12:22 am
The band's seams don't seem to align with the seams of the dome segments, so perhaps a protective feature where the nose cone attaches.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 01/31/2019 01:22 am
I don't understand why they are doing the side framing for the tent now.  Based on how those beams are spaced it doesn't look like the nose cone will fit through them even if it is re-rounded.

I don't think the fairing is salvageable...
Also, if they build it inside the tent, they can't lift it out, right?

I think the tent is being enclosed because it's time, and the new cone will be built on the pedestal same as before.
An enclosed tent might perhaps maybe help somewhat with the wind there.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Restless on 01/31/2019 01:40 am
Hi, it's not the surface corrosion that is of concern with stainless steel. It's "crevice corrosion", in the joins and edges and hidden bits where oxygen cannot reach the surface and form the protective layer. Without the oxygen to create the protective oxide layer, it starts sneakily.

We live on a sailing boat and every important bit of stainless has been replaced as after a couple of decades it cannot be trusted. I've had plenty of S/S nuts shatter trying to remove components. It's true about stainless steel rigging for holding up masts too. Many insurance companies advise only 10 years in the tropics before replacement.

Having said all of that, composition of the stainless is critical, I'm 100% sure Spacex have this covered. It's all very well understood, which is again the reason they are using stainless, it's well understood :)

I'm concerned about stress corrosion cracks that could lead to stainless skin burn through on re-entry. But like you said Spacex should be well aware of this.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Inoeth on 01/31/2019 02:44 am
it's definitely interesting that they're enclosing the tent with the squashed fairing inside... either they'll have to remove an entire wall again to get it out if it's repaired or else more than likely it's toast and they just want both privacy and wind protection for whatever other work they'll do in the tent  (my best guess is that it's something to do with the Raptor engines that may be headed their way in the next couple weeks?) in which case I agree they'll just build a new fairing on the pedestal like they did originally... tho perhaps they'll change how they build it a bit having learned from their first attempt....


As far as the stainless steel ships lasting - i think they'll have enough of a shelf life that things like the engines, etc will wear out far sooner than the steel and the ships will be retired to a museum long before wear and tear on the full ship's shell is in peril of rust,etc and during their active life SpaceX will eventually build some sort of VAB type building for them wherever they're eventually l launched from...

Frankly i'm just excited to see the launch pad itself finally truly come to life with all those tanks being installed. I'll be very happy when i see things like a water tower, lightening tower and pavement start to happen. At the rate they're going I think we'll see the first 'hop' sometime between late February and mid-March would be my guess...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SPadre on 01/31/2019 03:13 am
New video of Launch Pad and Starship Wednesday Jan 30

https://www.youtube.com/watch?v=JiylWgy_8y8
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: strato1 on 01/31/2019 07:17 am
I don't understand why they are doing the side framing for the tent now.  Based on how those beams are spaced it doesn't look like the nose cone will fit through them even if it is re-rounded.

I don't think the fairing is salvageable...
Also, if they build it inside the tent, they can't lift it out, right?

I think the tent is being enclosed because it's time, and the new cone will be built on the pedestal same as before.
An enclosed tent might perhaps maybe help somewhat with the wind there.

Tent most likely to hide disassembly of the fairing, of which the extent of permanent deformation is so large that repair is unlikely.  CEO said they would repair, so likely need to hide the tear down.  You could build the top 1/3 to 1/2 of the fairing hidden from view and then pull it out to claim in was repaired.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 01/31/2019 08:07 am
I don't understand why they are doing the side framing for the tent now.  Based on how those beams are spaced it doesn't look like the nose cone will fit through them even if it is re-rounded.

I don't think the fairing is salvageable...
Also, if they build it inside the tent, they can't lift it out, right?

I think the tent is being enclosed because it's time, and the new cone will be built on the pedestal same as before.
An enclosed tent might perhaps maybe help somewhat with the wind there.

Tent most likely to hide disassembly of the fairing, of which the extent of permanent deformation is so large that repair is unlikely.  CEO said they would repair, so likely need to hide the tear down.  You could build the top 1/3 to 1/2 of the fairing hidden from view and then pull it out to claim in was repaired.

Don't read too much into a tweet. "Repair" just means "go back to where we were". If this means an almost complete replacement, so be it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CraigLieb on 01/31/2019 09:41 am
If they intend to take it apart and then leverage elements that can be reused in the construction of a new fairing, wouldn’t the partially disassembled remains be vulnerable to catching the wind? Enclosing it could be a protective measure so pieces don’t go flying in case of another blow.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: guckyfan on 01/31/2019 10:39 am
Work on the enclosure of the tent ends began so fast after the fairing incident that it can not be the cause. The components must have been ordered before. They must have concluded though that the enclosure does not interfere with the work done on the destroyed fairing
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 01/31/2019 11:11 am
Work on the enclosure of the tent ends began so fast after the fairing incident that it can not be the cause. The components must have been ordered before. They must have concluded though that the enclosure does not interfere with the work done on the destroyed fairing

A "repaired" 9m fairing wouldn't even fit through the gaps between the new struts now and certainly not after they add panels.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: guckyfan on 01/31/2019 11:50 am
Work on the enclosure of the tent ends began so fast after the fairing incident that it can not be the cause. The components must have been ordered before. They must have concluded though that the enclosure does not interfere with the work done on the destroyed fairing

A "repaired" 9m fairing wouldn't even fit through the gaps between the new struts now and certainly not after they add panels.

Yes, that means the destroyed structure will be separated into components that fit and be reassembled outside from salvaged and new parts. Assuming it will be rebuilt vertical again it would not fit into the tent in any case.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 01/31/2019 01:07 pm
I don't understand why they are doing the side framing for the tent now.  Based on how those beams are spaced it doesn't look like the nose cone will fit through them even if it is re-rounded.

I don't think the fairing is salvageable...
Also, if they build it inside the tent, they can't lift it out, right?

I think the tent is being enclosed because it's time, and the new cone will be built on the pedestal same as before.
An enclosed tent might perhaps maybe help somewhat with the wind there.

Tent most likely to hide disassembly of the fairing, of which the extent of permanent deformation is so large that repair is unlikely.  CEO said they would repair, so likely need to hide the tear down.  You could build the top 1/3 to 1/2 of the fairing hidden from view and then pull it out to claim in was repaired.
I think "repair" refers to the whole BFH.  The fairing is toast since it's a lot faster and cheper to make a new one, and the end result is a known quantity.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 01/31/2019 01:34 pm
As least from my perspective it’s been a foregone conclusion since the structure pancaked that it was going to require a total breakdown and rebuild, so it’s no surprise the tent is getting side walls.

Why? It’s constructed of prebuilt sections of “rebar” and foil. The rebar is formed from horizontal hoops of various diameters interconnected with vertical rods. These sections were about ten feet tall and as I’ve said before, transportable by two workers. These sections were clad in the metal skin tack welded to the frame and then completed sections were stacked to build the conical fairing.

When it toppled it destroyed the structural integrity of the hoops. The hoops were the critical forming structure that the entire fairing was based on. These may have been prebuilt off-site and each one has a very specific geometry.

So new hoops (or hoop sections if they were built in segments) will have to be fabricated. Then new verticals will have to be attached. This can all happen under thetent. The completed rebar frame sections can then be transported sideways through the roller door (the upper sections can even be clad in the tent as well) then slowly the sections can once again be stacked with all the horizontal seams once again covered in strips and a new fairing will once again grow outdoors (though I really hope they learned a lesson in securing the thing against wind).

The hoops could be the long pole in the tent (pun intended) as we have no idea the lead time to fabricate.

When Elon tweeted “a few weeks to repair” it was tweeted alongside “I just found out”, so the wise would take the entire tweet with a grain of salt. For me, the moment I’d heard it had toppled I knew it was a goner.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: strato1 on 01/31/2019 01:52 pm
I don't understand why they are doing the side framing for the tent now.  Based on how those beams are spaced it doesn't look like the nose cone will fit through them even if it is re-rounded.

I don't think the fairing is salvageable...
Also, if they build it inside the tent, they can't lift it out, right?

I think the tent is being enclosed because it's time, and the new cone will be built on the pedestal same as before.
An enclosed tent might perhaps maybe help somewhat with the wind there.

Tent most likely to hide disassembly of the fairing, of which the extent of permanent deformation is so large that repair is unlikely.  CEO said they would repair, so likely need to hide the tear down.  You could build the top 1/3 to 1/2 of the fairing hidden from view and then pull it out to claim in was repaired.
I think "repair" refers to the whole BFH.  The fairing is toast since it's a lot faster and cheper to make a new one, and the end result is a known quantity.


Just pointing out that "repair" means 2 things.  Structurally, the permanent deformation may not make sense to recover.  From an optics standpoint, there are already resource management issues.  Most likely reason for hiding the disassembly is to make the scrapping/rebuilding less obvious … more political, less functional.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 01/31/2019 02:01 pm
Can we just take a step back with these notions of "hiding" things. This is an organization that makes videos with carnival music tracks showing 40 million dollar rockets blowing up trying to land. Sometimes a shed is just a shed.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Restless on 01/31/2019 02:23 pm
As least from my perspective it’s been a foregone conclusion since the structure pancaked that it was going to require a total breakdown and rebuild, so it’s no surprise the tent is getting side walls.

Why? It’s constructed of prebuilt sections of “rebar” and foil. The rebar is formed from horizontal hoops of various diameters interconnected with vertical rods. These sections were about ten feet tall and as I’ve said before, transportable by two workers. These sections were clad in the metal skin tack welded to the frame and then completed sections were stacked to build the conical fairing.

When it toppled it destroyed the structural integrity of the hoops. The hoops were the critical forming structure that the entire fairing was based on. These may have been prebuilt off-site and each one has a very specific
geometry.

So new hoops (or hoop sections if they were built in segments) will have to be fabricated. Then new verticals will have to be attached. This can all happen under thetent. The completed rebar frame sections can then be transported sideways through the roller door (the upper sections can even be clad in the tent as well) then slowly the sections can once again be stacked with all the horizontal seams once again covered in strips and a new fairing will once again grow outdoors (though I really hope they learned a lesson in securing the thing against wind).

The hoops could be the long pole in the tent (pun intended) as we have no idea the lead time to fabricate.

When Elon tweeted “a few weeks to repair” it was tweeted alongside “I just found out”, so the wise would take the entire tweet with a grain of salt. For me, the moment I’d heard it had toppled I knew it was a goner.

I just hope it comes out prettier the second time around......
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 01/31/2019 02:41 pm
Adding to John's thoughts, all of which I concur, my suspicion is that they'll also take this opportunity to alter the design a bit and stiffen the structure. Not sure if that's more cross-bracings, etc...but at some point this will be sitting on top of millions of dollars worth of Raptors, at a pad with sundry infrastructure, few structures around to buffet an ever present and ominous wind. (dramatic flare)

This won't be a one-for-one redo. They'll beef it up a bit, imo.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 01/31/2019 02:48 pm
This was lowered into the Hopper.
BCGal - could you notice if they lowered it on top of the dome (implying it's the top piece of the dome), or did it lower down into the dome, implying it's the center piece of the common bulkhead?


And thanks again!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 01/31/2019 02:52 pm
This was lowered into the Hopper.
BCGal - could you notice if they lowered it on top of the dome (implying it's the top piece of the dome), or did it lower down into the dome, implying it's the center piece of the common bulkhead?


And thanks again!

Down into the dome. It appeared to be a snug fit going in.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 01/31/2019 02:59 pm
This was lowered into the Hopper.
BCGal - could you notice if they lowered it on top of the dome (implying it's the top piece of the dome), or did it lower down into the dome, implying it's the center piece of the common bulkhead?


And thanks again!
It could be the top hatch if it was slightly off round. That way you'd have tank pressure making the seal instead of trying to blow it out. But the hole in the middle does look like it might be for the fuel line through the bottom tank.
 Reminds me of an extremely simple question that almost everybody gets wrong. "Why are manhole covers round?"
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 01/31/2019 03:00 pm
This pic was taken from Stargate this morning.

Any ideas as to what this is?  Temporary plug for top hole in tank header?   ???


has a bevel to it
______________
\                          /
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 01/31/2019 03:07 pm
Reminds me of an extremely simple question that almost everybody gets wrong. "Why are manhole covers round?"
That was a question used by Google as part of recruitment screening.  Shows the ability to apply academic knowledge to practical problems.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: mme on 01/31/2019 03:09 pm
I don't understand why they are doing the side framing for the tent now.  Based on how those beams are spaced it doesn't look like the nose cone will fit through them even if it is re-rounded.

I don't think the fairing is salvageable...
Also, if they build it inside the tent, they can't lift it out, right?

I think the tent is being enclosed because it's time, and the new cone will be built on the pedestal same as before.
An enclosed tent might perhaps maybe help somewhat with the wind there.

Tent most likely to hide disassembly of the fairing, of which the extent of permanent deformation is so large that repair is unlikely.  CEO said they would repair, so likely need to hide the tear down.  You could build the top 1/3 to 1/2 of the fairing hidden from view and then pull it out to claim in was repaired.
I think "repair" refers to the whole BFH.  The fairing is toast since it's a lot faster and cheper to make a new one, and the end result is a known quantity.


Just pointing out that "repair" means 2 things.  Structurally, the permanent deformation may not make sense to recover.  From an optics standpoint, there are already resource management issues.  Most likely reason for hiding the disassembly is to make the scrapping/rebuilding less obvious … more political, less functional.
I doubt SpaceX cares what a handful of random space enthusiasts think and I doubt anyone with any actual influence is freaked out because the fairing for a quick and dirty test mule blew over. This is the company with a CTO that releases "blooper reels" of tests blowing up and a CEO that says "if you aren't blowing things up occasionally you're not pushing hard enough." Anyone that's going to make hay out of the incident will make hay and putting the fairing in the tent will have zero effect on that.

My bet is they don't want bits they disassemble blowing away in the wind, like meekGee said. They also probably need an area out of the weather for all sorts of work that will be going on soon.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cheapchips on 01/31/2019 03:33 pm
Adding to John's thoughts, all of which I concur, my suspicion is that they'll also take this opportunity to alter the design a bit and stiffen the structure. Not sure if that's more cross-bracings, etc...but at some point this will be sitting on top of millions of dollars worth of Raptors, at a pad with sundry infrastructure, few structures around to buffet an ever present and ominous wind. (dramatic flare)

This won't be a one-for-one redo. They'll beef it up a bit, imo.

Why does it need extra cross braces?  SpaceX should have spec'd it properly for operating as part of the full hopper.
 Falling over during construction due to under cautious mooring isn't a design requirement.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: topo334 on 01/31/2019 03:55 pm
Any ideas as to what this is?  Temporary plug for top hole in tank header?   ???

Um, they moved the break room table outside to make room for the square dance and forgot to put it back?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BunkerTheHusky on 01/31/2019 04:18 pm
My thought on the matter is that the shed was going to be enclosed either way, but after the fairing blew over and pancaked, SpaceX engineers saw the impending shed work as a golden opportunity to give the disassembly workers a safe place to work. With wind being a factor here, and the fairing being smashed and torn in places, it would be a lot more difficult to rig it to have workers safely approach and work on it in the wind. They'll tear it down within the shed, and build a new one out in the open, probably with new protocols in place.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 01/31/2019 04:27 pm
Why does it need extra cross braces?  SpaceX should have spec'd it properly for operating as part of the full hopper.
 Falling over during construction due to under cautious mooring isn't a design requirement.

Unless under cautious mooring was due to the insufficient design structure.  Some speculated that as a mitigating factor in explaining the "apparent oversight" with respect to sufficient anchoring.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 01/31/2019 04:29 pm
Tent most likely to hide disassembly of the fairing, of which the extent of permanent deformation is so large that repair is unlikely.  CEO said they would repair, so likely need to hide the tear down.  You could build the top 1/3 to 1/2 of the fairing hidden from view and then pull it out to claim in was repaired.
"claim it was repaired"...
 
(mod) Casting this sort of aspersion is not warranted, especially repeatedly. We don't call entire companies liars... Don't do it. Try not to sound like a Tesla short... Thank you.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dataman on 01/31/2019 04:47 pm
Whats the status of the monster COPV?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 01/31/2019 04:49 pm
Whats the status of the monster COPV?
Um...That there is no such thing?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 01/31/2019 04:55 pm
Can we just take a step back with these notions of "hiding" things. This is an organization that makes videos with carnival music tracks showing 40 million dollar rockets blowing up trying to land. Sometimes a shed is just a shed.
Carnaval music indeed -yes. This is an ex shroud. It has pulled down the curtain and...
The only way that shroud is coming out is in pieces through the new smaller door they have installed.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 01/31/2019 04:57 pm
Whats the status of the monster COPV?
They blew it up in a pressure test last year - something else that has expired.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 01/31/2019 05:04 pm
Installing the flange.
I've been waiting for some flight-like hardware to be installed to the outside. This flange suits nicely. Interesting bolt hole pattern on it. Kind of surprised the holes don't run the entire perimeter And - don't these kind of bulkhead access plates have at least a double set of holes - one to bolt to the structure and one to bolt the access plate? Something isn't quite lining up here.

Sorry - I'm home sick today, so y'all will just have to deal with a post barrage. Just wait until my wife makes me my "sick medicine", aka a Manhattan...

 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: GORDAP on 01/31/2019 05:05 pm
Reminds me of an extremely simple question that almost everybody gets wrong. "Why are manhole covers round?"
That was a question used by Google as part of recruitment screening.  Shows the ability to apply academic knowledge to practical problems.

I know the answer that both of you have in mind.  But I contend the simplest answer is, 'because manholes are round'.   ::)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 01/31/2019 05:22 pm
Reminds me of an extremely simple question that almost everybody gets wrong. "Why are manhole covers round?"
That was a question used by Google as part of recruitment ...

off topic, but s/Google/Microsoft.
Google interview questions are much more about coding (at least in my experience).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MikeAtkinson on 01/31/2019 05:58 pm
Reminds me of an extremely simple question that almost everybody gets wrong. "Why are manhole covers round?"
That was a question used by Google as part of recruitment screening.  Shows the ability to apply academic knowledge to practical problems.

I know the answer that both of you have in mind.  But I contend the simplest answer is, 'because manholes are round'.   ::)

And sometimes they are not round: http://www.nal.ltd.uk/products/manhole-covers-and-frames/concrete-infill/

The question is a bit like "why are swans white?"
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 01/31/2019 06:23 pm
Installing the flange.
I've been waiting for some flight-like hardware to be installed to the outside. This flange suits nicely. Interesting bolt hole pattern on it. Kind of surprised the holes don't run the entire perimeter And - don't these kind of bulkhead access plates have at least a double set of holes - one to bolt to the structure and one to bolt the access plate? Something isn't quite lining up here.

Sorry - I'm home sick today, so y'all will just have to deal with a post barrage. Just wait until my wife makes me my "sick medicine", aka a Manhattan...

I looked at prior pics and this flange does have a different hole pattern on it. It is still in place. I will keep an eye on it.  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Santos on 01/31/2019 06:47 pm
Maybe the supplier for the hold-downs for the original TFH was the ACME Corporation of Chicago IL?  Based on the inspection being conducted by Wile E. Coyote in the most recent video in the Updates thread...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 01/31/2019 09:29 pm
Swans are not always white. Sometimes they are black. Kinda like my scowl that we went off topic to talk about them.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 01/31/2019 10:19 pm
Installing the flange.
I've been waiting for some flight-like hardware to be installed to the outside. This flange suits nicely. Interesting bolt hole pattern on it. Kind of surprised the holes don't run the entire perimeter And - don't these kind of bulkhead access plates have at least a double set of holes - one to bolt to the structure and one to bolt the access plate? Something isn't quite lining up here.

Sorry - I'm home sick today, so y'all will just have to deal with a post barrage. Just wait until my wife makes me my "sick medicine", aka a Manhattan...

I looked at prior pics and this flange does have a different hole pattern on it. It is still in place. I will keep an eye on it.  ;)

The bolt holes have been made all around the flange. I will watch for a double set to be added.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 01/31/2019 11:06 pm
Installing the flange.
I've been waiting for some flight-like hardware to be installed to the outside. This flange suits nicely. Interesting bolt hole pattern on it. Kind of surprised the holes don't run the entire perimeter And - don't these kind of bulkhead access plates have at least a double set of holes - one to bolt to the structure and one to bolt the access plate? Something isn't quite lining up here.

Sorry - I'm home sick today, so y'all will just have to deal with a post barrage. Just wait until my wife makes me my "sick medicine", aka a Manhattan...

I looked at prior pics and this flange does have a different hole pattern on it. It is still in place. I will keep an eye on it.  ;)

The bolt holes have been made all around the flange. I will watch for a double set to be added.
Someone here at work commented that an elliptical hole fits a tube at an angle.

So - three thrusters per flange? (Horizontal cluster)

EDIT: Actually the ellipse is too round.  Maybe tho, an external cluster pod, fed by two pipes that go through the flange.  In that case the flange is there to transfer mechanical loads, and seal the tank volume.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Scylla on 01/31/2019 11:18 pm
Installing the flange.
I've been waiting for some flight-like hardware to be installed to the outside. This flange suits nicely. Interesting bolt hole pattern on it. Kind of surprised the holes don't run the entire perimeter And - don't these kind of bulkhead access plates have at least a double set of holes - one to bolt to the structure and one to bolt the access plate? Something isn't quite lining up here.

Sorry - I'm home sick today, so y'all will just have to deal with a post barrage. Just wait until my wife makes me my "sick medicine", aka a Manhattan...

I looked at prior pics and this flange does have a different hole pattern on it. It is still in place. I will keep an eye on it.  ;)

The bolt holes have been made all around the flange. I will watch for a double set to be added.
Someone here at work commented that an elliptical hole fits a tube at an angle.

So - three thrusters per flange? (Horizontal cluster)

EDIT: Actually the ellipse is too round.  Maybe tho, an external cluster pod, fed by two pipes that go through the flange.  In that case the flange is there to transfer mechanical loads, and seal the tank volume.
But their are only two holes and they are at different elevations on the hopper. Wouldn't it need at least three holes at same elevation for symmetry if they were thrusters?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 01/31/2019 11:52 pm
Installing the flange.
I've been waiting for some flight-like hardware to be installed to the outside. This flange suits nicely. Interesting bolt hole pattern on it. Kind of surprised the holes don't run the entire perimeter And - don't these kind of bulkhead access plates have at least a double set of holes - one to bolt to the structure and one to bolt the access plate? Something isn't quite lining up here.

Sorry - I'm home sick today, so y'all will just have to deal with a post barrage. Just wait until my wife makes me my "sick medicine", aka a Manhattan...

I looked at prior pics and this flange does have a different hole pattern on it. It is still in place. I will keep an eye on it.  ;)

The bolt holes have been made all around the flange. I will watch for a double set to be added.
Someone here at work commented that an elliptical hole fits a tube at an angle.

So - three thrusters per flange? (Horizontal cluster)

EDIT: Actually the ellipse is too round.  Maybe tho, an external cluster pod, fed by two pipes that go through the flange.  In that case the flange is there to transfer mechanical loads, and seal the tank volume.
But their are only two holes and they are at different elevations on the hopper. Wouldn't it need at least three holes at same elevation for symmetry if they were thrusters?
Sigh.  Yup.

But maybe there's more (ACME) holes in the truck..  They ain't finished yet...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: aero on 01/31/2019 11:56 pm
Not to change the subject, but can anyone guess how they are going to get the nose cone out of the enclosed tent? It is bigger than the doors. In pieces, I guess.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/01/2019 12:19 am
Not to change the subject, but can anyone guess how they are going to get the nose cone out of the enclosed tent? It is bigger than the doors. In pieces, I guess.
I’d venture in trash bags...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/01/2019 12:33 am
Someone here at work commented that an elliptical hole fits a tube at an angle.

That's what I've been thinking all day. I envision some large internal structural tubes like the ones between the upper leg mounts being there and the elliptical plates being directly on the ends.  Or not.  So the function could be either flow or mechanical attachment.  Or to lesser odds, permanent mounting for a ventilation blower.  Umbilical connection plate goes there? 
Attach a Dreamchaser to each plate?
     "       Tesla                "        "    ? 
Attachment points for the ground handling roller cart?

Have we seen any of the tubes with ladders go into the thing?  For access from the bottom?

And as for the enclosing of the tently hanger, how about if I were to guess that's in preparation for working on the more real 2nd version.  Parts arrive and get assembled there and when they need to come out as you can see it only takes ~2d to get the end off the hanger to remove them.

Or perhaps once they get the tent enclosed they'll bolt the tent to the new structural attachment plates and with the assistance of some large helicopter sized blowers pushing air into the tent they'll use the tent as a hovercraft to move the hoppy thing.   
Or not.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 02/01/2019 08:09 am
They are still working on the flange. More bolt holes have been made. The Sprung structure is now fully enclosed.

A big thank you to you. Not as much engagement today, because we are all giddy about Raptor, but we still very much appreciate what you do!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 02/01/2019 12:29 pm
The flanges serve the same purpose as the same size and shape oval flanges on Falcon: to access the inside of the tanks without needing to squeeze through the propellant lines.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/01/2019 02:33 pm
edit: 
The flanges serve the same purpose as the same size and shape oval flanges on Falcon: to access the inside of the tanks without needing to squeeze through the propellant lines.
Some part of me didn't see this post before I wrote the words below but some part of me apparently did and kicked me off in that direction.

___________

No! 
No to what MeekGee's coworkers said.
No to what I said.  Just plain No!

The oval flanges aren't the result of matching the geometry of internal tubes that are cut at an angle.  They are simply access hatches into the tanks (thus two levels) and the oval shape is generated by the stresses in the thin wall pressure vessel that they're going through.  Circumferential stress is 2x longitudinal stress in a thin walled cylindrical pressure vessel such as this. That logic generates this oval shape.  Final answer.

Now that we've got that straightened out the corollary information is that if there are two ports that aren't on the same level and there are two tanks then the bulkhead between the tanks meets the wall somewhere between the two access ports.  I've not looked at the pictures to see the levels of the two ports but if they are close together it would narrow down the bulkhead attach plane and knowing the curvature of the visible top dome volume calculations can be made for the top tank.  With the volume for the top tank and knowing fuel ratio and propellant densities the size of the lower tank and location of the lower dome can be calculated.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/01/2019 02:52 pm
edit: 
The flanges serve the same purpose as the same size and shape oval flanges on Falcon: to access the inside of the tanks without needing to squeeze through the propellant lines.
Some part of me didn't see this post before I wrote the words below but some part of me apparently did and kicked me off in that direction.

___________

No! 
No to what MeekGee's coworkers said.
No to what I said.  Just plain No!

The oval flanges aren't the result of matching the geometry of internal tubes that are cut at an angle.  They are simply access hatches into the tanks (thus two levels) and the oval shape is generated by the stresses in the thin wall pressure vessel that they're going through.  Circumferential stress is 2x longitudinal stress in a thin walled cylindrical pressure vessel such as this. That logic generates this oval shape.  Final answer.

Now that we've got that straightened out the corollary information is that if there are two ports that aren't on the same level and there are two tanks then the bulkhead between the tanks meets the wall somewhere between the two access ports.  I've not looked at the pictures to see the levels of the two ports but if they are close together it would narrow down the bulkhead attach plane and knowing the curvature of the visible top dome volume calculations can be made for the top tank.  With the volume for the top tank and knowing fuel ratio and propellant densities the size of the lower tank and location of the lower dome can be calculated.
That's the obvious and boring answer...

All the guesswork above is trying to find more exotic options...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/01/2019 04:37 pm
The scaffolding does appear to have only been used for flange mounting so far. Or have we seen any other outside work done from the scaffolding, like welding?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kansan52 on 02/01/2019 04:38 pm
Speculating font on:

Flame trench being dug at launch site for Hopper?

Speculation font off:

Disclaimer. Can't remember guessing correctly so far.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: matthewkantar on 02/01/2019 04:53 pm
The scaffolding does appear to have only been used for flange mounting so far. Or have we seen any other outside work done from the scaffolding, like welding?

You can see they are using the scaffolding to install what I think is the last piece of plate in the upper tank dome. See detail from BCG shot below.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 02/01/2019 05:00 pm
Speculating font on:

Flame trench being dug at launch site for Hopper?

Speculation font off:

Disclaimer. Can't remember guessing correctly so far.

Speculation>
They will put in a steel plate topped landing pad and fly hopper off that...
(think fixed ASDS top on steroids)
<end my version of what will be used
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/01/2019 07:03 pm
I happened to spot this today.  ;D

Ohhh... what is it? GSE-to-Hopper connections?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 02/01/2019 07:27 pm
I happened to spot this today.  ;D

Ohhh... what is it? GSE-to-Hopper connections?

I actually don't precisely know or care what it is. All I know is the rocket will look completely steampunk/retrofuturistic.  :o
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/01/2019 07:50 pm
What do you guys think about the possibility that the steel plates being added are to move the cg so it matches the actual SS? Would obviously increase the moment s of inertia as well.

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris_Pi on 02/01/2019 10:36 pm
I happened to spot this today.  ;D

Ohhh... what is it? GSE-to-Hopper connections?

Once I saw it was on the bottom edge, I was thinking TSM connection too. If it's that good chance it'll sprout another on the other side. Straight across is a leg though. Maybe 120° is far enough. ???
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: alienmike on 02/01/2019 10:40 pm
I happened to spot this today.  ;D

Ohhh... what is it? GSE-to-Hopper connections?

Looks like a good place for a cowboy to ride.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/02/2019 04:13 pm
That one is definitely flight proven.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 02/03/2019 09:15 pm
Cropped BCG’s pic. Note ports cut into hopper above what we think is the attachment for GSE. These form a line up the hopper. Will this be like what is covered by the F9 raceway? Is this an attachment for the feed lines up to the cryogenic-tanks?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris Bergin on 02/04/2019 11:54 am
Discuss the hardware. No detailing with petty posts about Elon tweet timelines.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 02/04/2019 01:02 pm
Cropped BCG’s pic. Note ports cut into hopper above what we think is the attachment for GSE. These form a line up the hopper. Will this be like what is covered by the F9 raceway? Is this an attachment for the feed lines up to the cryogenic-tanks?
Think you are right, its the return piping you see outside on all rockets, return of overflow liquid, gass for pressurization, wondered why it was not shown on starship.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Crispy on 02/04/2019 02:14 pm
Cropped BCG’s pic. Note ports cut into hopper above what we think is the attachment for GSE. These form a line up the hopper. Will this be like what is covered by the F9 raceway? Is this an attachment for the feed lines up to the cryogenic-tanks?
Think you are right, its the return piping you see outside on all rockets, return of overflow liquid, gass for pressurization, wondered why it was not shown on starship.
It might be contained in the interstitial space between the inner and outer hulls, in the final version.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 02/04/2019 05:41 pm
Second GSE connection for lower tank
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/04/2019 06:33 pm
Second GSE connection.

I'm done for - I've just realized I'm an addict. I keep finding myself beginning to sweat and tremble, hitting the "Unread Topics" button in hopes of a post in the BFH Updates and Photos thread from BCGal or Nomadd. And when there's not I'm distraught, and when there is I sweep everything else to the side until I get my fix.

Thanks a lot - you've ruined me.

I

WANT

MORE!

(And yes - looks like it's another GSE connection. And there's a lot of gas (welding) lines both running up the business and of the BFH as well as through a manhole. They are really burning the midnight oil to get this thing flight worthy...)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rsdavis9 on 02/04/2019 07:07 pm
[/font][/size]Second GSE connection.

I'm done for - I've just realized I'm an addict. I keep finding myself beginning to sweat and tremble, hitting the "Unread Topics" button in hopes of a post in the BFH Updates & Photos thread from BCGal or Nomadd. And when there's not I'm distraught, and when there is I sweep everything else to the side until I get my fix.

Thanks a lot - you've ruined me.

I

WANT

MORE!

(And yes - looks like it's another GSE connection. And there's a lot of gas (welding) lines both running up the business and of the BFH as well as through a manhole. They are really burning the midnight oil to get this thing flight worthy...)

I know the feeling. It seems if there is no news for a day I start worrying that I might have missed something. :)

Its a race between the engine(s) completing the macgregor testing and having the ship ready for installation.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ngkiwi on 02/05/2019 12:39 am
And there I was thinking they would put the GSE connection in the base of the hopper - where the connection would be for bum to bum refuelling in orbit - yes I know the hopper is not going to orbit.  I am picking they will still require a side mounted GSE connection for fuelling before launch, and it would be a lot quicker to build a side mount (existing expertise) rather than an end mount (new).  Perhaps another day another iteration.

Thanks to SpaceX for giving us the opportunity to see a 'spaceship' being made.  Are these welding people, the normal LA rocket makers or local guys; both of course have awesome bragging rights.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: xyv on 02/05/2019 01:10 am
[/font][/size]Second GSE connection.

I'm done for - I've just realized I'm an addict. I keep finding myself beginning to sweat and tremble, hitting the "Unread Topics" button in hopes of a post in the BFH Updates & Photos thread from BCGal or Nomadd. And when there's not I'm distraught, and when there is I sweep everything else to the side until I get my fix.

Thanks a lot - you've ruined me.

I

WANT

MORE!

(And yes - looks like it's another GSE connection. And there's a lot of gas (welding) lines both running up the business and of the BFH as well as through a manhole. They are really burning the midnight oil to get this thing flight worthy...)

Who ruined you?  ;D  You're the one that had the nerve to come out and claim this water tower was going to fly.  I've spent the last 2 months checking every day for any progress...and joined L2 to not miss anything.  Good fix today though ehh?  Nomadd has a drone up and running and the full scale Raptor has fired.  I grew up in the 60's and this is the kind of space milestone pace we got used to.  And then we didn't...for way too long.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/05/2019 02:00 am
And I’m so happy to have this addiction and the associated support group to help me get through it...

Looking at BCGal’s last photo of the second “GSE plumbing shelf”, you can see the marked small rectangles running up the skin above this fitting. They’re going to install a vertical column of rectangular standoffs up the side, most likely for external plumbing/electrical runs up the hopper, just like they did above the other one.

I love that laying around someplace at the Hopper shipyard is a set of plans for this thing. Those would be something to see. Maybe we could get Nomadd’s nose under the flap of that tent...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThereIWas3 on 02/05/2019 03:36 am
I would expect all the GSE connections on the real vehicle to be on the bottom, just like the in-flight refueling connection.  After all, why have two ways of fuelling these vehicles when one will do?  The real vehicle has to do EDL at interplanetary speeds and you don't want any extra stuff hanging outside.  The Hopper has no such requirement and can be "ugly".
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 02/05/2019 03:53 am
And I’m so happy to have this addiction and the associated support group to help me get through it...

Dude, we're enablers.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Falcon H on 02/05/2019 03:50 pm
Did they install an inner bulkhead?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/05/2019 04:12 pm
Did they install an inner bulkhead?

They must have done it, since they capped off the top.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/05/2019 04:29 pm
Did they install an inner bulkhead?
Pretty sure you can see the inner bulkhead from the initial drone footage, the one from the local news channel back in the day.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/05/2019 07:20 pm
Its time to build another one I'm telling ya.  Toys get lost, stolen, stepped on, blow up in big fireballs all the time and you don't want a 3-4 month delay while you wait for Santa to bring you another one.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/05/2019 07:23 pm
Its time to build another one I'm telling ya.  Toys get lost, stolen, stepped on, blow up in big fireballs all the time and you don't want a 3-4 month delay while you wait for Santa to bring you another one.
Speaking of which - FTS...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: archae86 on 02/05/2019 07:25 pm
If they started building another one now, most likely they'd miss out on changes they would wish based on what they'll learn by observation or just think of between now and then.  Now it might make a lot of sense to work on building some long lead-time items that seem least likely to be obsoleted by events and learnings.

Speaking of components, has not Elon said they are already building parts of the next higher performance test item?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rsdavis9 on 02/05/2019 07:36 pm
If they started building another one now, most likely they'd miss out on changes they would wish based on what they'll learn by observation or just think of between now and then.  Now it might make a lot of sense to work on building some long lead-time items that seem least likely to be obsoleted by events and learnings.

Speaking of components, has not Elon said they are already building parts of the next higher performance test item?

Thats what Elon said.
I have not seen any evidence of where(san pedro?) or if.
Any info or pcis?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/05/2019 09:32 pm
Gotta love that they can use the BFH itself as a ground for the welders...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MizaruSpaceXNut on 02/05/2019 10:14 pm
Gotta love that they can use the BFH itself as a ground for the welders...

SOP unless told otherwise! On start of third shift, met Rufus pushing a welding machine, "What'cha gonn'a do

about them burnt up wires?" says he? Found the chalky looking conduit and replaced the wires.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 02/05/2019 11:06 pm
A Rombus-style bowl pad, suitably adapted for tripod leg clamps?

Those upper leg tubes tie into  the triangular truss at the top of the structure, so they should be strong enough.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/06/2019 02:27 am
A Rombus-style bowl pad, suitably adapted for tripod leg clamps?

Those upper leg tubes tie into  the triangular truss at the top of the structure, so they should be strong enough.

Nomadd mentioned the pad may be concave and HMXHMX posted this exact image a while ago: https://forum.nasaspaceflight.com/index.php?topic=47001.msg1891801#msg1891801
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HMXHMX on 02/06/2019 04:42 am
A Rombus-style bowl pad, suitably adapted for tripod leg clamps?

Those upper leg tubes tie into  the triangular truss at the top of the structure, so they should be strong enough.

Nomadd mentioned the pad may be concave and HMXHMX posted this exact image a while ago: https://forum.nasaspaceflight.com/index.php?topic=47001.msg1891801#msg1891801

Just to be clear, I wasn't suggesting the Bono Rombus-style pad for the Hopper, but for the first stage's enormous thrust level (sound suppression will be an issue).  I don't necessarily think the Hopper pad will be concave.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: vaporcobra on 02/06/2019 05:08 am
A Rombus-style bowl pad, suitably adapted for tripod leg clamps?

Those upper leg tubes tie into  the triangular truss at the top of the structure, so they should be strong enough.

Nomadd mentioned the pad may be concave and HMXHMX posted this exact image a while ago: https://forum.nasaspaceflight.com/index.php?topic=47001.msg1891801#msg1891801

Just to be clear, I wasn't suggesting the Bono Rombus-style pad for the Hopper, but for the first stage's enormous thrust level (sound suppression will be an issue).  I don't necessarily think the Hopper pad will be concave.

Compared to Saturn V (35.1 MN) and Nova (~61.9 MN), both of which 39A was designed to support (survive?), BFR's 61.8 MN probably indicates that there need not be a significant departure from a traditional flame duct and deluge system. That's not to say that launch pad design couldn't benefit from major innovation, but it shouldn't be assumed that BFR will need a radically different solution.

The fact that Musk is acting like SpaceX needs to do some extreme penny-pinching to build Starlink and BFR also dramatically lowers the odds of risky capital-intensive infrastructure projects being chosen over proven stand-ins.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HMXHMX on 02/06/2019 05:20 am
A Rombus-style bowl pad, suitably adapted for tripod leg clamps?

Those upper leg tubes tie into  the triangular truss at the top of the structure, so they should be strong enough.

Nomadd mentioned the pad may be concave and HMXHMX posted this exact image a while ago: https://forum.nasaspaceflight.com/index.php?topic=47001.msg1891801#msg1891801

Just to be clear, I wasn't suggesting the Bono Rombus-style pad for the Hopper, but for the first stage's enormous thrust level (sound suppression will be an issue).  I don't necessarily think the Hopper pad will be concave.

Compared to Saturn V (35.1 MN) and Nova (~61.9 MN), both of which 39A was designed to support (survive?), BFR's 61.8 MN probably indicates that there need not be a significant departure from a traditional flame duct and deluge system. That's not to say that launch pad design couldn't benefit from major innovation, but it shouldn't be assumed that BFR will need a radically different solution.

The fact that Musk is acting like SpaceX needs to do some extreme penny-pinching to build Starlink and BFR also dramatically lowers the odds of risky capital-intensive infrastructure projects being chosen over proven stand-ins.

Nova may have been too big for 39A, no matter what the specs may have read – "survive" is a good choice.  By the way, Rombus would have been 79.8MN.  Or as we old missile men say, 17.9 million-lbf!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: space_snap828 on 02/06/2019 01:47 pm
Given that they are building this outdoors, is there danger that contamination could damage the engines when they fire it up? Dirt, water, even bird poop could end up inside the tanks, right? Does anyone know if this is a problem, and if so, how they would prevent it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/06/2019 01:55 pm
Given that they are building this outdoors, is there danger that contamination could damage the engines when they fire it up? Dirt, water, even bird poop could end up inside the tanks, right? Does anyone know if this is a problem, and if so, how they would prevent it?
The manhole ports allow human entry into these spaces for final cleaning. They will not doubt be purged with He to test for leaks, and then will probably have a vacuum pulled prior to loading propellants. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 02/06/2019 02:03 pm
Given that they are building this outdoors, is there danger that contamination could damage the engines when they fire it up? Dirt, water, even bird poop could end up inside the tanks, right? Does anyone know if this is a problem, and if so, how they would prevent it?
The manhole ports allow human entry into these spaces for final cleaning. They will not doubt be purged with He to test for leaks, and then will probably have a vacuum pulled prior to loading propellants.

I'd suspect a full flush with a more active cleansing agent that removes anything capable of reacting with liquid oxygen or methane inside the fuel tanks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 02/06/2019 02:04 pm
Given that they are building this outdoors, is there danger that contamination could damage the engines when they fire it up? Dirt, water, even bird poop could end up inside the tanks, right? Does anyone know if this is a problem, and if so, how they would prevent it?

https://www.airspacemag.com/space/is-spacex-changing-the-rocket-equation-132285884/?page=2

Quote
Part of the Merlin’s qualification testing involves feeding a stainless steel nut into the fuel and oxidizer lines while the engine is running—a test that would destroy most engines but leaves the Merlin running basically unhindered.

I don't think they would accept something less robust for their Mars engine.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: space_snap828 on 02/06/2019 02:31 pm
Quote
Part of the Merlin’s qualification testing involves feeding a stainless steel nut into the fuel and oxidizer lines while the engine is running—a test that would destroy most engines but leaves the Merlin running basically unhindered.
Awesome to know. What I've been concerned about the whole time is that their state-of-the-art new engine will blow up in flight due to the crude construction methods we are seeing. If it can tolerate a metal fragment, I suppose it can withstand most anything.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: billh on 02/06/2019 02:35 pm
I can't believe nobody's talking about all the juicy detail we see in this picture from BCG. What are we looking at here?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: kevinof on 02/06/2019 02:47 pm
Interesting. Hadn't seen that. I'm a sailor, not a rocket man so I've no idea what all that is.

I can't believe nobody's talking about all the juicy detail we see in this picture from BCG. What are we looking at here?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SPadre on 02/06/2019 02:56 pm
Video from Tuesday  ;)
Upcoming videos will include more essential insider local info for those traveling to South Padre Island to watch or film launches.

https://www.youtube.com/watch?v=_IpTu_8favY
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/06/2019 03:22 pm
There appears to be no shortage of cables (and presumably hoses) going into the access hatch in the side and to a lesser extent the dome.  Presumably a number of welding dudes in there making sparks, melting stuff and sticking things together.  I wonder if that red fan is still involved and where.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/06/2019 03:38 pm
I can't believe nobody's talking about all the juicy detail we see in this picture from BCG. What are we looking at here?

two big valves? and a bunch of sensors?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HMXHMX on 02/06/2019 03:41 pm
I can't believe nobody's talking about all the juicy detail we see in this picture from BCG. What are we looking at here?

Presumably vent valves.  Right hand one may be for top tank with the internal "T" being a diffuser, but it may be unfinished.  Left might be for plumbing to lower tank.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: uhuznaa on 02/06/2019 06:17 pm
I can't get over how courageous (or desperate) they are to build this thing this way out in the open. Yes, it's just a hopper for testing landings and flights to 500 or maybe 5000 m, but it's still a frakking rocket. You rarely (if ever) see even simple airplanes being built this way. Ships, yes...

I mean, yes, I could even understand them switching to a "no clean room" policy just because the final product is meant to go to Mars and probably being parked there for years and maintained and possibly being repaired sitting on the ground with dust being blown around, so this somehow would make sense. It also saves lots of money, I guess. But as the blown over "fairing" has shown all of this is risky and exposes what they're building to lots of failure modes that you usually try hard to steer around.

Whatever, I think Elon Musk has a love affair with the idea of "counter-intuitive" right now... and you may very well call this desperation. SpaceX won't be able to build their two stage fully reusable space craft without spending a few billion dollars and they don't have this kind of money and won't be able to earn it just with the F9 launching sats in the next couple of years, so they need to make visible progress just to try and attract investors. I'm really curious who will invest into that. Because honestly I can't imagine SpaceX to build even something to just launch their StarLink constellation by this means without some serious cash injection.

Or will they be able to design, engineer and build a revolutionary reusable launcher on a dime just by being very clever and courageous? If they really will manage to fly and land this contraption within the next months or so this will start to look almost possible and somehow I guess this is what it is there for.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/06/2019 06:24 pm
I can't get over how courageous (or desperate) they are to build this thing this way out in the open. Yes, it's just a hopper for testing landings and flights to 500 or maybe 5000 m, but it's still a frakking rocket. You rarely (if ever) see even simple airplanes being built this way. Ships, yes...

I mean, yes, I could even understand them switching to a "no clean room" policy just because the final product is meant to go to Mars and probably being parked there for years and maintained and possibly being repaired sitting on the ground with dust being blown around, so this somehow would make sense. It also saves lots of money, I guess. But as the blown over "fairing" has shown all of this is risky and exposes what they're building to lots of failure modes that you usually try hard to steer around.

Whatever, I think Elon Musk has a love affair with the idea of "counter-intuitive" right now... and you may very well call this desperation. SpaceX won't be able to build their two stage fully reusable space craft without spending a few billion dollars and they don't have this kind of money and won't be able to earn it just with the F9 launching sats in the next couple of years, so they need to make visible progress just to try and attract investors. I'm really curious who will invest into that. Because honestly I can't imagine SpaceX to build even something to just launch their StarLink constellation by this means without some serious cash injection.

Or will they be able to design, engineer and build a revolutionary reusable launcher on a dime just by being very clever and courageous? If they really will manage to fly and land this contraption within the next months or so this will start to look almost possible and somehow I guess this is what it is there for.

I don't get the connection between "build in the open" and "attract investors". Wouldn't investors be able to see progress even if they built it in secret? It's not like they are reading this thread for news. If you have the kind of cash SpaceX needs you can get direct access.

SpaceX has always done things "as cheap as possible, as long as it works". This is no different.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: abaddon on 02/06/2019 06:33 pm
I guess it might attract the attention of investors that are not usually engaged in this arena.  That seems more likely to be an accident than intentional though.

I mean, the hardest part of this thing is the engine, and it seems like they are very close to that.  A Starship that isn't perfect could still make Starlink feasible and could then enable the revenue that would fund the Starship that could go to Mars.  SpaceX is not trying to go that way but it's a possible fallback if they're just too ambitious in the initial version of Starship.

This is all veering off-topic, probably best to focus back on the hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: krsears on 02/06/2019 06:43 pm
Let us all not forget that the last numbers that EM gave about total costs for SH/SS were when SpaceX was going to use composites.  We've since found out that the costs for materials has dropped by some 66x from $200ish per kg to $3ish per kg.

This doesn't count in the savings in labor.  The costs for the skills necessary for steel vs composite are quite different.  This part is also quite dependent on time, and the less time spent building, the lower the cost that is incurred.

There is also the situation that steel construction does not need "clean" environments for fabrication like composites do.  Getting contaminants in between the composite layers would be catastrophic, not so with steel.  Now SpaceX doesn't need the additional costs of (or the time to build) a rather large production building.  That alone is a LOT of cost savings.

Kendall
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: uhuznaa on 02/06/2019 06:55 pm
I can't get over how courageous (or desperate) they are to build this thing this way out in the open. Yes, it's just a hopper for testing landings and flights to 500 or maybe 5000 m, but it's still a frakking rocket. You rarely (if ever) see even simple airplanes being built this way. Ships, yes...

I mean, yes, I could even understand them switching to a "no clean room" policy just because the final product is meant to go to Mars and probably being parked there for years and maintained and possibly being repaired sitting on the ground with dust being blown around, so this somehow would make sense. It also saves lots of money, I guess. But as the blown over "fairing" has shown all of this is risky and exposes what they're building to lots of failure modes that you usually try hard to steer around.

Whatever, I think Elon Musk has a love affair with the idea of "counter-intuitive" right now... and you may very well call this desperation. SpaceX won't be able to build their two stage fully reusable space craft without spending a few billion dollars and they don't have this kind of money and won't be able to earn it just with the F9 launching sats in the next couple of years, so they need to make visible progress just to try and attract investors. I'm really curious who will invest into that. Because honestly I can't imagine SpaceX to build even something to just launch their StarLink constellation by this means without some serious cash injection.

Or will they be able to design, engineer and build a revolutionary reusable launcher on a dime just by being very clever and courageous? If they really will manage to fly and land this contraption within the next months or so this will start to look almost possible and somehow I guess this is what it is there for.

I don't get the connection between "build in the open" and "attract investors". Wouldn't investors be able to see progress even if they built it in secret? It's not like they are reading this thread for news. If you have the kind of cash SpaceX needs you can get direct access.

SpaceX has always done things "as cheap as possible, as long as it works". This is no different.

The "build in the open" is just a side effect of "build it right here, right now and without spending more money on it than you absolutely have to" because constructing a building for that close enough to where you want to test it would be much more expensive. And yes, SpaceX always does the "as cheap as possible" but this is on another level. And not strapping down your fairing good enough to withstand a mild storm isn't "as cheap as possible as long as it works", it's outright "as cheap as possible".
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/06/2019 07:27 pm
I don't get the connection between "build in the open" and "attract investors". Wouldn't investors be able to see progress even if they built it in secret? It's not like they are reading this thread for news. If you have the kind of cash SpaceX needs you can get direct access.

SpaceX has always done things "as cheap as possible, as long as it works". This is no different.
In various news pieces i've read the past 6 months I have noticed an high amount of skepticism of BFR, with a "i'll believe it when i see it" attitude, if it's mentioned in the article at all. They mention Vulcan, SLS, Ariane 6, FH, and even New Glenn but not BFR. Or if BFR is mentioned it's siloed off in a separate paragraph like "crazy old SpaceX is at it again."

for example there's a Ars interview with Tory Bruno (https://arstechnica.com/science/2018/12/ula-chief-tory-bruno-on-competing-with-blue-origin-spacex-rocket-landings/) where he doesn't mention BFR even though it's nominally going to launch the same year as Vulcan.
Here's another Ars article (https://arstechnica.com/science/2018/07/the-year-2020-could-see-the-unheard-of-debut-of-four-big-rockets-or-not/) with a siloed paragraph.(not to pick on Eric, but these two stand out in my memory)

So while i don't think it's about attracting investors, it might be partly about dispelling skepticism. a successful BFH will go a long way toward doing that.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: matthewkantar on 02/06/2019 07:27 pm
In BCG’s recent photo, it is still jarring to see aerospace hardware next to rusty old bent welding dogs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/06/2019 07:43 pm
Video from Tuesday  ;)
Upcoming videos will include more essential insider local info for those traveling to South Padre Island to watch or film launches.

https://www.youtube.com/watch?v=_IpTu_8favY

Thank you for your videos! Might add a bit ot two for people that did not follow Nomadd's adventures regarding Rattlesnakes with security patches, rocket Skunks and Raptors hiding in the high grass?

Also, what are those bits:
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: flyright on 02/06/2019 07:59 pm
Video from Tuesday  ;)
Upcoming videos will include more essential insider local info for those traveling to South Padre Island to watch or film launches.

https://www.youtube.com/watch?v=_IpTu_8favY

Thank you for your videos! Might add a bit ot two for people that did not follow Nomadd's adventures regarding Rattlesnakes with security patches, rocket Skunks and Raptors hiding in the high grass?

Also, what are those bits:

It's been suggested that those are struts for mounting COPVs.
Maybe for cold gas RCS?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ajmarco on 02/06/2019 08:04 pm

Also, what are those bits:

Looking at the screen grab, they seem to be spacers/supports for other tube/piping. The one on the right has a pipe going through it and then angling into the top of the dome.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lemurion on 02/06/2019 08:18 pm
I don't get the connection between "build in the open" and "attract investors". Wouldn't investors be able to see progress even if they built it in secret? It's not like they are reading this thread for news. If you have the kind of cash SpaceX needs you can get direct access.

SpaceX has always done things "as cheap as possible, as long as it works". This is no different.
In various news pieces i've read the past 6 months I have noticed an high amount of skepticism of BFR, with a "i'll believe it when i see it" attitude, if it's mentioned in the article at all. They mention Vulcan, SLS, Ariane 6, FH, and even New Glenn but not BFR. Or if BFR is mentioned it's siloed off in a separate paragraph like "crazy old SpaceX is at it again."

for example there's a Ars interview with Tory Bruno (https://arstechnica.com/science/2018/12/ula-chief-tory-bruno-on-competing-with-blue-origin-spacex-rocket-landings/) where he doesn't mention BFR even though it's nominally going to launch the same year as Vulcan.
Here's another Ars article (https://arstechnica.com/science/2018/07/the-year-2020-could-see-the-unheard-of-debut-of-four-big-rockets-or-not/) with a siloed paragraph.(not to pick on Eric, but these two stand out in my memory)

So while i don't think it's about attracting investors, it might be partly about dispelling skepticism. a successful BFH will go a long way toward doing that.

I've noticed the same thing, as if BFR is the least real of these rockets even though it's showing the most actual progress. It has a flight test article under construction and the full-size engine has fired.

I really think it's almost like the fabled ostrich approach. If the competitors keep their heads in the sand and pretend BFR doesn't really have the same level of reality as their own projects they don't have to worry about the comparison between their designs and BFR's capabilities.

Putting the BFH out there in plain sight is one way to fight that idea. A public build and demonstration makes it that much harder to argue that BFR (Starship/Super Heavy) is in some way nebulous when the stainless steel reality is right there in the open.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/06/2019 08:20 pm
(1) SpaceX won't be able to build their two stage fully reusable space craft without spending a few billion dollars and they don't have this kind of money and won't be able to earn it just with the F9 launching sats in the next couple of years, so they need to make visible progress just to try and attract investors. I'm really curious who will invest into that.

(2) Because honestly I can't imagine SpaceX to build even something to just launch their StarLink constellation by this means without some serious cash injection.

(3) Or will they be able to design, engineer and build a revolutionary reusable launcher on a dime just by being very clever and courageous? If they really will manage to fly and land this contraption within the next months or so this will start to look almost possible and somehow I guess this is what it is there for.

(1) [Jim] Wrong [/Jim]

(2) I can

(3) They will be able to build it on a dime (IMO) and if they can't they may or may not need cash injections based on how aggressively they want to chase the timeline vs. proceed slower.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 02/06/2019 08:22 pm
I don't get the connection between "build in the open" and "attract investors". Wouldn't investors be able to see progress even if they built it in secret? It's not like they are reading this thread for news. If you have the kind of cash SpaceX needs you can get direct access.

SpaceX has always done things "as cheap as possible, as long as it works". This is no different.
In various news pieces i've read the past 6 months I have noticed an high amount of skepticism of BFR, with a "i'll believe it when i see it" attitude, if it's mentioned in the article at all. They mention Vulcan, SLS, Ariane 6, FH, and even New Glenn but not BFR. Or if BFR is mentioned it's siloed off in a separate paragraph like "crazy old SpaceX is at it again."

for example there's a Ars interview with Tory Bruno (https://arstechnica.com/science/2018/12/ula-chief-tory-bruno-on-competing-with-blue-origin-spacex-rocket-landings/) where he doesn't mention BFR even though it's nominally going to launch the same year as Vulcan.
Here's another Ars article (https://arstechnica.com/science/2018/07/the-year-2020-could-see-the-unheard-of-debut-of-four-big-rockets-or-not/) with a siloed paragraph.(not to pick on Eric, but these two stand out in my memory)

So while i don't think it's about attracting investors, it might be partly about dispelling skepticism. a successful BFH will go a long way toward doing that.

I'm in the camp with others who say that the BF design is anti-fragile, inherently robust.  Don't need highest thrust or ISP #s to make orbit with tens of tonnes payload.  Don't need full 31 engine 1st stage to be a viable satellite launcher.  No longer need expensive tooling for very expensive per Kg carbon fiber.

We see signs that Elon is de-scoping the design hurdles for the 1st generation operational craft. This reduces R&D time and $$.

The Hopper is key.  It needs to demonstrate that Raptor engines are reliably flight worthy and validate flight control algorithms and code paths.  Really hoping that all goes well with engine tests @MacGregor so the Hopper can fly and validate or highlight change where needed for the orbital build SS supposedly following on quickly (this year).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/06/2019 08:23 pm
I can't get over how courageous (or desperate) they are to build this thing this way out in the open. Yes, it's just a hopper for testing landings and flights to 500 or maybe 5000 m, but it's still a frakking rocket. You rarely (if ever) see even simple airplanes being built this way. Ships, yes...

I mean, yes, I could even understand them switching to a "no clean room" policy just because the final product is meant to go to Mars and probably being parked there for years and maintained and possibly being repaired sitting on the ground with dust being blown around, so this somehow would make sense. It also saves lots of money, I guess. But as the blown over "fairing" has shown all of this is risky and exposes what they're building to lots of failure modes that you usually try hard to steer around.

Whatever, I think Elon Musk has a love affair with the idea of "counter-intuitive" right now... and you may very well call this desperation. SpaceX won't be able to build their two stage fully reusable space craft without spending a few billion dollars and they don't have this kind of money and won't be able to earn it just with the F9 launching sats in the next couple of years, so they need to make visible progress just to try and attract investors. I'm really curious who will invest into that. Because honestly I can't imagine SpaceX to build even something to just launch their StarLink constellation by this means without some serious cash injection.

Or will they be able to design, engineer and build a revolutionary reusable launcher on a dime just by being very clever and courageous? If they really will manage to fly and land this contraption within the next months or so this will start to look almost possible and somehow I guess this is what it is there for.

I don't get the connection between "build in the open" and "attract investors". Wouldn't investors be able to see progress even if they built it in secret? It's not like they are reading this thread for news. If you have the kind of cash SpaceX needs you can get direct access.

SpaceX has always done things "as cheap as possible, as long as it works". This is no different.

There really isn't.  His old-school thinking has him casting about for explanations even though they don't really make sense.

It may be some kind of marginal side-effect.  But the main thing is two-fold:  (1) Elon has a love affair with getting s**t done; and (2) Elon understands there is a great deal of value in public enthusiasm.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rsdavis9 on 02/06/2019 08:35 pm
I can't get over how courageous (or desperate) they are to build this thing this way out in the open. Yes, it's just a hopper for testing landings and flights to 500 or maybe 5000 m, but it's still a frakking rocket. You rarely (if ever) see even simple airplanes being built this way. Ships, yes...

I mean, yes, I could even understand them switching to a "no clean room" policy just because the final product is meant to go to Mars and probably being parked there for years and maintained and possibly being repaired sitting on the ground with dust being blown around, so this somehow would make sense. It also saves lots of money, I guess. But as the blown over "fairing" has shown all of this is risky and exposes what they're building to lots of failure modes that you usually try hard to steer around.

Whatever, I think Elon Musk has a love affair with the idea of "counter-intuitive" right now... and you may very well call this desperation. SpaceX won't be able to build their two stage fully reusable space craft without spending a few billion dollars and they don't have this kind of money and won't be able to earn it just with the F9 launching sats in the next couple of years, so they need to make visible progress just to try and attract investors. I'm really curious who will invest into that. Because honestly I can't imagine SpaceX to build even something to just launch their StarLink constellation by this means without some serious cash injection.

Or will they be able to design, engineer and build a revolutionary reusable launcher on a dime just by being very clever and courageous? If they really will manage to fly and land this contraption within the next months or so this will start to look almost possible and somehow I guess this is what it is there for.

I don't get the connection between "build in the open" and "attract investors". Wouldn't investors be able to see progress even if they built it in secret? It's not like they are reading this thread for news. If you have the kind of cash SpaceX needs you can get direct access.

SpaceX has always done things "as cheap as possible, as long as it works". This is no different.

There really isn't.  His old-school thinking has him casting about for explanations even though they don't really make sense.

It may be some kind of marginal side-effect.  But the main thing is two-fold:  (1) Elon has a love affair with getting s**t done; and (2) Elon understands there is a great deal of value in public enthusiasm.
2) Or elon can't help himself and wants to share his enthusiasm.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/06/2019 08:41 pm
There is probably little or no comparison between the construction of the hopper and the Star Ship prototype other than they both use Stainless Steel:

- Hopper can afford to be very heavy, so they are using civil engineering safety factors (~5) and construction techniques to rapidly and cheaply build a test vehicle.

- Star Ship will be built with safety factor of ~1.5 which require aerospace quality production techniques.

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/06/2019 08:47 pm
On of my favorite things about the BFH threads, and why I focus on them so much, is because not only is it really amazing to see the potential future of human spaceflight unfold before us in plain view, but because it's an amazing study in human psychology, and the power of the group mentality.

It reminds me of the same thing that happened back in December of 2015, and again in 2016, when there was so much negativity, doubt, and out and out dissension surrounding recoverability and reuse. That was only three years ago, and now those voices are almost completely silent.

But this is so much more - and it's built on the back of that same F9R program. Sometimes people have a very hard time letting go of established norms, and so when something is so far out of that norm it becomes an aberration - something that must be wrong or fake.

This is not desperation on the part of SpaceX - this is brilliance at work. I won't even bother going into why - because it's literally happening before our eyes. SpaceX, more than literally any other entity in the world, has a firm grasp on how to _really_ build a rocket. Not on how it _should_ be built, or how is _has_ been built, but on what is really necessary vs what is just dogmatic established standard. And SpaceX's willingness to fail, to do mistakes and then critically examine those mistakes and learn valuable lessons and move forward, is sorely lacking in the rest of the industry these days - with stock holders and political agendas carrying far more importance than boldly pushing forward.

Believe it or not, I'm not a SpaceX amazing people. I absolutely hate that term. I'm an engineer, adventurer, and someone who's been incredibly frustrated with the stagnation we've been drowning in for the past so many decades.

So go SpaceX, go Blue Origin, go Rocket Labs, go Relativity Space, go Made In Space, go Bigelow Aerospace - it's about freekin time...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Spindog on 02/06/2019 08:50 pm
I don't get the connection between "build in the open" and "attract investors". Wouldn't investors be able to see progress even if they built it in secret? It's not like they are reading this thread for news. If you have the kind of cash SpaceX needs you can get direct access.

SpaceX has always done things "as cheap as possible, as long as it works". This is no different.
In various news pieces i've read the past 6 months I have noticed an high amount of skepticism of BFR, with a "i'll believe it when i see it" attitude, if it's mentioned in the article at all. They mention Vulcan, SLS, Ariane 6, FH, and even New Glenn but not BFR. Or if BFR is mentioned it's siloed off in a separate paragraph like "crazy old SpaceX is at it again."

for example there's a Ars interview with Tory Bruno (https://arstechnica.com/science/2018/12/ula-chief-tory-bruno-on-competing-with-blue-origin-spacex-rocket-landings/) where he doesn't mention BFR even though it's nominally going to launch the same year as Vulcan.
Here's another Ars article (https://arstechnica.com/science/2018/07/the-year-2020-could-see-the-unheard-of-debut-of-four-big-rockets-or-not/) with a siloed paragraph.(not to pick on Eric, but these two stand out in my memory)

So while i don't think it's about attracting investors, it might be partly about dispelling skepticism. a successful BFH will go a long way toward doing that.

I've noticed the same thing, as if BFR is the least real of these rockets even though it's showing the most actual progress. It has a flight test article under construction and the full-size engine has fired.

I really think it's almost like the fabled ostrich approach. If the competitors keep their heads in the sand and pretend BFR doesn't really have the same level of reality as their own projects they don't have to worry about the comparison between their designs and BFR's capabilities.

Putting the BFH out there in plain sight is one way to fight that idea. A public build and demonstration makes it that much harder to argue that BFR (Starship/Super Heavy) is in some way nebulous when the stainless steel reality is right there in the open.

I think it's a symptom of the unconventional and ambitious nature of the SS. How can they just change to steel construction? Building it in the open? Sure, the raptor seems to work but it hasn't been flight tested yet! And raptor is an advanced design never before used on a rocket! Radical heatshield concept that's never really been tested! It's too darn big! It has too many engines! In-space refueling has never before been tested. How can it really start earning money? And on and on ...
As much as I want to see it succeed I must admit it all seems like too big a challenge. I find it nearly impossible to be as optimistic as I wish I was. Even seeing the 3 engine BFH fly won't convince that many people to take it seriously.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/06/2019 08:54 pm
I can't get over how courageous (or desperate) they are to build this thing this way out in the open. Yes, it's just a hopper for testing landings and flights to 500 or maybe 5000 m, but it's still a frakking rocket. You rarely (if ever) see even simple airplanes being built this way. Ships, yes...

I mean, yes, I could even understand them switching to a "no clean room" policy just because the final product is meant to go to Mars and probably being parked there for years and maintained and possibly being repaired sitting on the ground with dust being blown around, so this somehow would make sense. It also saves lots of money, I guess. But as the blown over "fairing" has shown all of this is risky and exposes what they're building to lots of failure modes that you usually try hard to steer around.

Whatever, I think Elon Musk has a love affair with the idea of "counter-intuitive" right now... and you may very well call this desperation. SpaceX won't be able to build their two stage fully reusable space craft without spending a few billion dollars and they don't have this kind of money and won't be able to earn it just with the F9 launching sats in the next couple of years, so they need to make visible progress just to try and attract investors. I'm really curious who will invest into that. Because honestly I can't imagine SpaceX to build even something to just launch their StarLink constellation by this means without some serious cash injection.

Or will they be able to design, engineer and build a revolutionary reusable launcher on a dime just by being very clever and courageous? If they really will manage to fly and land this contraption within the next months or so this will start to look almost possible and somehow I guess this is what it is there for.

I don't get the connection between "build in the open" and "attract investors". Wouldn't investors be able to see progress even if they built it in secret? It's not like they are reading this thread for news. If you have the kind of cash SpaceX needs you can get direct access.

SpaceX has always done things "as cheap as possible, as long as it works". This is no different.

The "build in the open" is just a side effect of "build it right here, right now and without spending more money on it than you absolutely have to" because constructing a building for that close enough to where you want to test it would be much more expensive. And yes, SpaceX always does the "as cheap as possible" but this is on another level. And not strapping down your fairing good enough to withstand a mild storm isn't "as cheap as possible as long as it works", it's outright "as cheap as possible".

They can probably hop the engine section without the hat, so I'd say it still works even if it doesn't meet Elon's standard for "making it [look] real". The hat isn't real anyway.

If they don't need a building, then not using a building reeks of pragmatism, not desperation.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 02/06/2019 09:45 pm
I'm an engineer, adventurer, and someone who's been incredibly frustrated with the stagnation we've been drowning in for the past so many decades.

So go SpaceX, go Blue Origin, go Rocket Labs, go Relativity Space, go Made In Space, go Bigelow Aerospace - it's about freekin time...

I wasn't born for Apollo 11 and I sure intend to be alive for the Mars landing, so yup, I'm with you.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/06/2019 09:59 pm
I'm an engineer, adventurer, and someone who's been incredibly frustrated with the stagnation we've been drowning in for the past so many decades.

So go SpaceX, go Blue Origin, go Rocket Labs, go Relativity Space, go Made In Space, go Bigelow Aerospace - it's about freekin time...

I wasn't born for Apollo 11 and I sure intend to be alive for the Mars landing, so yup, I'm with you.
Yup - was born in ‘65, watched the landing as a wee lad and have been in love with space ever since. Was always intending on going into that realm, but ended up turning south...

Personally I think one reason I drifted from my original path was because after Apollo there was, for me, no sense of adventure or of pushing the limits with human exploration. But for the first time in a long time I can finally say we actually have a chance to regain that.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WindyCity on 02/06/2019 10:07 pm
Why do conventional thinkers in the aerospace industry discount the likelihood of the success of SS, or even the BFH? I suspect that it's for the same reason that they laughed at Elon Musk when he founded SpaceX; it's for the same reason that they called a reusable orbital class booster a pipe dream. The "experts" have poo-pooed, euphemistically, most of what the South African émigré has done over his career all along. Of course SS will never succeed! Nothing like it has ever been done before! QED.

{Except that some of the "revolutionary" technologies he's employing—e.g., stainless steel fuselage and transpiration cooling—have been done before (and are being done).}
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/06/2019 11:12 pm
I think it's a symptom of the unconventional and ambitious nature of the SS. How can they just change to steel construction? Building it in the open? Sure, the raptor seems to work but it hasn't been flight tested yet! And raptor is an advanced design never before used on a rocket! Radical heatshield concept that's never really been tested! It's too darn big! It has too many engines! In-space refueling has never before been tested. How can it really start earning money? And on and on ...

As much as I want to see it succeed I must admit it all seems like too big a challenge. I find it nearly impossible to be as optimistic as I wish I was. Even seeing the 3 engine BFH fly won't convince that many people to take it seriously.

When you look at it that way, it does sound daunting.  But at the risk of coaxing you too far over the enthusiasm cliff, allow me to make this case.

We start here with a company that has tremendous baseline of experience with all the systems necessary except active transpiration cooling.  They have a paradigm-shifting Falcon architecture that provides them (A) a cash-flow ---and--- (B) Falcon booster development and fabrication expense avoidance.

With recent developments we have an aggressive convergence on a simplified design with an absolute minimum of unknowns for such an ambitious project.  We've got single-stick simplicity, well-known inexpensive material, no anticipated impediments to validating and refining the Raptor redesign, experience with booster landing avionics, and numerous options for reasonable investment requirements in GSE for launch and landing.  The unknowns seem to be (1) high-mach controls (low risk of intractability), (2) on-orbit refueling (low risk of intractability) and (3) active transpiration cooling (medium risk of intractability).  I personally think I might be over-conservative on (3).

But what eliminates most of the concern from my perspective is this.  SpaceX's cost-structure due to reusability provides them a relatively stable investment stream for SH/SS without necessarily requiring augmented funding and the ability to step-wise refine their testing program.

Right now today, they are building all the pieces of the next step of testing for almost nothing in the big scheme of things and paying for it out of existing operations.  They don't have to spend that next money until testing has validated that they can move to that next step.  There will always be RUD risk but they should be able to mitigate that risk based on their past experience and need to progress judiciously. 

While they have an aggressive timeline (with a hard deadline re: StarLink), they have the luxury to simply extend their timeline if things can't be achieved as fast as desired.  In time, I don't think any of their current direct SH/SS plans have risk of not being achievable.   The biggest risk in the extended timeline scenario would be that unexpected RUDs or being overtaken by a BO wiping out their cash-flow for SH/SS development.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/06/2019 11:22 pm
This veers into "who has the best business strategy" but what you said resonates, AC in NC. As long as SS/SH start flying not too long after NG, the cash flow will continue. Less launches since they ate the backlog, but they will mop up most of the deals until NG has gotten past at least the first launch. So they have cash. When SS/SH come on line, even in a reduced/stunted form (as old speedevil posts analyse in depth) it will undercut NG so much that SpaceX retiurn to market dominance even if Blue was winning that for a bit.. So the money's gonna be there.

But all of this is off topic. There is a thread for finance and a thread for strategy re Blue. Let's stick to the technical aspects
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WindyCity on 02/06/2019 11:23 pm
The biggest risk in the extended timeline scenario would be that unexpected RUDs or being overtaken by a BO wiping out their cash-flow for SH/SS development.

Consider also that Raptor development is already a sunk cost, paid for largely out of commercial revenues. Conceivably, the rocket engine represents the greatest investment required for  project completion. ECLSS is still a question mark in my mind, but I have read posts suggesting that existing systems for Dragon could be modified at least for LEO or lunar missions, thereby reducing costs considerably.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JH on 02/06/2019 11:40 pm
But this is so much more - and it's built on the back of that same F9R program. Sometimes people have a very hard time letting go of established norms, and so when something is so far out of that norm it becomes an aberration - something that must be wrong or fake.

This is not desperation on the part of SpaceX - this is brilliance at work. I won't even bother going into why - because it's literally happening before our eyes. SpaceX, more than literally any other entity in the world, has a firm grasp on how to _really_ build a rocket. Not on how it _should_ be built, or how is _has_ been built, but on what is really necessary vs what is just dogmatic established standard. And SpaceX's willingness to fail, to do mistakes and then critically examine those mistakes and learn valuable lessons and move forward, is sorely lacking in the rest of the industry these days - with stock holders and political agendas carrying far more importance than boldly pushing forward.

Without deep mastery of a field, it is very difficult to tell whether the generally accepted "best practice" of how to do something is the result of real limits or cargo cult engineering. SpaceX (and other Musk ventures) seems to probe for and eliminate cargo cult design decisions. It is therefore extremely hard for almost anyone to predict what they will do.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/07/2019 01:36 am
There is probably little or no comparison between the construction of the hopper and the Star Ship prototype other than they both use Stainless Steel:

- Hopper can afford to be very heavy, so they are using civil engineering safety factors (~5) and construction techniques to rapidly and cheaply build a test vehicle.

- Star Ship will be built with safety factor of ~1.5 which require aerospace quality production techniques.

John

I'm in the camp that they'll use the hopper construction method (vertical stacking in the open, hand welding, etc) to build the orbital prototype, this is based on various observations (no new factory location, Elon gangho on orbital prototype timeline, etc), but I'd like to hear more about any objections based on construction techniques and safety factors. Specifically:
1. What would be the dry mass difference between a safety factor 5 build and safety factor 1.5 build? Is it 5/1.5 = 3.33x?
2. Could they use the current construction method and still ends up needing a smaller safety factor? If not, could they use a hybrid method which still doesn't require a full factory to achieve the necessary dry mass/safety factor, for example building sections inside tent using some tooling, but stacking them outside by hand.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/07/2019 02:04 am
There is probably little or no comparison between the construction of the hopper and the Star Ship prototype other than they both use Stainless Steel:

- Hopper can afford to be very heavy, so they are using civil engineering safety factors (~5) and construction techniques to rapidly and cheaply build a test vehicle.

- Star Ship will be built with safety factor of ~1.5 which require aerospace quality production techniques.

John

I'm in the camp that they'll use the hopper construction method (vertical stacking in the open, hand welding, etc) to build the orbital prototype, this is based on various observations (no new factory location, Elon gangho on orbital prototype timeline, etc), but I'd like to hear more about any objections based on construction techniques and safety factors. Specifically:
1. What would be the dry mass difference between a safety factor 5 build and safety factor 1.5 build? Is it 5/1.5 = 3.33x?
2. Could they use the current construction method and still ends up needing a smaller safety factor? If not, could they use a hybrid method which still doesn't require a full factory to achieve the necessary dry mass/safety factor, for example building sections inside tent using some tooling, but stacking them outside by hand.

- 1) Yes, that would be 3.33 times heavier. Also the welds can be about 1/3 weaker. The hopper is being constructed of 6 mm or thicker plate. The Star Ship tanks will be 1 - 2 mm thick and the TPS face sheets will probably be on the order of .2 - .4 mm thick. These are really thin and will probably be resistance welded.

- 2) Lower safety margins require tighter quality standards. I believe some form of automatic welding will be used to obtain higher weld quality. I don't believe they would need a full factory, but some infrastructure would probably be needed to provide good conditions for work and QA etc.

Again just speculation, so we will see.

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/07/2019 02:14 am
I'm in the camp that they'll use the hopper construction method (vertical stacking in the open, hand welding, etc) to build the orbital prototype, this is based on various observations (no new factory location, Elon gangho on orbital prototype timeline, etc)

There is ZERO chance that the orbital prototype will be hand-welded together.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/07/2019 02:46 am
Oh but there is a chance that it can be hand welded with good quality assurance.  Two things that may be going in "our" favor here.

1) Cryoforming the tanks after welding exposes them to significantly higher stresses than they will ever see in flight.  There in one step without even NDTing every mm of weld individually you find out in one simultaneous step if your welds have strength in excess of the parent material or not (and maybe leak test the entire structure in the same single step).  You're not doing some indirect test like x-rays and using logic to infer whether the welds will handle the stress, you are actually testing all welds to higher stresses than they will ever see in use.

2) If they choose to have taylor rolled sheet stock that is thin across the bulk of the sheet width and thicker, conceptually 4x thicker for a thin strip at the edges it will allow them to do low tech welds and have high safety factors and keep the HAZ away from the thin material.  And if the thickened strips end up being called ribs, rings, or longerons that keep the structure from flopping about when not pressurized that's like eating your cake and eating it two.

edit: So to show how this would look I've made two roll formed panels and welded them together.  Watch it, the weld is still red hot.  In reality the panel widths would probably be greater between welds but I've got screen width to consider so I made them a bit narrow.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Restless on 02/07/2019 02:57 am
There is probably little or no comparison between the construction of the hopper and the Star Ship prototype other than they both use Stainless Steel:

- Hopper can afford to be very heavy, so they are using civil engineering safety factors (~5) and construction techniques to rapidly and cheaply build a test vehicle.

- Star Ship will be built with safety factor of ~1.5 which require aerospace quality production techniques.

John

True enough, but the LNG and LOX tanks still have to be free of leaks. I'm concerned that these field-welded vessels will pass leak tests. There's a tube trailer of helium parked at the dish area. Presumably this is to pressure these tanks with a few psi and check welds with a sniffer tube going to a helium mass spec detector. They may have a dickens of a time if a lot of weld leaks have to be ground out and redone. I would guess these water tank welders are probably not ASME code certified.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/07/2019 03:21 am
Water tanks tend not to leak, though, or so I thought.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Restless on 02/07/2019 04:58 am
These water tanks have to hold cryogenic LOX and LNG. Zero tolerance for leaks.......
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Semmel on 02/07/2019 07:18 am
I really think it's almost like the fabled ostrich approach. If the competitors keep their heads in the sand and pretend BFR doesn't really have the same level of reality as their own projects they don't have to worry about the comparison between their designs and BFR's capabilities.

I am a bit late to this discussion (one has to sleep from time to time), but I think its a combination of two things.

First, ULA, Ariane, Roscosmos, and all the others do what they know since 50 years. Improvements, yeah, but there are the processes and they know its going to work. THAT almost always trumps all fancy design improvements that are risky. Just look at ULA how long it takes them to develop IVF. Its infuriatingly slow. And thats because its a radical change to what they know will work. Applying this to their observation of SH/SS: "Yeah, good luck SpaceX!"

The second factor is, what IF SH/SS works as advertised? That would be a disaster! There is nothing in the present or foreseeable future in the plans of any other rocket company except BO (which is another pesky usurper) that could even faintly match capabilities and economics of SH/SS. When a company like ULA is faced with a market change of that magnitude, where it realistically cant do anything to change the tide, it knows its going to be swept aside. ULE and the others will still exist on after the flood came, but they will not know in what form. It can only ignore the fact as long as possible to make the most of the present and near future.

And thats true by extension to NASA/Congress (read SLS) and DOD et al. (read EELV program). All these billions and billions of dollars are a giant waste of time, talent and money in comparison to SH/SS. Again IF (big IF) SH/SS works as intended, then THIS is how rockets are done right. And by logic everyone is doing it wrong. Thats hard to accept and stomach. No wonder its ignored. Especially after Shuttle, which promised all the same things as SH/SS, yet reality was different. Just look at what the second E in EELV means to get an idea of the mindset.

Enough of a rant. Thats how I see it. Journalists dont want to come about as crazy for pointing out the idiocracy that blossoms all around. So they float with the current, you cant blame them for it. I bet, secretly, most of the big players, journalists and anyone who cares cheer for SH/SS. Its the enabler that would ultimately make their childhood dreams come true and reignite the Moon infection, maybe get to Mars. None of the other systems have a realistic chance to do that. Not even NG.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 02/07/2019 08:18 am
These water tanks have to hold cryogenic LOX and LNG. Zero tolerance for leaks.......

So, they employ good welders.

Too much concern in this thread from people who are not experts in the required fields.

Welding as a technology has been around for a long time. Inside, outside, big, small, it's a solved problem.

Cleaning tanks is also a solved problem.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: kevinof on 02/07/2019 08:28 am
Yeah I do chuckle at some of the concerns raised (maybe it's an NSF thing). People seem to forget that the boys at SpaceX know a thing or two about building rockets, welding, leak detection, launch pads and so on.

I suspect they have answers to these questions (and solutions) going back months, if not years.

These water tanks have to hold cryogenic LOX and LNG. Zero tolerance for leaks.......

So, they employ good welders.

Too much concern in this thread from people who are not experts in the required fields.

Welding as a technology has been around for a long time. Inside, outside, big, small, it's a solved problem.

Cleaning tanks is also a solved problem.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 02/07/2019 08:33 am
Yeah I do chuckle at some of the concerns raised (maybe it's an NSF thing). People seem to forget that the boys at SpaceX know a thing or two about building rockets, welding, leak detection, launch pads and so on.

I suspect they have answers to these questions (and solutions) going back months, if not years.

These water tanks have to hold cryogenic LOX and LNG. Zero tolerance for leaks.......

So, they employ good welders.

Too much concern in this thread from people who are not experts in the required fields.

Welding as a technology has been around for a long time. Inside, outside, big, small, it's a solved problem.

Cleaning tanks is also a solved problem.

Not just here, the Facebook group is also rife with it. You'd think Google hadn't been invented given some of the stuff that comes up.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: yokem55 on 02/07/2019 02:02 pm
With Elon's Raptor tweet, we can make a good estimate of the hopper's liftoff mass. 3x170 metric tons comes to 510 tons of force. A liftoff TWR of 1.1 would put the mass of the vehicle at ~463 metric tons.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/07/2019 02:05 pm
These water tanks have to hold cryogenic LOX and LNG. Zero tolerance for leaks.......
Why do you say that?  I mean its fun to say and it sounds sciency but why would that be the case?

Thought experiment, let's take a perfect SH/SS and I'll hand you a laser and let you pop a .05mm hole in the tank of your choice in the location of your choice then we launch it to Mars and back with people in it.  What failure mode would this send us down?

I think its a low bar to make a water tight joint.  Maybe not helium tight but water tank tight.  What would be the detriment if there was a small leak?  Say, 10cc / day liquid.  Even if into the passenger compartment.  The real problem as I see it is reliably getting a good structural joint and as I pointed out above its not difficult given the material, cryoforming and the possibility that stainless offers to weld on thicker sections.

Also, another angle that hasn't been brought up is that when welding thicker sections such as the current water tower style construction or the locally thickened joint that I propose you don't do the whole weld in one pass.  It would at the minimum be done in two passes, one from each side.  That makes a big difference the probability of leakage.  If you assume some discrete number of defects over the total length of weld then what are the odds that two defects on opposite sides of a weld joint are directly in line forming a leak path?   There's going to be a lot of zeros after the decimal before you get to a non-zero digit on that probability.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 02/07/2019 02:41 pm
A section of external plumbing has been added.

I "know" it's not a small rocket, but the pipe looks like a toothpick.

Then you realize it's has an ID of >4in :o


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RedLineTrain on 02/07/2019 02:52 pm
There is probably little or no comparison between the construction of the hopper and the Star Ship prototype other than they both use Stainless Steel:

- Hopper can afford to be very heavy, so they are using civil engineering safety factors (~5) and construction techniques to rapidly and cheaply build a test vehicle.

- Star Ship will be built with safety factor of ~1.5 which require aerospace quality production techniques.

John

I'm in the camp that they'll use the hopper construction method (vertical stacking in the open, hand welding, etc) to build the orbital prototype, this is based on various observations (no new factory location, Elon gangho on orbital prototype timeline, etc), but I'd like to hear more about any objections based on construction techniques and safety factors. Specifically:
1. What would be the dry mass difference between a safety factor 5 build and safety factor 1.5 build? Is it 5/1.5 = 3.33x?
2. Could they use the current construction method and still ends up needing a smaller safety factor? If not, could they use a hybrid method which still doesn't require a full factory to achieve the necessary dry mass/safety factor, for example building sections inside tent using some tooling, but stacking them outside by hand.

- 1) Yes, that would be 3.33 times heavier. Also the welds can be about 1/3 weaker. The hopper is being constructed of 6 mm or thicker plate. The Star Ship tanks will be 1 - 2 mm thick and the TPS face sheets will probably be on the order of .2 - .4 mm thick. These are really thin and will probably be resistance welded.

- 2) Lower safety margins require tighter quality standards. I believe some form of automatic welding will be used to obtain higher weld quality. I don't believe they would need a full factory, but some infrastructure would probably be needed to provide good conditions for work and QA etc.

Again just speculation, so we will see.

John

Attached is the 2014 presentation "The 1.5 & 1.4 Ultimate Factors of Safety for Aircraft & Spacecraft -- History, Definition and Applications" from Modlin and Zipay that details some of the history of safety margins in use.

Interestingly, it discusses in some detail the history of steel use in aircraft.  Though not 301 stainless.  It also discusses the non-linearity of weight gain from increases in the safety margin -- i.e., a 1.5 safety factor instead of 1.4 safety factor increases weight by 4% rather than 7%.  If the equation held in an extreme case for stainless steel rockets, a 5x safety factor instead of a 1.5x safety factor would increase the weight by ((5/1.5)^0.64 -1) x 100%, or 120%.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Restless on 02/07/2019 03:36 pm
These water tanks have to hold cryogenic LOX and LNG. Zero tolerance for leaks.......
Why do you say that?  I mean its fun to say and it sounds sciency but why would that be the case?

Thought experiment, let's take a perfect SH/SS and I'll hand you a laser and let you pop a .05mm hole in the tank of your choice in the location of your choice then we launch it to Mars and back with people in it.  What failure mode would this send us down?

I think its a low bar to make a water tight joint.  Maybe not helium tight but water tank tight.  What would be the detriment if there was a small leak?  Say, 10cc / day liquid.  Even if into the passenger compartment.  The real problem as I see it is reliably getting a good structural joint and as I pointed out above its not difficult given the material, cryoforming and the possibility that stainless offers to weld on thicker sections.

I get  what you're saying, but if Spacex didn't think leaks were a big deal then they wouldn't have the helium tube trailer at the site.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/07/2019 03:40 pm
True enough, but the LNG and LOX tanks still have to be free of leaks. I'm concerned that these field-welded vessels will pass leak tests. There's a tube trailer of helium parked at the dish area. Presumably this is to pressure these tanks with a few psi and check welds with a sniffer tube going to a helium mass spec detector. They may have a dickens of a time if a lot of weld leaks have to be ground out and redone. I would guess these water tank welders are probably not ASME code certified.

Assuming the crew is from Caldwell, they do seem to be ASME certified: http://www.caldwellwatertanks.com/quality-assurance.html

Quote
Caldwell maintains current welder qualification records for all active welders. Procedures, processes and welders are qualified in accordance with ASME B&PVC Section IX Articles II and III and AWWA D-100 Section 8.3.

Caldwell doesn't just build water tanks, they build industrial tanks too: http://www.caldwellindustrial.com/experience.html
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 02/07/2019 03:47 pm
I'm in the camp that they'll use the hopper construction method (vertical stacking in the open, hand welding, etc) to build the orbital prototype, this is based on various observations (no new factory location, Elon gangho on orbital prototype timeline, etc)

There is ZERO chance that the orbital prototype will be hand-welded together.

Agreed. I do not believe that hand welding will be used with the possible exception of a few minor sections after the main airframe is complete.  That said, note that the estimable Saturn V had the fuel & oxidizer entires into the F-1 combustion chamber hand drilled.  One of myriad reasons that it is easier and cheaper today 50+ years later to design & build a Saturn+ vehicle.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 02/07/2019 04:11 pm
I'm in the camp that they'll use the hopper construction method (vertical stacking in the open, hand welding, etc) to build the orbital prototype, this is based on various observations (no new factory location, Elon gangho on orbital prototype timeline, etc)

There is ZERO chance that the orbital prototype will be hand-welded together.

Agreed. I do not believe that hand welding will be used with the possible exception of a few minor sections after the main airframe is complete.  That said, note that the estimable Saturn V had the fuel & oxidizer entires into the F-1 combustion chamber hand drilled.  One of myriad reasons that it is easier and cheaper today 50+ years later to design & build a Saturn+ vehicle.

Disagreed. I see no reason why good human welder could not do a perfectly good job of this. Try thinking about what sort of machine would be required to weld something like this together, bearing in mind they don't need a lot of them. The machine would probably be bigger than the SS itself. The only bit that could 'easily' be automated would be the tanks, that still leaves a lot of stuff.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 02/07/2019 05:17 pm
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Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rsdavis9 on 02/07/2019 06:35 pm
I'm in the camp that they'll use the hopper construction method (vertical stacking in the open, hand welding, etc) to build the orbital prototype, this is based on various observations (no new factory location, Elon gangho on orbital prototype timeline, etc)

There is ZERO chance that the orbital prototype will be hand-welded together.

Agreed. I do not believe that hand welding will be used with the possible exception of a few minor sections after the main airframe is complete.  That said, note that the estimable Saturn V had the fuel & oxidizer entires into the F-1 combustion chamber hand drilled.  One of myriad reasons that it is easier and cheaper today 50+ years later to design & build a Saturn+ vehicle.

Disagreed. I see no reason why good human welder could not do a perfectly good job of this. Try thinking about what sort of machine would be required to weld something like this together, bearing in mind they don't need a lot of them. The machine would probably be bigger than the SS itself. The only bit that could 'easily' be automated would be the tanks, that still leaves a lot of stuff.

I see lots of trucks on the highway with stainless steel tanks carrying:
LNG
Milk
LN2
LOX
Propane

I assume all of these are hand welded?
They seem to be pretty leak proof.

Now they are probably overbuilt and don't have the 3g plus of ascent to orbit to stress them.
 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: niwax on 02/07/2019 06:57 pm
I'm in the camp that they'll use the hopper construction method (vertical stacking in the open, hand welding, etc) to build the orbital prototype, this is based on various observations (no new factory location, Elon gangho on orbital prototype timeline, etc)

There is ZERO chance that the orbital prototype will be hand-welded together.

Agreed. I do not believe that hand welding will be used with the possible exception of a few minor sections after the main airframe is complete.  That said, note that the estimable Saturn V had the fuel & oxidizer entires into the F-1 combustion chamber hand drilled.  One of myriad reasons that it is easier and cheaper today 50+ years later to design & build a Saturn+ vehicle.

Disagreed. I see no reason why good human welder could not do a perfectly good job of this. Try thinking about what sort of machine would be required to weld something like this together, bearing in mind they don't need a lot of them. The machine would probably be bigger than the SS itself. The only bit that could 'easily' be automated would be the tanks, that still leaves a lot of stuff.

I see lots of trucks on the highway with stainless steel tanks carrying:
LNG
Milk
LN2
LOX
Propane

I assume all of these are hand welded?
They seem to be pretty leak proof.

Now they are probably overbuilt and don't have the 3g plus of ascent to orbit to stress them.

Welding up LNG equipment is literally the skill set of every plumber.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/07/2019 07:02 pm
I'm not sure why so many people think that "SpaceX hand welds one thing" means that "SpaceX will hand weld all things".  ???

Again - Do not assume that the construction of this one-off hopper test article has anything to do with how the real Starships will be built.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: krsears on 02/07/2019 07:03 pm
I'm in the camp that they'll use the hopper construction method (vertical stacking in the open, hand welding, etc) to build the orbital prototype, this is based on various observations (no new factory location, Elon gangho on orbital prototype timeline, etc)

There is ZERO chance that the orbital prototype will be hand-welded together.

Agreed. I do not believe that hand welding will be used with the possible exception of a few minor sections after the main airframe is complete.  That said, note that the estimable Saturn V had the fuel & oxidizer entires into the F-1 combustion chamber hand drilled.  One of myriad reasons that it is easier and cheaper today 50+ years later to design & build a Saturn+ vehicle.

Disagreed. I see no reason why good human welder could not do a perfectly good job of this. Try thinking about what sort of machine would be required to weld something like this together, bearing in mind they don't need a lot of them. The machine would probably be bigger than the SS itself. The only bit that could 'easily' be automated would be the tanks, that still leaves a lot of stuff.

I see lots of trucks on the highway with stainless steel tanks carrying:
LNG
Milk
LN2
LOX
Propane

I assume all of these are hand welded?
They seem to be pretty leak proof.

Now they are probably overbuilt and don't have the 3g plus of ascent to orbit to stress them.

Welding up LNG equipment is literally the skill set of every plumber.

A bit of Elitism creeping in.  Doubt that "lowly welder's without a college degree can't possibly be capable of 'Aerospace Quality' work."  Look back in the threads at the denigration of the guys working on the "water tank" that suddenly became a Hopper.

Some people just can't get it in their heads that there are a LOT of highly qualified people without college degrees.

Kendall
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rsdavis9 on 02/07/2019 07:10 pm
I'm not sure why so many people think that "SpaceX hand welds one thing" means that "SpaceX will hand weld all things".  ???

Again - Do not assume that the construction of this one-off hopper test article has anything to do with how the real Starships will be built.

So obvious thing that is machine welded in f9 is the friction stir welding the AlLi tanks.
Do they hand weld in the fittings? Top manhole, Liquid in, Liquid out?

They do the friction stir welding because it gives them a "seamless" joint which is stronger.
Is there the same reason to do FSW for stainless steel? Or some other machine welding method.
Or is stainless just easier to hand weld and get full strength seams.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/07/2019 07:16 pm
Welding up LNG equipment is literally the skill set of every plumber.
Well, yes and no, the conversation seems to be moving away from the point and I want to focus it back a bit.  When you're welding industrial thickness pipe, tanks, pressure vessels, etc. the walls are thick and the safety factors are large.  For situations like this the pool of qualified welders is very deep.  I'd suspect that for something like a high pressure natural gas line someone like myself who on average picks up a TIG torch once in 8 years could make a serviceable weld that would work the lifetime of the pipeline, though that weld would probably get flagged in the inspection phase and wouldn't have the strength of a weld placed by someone normally skilled in the art of welding high pressure gas lines.  That's because of the relatively large safety factor in general industry.  But when you take it to aerospace stress levels, that's what the conversation here as about.  We're talking about for the general case welding where a weld ~30% less than the best possible weld means that the weld fails and when that weld fails generally everything else in the machine fails other than the flammability of the fuel.

Now having said that I think that the solution I offered above does take something that is normally super sensitive in the skill set required and the quality control necessary and moves it into the realm of being able to be welded in a field by someone of good industrial skill.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/07/2019 07:19 pm
Not just here, the Facebook group is also rife with it. You'd think Google hadn't been invented given some of the stuff that comes up.
We do our best to tamp that down over there. It's harder given the nature of the audience.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/07/2019 07:30 pm
A bit of Elitism creeping in.  Doubt that "lowly welder's without a college degree can't possibly be capable of 'Aerospace Quality' work."  Look back in the threads at the denigration of the guys working on the "water tank" that suddenly became a Hopper.

And a bit of reverse elitism creeping in as well. Everyone does not have the same skills. Just because your are a welder does not mean that the you have the skill for aerospace level work.

Some people just can't get it in their heads that there are a LOT of highly qualified people without college degrees.

Where did *that* come from? Did I miss some kind of college elitism being expressed here?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bob the martian on 02/07/2019 08:11 pm
I'm not sure why so many people think that "SpaceX hand welds one thing" means that "SpaceX will hand weld all things".  ???

Again - Do not assume that the construction of this one-off hopper test article has anything to do with how the real Starships will be built.

Exactly.

I'm sure the orbital prototype and production vehicles will be built in a different manner.  SpaceX made a big deal about the F9 tanks being FSW, and I imagine the orbital prototype and production vehicles will use FSW where they're able. 

This thing is going to go up, what, a few thousand feet and come back down?  The tanks don't need to be welded to the same kind of tolerances as something going into orbit.  It's not going to experience the same kinds of loads as an actual flight vehicle.  So yeah, it makes sense to build it with cheap(er) local guys who know how to weld big tanks, reserving your more specialized workforce for the orbital product. 

It's a test article for the engines and software, for a specific portion of the flight.  There's no reason to expect this to be representative of the final product. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Star One on 02/07/2019 08:11 pm
I'm not sure why so many people think that "SpaceX hand welds one thing" means that "SpaceX will hand weld all things".  ???

Again - Do not assume that the construction of this one-off hopper test article has anything to do with how the real Starships will be built.

Isn’t the Starship’s construction meant to be highly automated, and this is part of cost reductions in its manufacture?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RedLineTrain on 02/07/2019 08:16 pm
Here's a good relevant wiki article (https://www.engineeringtoolbox.com/factors-safety-fos-d_1624.html) about factors of safety.  I don't think anybody knows what an appropriate factor of safety would be for a stainless steel rocket welded in the field and coldformed at cryo thereafter.  But pressure vessels typically have factors of safety of 3.5x - 6x and structural steel in buildings typically has a factor of safety of 4x - 6x.

If we assume that a 4x factor of safety is required, that would increase the dry weight of the SS/SH by ((4/1.5)^0.64-1) x 100%, or 87%.  Maybe the coldforming at cryo makes a 3x factor of safety sufficient, resulting in a dry weight increase of ((3/1.5)^0.64-1) x 100%, or 56%.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 02/07/2019 08:34 pm
I'm not sure why so many people think that "SpaceX hand welds one thing" means that "SpaceX will hand weld all things".  ???

Again - Do not assume that the construction of this one-off hopper test article has anything to do with how the real Starships will be built.

Isn’t the Starship’s construction meant to be highly automated, and this is part of cost reductions in its manufacture?

Although I believe that major seams will be machine welded and I guess you could call this a form of automation, I doubt that Starship construction will be "highly automated".  As someone who designed and built hardware software products in the hundreds to low thousands, high automation makes little sense there for cost reduction.  Quality control, sameness of all assemblies, yes.  That is what I expect for SS.  No hand drilling of combustion chamber injector holes like with Saturn V.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/07/2019 09:26 pm
Here's a good relevant wiki article (https://www.engineeringtoolbox.com/factors-safety-fos-d_1624.html) about factors of safety.  I don't think anybody knows what an appropriate factor of safety would be for a stainless steel rocket welded in the field and coldformed at cryo thereafter.  But pressure vessels typically have factors of safety of 3.5x - 6x and structural steel in buildings typically has a factor of safety of 4x - 6x.

If we assume that a 4x factor of safety is required, that would increase the dry weight of the SS/SH by ((4/1.5)^0.64-1) x 100%, or 87%.  Maybe the coldforming at cryo makes a 3x factor of safety sufficient, resulting in a dry weight increase of ((3/1.5)^0.64-1) x 100%, or 56%.
I would be surprised at 4x safety factors, at least at first... maybe in the second version. But I would think more like the standard rocket factor of 1.4-1.5 or so?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RedLineTrain on 02/07/2019 09:40 pm
I would be surprised at 4x safety factors, at least at first... maybe in the second version. But I would think more like the standard rocket factor of 1.4-1.5 or so?

But then you probably can't assemble it in the field using the methods demonstrated.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/07/2019 09:47 pm
I would be surprised at 4x safety factors, at least at first... maybe in the second version. But I would think more like the standard rocket factor of 1.4-1.5 or so?

But then you probably can't assemble it in the field using the methods demonstrated.

Unless you do as I've suggested in which case you can.   1.4-1.5[*] SF in the bulk material .and. 4 [*] SF in the field welded joints.  There, conundrum solved.

     * adjust numbers to fit the safety factors you personally advocate for so you are reading my message not arguing with my example numbers.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HMXHMX on 02/07/2019 09:55 pm
Here's a good relevant wiki article (https://www.engineeringtoolbox.com/factors-safety-fos-d_1624.html) about factors of safety.  I don't think anybody knows what an appropriate factor of safety would be for a stainless steel rocket welded in the field and coldformed at cryo thereafter.  But pressure vessels typically have factors of safety of 3.5x - 6x and structural steel in buildings typically has a factor of safety of 4x - 6x.

If we assume that a 4x factor of safety is required, that would increase the dry weight of the SS/SH by ((4/1.5)^0.64-1) x 100%, or 87%.  Maybe the coldforming at cryo makes a 3x factor of safety sufficient, resulting in a dry weight increase of ((3/1.5)^0.64-1) x 100%, or 56%.
I would be surprised at 4x safety factors, at least at first... maybe in the second version. But I would think more like the standard rocket factor of 1.4-1.5 or so?

I think SpaceX realized they could use industrial safety factors of 3-6 for the tanks, and thus build in the field.  Weight really isn't an issue for the first hopper.  The construction techniques being used for this hopper are in no way comparable to what the Starship will employ.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Roy_H on 02/07/2019 10:02 pm
Isn’t the Starship’s construction meant to be highly automated, and this is part of cost reductions in its manufacture?

No. The expectation is to build very few and re-use them. I know where you got that idea from, Elon has suggested that at some future date hundreds would be built for P2P flights on earth competing with supersonic aircraft. I don't think that is a workable business plan. Huge expense and higher risk to save a couple of hours flying time and have to take off and land at remote places that will add significant travel time to access equals no benefit.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/07/2019 10:16 pm
...  Elon has suggested that at some future date hundreds would be built for P2P flights on earth competing with supersonic aircraft. I don't think that is a workable business plan. Huge expense and higher risk to save a couple of hours flying time and have to take off and land at remote places that will add significant travel time to access equals no benefit.
Off topic for this thread.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/07/2019 10:21 pm
There may be parallels between SpaceX and Tesla that apply here.  From what I understand they share some Elements of Management (EM for short).  When FSW was chosen for F9 one of the factors would have been that it was the automated whiz bang cool thing that someone with a programming background would latch onto, and it would fit into the alien dreadnaught vision of manufacturing.  But as seen at Tesla, some of that alien dreadnaught automation vision can fade in light of manufacturing reality.  There was a change at Tesla ~6 months back and now they see humans to be the superstar for manufacturing rather than automation.  In reality its not all robots or all people that are the right solution for Tesla but rather freeing up the manufacturing experts to do what they're good at but my point is that there are currently EM at SpaceX that may be in favor of welding with people in a tent.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Coastal Ron on 02/07/2019 10:37 pm
When FSW was chosen for F9 one of the factors would have been that it was the automated whiz bang cool thing that someone with a programming background would latch onto, and it would fit into the alien dreadnaught vision of manufacturing.

Friction stir welding (FSW) was already a known manufacturing option when SpaceX made the decision to use it, and I think for such a very specific application it made a lot of sense to everyone in manufacturing. And it's pretty much limited to one type of work, welding large tubes together, so the ROI is easy to understand in direct costs and quality.

Quote
But as seen at Tesla, some of that alien dreadnaught automation vision can fade in light of manufacturing reality.  There was a change at Tesla ~6 months back and now they see humans to be the superstar for manufacturing rather than automation.

I've worked in factories, but not Tesla or car manufacturing, however in general you can (or should) only automate what you understand, and it appears that Tesla forced automation into the factory before they clearly understood what was needed. Humans are infinitely flexible production assets, so of course the fallback is to use humans until they learn what their real automation needs are.

Quote
In reality its not all robots or all people that are the right solution for Tesla but rather freeing up the manufacturing experts to do what they're good at but my point is that there are currently EM at SpaceX that may be in favor of welding with people in a tent.

It makes no sense at all to automate the production of what could be a one-off product. And until the design is proven and stabilizes I would not be surprised if we see a lot of human labor being used to produce the SS and SH. It made perfect sense to me that they would be handcrafting the puddle jumper...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/07/2019 10:41 pm
A bunch of years ago ~1995 I was at the Smithsonian looking at an F-1 engine on display.  The most notable thing that stood out to me was the crappyness of the welds on something that 30 years earlier had been the greatest effort of the greatest civilization in human history.  My thought was that there was no (1995 then current) shop that would have put out work like that.  Definitely hand made welds using lesser technology weld machines than what is available now.  But you know what?  They all worked and they got us to the moon.  Key thing is that if you engineer the joint to be tolerant you can tolerate what you engineer it to be tolerant of, which may be an average weld.

Let me paraphrase my advocacy of this thusly, I'll name it the "big dumb weld joint" method.  Big dumb weldments may be the way to build rockets.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/07/2019 10:52 pm
I'm not sure why so many people think that "SpaceX hand welds one thing" means that "SpaceX will hand weld all things".  ???

Again - Do not assume that the construction of this one-off hopper test article has anything to do with how the real Starships will be built.

So obvious thing that is machine welded in f9 is the friction stir welding the AlLi tanks.
Do they hand weld in the fittings? Top manhole, Liquid in, Liquid out?

They do the friction stir welding because it gives them a "seamless" joint which is stronger.
Is there the same reason to do FSW for stainless steel? Or some other machine welding method.
Or is stainless just easier to hand weld and get full strength seams.

SpaceX does hand weld many Falcon 9 components.

However, aluminum components are a lot thicker for the same strength. Hand welding thin sheets of steel is hard, that's why they are usually joined by a resistance welding machine.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DistantTemple on 02/07/2019 10:59 pm
FWIW, IMO EM will "design it for manufacture". His goal is Mars on an industrial scale. OK the first prototypes wont be automated, but automation will always be in their sights, and both SH and SS designs' will be optimised for efficient manufacture, and the manufacturing process will be planned at the same time. Anything that is hard to manufacture through compromise will be a thorn in their side. They have been through this process with the Merlin (600 manufactured?) The F9, and of course Tesla has had it in droves! Also making miles of perfect welds on the body, in thin material, using laser, ultrasound, resistance ... etc must lend itself to at least semi-automation! And produce a more even and safer product.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/07/2019 11:04 pm
Oh but there is a chance that it can be hand welded with good quality assurance.  Two things that may be going in "our" favor here.

1) Cryoforming the tanks after welding exposes them to significantly higher stresses than they will ever see in flight.  There in one step without even NDTing every mm of weld individually you find out in one simultaneous step if your welds have strength in excess of the parent material or not (and maybe leak test the entire structure in the same single step).  You're not doing some indirect test like x-rays and using logic to infer whether the welds will handle the stress, you are actually testing all welds to higher stresses than they will ever see in use.

2) If they choose to have taylor rolled sheet stock that is thin across the bulk of the sheet width and thicker, conceptually 4x thicker for a thin strip at the edges it will allow them to do low tech welds and have high safety factors and keep the HAZ away from the thin material.  And if the thickened strips end up being called ribs, rings, or longerons that keep the structure from flopping about when not pressurized that's like eating your cake and eating it two.

edit: So to show how this would look I've made two roll formed panels and welded them together.  Watch it, the weld is still red hot.  In reality the panel widths would probably be greater between welds but I've got screen width to consider so I made them a bit narrow.

I think it would be easier to just use plane sheets and lap weld them using a rolling resistance welder. The lap automatically gives you a safety factor. This is how the Atlas did it.

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ejb749 on 02/07/2019 11:22 pm
Those red tanks look familiar.
https://forum.nasaspaceflight.com/index.php?topic=41018.msg1690878#msg1690878 (https://forum.nasaspaceflight.com/index.php?topic=41018.msg1690878#msg1690878)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/07/2019 11:24 pm
Just saw this tank being secured to the dome.
I saw four of those on pallets next door a week ago. Through an open door, so photos seemed like poor form.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/07/2019 11:36 pm
Does anyone have a reasonably well thought out estimate of the weight of the hopper empty?  How many Raptors are we expecting to show up before they light a fire under it for the first time?  1?  2?  3?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/08/2019 12:00 am
I'm in the camp that they'll use the hopper construction method (vertical stacking in the open, hand welding, etc) to build the orbital prototype, this is based on various observations (no new factory location, Elon gangho on orbital prototype timeline, etc)

There is ZERO chance that the orbital prototype will be hand-welded together.

Agreed. I do not believe that hand welding will be used with the possible exception of a few minor sections after the main airframe is complete.  That said, note that the estimable Saturn V had the fuel & oxidizer entires into the F-1 combustion chamber hand drilled.  One of myriad reasons that it is easier and cheaper today 50+ years later to design & build a Saturn+ vehicle.

Disagreed. I see no reason why good human welder could not do a perfectly good job of this. Try thinking about what sort of machine would be required to weld something like this together, bearing in mind they don't need a lot of them. The machine would probably be bigger than the SS itself. The only bit that could 'easily' be automated would be the tanks, that still leaves a lot of stuff.

- Tanks and passenger compartment are the bulk of the Star Ship.

- A rolling resistance welder welding a lap joints as in Atlas tank construction. Rollers would only have to bridge barrel section height. Why reinvent the wheel? Atlas tanks were among the lightest tanks ever engineered for a rocket.

- Agree that there will lots of hand welding, just not for the basic pressure vessel shells.

John




Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 02/08/2019 12:21 am
Just saw this tank being secured to the dome.
I saw four of those on pallets next door a week ago. Through an open door, so photos seemed like poor form.

I give them that same respect.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/08/2019 12:59 am
Here's a good relevant wiki article (https://www.engineeringtoolbox.com/factors-safety-fos-d_1624.html) about factors of safety.  I don't think anybody knows what an appropriate factor of safety would be for a stainless steel rocket welded in the field and coldformed at cryo thereafter.  But pressure vessels typically have factors of safety of 3.5x - 6x and structural steel in buildings typically has a factor of safety of 4x - 6x.

If we assume that a 4x factor of safety is required, that would increase the dry weight of the SS/SH by ((4/1.5)^0.64-1) x 100%, or 87%.  Maybe the coldforming at cryo makes a 3x factor of safety sufficient, resulting in a dry weight increase of ((3/1.5)^0.64-1) x 100%, or 56%.
I would be surprised at 4x safety factors, at least at first... maybe in the second version. But I would think more like the standard rocket factor of 1.4-1.5 or so?

- I believe you have got it backwards. A safety factor of 5 means that you design the structure to handle 5 times the calculated maximum load you expect the structure to actually see in service. A very conservative safety factor allows one to: - simplify analysis, lower material quality, lower construction quality, lower inspection quality, account for weathering / corrosion, allow for unexpected loading conditions, etc... For a pure pressure vessel, a tank with a safety factor of 5 will weigh 3.33 times as much as a safety factor of 1.5.  When you use the structure, you will only be stressing it 1/5 of the stress you designed it for. This is what allows for quick and dirty construction.

- Aerospace safety factors vary depending on many factors, but the default starting point is 1.5. Unmanned rocket tanks  (if I remember) use 1.35. Very little leeway for any variation in materials or workmanship.

- Safety factors also vary depending on how a material fails. A brittle material (little or no plastic deformation) will usually have a higher safety factor. For example Carbon fiber composites are pretty brittle and so safety factors as high as 2.0 have been used in wing spars. Again, it all depends on how well the loads, the analysis and the materials are characterized as well as the consequences of the failure.

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/08/2019 01:04 am
I've duly noted that HMXHMX and livingjw are not in my camp on the welding fussiness issue.  We'll see.

Regarding the things that look mildly like light switch cover plates smattered on the side of the hopper, the slots and round holes look somewhat reminicsent of the slots and / or holes you'd see in rolled steel strut of the type that electricians and plumbers use to anchor wiring and plumbing to walls and ceilings.  But its not exactly that.  Just throwing the idea out there to see if it lights up an idea in someone else's mind.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Metalskin on 02/08/2019 02:07 am
The first line of text on the tanks reads:

"Remove before tank closeout"

The second line was too hard to decipher sorry. Something along the line of:

"Protective covers for <unknown>-<unknown> <unknown>"

:edit:

If I should not have posted this here, then my apologies. I wasn't sure if it belonged here or not.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/08/2019 02:15 am
I've duly noted that HMXHMX and livingjw are not in my camp on the welding fussiness issue.  We'll see.
Naaa... what do those guys know? They're just rocket designers with decades of experience, LOL
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/08/2019 02:32 am
I'm not sure why so many people think that "SpaceX hand welds one thing" means that "SpaceX will hand weld all things".  ???

Again - Do not assume that the construction of this one-off hopper test article has anything to do with how the real Starships will be built.

That is not the assumption I'm making. The assumptions I used are:
1. SpaceX doesn't have a secret factory somewhere with 9m steel tank tooling inside
2. Elon's tweet about having orbital prototype ready in June means June this year, and his schedule estimate is not much worse than the usual Elon time (factor of 2 or so).

I'd like to hear objections with a reason, Jim style absolutes like "ZERO", "all things" are not helpful, especially when there's no inside knowledge behind it.

And what is a "real" Starship anyway? Are we sure the orbital prototype is a "real" Starship? Note even if we triple the dry mass of 85t, a Starship would still have 5.4 km/s of delta-v, enough for it to reach Mach 10 or so to do heat shield and control surface testing.

Edit: BTW, all these factor of safety talk reminds me, this is not the first time SpaceX used industrial grade material instead of aerospace grade material on their vehicle, the struts failed on CRS-7 was also industrial grade, and it's steel too. Of course that use of industrial grade material bite them in the behind, but hey I didn't say hand welding in the open is the greatest idea either, it's just what is necessary to get things done given the funding situation.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: masterxel on 02/08/2019 03:40 am
The first line of text on the tanks reads:

"Remove before tank closeout"

The second line was too hard to decipher sorry. Something along the line of:

"Protective covers for <unknown>-<unknown> <unknown>"

My guess answer for tonight is "Protective covers for compressed-gas COPV"
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/08/2019 06:25 am
I'm not sure why so many people think that "SpaceX hand welds one thing" means that "SpaceX will hand weld all things".  ???

Again - Do not assume that the construction of this one-off hopper test article has anything to do with how the real Starships will be built.

That is not the assumption I'm making. The assumptions I used are:
1. SpaceX doesn't have a secret factory somewhere with 9m steel tank tooling inside
2. Elon's tweet about having orbital prototype ready in June means June this year, and his schedule estimate is not much worse than the usual Elon time (factor of 2 or so).

I'd like to hear objections with a reason, Jim style absolutes like "ZERO", "all things" are not helpful, especially when there's no inside knowledge behind it.

1. I firmly believe that an assembly building will be erected somewhere in the Boca Chica area in the next few months where machinery to perform tank welds can be installed. (Or an existing building leased) The type of assembly and welding machinery that livingjw has explained should be able to be installed fairly quickly once a building has been erected. This will be essential for welding the tanks.
2. I also believe that June is very optimistic, it could easily happen late this year or even next, depending on how quickly the infrastructure is put in place. (also assuming that they are happy enough with the design to build a prototype)

And what is a "real" Starship anyway? Are we sure the orbital prototype is a "real" Starship? Note even if we triple the dry mass of 85t, a Starship would still have 5.4 km/s of delta-v, enough for it to reach Mach 10 or so to do heat shield and control surface testing.

To really test the heat shield technology, they need to go faster. I think they fully intend to make a near orbital prototype. Otherwise they will need another test article after that - which is of course a distinct possibility.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: woods170 on 02/08/2019 06:39 am
The first line of text on the tanks reads:

"Remove before tank closeout"

The second line was too hard to decipher sorry. Something along the line of:

"Protective covers for <unknown>-<unknown> <unknown>"

My guess answer for tonight is "Protective covers for compressed-gas COPV"

That is in fact almost exactly it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: strato1 on 02/08/2019 06:40 am
(1) SpaceX won't be able to build their two stage fully reusable space craft without spending a few billion dollars and they don't have this kind of money and won't be able to earn it just with the F9 launching sats in the next couple of years, so they need to make visible progress just to try and attract investors. I'm really curious who will invest into that.

(2) Because honestly I can't imagine SpaceX to build even something to just launch their StarLink constellation by this means without some serious cash injection.

(3) Or will they be able to design, engineer and build a revolutionary reusable launcher on a dime just by being very clever and courageous? If they really will manage to fly and land this contraption within the next months or so this will start to look almost possible and somehow I guess this is what it is there for.

(1) [Jim] Wrong [/Jim]

(2) I can

(3) They will be able to build it on a dime (IMO) and if they can't they may or may not need cash injections based on how aggressively they want to chase the timeline vs. proceed slower.

They had multiple failed raise attempts in 2018.  I'm curious, can you present what basis you have for them not needing capital for a rocket development program?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: guckyfan on 02/08/2019 08:03 am
They had multiple failed raise attempts in 2018.

They raised $500 million instead of the initial aim of $750 million. The pivot to steel from carbon happened in that timeframe and it may have reduced expected cost by that much.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Star One on 02/08/2019 09:00 am
From what people have said on here after my comment about automated production it sounds more like the Starship is going to be built like ocean liner production. With no two quite the same due to incremental improvements and little quirks of human construction.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 02/08/2019 01:01 pm
From what people have said on here after my comment about automated production it sounds more like the Starship is going to be built like ocean liner production. With no two quite the same due to incremental improvements and little quirks of human construction.
By all accounts, that was also the case for Falcon.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 02/08/2019 01:41 pm
A bunch of years ago ~1995 I was at the Smithsonian looking at an F-1 engine on display.  The most notable thing that stood out to me was the crappyness of the welds on something that 30 years earlier had been the greatest effort of the greatest civilization in human history.  My thought was that there was no (1995 then current) shop that would have put out work like that.  Definitely hand made welds using lesser technology weld machines than what is available now.  But you know what?  They all worked and they got us to the moon.  Key thing is that if you engineer the joint to be tolerant you can tolerate what you engineer it to be tolerant of, which may be an average weld.

Let me paraphrase my advocacy of this thusly, I'll name it the "big dumb weld joint" method.  Big dumb weldments may be the way to build rockets.

This. What a weld looks like on the outside is irrelevent. It is what is inside that counts. Hence the welds on the outside of Dragon look well dodgy, and if anyone has seen a Russian Soyuz, their welds look as rough as a badgers arse. And yet they have been a safe workhorse for 50 years.

I going to stick in the camp of a highly skilled human welder (not a plumber) is going to be a faster way of building the SS than building the machines to build the machines, and just as safe. I'd go as far to say that the move to stainless has actually made it much cheaper, simply because you DONT need the machines to build the machines i.e the huge mandrels, the CF winders, the autoclaves etc.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rsdavis9 on 02/08/2019 01:45 pm
I'll vote for the rolled resistance weld of lap joints. Seems like the easiest way to do joining of thin sheets to thin sheets and thin sheets to "hat stringers".
Everything else probably simple human welds.
So a little bit of both.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edkyle99 on 02/08/2019 01:56 pm
With Elon's Raptor tweet, we can make a good estimate of the hopper's liftoff mass. 3x170 metric tons comes to 510 tons of force. A liftoff TWR of 1.1 would put the mass of the vehicle at ~463 metric tons.
More than an entire Atlas 521, or any Delta 4 Medium.  Almost as much as an Atlas 531.  Roughly equal to one-and-a-half Soyuz launch vehicles, or one-and-a-half of the original, Merlin 1C-powered Falcon 9 rockets.  Heavier than a 747.

 - Ed Kyle
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 02/08/2019 02:48 pm
I'll vote for the rolled resistance weld of lap joints. Seems like the easiest way to do joining of thin sheets to thin sheets and thin sheets to "hat stringers".
Everything else probably simple human welds.
So a little bit of both.

Are they thin sheets though? And does anyone have links to rolled resitence welding, not finding any specs on its thickness capacity in stainless.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/08/2019 02:50 pm
Hence the welds on the outside of Dragon look well dodgy
Any examples you can point to? FYI all the lines and bumps on the white exterior of Dragon in this picture aren't welds.

I know it's off topic but this isn't the first time (https://forum.nasaspaceflight.com/index.php?topic=46795.msg1892915#msg1892915) you've made this claim.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/08/2019 03:06 pm
I'll vote for the rolled resistance weld of lap joints. Seems like the easiest way to do joining of thin sheets to thin sheets and thin sheets to "hat stringers".
Everything else probably simple human welds.
So a little bit of both.

Are they thin sheets though? And does anyone have links to rolled resitence welding, not finding any specs on its thickness capacity in stainless.

http://www.worldstainless.org/Files/issf/non-image-files/PDF/Euro_Inox/BrochureWeldability_EN.pdf

Tank thicknesses all fall with in the ranges shown in the table.

Also check out the following site. Thousands of photos of atlas development including hundreds showing manufacturing tooling and resistance welding machines.
https://www.flickr.com/photos/sdasmarchives/sets/72157649485000247/

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/08/2019 03:47 pm
OK, I can't help myself. State of the art Computer (and operator) in the early 1970's when my career started. Back then computers were women's work. Funny how things change.
Mod, feel free to delete.

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RonM on 02/08/2019 04:08 pm
With Elon's Raptor tweet, we can make a good estimate of the hopper's liftoff mass. 3x170 metric tons comes to 510 tons of force. A liftoff TWR of 1.1 would put the mass of the vehicle at ~463 metric tons.
More than an entire Atlas 521, or any Delta 4 Medium.  Almost as much as an Atlas 531.  Roughly equal to one-and-a-half Soyuz launch vehicles, or one-and-a-half of the original, Merlin 1C-powered Falcon 9 rockets.  Heavier than a 747.

 - Ed Kyle

And less than a Saturn SII. So, what's your point? Gee, I guess we can't build rockets as big as we did 60 years ago.  ::)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DistantTemple on 02/08/2019 04:20 pm
...snip...
And less than a Saturn SII. So, what's your point? Gee, I guess we can't build rockets as big as we did 60 years ago.  ::)
(About the same as an F9 at 549,054Kg)
1) this is "just" a down-sized test hopper - and its in the same class or bigger than so much of the world's rocket fleet....

2) hold on...... mustn't forget a little detail... this is the "second stage"... and we're comparing it with... the WHOLE of these rockets! Just amazing for a few weeks in a field with some roughnecks!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dglow on 02/08/2019 04:38 pm
With Elon's Raptor tweet, we can make a good estimate of the hopper's liftoff mass. 3x170 metric tons comes to 510 tons of force. A liftoff TWR of 1.1 would put the mass of the vehicle at ~463 metric tons.
More than an entire Atlas 521, or any Delta 4 Medium.  Almost as much as an Atlas 531.  Roughly equal to one-and-a-half Soyuz launch vehicles, or one-and-a-half of the original, Merlin 1C-powered Falcon 9 rockets.  Heavier than a 747.

 - Ed Kyle

And less than a Saturn SII. So, what's your point? Gee, I guess we can't build rockets as big as we did 60 years ago.  ::)

Whoa... I think Ed was just providing some useful perspective.  (thank you, Ed!)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/08/2019 04:39 pm
...snip...
And less than a Saturn SII. So, what's your point? Gee, I guess we can't build rockets as big as we did 60 years ago.  ::)
(About the same as an F9 at 549,054Kg)
1) this is "just" a down-sized test hopper - and its in the same class or bigger than so much of the world's rocket fleet....

2) hold on...... mustn't forget a little detail... this is the "second stage"... and we're comparing it with... the WHOLE of these rockets! Just amazing for a few weeks in a field with some roughnecks!

The S-II is a second stage also. The hopper will be smaller than the Saturn V stack from the S-II upwards, but full size Starship will be much heavier.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/08/2019 04:48 pm
OK, I can't help myself. State of the art Computer (and operator) in the early 1970's when my career started. Back then computers were women's work. Funny how things change.
Mod, feel free to delete.

John
Rockets have come a ways, but looking at my 128GB micro sd card and those, what, 14MB (?) hard drives, maybe not so far.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RonM on 02/08/2019 05:12 pm
With Elon's Raptor tweet, we can make a good estimate of the hopper's liftoff mass. 3x170 metric tons comes to 510 tons of force. A liftoff TWR of 1.1 would put the mass of the vehicle at ~463 metric tons.
More than an entire Atlas 521, or any Delta 4 Medium.  Almost as much as an Atlas 531.  Roughly equal to one-and-a-half Soyuz launch vehicles, or one-and-a-half of the original, Merlin 1C-powered Falcon 9 rockets.  Heavier than a 747.

 - Ed Kyle

And less than a Saturn SII. So, what's your point? Gee, I guess we can't build rockets as big as we did 60 years ago.  ::)

Whoa... I think Ed was just providing some useful perspective.  (thank you, Ed!)

Sorry if I took that the wrong way. I just got use to Ed making negative comments about SpaceX.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 02/08/2019 05:36 pm
From what people have said on here after my comment about automated production it sounds more like the Starship is going to be built like ocean liner production. With no two quite the same due to incremental improvements and little quirks of human construction.

Yes & no.
Viking has built a fleet of identical river ships & is building a fleet of identical ocean ships.  Only one ocean ship is different and in a small way with a planetarium on Orion.
I think you're correct though that SpaceX will keep making incremental improvements build to build.
But none of us actually KNOW.  We're simply speculating based on our engineering/manufacturing experience and on what we observe in SpaceX's corporate culture.

Back to BFH which I believe is being built somewhat but not totally differently than the first orbital version & subsequent full scale Starships will be built.  Since the mass of the BFH is not critical, techniques and shortcuts allow them to build more of a battleship version with overly heavy airframe, etc.  It's a test vehicle for engines and flight control systems.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lemurion on 02/08/2019 06:31 pm
I agree that Hopper is being built without regard for weight, or at least without the same regard for weight as the orbital Starship, but I don’t think that’s the whole story. Knowing SpaceX and its propensity for working from first principles I wouldn’t be at all surprised to discover that one reason for the hand welding and outdoor construction approach with the Hopper is to get practical experience to see if it is worth attempting on later versions.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 02/08/2019 06:49 pm
WRT calling Starship a second stage...

It's technically only a second stage when launching from Earth needing the booster (SH). It is not a second stage when launching from the Moon or Mars.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 02/08/2019 06:57 pm
I agree that Hopper is being built without regard for weight, or at least without the same regard for weight as the orbital Starship, but I don’t think that’s the whole story. Knowing SpaceX and its propensity for working from first principles I wouldn’t be at all surprised to discover that one reason for the hand welding and outdoor construction approach with the Hopper is to get practical experience to see if it is worth attempting on later versions.
It seems like we have this debate every 20 pages or so. Hopper is a flying water tank for Raptor and avionics testing. I guarantee you the Starship that is built for a "crewed" lunar fly-by, will be constructed with very different allowances and in a fully controlled enclosure of some kind.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DistantTemple on 02/08/2019 06:58 pm
WRT calling Starship a second stage...

It's technically only a second stage when launching from Earth needing the booster (SH). It is not a second stage when launching from the Moon or Mars.
Yes thanks you are right. But the initial context was lighthearted comparisons about BFWT's (BFH) size in respect to other Earth launched rockets. I didn't even think about the hopper on Mars. :-)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lemurion on 02/08/2019 07:33 pm
I agree that Hopper is being built without regard for weight, or at least without the same regard for weight as the orbital Starship, but I don’t think that’s the whole story. Knowing SpaceX and its propensity for working from first principles I wouldn’t be at all surprised to discover that one reason for the hand welding and outdoor construction approach with the Hopper is to get practical experience to see if it is worth attempting on later versions.
It seems like we have this debate every 20 pages or so. Hopper is a flying water tank for Raptor and avionics testing. I guarantee you the Starship that is built for a "crewed" lunar fly-by, will be constructed with very different allowances and in a fully controlled enclosure of some kind.

I personally wouldn’t be surprised at all if that proves to be the case. I simply think that SpaceX is holding off on making a final decision until they have analyzed the experience from building the Hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: t3kboi on 02/08/2019 09:00 pm
... Hand welding thin sheets of steel is hard, that's why they are usually joined by a resistance welding machine.

As a hand welder (primarily MIG which is clunkier than TIG) - There is NOTHING that SpaceX is using in the hopper construction details we have seen that I would even consider thin.

When I first  learned to weld, I would commonly have too much heat penetration, and occasional blowthrough on thin sheet - but in a matter of single-digit hours of practice, this became a non-issue.

I routinely welded 24 gauge panels to each other, around complex curves and geometry, and to non-like materials. (dissimilar thickness)

Look at the mm thickness of 24 gauge here, and you can see it is nothing like the 2mm plus panels engaged in use on the hopper:
Stainless Steel Gauge Thickness
GA     IN     MM
24   .025   .635

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/08/2019 09:35 pm
(1) SpaceX won't be able to build their two stage fully reusable space craft without spending a few billion dollars and they don't have this kind of money and won't be able to earn it just with the F9 launching sats in the next couple of years, so they need to make visible progress just to try and attract investors. I'm really curious who will invest into that.

(2) Because honestly I can't imagine SpaceX to build even something to just launch their StarLink constellation by this means without some serious cash injection.

(3) Or will they be able to design, engineer and build a revolutionary reusable launcher on a dime just by being very clever and courageous? If they really will manage to fly and land this contraption within the next months or so this will start to look almost possible and somehow I guess this is what it is there for.

(1) [Jim] Wrong [/Jim]

(2) I can

(3) They will be able to build it on a dime (IMO) and if they can't they may or may not need cash injections based on how aggressively they want to chase the timeline vs. proceed slower.

They had multiple failed raise attempts in 2018.  I'm curious, can you present what basis you have for them not needing capital for a rocket development program?

It's my belief that it's possible for SpaceX to develop the Starship system from cash flow.  Unless the SpaceX Falcon business collapses, Starship can be developed without funding.  In short, they can always extend the timeline.  It's a common misconception that SpaceX EVER needs to turn a profit.  It needs cash-flow and Falcon should continue to deliver that (IMO) throughout the time necessary to develop the Starship system. 

They certainly might (1) FAIL Completely (RUDs, BO, or something unexpected ruins their business), or (2) FAIL b/c Unexpected Key-Man Issues become un-recoverable, or (3) FAIL b/c some technical problem is intractable, or (4) MISS by losing Starlink because Starship slowness, competition, or technical issues leaving Starship to limp along on Falcon revenue.  However, IMO Falcon is a "cash-flow cow" for the near future and I think the Starship system can be developed to fruition from that.

None of that is to say that timeline, risk, or other factors might drive the desire to sensibly raise funds.  But it's NOT (IMO) because the Starship system cannot be realized without that dilution of ownership.  Only because it makes sense.

In my opinion, you see it COMPLETELY in the ownership structure of SpaceX and Tesla.  Equity-balance is an incredible driving factor in the possibility of these dreams to be achievable.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/08/2019 09:57 pm
... Hand welding thin sheets of steel is hard, that's why they are usually joined by a resistance welding machine.

As a hand welder (primarily MIG which is clunkier than TIG) - There is NOTHING that SpaceX is using in the hopper construction details we have seen that I would even consider thin.

When I first  learned to weld, I would commonly have too much heat penetration, and occasional blowthrough on thin sheet - but in a matter of single-digit hours of practice, this became a non-issue.

I routinely welded 24 gauge panels to each other, around complex curves and geometry, and to non-like materials. (dissimilar thickness)

Look at the mm thickness of 24 gauge here, and you can see it is nothing like the 2mm plus panels engaged in use on the hopper:
Stainless Steel Gauge Thickness
GA     IN     MM
24   .025   .635

I wasn't referring to the hopper, that isn't thin sheet (well, at least the tank section isn't) and isn't designed with flight hardware safety factors. I'm talking about the orbital vehicle.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/08/2019 10:05 pm
WRT calling Starship a second stage...

It's technically only a second stage when launching from Earth needing the booster (SH). It is not a second stage when launching from the Moon or Mars.

To this point, EM had a tweet today (#3 in this group:  https://forum.nasaspaceflight.com/index.php?topic=47352.msg1909305#msg1909305 )

EDA had a question about naming.  I interpret it to mean:

1)  Call the system "Starship" (previously BFR)
2)  Call the payload stage "Starship" (previously BFS)
3)  When necessary, call the booster "Super Heavy" (previously BFB)

Tentatively I've been using "Starship System" as we transition to the new terminology based on that tweet.  But I think what EM is saying is to eventually just use SS and infer the elements involved from the context using SH only when necessary.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: t3kboi on 02/08/2019 10:23 pm

I wasn't referring to the hopper, that isn't thin sheet (well, at least the tank section isn't) and isn't designed with flight hardware safety factors. I'm talking about the orbital vehicle.

And my (albeit not stated directly) point  is that there will be NOTHING on a real orbital version that will be less than 2mm anywhere.....

 :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/08/2019 10:37 pm

I wasn't referring to the hopper, that isn't thin sheet (well, at least the tank section isn't) and isn't designed with flight hardware safety factors. I'm talking about the orbital vehicle.

And my (albeit not stated directly) point  is that there will be NOTHING on a real orbital version that will be less than 2mm anywhere.....

 :)

I wouldn't count on that. 2 mm of EFH 301 SS in a 9 meter tank has a hoop stress safety factor of ~3 against a tank pressure of 3 atmospheres. Since aerospace structural safety factors are usually about 1.5 or less, a double wall structure could have each wall under 1 mm.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/09/2019 01:22 am

I wasn't referring to the hopper, that isn't thin sheet (well, at least the tank section isn't) and isn't designed with flight hardware safety factors. I'm talking about the orbital vehicle.

And my (albeit not stated directly) point  is that there will be NOTHING on a real orbital version that will be less than 2mm anywhere.....

 :)

I wouldn't count on that. 2 mm of EFH 301 SS in a 9 meter tank has a hoop stress safety factor of ~3 against a tank pressure of 3 atmospheres. Since aerospace structural safety factors are usually about 1.5 or less, a double wall structure could have each wall under 1 mm.

Note each mm thickness of stainless steel on Starship cost 10t of dry mass, so a a thickness of 2~3mm is not a problem. oldAtlas_Eguy pointed out they could start with 5mm at the bottom and gradually reduces to 2.5mm at the top, this would give 36t of dry mass (https://forum.nasaspaceflight.com/index.php?topic=46795.msg1886337#msg1886337).

Also in the old ITS AMA, Elon mentioned the ship should be able to take 2 to 3 times higher peak load without breaking up (https://www.reddit.com/r/spacex/comments/590wi9/i_am_elon_musk_ask_me_anything_about_becoming_a/d94ub7h/), so it's possible they're designing for more than 1.5 factor of safety.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/09/2019 01:36 am
Again, Atlas balloon tank thicknesses are less than a mm. Star Ship tank walls will be about 3 times thicker, assuming same pressures and material allowables and 3 times the diameter.

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edkyle99 on 02/09/2019 03:01 am
With Elon's Raptor tweet, we can make a good estimate of the hopper's liftoff mass. 3x170 metric tons comes to 510 tons of force. A liftoff TWR of 1.1 would put the mass of the vehicle at ~463 metric tons.
More than an entire Atlas 521, or any Delta 4 Medium.  Almost as much as an Atlas 531.  Roughly equal to one-and-a-half Soyuz launch vehicles, or one-and-a-half of the original, Merlin 1C-powered Falcon 9 rockets.  Heavier than a 747.

 - Ed Kyle

And less than a Saturn SII. So, what's your point? Gee, I guess we can't build rockets as big as we did 60 years ago.  ::)

Whoa... I think Ed was just providing some useful perspective.  (thank you, Ed!)

Sorry if I took that the wrong way. I just got use to Ed making negative comments about SpaceX.
I was just pondering the size of this thing, which is *only a scaled test article of the smaller upper stage of the planned flying machine*.     

 - Ed Kyle
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/09/2019 03:36 am
Again, Atlas balloon tank thicknesses are less than a mm. Star Ship tank walls will be about 3 times thicker, assuming same pressures and material allowables and 3 times the diameter.

John

So we need about 1mm thickness at the top of the Starship tank to match Atlas balloon tank. What if we take oldAtlas_Eguy's suggestion and make the top thickness 2.5mm, does that mean we get 2.5x increase in factor of safety? And assuming Atlas uses factor of safety 1.2, we just need to increase thickness on top to 4.2mm to reach industrial safety factor of 5? This results in a tank mass of ~60t which is not that high, so if I didn't make a mistake in this line of reasoning, then using industrial safety factor of 5 in orbital prototype construction is feasible.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/09/2019 04:00 am
Again, Atlas balloon tank thicknesses are less than a mm. Star Ship tank walls will be about 3 times thicker, assuming same pressures and material allowables and 3 times the diameter.

John

So we need about 1mm thickness at the top of the Starship tank to match Atlas balloon tank. What if we take oldAtlas_Eguy's suggestion and make the top thickness 2.5mm, does that mean we get 2.5x increase in factor of safety? And assuming Atlas uses factor of safety 1.2, we just need to increase thickness on top to 4.2mm to reach industrial safety factor of 5? This results in a tank mass of ~60t which is not that high, so if I didn't make a mistake in this line of reasoning, then using industrial safety factor of 5 in orbital prototype construction is feasible.

Why would want to do that? It would greatly reduce the ships maximum delta V and increase its weight. You need as much safety factor as you need. More than you need just makes things worse. Can you even resistance weld such thick plate? I think not.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/09/2019 04:17 am
Again, Atlas balloon tank thicknesses are less than a mm. Star Ship tank walls will be about 3 times thicker, assuming same pressures and material allowables and 3 times the diameter.

John

So we need about 1mm thickness at the top of the Starship tank to match Atlas balloon tank. What if we take oldAtlas_Eguy's suggestion and make the top thickness 2.5mm, does that mean we get 2.5x increase in factor of safety? And assuming Atlas uses factor of safety 1.2, we just need to increase thickness on top to 4.2mm to reach industrial safety factor of 5? This results in a tank mass of ~60t which is not that high, so if I didn't make a mistake in this line of reasoning, then using industrial safety factor of 5 in orbital prototype construction is feasible.

Why would want to do that? It would greatly reduce the ships maximum delta V and increase its weight. You need as much safety factor as you need. More than you need just makes things worse. Can you even resistance weld such thick plate? I think not.

They wouldn't want to do this for production version of Starship, but I was thinking about the previous discussion about whether the orbital prototype of Starship can be hand welded in the open or does it need factory and tooling. I think the conclusion from that discussion is industrial factor of safety 5 is needed if they want to do this in the open with hand welding, it seems to me this calculation just shows a safety factor of 5 would not make orbital prototype too heavy, thus lends more support to the hypothesis that SpaceX could indeed build the orbital prototype out in the open without a factory.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jketch on 02/09/2019 04:32 am
Again, Atlas balloon tank thicknesses are less than a mm. Star Ship tank walls will be about 3 times thicker, assuming same pressures and material allowables and 3 times the diameter.

John

So we need about 1mm thickness at the top of the Starship tank to match Atlas balloon tank. What if we take oldAtlas_Eguy's suggestion and make the top thickness 2.5mm, does that mean we get 2.5x increase in factor of safety? And assuming Atlas uses factor of safety 1.2, we just need to increase thickness on top to 4.2mm to reach industrial safety factor of 5? This results in a tank mass of ~60t which is not that high, so if I didn't make a mistake in this line of reasoning, then using industrial safety factor of 5 in orbital prototype construction is feasible.

Why would want to do that? It would greatly reduce the ships maximum delta V and increase its weight. You need as much safety factor as you need. More than you need just makes things worse. Can you even resistance weld such thick plate? I think not.

They wouldn't want to do this for production version of Starship, but I was thinking about the previous discussion about whether the orbital prototype of Starship can be hand welded in the open or does it need factory and tooling. I think the conclusion from that discussion is industrial factor of safety 5 is needed if they want to do this in the open with hand welding, it seems to me this calculation just shows a safety factor of 5 would not make orbital prototype too heavy, thus lends more support to the hypothesis that SpaceX could indeed build the orbital prototype out in the open without a factory.

A Starship with a tank weighing 60 tons can't make it to orbit and back as an SSTO. If you assume the total dry mass of the craft is 80t (to account for engines, legs, etc.), and assume it will require 10t of methane for transpiration cooling for reentry, the effective dry mass is 90t, per Wiki, SS carries 1100t of propellant, for a total mass of 1190t. The delta-v available to this craft is ln(1190/90)*3.2 km/s=8.25 km/s. That's more than orbital velocity, but given atmospheric drag and gravity losses, you typically need on the order of 9km/s to get to LEO. The only way SS goes to orbit as a single stage is if the effective dry mass (including methane needed for cooling and any propellant needed for landing) is less than 70t. I doubt that can be accomplished with a safety factor of 5.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 02/09/2019 11:21 am
Hence the welds on the outside of Dragon look well dodgy
Any examples you can point to? FYI all the lines and bumps on the white exterior of Dragon in this picture aren't welds.

I know it's off topic but this isn't the first time (https://forum.nasaspaceflight.com/index.php?topic=46795.msg1892915#msg1892915) you've made this claim.

Very high resolution image of the docking adapter as the Dragon approaches the ISS, taken by Oleg Artemyev.

https://www.elonx.cz/wp-content/uploads/2018/02/51R6455-1.jpg

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/09/2019 11:23 am
A Starship with a tank weighing 60 tons can't make it to orbit and back as an SSTO. If you assume the total dry mass of the craft is 80t (to account for engines, legs, etc.), and assume it will require 10t of methane for transpiration cooling for reentry, the effective dry mass is 90t, per Wiki, SS carries 1100t of propellant, for a total mass of 1190t. The delta-v available to this craft is ln(1190/90)*3.2 km/s=8.25 km/s. That's more than orbital velocity, but given atmospheric drag and gravity losses, you typically need on the order of 9km/s to get to LEO. The only way SS goes to orbit as a single stage is if the effective dry mass (including methane needed for cooling and any propellant needed for landing) is less than 70t. I doubt that can be accomplished with a safety factor of 5.

Right, I wouldn't use 80t total, that seems to be too low, lower than the official dry mass for BFS (85t). I think 100t total dry mass is probably a safe bet for 60t tank/structure, this would give delta-v of about 7.4 km/s with 20t fuel reserve (the actual delta-v would probably be a bit higher since we're using sea level Isp).

I think the key point is that you don't need to go all the way to orbit to test the heat shield, you can do this by flying a suborbital trajectory with high mach number. X-33 planned to test its heat shield by flying up to mach 13. With 7.4 km/s delta-v you can get up to mach 18 or so, more than enough to test the heat shield.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 02/09/2019 11:59 am
Again, Atlas balloon tank thicknesses are less than a mm. Star Ship tank walls will be about 3 times thicker, assuming same pressures and material allowables and 3 times the diameter.

John

So we need about 1mm thickness at the top of the Starship tank to match Atlas balloon tank. What if we take oldAtlas_Eguy's suggestion and make the top thickness 2.5mm, does that mean we get 2.5x increase in factor of safety? And assuming Atlas uses factor of safety 1.2, we just need to increase thickness on top to 4.2mm to reach industrial safety factor of 5? This results in a tank mass of ~60t which is not that high, so if I didn't make a mistake in this line of reasoning, then using industrial safety factor of 5 in orbital prototype construction is feasible.

Why would want to do that? It would greatly reduce the ships maximum delta V and increase its weight. You need as much safety factor as you need. More than you need just makes things worse. Can you even resistance weld such thick plate? I think not.

They wouldn't want to do this for production version of Starship, but I was thinking about the previous discussion about whether the orbital prototype of Starship can be hand welded in the open or does it need factory and tooling. I think the conclusion from that discussion is industrial factor of safety 5 is needed if they want to do this in the open with hand welding, it seems to me this calculation just shows a safety factor of 5 would not make orbital prototype too heavy, thus lends more support to the hypothesis that SpaceX could indeed build the orbital prototype out in the open without a factory.

A Starship with a tank weighing 60 tons can't make it to orbit and back as an SSTO. If you assume the total dry mass of the craft is 80t (to account for engines, legs, etc.), and assume it will require 10t of methane for transpiration cooling for reentry, the effective dry mass is 90t, per Wiki, SS carries 1100t of propellant, for a total mass of 1190t. The delta-v available to this craft is ln(1190/90)*3.2 km/s=8.25 km/s. That's more than orbital velocity, but given atmospheric drag and gravity losses, you typically need on the order of 9km/s to get to LEO. The only way SS goes to orbit as a single stage is if the effective dry mass (including methane needed for cooling and any propellant needed for landing) is less than 70t. I doubt that can be accomplished with a safety factor of 5.
Someone on reddit published a delta v calculation for the hopper. Comments?

https://www.reddit.com/r/SpaceXLounge/comments/ao57df/deltav_calulation_for_starship_hopper
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/09/2019 12:16 pm
Hence the welds on the outside of Dragon look well dodgy
Any examples you can point to? FYI all the lines and bumps on the white exterior of Dragon in this picture aren't welds.

I know it's off topic but this isn't the first time (https://forum.nasaspaceflight.com/index.php?topic=46795.msg1892915#msg1892915) you've made this claim.

Very high resolution image of the docking adapter as the Dragon approaches the ISS, taken by Oleg Artemyev.

https://www.elonx.cz/wp-content/uploads/2018/02/51R6455-1.jpg
I only see some caulk beads?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/09/2019 12:28 pm
Again, Atlas balloon tank thicknesses are less than a mm. Star Ship tank walls will be about 3 times thicker, assuming same pressures and material allowables and 3 times the diameter.

John

So we need about 1mm thickness at the top of the Starship tank to match Atlas balloon tank. What if we take oldAtlas_Eguy's suggestion and make the top thickness 2.5mm, does that mean we get 2.5x increase in factor of safety? And assuming Atlas uses factor of safety 1.2, we just need to increase thickness on top to 4.2mm to reach industrial safety factor of 5? This results in a tank mass of ~60t which is not that high, so if I didn't make a mistake in this line of reasoning, then using industrial safety factor of 5 in orbital prototype construction is feasible.

Why would want to do that? It would greatly reduce the ships maximum delta V and increase its weight. You need as much safety factor as you need. More than you need just makes things worse. Can you even resistance weld such thick plate? I think not.

They wouldn't want to do this for production version of Starship, but I was thinking about the previous discussion about whether the orbital prototype of Starship can be hand welded in the open or does it need factory and tooling. I think the conclusion from that discussion is industrial factor of safety 5 is needed if they want to do this in the open with hand welding, it seems to me this calculation just shows a safety factor of 5 would not make orbital prototype too heavy, thus lends more support to the hypothesis that SpaceX could indeed build the orbital prototype out in the open without a factory.

A Starship with a tank weighing 60 tons can't make it to orbit and back as an SSTO. If you assume the total dry mass of the craft is 80t (to account for engines, legs, etc.), and assume it will require 10t of methane for transpiration cooling for reentry, the effective dry mass is 90t, per Wiki, SS carries 1100t of propellant, for a total mass of 1190t. The delta-v available to this craft is ln(1190/90)*3.2 km/s=8.25 km/s. That's more than orbital velocity, but given atmospheric drag and gravity losses, you typically need on the order of 9km/s to get to LEO. The only way SS goes to orbit as a single stage is if the effective dry mass (including methane needed for cooling and any propellant needed for landing) is less than 70t. I doubt that can be accomplished with a safety factor of 5.

I agrees that reusable SSTO with a structural safety factor of 5 is insane and not going to happen for a while if ever. However, there are some issues with your assumptions:

Musk never said it could get to orbit and back as SSTO. Just that it could get to orbit.

Also, average exhaust velocity is higher than 3.2 km/s. Most of an SSTO ascent is done in vacuum, where the exhaust velocity is about 3.5 km/s. The average is about 3.35-3.4 km/s.

Also, Starship is lightly longer than the 2017 version that had 1100 t propellant load. It's not clear how much of that new length is propellant, but each meter of tank length adds about 60 tonnes of propellant.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/09/2019 12:38 pm

I wasn't referring to the hopper, that isn't thin sheet (well, at least the tank section isn't) and isn't designed with flight hardware safety factors. I'm talking about the orbital vehicle.

And my (albeit not stated directly) point  is that there will be NOTHING on a real orbital version that will be less than 2mm anywhere.....

 :)

I wouldn't count on that. 2 mm of EFH 301 SS in a 9 meter tank has a hoop stress safety factor of ~3 against a tank pressure of 3 atmospheres. Since aerospace structural safety factors are usually about 1.5 or less, a double wall structure could have each wall under 1 mm.

Note each mm thickness of stainless steel on Starship cost 10t of dry mass, so a a thickness of 2~3mm is not a problem. oldAtlas_Eguy pointed out they could start with 5mm at the bottom and gradually reduces to 2.5mm at the top, this would give 36t of dry mass (https://forum.nasaspaceflight.com/index.php?topic=46795.msg1886337#msg1886337).

Also in the old ITS AMA, Elon mentioned the ship should be able to take 2 to 3 times higher peak load without breaking up (https://www.reddit.com/r/spacex/comments/590wi9/i_am_elon_musk_ask_me_anything_about_becoming_a/d94ub7h/), so it's possible they're designing for more than 1.5 factor of safety.

Reentry structural loads are likely much less than ascent loads, so a SF of 1.5 on ascent and 2-3 on entry are not mutually exclusive.

Take whatever total structure thickness you want, and remember that the thinnest sheets that they need to weld are at best half that, because it's a double wall design. And that's only if both walls are the same thickness and whatever holds them apart takes no hoop stress.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 02/09/2019 12:46 pm
Hence the welds on the outside of Dragon look well dodgy
Any examples you can point to? FYI all the lines and bumps on the white exterior of Dragon in this picture aren't welds.

I know it's off topic but this isn't the first time (https://forum.nasaspaceflight.com/index.php?topic=46795.msg1892915#msg1892915) you've made this claim.

Very high resolution image of the docking adapter as the Dragon approaches the ISS, taken by Oleg Artemyev.

https://www.elonx.cz/wp-content/uploads/2018/02/51R6455-1.jpg
I only see some caulk beads?

Some caulk, some welds I reckon, but the concept is the same - it's does not have to look neat to be good enough for the job. Just look at the of the edges of the shell! A welding teacher once told me that as long as the weld does the job, aesthetics are unimportant. Note, I am not a professional welder, except as a hobby.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/09/2019 12:53 pm
I believe a safety factor of 5 is used in civil engineering. Most industrial engineering projects probably use much less.

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rsdavis9 on 02/09/2019 01:19 pm
The double hull may only be on the windward side. I think the inner hull will be the structural part with mm of thickness and stringers. The outer shell with the holes will probably be very thin. Maybe .5 mm or less.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: northstar on 02/09/2019 02:57 pm
In civil/structural Engineering (at least in limit states design) the load factors are not as high as you would think. 

We typically increase calculated live loads by 1.5x, dead loads by 1.25x, and separately derate material yield strength by a separate factor, typically 0.9x for structural steel.  That combined gives a factor of safety of 1.66 x for factored live loads and yield strength.  Now ultimate strength is higher than yield strength but you don't want your structure to yield in normal use.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/09/2019 03:47 pm
In civil/structural Engineering (at least in limit states design) the load factors are not as high as you would think. 

We typically increase calculated live loads by 1.5x, dead loads by 1.25x, and separately derate material yield strength by a separate factor, typically 0.9x for structural steel.  That combined gives a factor of safety of 1.66 x for factored live loads and yield strength.  Now ultimate strength is higher than yield strength but you don't want your structure to yield in normal use.

Speaking of yielding, annealed austinitic SS gains large amounts of strength when it yields, particularly at cryo temperatures. If you stress annealed 301 SS at 80 K to 20% strain it nearly triples in strength from the cold work... as it plasticly deforms, it gets stronger and will eventually stop yielding unless the loads increase correspondingly.

So yes, you don't want yielding in normal use, but yielding (possibly cryoforming) will likely be part of the manufacturing process, and the strength gain can be added into the safety factor against an off-nominal load state. You can run an annealed part right up against its yield strength (as long as yielding doesn't affect the performance of other parts), because not only is the UTS much higher, but the yield strength of the deformed part is also much higher. You'll want to replace the part if it sees an off-nominal load case, but it won't get anywhere near breaking unless you really miscalculated the loading.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Coastal Ron on 02/09/2019 03:57 pm
The double hull may only be on the windward side. I think the inner hull will be the structural part with mm of thickness and stringers. The outer shell with the holes will probably be very thin. Maybe .5 mm or less.

I believe Musk has already stated that a double hull for the operational version would be on the windward side, and that it would also be structural.

For the Hopper though, it is being built for test altitudes that won't need hull cooling. The Hopper seems like it's really just a flying engine test stand, and not a re-entry test vehicle.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/09/2019 04:04 pm
You can have a SF of 5 on the hand welds with only a small portion of the weight penalty that you guys are talking about if you do it the way that I suggested.  They are not linked unless you are just going to the store and buying flat sheet stock.  Also, as someone stated, the outer sheet can be very thin, it only needs to handle the loads imposed by fluid flows and can be stabilized by hoop tension and its attachments to the more structural inner layer.  And, it seems to me that you don't necessarily need to keep the temperature of the outer layer below the annealing temperature since the strength requirements aren't high on the outer layer.  But there may be a need to keep the temperature of the outer layer cooler in order to preserve reflectivity.  I'm not buying that just because a 50 year old Atlas design was done a certain way and came up with a very light tank that its the way to go given the current requirements (double wall(s) (arguably the desire for ship type construction), moving quickly (less specialized equipment), repairability).  My take on Elonic first principles thinking* is that it can be done better / easier / faster using different technology.  Maybe not exactly the method I propose but I'll bet its not just pulling out a 50 year old recipe and executing it.

* Its interesting in reading NSF posts how its very common for people to say "the method that SpaceX uses is"... followed by whatever line of thinking they personally favor.  Which is more or less what I've done here.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/09/2019 04:15 pm
(mud hut)

Bad us.

All of the posts on this thread since #293 and many before aren't pertinent to "Phase 1 Big Falcon Hopper" & should be in the engineering discussion.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: joek on 02/10/2019 01:46 am
OK, I can't help myself. State of the art Computer (and operator) in the early 1970's when my career started. Back then computers were women's work. Funny how things change.
...

Sorry, no.  You must have come from a different universe.  "Back then" anything having to do with computers was most definitely not "women's work".

Only time I ever saw a female close to a computer those days (operator or programmer) was in marketing materials such as what you posted.  Unless you count data entry (e.g., IBM-026/029 punchcard) operators, which were glorified typists.

Yes, off-topic.  Sorry for going off.  But feel the need to correct the record. The statement "Back then computers were women's work." is a seriously incorrect statement, the image posted is marketing BS, and in no way indicative of reality at that time.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: krsears on 02/10/2019 03:06 am
OK, I can't help myself. State of the art Computer (and operator) in the early 1970's when my career started. Back then computers were women's work. Funny how things change.
...

Sorry, no.  You must have come from a different universe.  "Back then" anything having to do with computers was most definitely not "women's work".

Only time I ever saw a female close to a computer those days (operator or programmer) was in marketing materials such as what you posted.  Unless you count data entry (e.g., IBM-026/029 punchcard) operators, which were glorified typists.

Yes, off-topic.  Sorry for going off.  But feel the need to correct the record. The statement "Back then computers were women's work." is a seriously incorrect statement, the image posted is marketing BS, and in no way indicative of reality at that time.

I have to disagree.  The situation here in the Midwest was the same as livingjw's experience back then.

Kendall
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 02/10/2019 03:52 am
In 1970's Midwest medical   computerization was hitting hard. CT was rolling out and other emerging technical professions were 90%+ female. Many still are.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/10/2019 04:04 am
I hope this puts this odd little sub-discussion to rest


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris Bergin on 02/10/2019 05:01 pm
I see COPVs!

Some pics from this morning.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: gosnold on 02/10/2019 05:05 pm
I thought they wanted to use autogenous pressurization?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureMartian97 on 02/10/2019 05:08 pm
I thought they wanted to use autogenous pressurization?

No point in making the hopper more complex and test an all new system like that when COPV's work just fine for this application.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: janky on 02/10/2019 05:09 pm

sorry to come out of left field on a tangent, but i was looking at those pictures of the pad under construction and considering the hopper appears to have relatively rigid landing feet, are we expecting them to build some kind of "soft" landing pad? could that be what the three tubes on the new landing pad are to support? three separate vertical pads that could move up and down a bit? elon talked about eliminating legs all together in the past, right?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/10/2019 05:11 pm
Those could be storing cold gas for RCS.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/10/2019 05:21 pm

sorry to come out of left field on a tangent, but i was looking at those pictures of the pad under construction and considering the hopper appears to have relatively rigid landing feet, are we expecting them to build some kind of "soft" landing pad? could that be what the three tubes on the new landing pad are to support? three separate vertical pads that could move up and down a bit? elon talked about eliminating legs all together in the past, right?

https://forum.nasaspaceflight.com/index.php?topic=47352.msg1907676#msg1907676

https://twitter.com/elonmusk/status/1083571038619922432
Tweet Content  Will there be some kind of shock absorbers installed on the feet of the landing legs? Yes
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureMartian97 on 02/10/2019 05:23 pm


sorry to come out of left field on a tangent, but i was looking at those pictures of the pad under construction and considering the hopper appears to have relatively rigid landing feet, are we expecting them to build some kind of "soft" landing pad? could that be what the three tubes on the new landing pad are to support? three separate vertical pads that could move up and down a bit? elon talked about eliminating legs all together in the past, right?

Elon said they would install some type of shock absorber onto the hopper so it'll still probably be a concrete pad imo. And the talk of removing the landing legs are meant for the booster eventually, not the starship.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Spindog on 02/10/2019 05:46 pm
I thought they wanted to use autogenous pressurization?

No point in making the hopper more complex and test an all new system like that when COPV's work just fine for this application.

The COPV's could be for nitrogen for the cold gas thrusters or for something like strut pressurization or structural pressurization for non-tank areas. Or maybe for tank structural pressurization prior to fuel loading. Though Elon said structural pressurization is not required they could still use some as a safety factor when payload mass is loaded.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 02/10/2019 06:46 pm
I thought they wanted to use autogenous pressurization?

No point in making the hopper more complex and test an all new system like that when COPV's work just fine for this application.

The COPV's could be for nitrogen for the cold gas thrusters or for something like strut pressurization or structural pressurization for non-tank areas. Or maybe for tank structural pressurization prior to fuel loading. Though Elon said structural pressurization is not required they could still use some as a safety factor when payload mass is loaded.

Or for system purge of methane
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ngkiwi on 02/11/2019 02:07 am
Does anybody know why the launch/landing pad was dug out as three circular holes to what appears to be a couple of metres depth. 
Did they eventually dig it out to one large hole or leave it as three holes (one for each hopper leg?)

Here is the three hole pic, credit Austin Barnard,: https://forum.nasaspaceflight.com/index.php?topic=47120.140
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris_Pi on 02/11/2019 05:36 am
Big blocks of concrete poured in each hole. Then large, short pipes bolted on top coming up to about ground-level and backfilled. Here's what it looks like now:

New Drone videos from Austin Barnard going up:

https://twitter.com/austinbarnard45/status/1094744511232778241

https://www.youtube.com/watch?v=RPWC5A_d2ZM

https://twitter.com/austinbarnard45/status/1094748123208011776

https://twitter.com/austinbarnard45/status/1094748381296119808
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/11/2019 09:14 pm
They are attaching a section of pipe from the bottom of the Hopper to the fin. On each side of the fins.

Structural reenforcements? The start of some sort of shock absorber build?

I gotta say, while we can not see inside the lower part of the Hopper and dont know the status of the Fairing, the outside of the lower part of the Hopper looks closer and closer to being finished. Maybe that part is not far off the 4 week ideal timeline Elon suggested. Pad is also progressing well. Raptors too. If the fairing issue was not there, i would be quite optimistic seeing at least the 8 week target work out. But the lack of a visible Fairing rebuild/replacement makes me wonder if they will possibly really do static fires or even short hops without the Fairing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 02/11/2019 09:16 pm


They are attaching a section of pipe from the bottom of the Hopper to the fin. On each side of the fins.

Structural reenforcements? The start of some sort of shock absorber build?

Shock absorbers were my first thought as well.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/11/2019 09:23 pm


They are attaching a section of pipe from the bottom of the Hopper to the fin. On each side of the fins.

Structural reenforcements? The start of some sort of shock absorber build?

Shock absorbers were my first thought as well.
Highly doubt it - they are welding both ends, plus the central tube is also welded on the inside - so no shock absorbing can happen. To me it looks like lateral stiffeners - the existing top / bottom tubes have no lateral stress resistance as they are co-planar.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/11/2019 10:51 pm
Changes on the dome.

Wow!  Next thing you know I'll bet Nomadd is going to be asking them to paint his name up there as well.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Arb on 02/11/2019 10:57 pm
Ninjaed, but all that stuff on top of the tank is very reminiscent of the top of an F9 booster (inside the inter-stage).

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cppetrie on 02/12/2019 12:18 am
Ninjaed, but all that stuff on top of the tank is very reminiscent of the top of an F9 booster (inside the inter-stage).
Use what you know to test what you don’t.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/12/2019 12:51 am
Changes on the dome.

Wow!  Next thing you know I'll bet Nomadd is going to be asking them to paint his name up there as well.
I told her to stay off of that thing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Prettz on 02/12/2019 02:21 am
Why has no one who's got Musk's attention on twitter asked him about autogenous pressurization for the hopper?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: willimike on 02/12/2019 02:35 am
Why has no one who's got Musk's attention on twitter asked him about autogenous pressurization for the hopper?

They have "Will hopper have autogenous pressurization" and his answer was "Yes"

https://twitter.com/somepitch/status/1083570222521561088 (https://twitter.com/somepitch/status/1083570222521561088)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Prettz on 02/12/2019 02:56 am
Not sure how I missed that one. Glad to hear it's yes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/12/2019 03:17 am
Not sure how I missed that one. Glad to hear it's yes.
If only we were sure what the definition of the word "it" is.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bogeyman on 02/12/2019 05:24 am
Found this one: https://space.stackexchange.com/questions/18441/autogenous-pressurization-with-sub-cooled-propellant
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: strato1 on 02/12/2019 06:07 am
Does anyone have a feel for whether the Falcon 9 and Heavy launch certification evaluation would have any impact on the hopper?

https://media.defense.gov/2019/Feb/11/2002088764/-1/-1/1/D2019-D000PT-0059.000.PDF (https://media.defense.gov/2019/Feb/11/2002088764/-1/-1/1/D2019-D000PT-0059.000.PDF)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: flyright on 02/12/2019 07:09 am
Does anyone have a feel for whether the Falcon 9 and Heavy launch certification evaluation would have any impact on the hopper?

https://media.defense.gov/2019/Feb/11/2002088764/-1/-1/1/D2019-D000PT-0059.000.PDF (https://media.defense.gov/2019/Feb/11/2002088764/-1/-1/1/D2019-D000PT-0059.000.PDF)

Why would it?
The hopper will never be certified by the Air Force. It is a test article.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/12/2019 04:27 pm
The access port with flange installed. Some new holes for plumbing and wiring. A closeup shot of a lateral stiffener. The have four attached. None where the scaffolding is.

bcg:  What happened to the pixel dimensions on these latest pictures?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/12/2019 04:39 pm
Highly doubt it - they are welding both ends, plus the central tube is also welded on the inside - so no shock absorbing can happen. To me it looks like lateral stiffeners - the existing top / bottom tubes have no lateral stress resistance as they are co-planar.
I wonder how they'll get the required lateral stiffness on the production SS.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/12/2019 05:02 pm
The access port with flange installed. Some new holes for plumbing and wiring. A closeup shot of a lateral stiffener. The have four attached. None where the scaffolding is.

I like the cabling attached with Zipties. :D

The foil above the access port can obviously be removed fast, but given how much traffic we saw going in and out, covering it up might hint at
A: They do not expect a lot of traffic through that port in the near future, which means we might be closer to finish / Hopper move;
And/or B: The inner cleanup / surface preparation might have progressed so far, that protecting the inner parts from dirt intrusion / birds flying in looking for a nesting place becomes something worth considering, as not a whole lot of "dirty" work remains to be done inside. Which also means we are closer to finish / Hopper move.

(And yes, "closer to" is sort of meaningless without numbers, but hey i dont have any.)

[Edit]
C: It might also hint at the fact that they have no more permanent cover, like a hatch, ready yet. Which i find a bit puzzling. I do not expect them to fly with that access port open. Maybe they still need to get in and out more often, so closing the port up and reopening with all those bolts and screws is too much of a hazzle and will happen last.
[/Edit]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kenm on 02/12/2019 06:37 pm
Highly doubt it - they are welding both ends, plus the central tube is also welded on the inside - so no shock absorbing can happen. To me it looks like lateral stiffeners - the existing top / bottom tubes have no lateral stress resistance as they are co-planar.
I wonder how they'll get the required lateral stiffness on the production SS.
When there was discussion about how to actuate the two movable fins most were looking at hydraulic motors at the root of the fins to match the clean lines of the models we have seen I thought that hydraulic or linear electric actuating struts might be a better solution.
They would make the ship look a bit like a small Cessna but it would reduce the torque on the root of the fins and the struts would be protected from heating during the skydiver portion of the reentry.
The third fin could have a couple of fixed struts to hold it in place.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 02/12/2019 07:39 pm
The Hopper build is going totally Kerbal: " Need more struts!"

Coming up next (mark my words): wire bracing. If it worked on a Sopwith Camel it'll work on the Hopper as well.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 02/12/2019 10:15 pm
The access port with flange installed. Some new holes for plumbing and wiring. A closeup shot of a lateral stiffener. The have four attached. None where the scaffolding is.

bcg:  What happened to the pixel dimensions on these latest pictures?
I cropped my original photos to show what was necessary. :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/12/2019 11:21 pm
The access port with flange installed. Some new holes for plumbing and wiring. A closeup shot of a lateral stiffener. The have four attached. None where the scaffolding is.

bcg:  What happened to the pixel dimensions on these latest pictures?
I cropped my original photos to show what was necessary. :)

OK.  But!!! ......   ;D

There's no Cropping in Spaceball!!!!!   Sorry.  Was just missing the full-size one's for documentary purposes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/13/2019 01:28 am
The access port with flange installed. Some new holes for plumbing and wiring. A closeup shot of a lateral stiffener. The have four attached. None where the scaffolding is.

That's a lot of holes, more than I was expecting, anyone has idea on what they're for?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/13/2019 04:49 pm
I assume this implies that autogenous pressurization will also be functioning on BFH?
https://twitter.com/elonmusk/status/1095551826668138496
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Norm38 on 02/13/2019 05:03 pm
^^^ I would be very surprised. Testing out all the engine plumbing and tank issues has to be a major focus of the hopper.  If there are transients, surges, drops, etc in pressure, they need to know that now.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jketch on 02/13/2019 06:35 pm
I think it's still ambiguous. He may not see the BFH as "Starship version 1."
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: matthewkantar on 02/13/2019 06:46 pm
Why would they waste the money on helium while passing up an opportunity to do higher fidelity testing using a low value asset?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Tulse on 02/13/2019 07:00 pm
Some photos of the Hopper show it with red COPVs, which would suggest it will use that for pressurizing the main tanks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: butters on 02/13/2019 07:02 pm
Some photos of the Hopper show it with red COPVs, which would suggest it will use that for pressurizing the main tanks.

COPVs could be for the cold gas thrusters, right?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AbuSimbel on 02/13/2019 07:03 pm
Looks like SpaceX hosted an event inside what seems to be the Hopper tent today

Edit: or maybe something related to Stargate? Unfortunately I only found a single source on twitter
https://twitter.com/hugoAvC/status/1095748465156603904

https://twitter.com/hugoAvC/status/1095749652358533120
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 02/13/2019 07:06 pm
Why the sudden RUSH to build & fly The Hopper?
Note that NASA is soliciting Lunar Lander bids from commercial providers.
WILD SPECULATION...
Rush to build The Hopper is because SpaceX is proposing to NASA a 3 Raptor, in space only lunar lander smaller than regular Starship but without heat shield etc. Regular Starship refueled in LEO transits to the sacred Lunar Tollboth where the SpaceX Luna Hopper gets refueled and gets another 50 tonnes or whatever payload from Earth to bring on down.
Demonstrating The BOCA Hopper makes it more "real" to NASA.  Remember Eric Berger saying "NASA" does not believe that BFwhatever/SuperHeavy/Starship is real?  Therefore NASA "ignores" SpaceX's claimed next generation transport system.

Elon - this retired engineer is available to consult on all your SpaceX designs. Transportation, hotel, meals and single malt beverages only requirements.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Tulse on 02/13/2019 07:07 pm
COPVs could be for the cold gas thrusters, right?
Good point.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 02/13/2019 08:22 pm
Why the sudden RUSH to build & fly The Hopper?
Note that NASA is soliciting Lunar Lander bids from commercial providers.

Nah, they have a customer with gigabucks they're trying to keep happy. Flying on-time is going to be a challenge. There's no time to waste.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MizaruSpaceXNut on 02/13/2019 08:52 pm
Some photos of the Hopper show it with red COPVs, which would suggest it will use that for pressurizing the main tanks.
They might be for the pressure supply to operate the valves! I saw only one line going to the valves, indicating

a spring return.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 02/13/2019 08:59 pm
Why the sudden RUSH to build & fly The Hopper?
Note that NASA is soliciting Lunar Lander bids from commercial providers.
WILD SPECULATION...
Rush to build The Hopper is because SpaceX is proposing to NASA a 3 Raptor, in space only lunar lander smaller than regular Starship but without heat shield etc. Regular Starship refueled in LEO transits to the sacred Lunar Tollboth where the SpaceX Luna Hopper gets refueled and gets another 50 tonnes or whatever payload from Earth to bring on down.
Demonstrating The BOCA Hopper makes it more "real" to NASA.  Remember Eric Berger saying "NASA" does not believe that BFwhatever/SuperHeavy/Starship is real?  Therefore NASA "ignores" SpaceX's claimed next generation transport system.

Elon - this retired engineer is available to consult on all your SpaceX designs. Transportation, hotel, meals and single malt beverages only requirements.
I think this is norml for SpaceX. They also need to get Starship/Superheavy operational as quickly as possible to launch Starlink. And they need that to fund the Mars missions
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 02/13/2019 09:43 pm
I assume this implies that autogenous pressurization will also be functioning on BFH?

^^^ I would be very surprised. Testing out all the engine plumbing and tank issues has to be a major focus of the hopper.  If there are transients, surges, drops, etc in pressure, they need to know that now.
I think it's still ambiguous. He may not see the BFH as "Starship version 1."
Why would they waste the money on helium while passing up an opportunity to do higher fidelity testing using a low value asset?

If you look at how they used Grasshoppers 1&2, they started with the basic, well-understood stuff, then added new things like restarting engines in flight, translating via engine gimbaling, & moving on up to hoverslams!

Odds are they’ll take the same path with BFH — start with He or Nitrogen pressurant to start & wring out the engines, including all-new stuff like in-flight restart of a FFSC via sparkplug / torch, then after they have that stuff down, move on to autogenous pressurization.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/13/2019 10:52 pm
I assume this implies that autogenous pressurization will also be functioning on BFH?

^^^ I would be very surprised. Testing out all the engine plumbing and tank issues has to be a major focus of the hopper.  If there are transients, surges, drops, etc in pressure, they need to know that now.
I think it's still ambiguous. He may not see the BFH as "Starship version 1."
Why would they waste the money on helium while passing up an opportunity to do higher fidelity testing using a low value asset?

If you look at how they used Grasshoppers 1&2, they started with the basic, well-understood stuff, then added new things like restarting engines in flight, translating via engine gimbaling, & moving on up to hoverslams!

Odds are they’ll take the same path with BFH — start with He or Nitrogen pressurant to start & wring out the engines, including all-new stuff like in-flight restart of a FFSC via sparkplug / torch, then after they have that stuff down, move on to autogenous pressurization.

Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.

https://twitter.com/somepitch/status/1083630158408384512
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/13/2019 10:55 pm
Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.

Is it not possible, as has been suggested before, that tweet could be interpreted either way?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 02/13/2019 11:07 pm
Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.

Is it not possible, as has been suggested before, that tweet could be interpreted either way?

ISTM the main topic of the conversation was the Hopper. The Orbital vehicle was only mentioned in a comparison of height & snoothness.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/13/2019 11:09 pm
Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.

Is it not possible, as has been suggested before, that tweet could be interpreted either way?

Maybe, and things change pretty quickly on this project anyway, so the plan then might not be the same as the plan now. Seems pretty clear to me though.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/13/2019 11:58 pm
 Does the Hopper tanks being so short and the resulting low head pressure before takeoff make much difference?  How would you normally get high enough tank pressure before the engines crank up to provide autogenous?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 02/14/2019 12:03 am
Does the Hopper tanks being so short and the resulting low head pressure before takeoff make much difference?  How would you normally get high enough tank pressure before the engines crank up to provide autogenous?

I suppose you could include some electric heating, all you must do to increase pressure is increase the temperature of some of the methane. I don't know how much energy you'd have to dump before the engines are giving you more than you need.

Alternatively, there could be enough head pressure (some excess) built in before engine start to make sure there's enough pressure between the moment the engines start sucking fuel and the autogenous pressurization lines start providing header pressure. This seems to me more likely and considerably simpler.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/14/2019 12:23 am
Does the Hopper tanks being so short and the resulting low head pressure before takeoff make much difference?  How would you normally get high enough tank pressure before the engines crank up to provide autogenous?

Tank pressure, and hence head, will build up as propellants heat up sitting on the pad. Will vent as needed to maintain desired pressure. A few percent Ullage volume buffers tank pressure. Engines will be able to feed pressurants within a second or two.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/14/2019 12:50 am
BFH tanks are also larger than SS header tanks and those will work fine for landing without helium.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/14/2019 01:27 am
Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.

Is it not possible, as has been suggested before, that tweet could be interpreted either way?

Maybe, and things change pretty quickly on this project anyway, so the plan then might not be the same as the plan now. Seems pretty clear to me though.

I don't think anything is changing with the project.   The speed they're moving is so incredible, this has been laid out to the last detail over probably the last 6 months.

Both Hopper and Pad, that is.

There was one mishap, and you can see that a replacement fairing hasn't shown up overnight...  It takes time to execute.  But all the other pieces are arriving JIT, and that's just amazing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: xyv on 02/14/2019 01:40 am
Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.

Is it not possible, as has been suggested before, that tweet could be interpreted either way?

Maybe, and things change pretty quickly on this project anyway, so the plan then might not be the same as the plan now. Seems pretty clear to me though.

I don't think anything is changing with the project.   The speed they're moving is so incredible, this has been laid out to the last detail of probably the last 6 months.

Both Hopper and Pad, that is.

There was one mishap, and you can see that a replacement fairing hasn't shown up overnight...  It takes time to execute.  But all the other pieces are arriving JIT, and that's just amazing.

^^^this^^^

I manage a small systems engineering organization in completely different field, and Space X is one of the companies I look to as a model of agile ability in systems engineering.  An equal component to success in development is project management and the hopper is practically a case study in large project orchestration.  The sheer amount of parallel synchronized activity at Boca Chica is breathtaking.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 02/14/2019 02:09 am
Does the Hopper tanks being so short and the resulting low head pressure before takeoff make much difference?  How would you normally get high enough tank pressure before the engines crank up to provide autogenous?

Tank pressure, and hence head, will build up as propellants heat up sitting on the pad. Will vent as needed to maintain desired pressure. A few percent Ullage volume buffers tank pressure. Engines will be able to feed pressurants within a second or two.
Autogenous pressurization at least on the Centaur replacement is designed to have high pressure tanks as an buffer and its no issue pressurizing before takeoff.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CardBoardBoxProcessor on 02/14/2019 02:10 am
I honestly do not think we are going to see a return of the upper fairing section, atleast not as we knew it. They will probably just cap it off with a shorter version or not at all.  They got their PR picture and are now making ti work. they are even adding leg reinforcements and everything, moving it away from the streamline sleek actual star ship analog and to a functional hopper. which does not need a pretty top anymore and will not resemble what it once was now that the GSE is being added.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/14/2019 02:34 am
I honestly do not think we are going to see a return of the upper fairing section, atleast not as we knew it. They will probably just cap it off with a shorter version or not at all.  They got their PR picture and are now making ti work. they are even adding leg reinforcements and everything, moving it away from the streamline sleek actual star ship analog and to a functional hopper. which does not need a pretty top anymore and will not resemble what it once was now that the GSE is being added.
That "pretty top" might be important for testing landing characteristics, particularly in the wind. The closer it is to Starship shape, the better the data will be. Better to work the bugs out of your software on a flying water tank than a 200 million dollar full up prototype.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/14/2019 03:00 am
I honestly do not think we are going to see a return of the upper fairing section, atleast not as we knew it. They will probably just cap it off with a shorter version or not at all.  They got their PR picture and are now making ti work. they are even adding leg reinforcements and everything, moving it away from the streamline sleek actual star ship analog and to a functional hopper. which does not need a pretty top anymore and will not resemble what it once was now that the GSE is being added.

I totally agree.
I think.
Maybe?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/14/2019 04:03 am
Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.

Is it not possible, as has been suggested before, that tweet could be interpreted either way?

Maybe, and things change pretty quickly on this project anyway, so the plan then might not be the same as the plan now. Seems pretty clear to me though.

I don't think anything is changing with the project.   The speed they're moving is so incredible, this has been laid out to the last detail of probably the last 6 months.

Both Hopper and Pad, that is.

There was one mishap, and you can see that a replacement fairing hasn't shown up overnight...  It takes time to execute.  But all the other pieces are arriving JIT, and that's just amazing.

^^^this^^^

I manage a small systems engineering organization in completely different field, and Space X is one of the companies I look to as a model of agile ability in systems engineering.  An equal component to success in development is project management and the hopper is practically a case study in large project orchestration.  The sheer amount of parallel synchronized activity at Boca Chica is breathtaking.

It's not mutually exclusive. You've really mastered development when your changes look like you planned them that way all along.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Inoeth on 02/14/2019 04:12 am
I honestly do not think we are going to see a return of the upper fairing section, atleast not as we knew it. They will probably just cap it off with a shorter version or not at all.  They got their PR picture and are now making ti work. they are even adding leg reinforcements and everything, moving it away from the streamline sleek actual star ship analog and to a functional hopper. which does not need a pretty top anymore and will not resemble what it once was now that the GSE is being added.
That "pretty top" might be important for testing landing characteristics, particularly in the wind. The closer it is to Starship shape, the better the data will be. Better to work the bugs out of your software on a flying water tank than a 200 million dollar full up prototype.

I have to agree- the fairing is both structural in terms of testing aerodynamics as well as aesthetic. They definitely want to get the most data they can from the hops before they commit the full sized prototype. Additionally, Elon and SpaceX are fully aware that every single hop test that they do will be filmed and shared - both by people who live in the area like Austin Barnard, Nomadd and BocaChicaGal and most likely SpaceX themselves- they'll want the positive PR of having the hopper look complete when it flies - as it will be compared with earlier renders and pictures.

It will be interesting if at some point the wall of the tent comes down and out comes a newly built fairing or if they build the new one outside or whatever... tho I think a big part of walling off the tent was more for doing more critical work with protection from the weather and less to do with hiding anything per say. I certainly expect them to store the new Raptor engines there before they're installed for example...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/14/2019 04:14 am
Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.

Is it not possible, as has been suggested before, that tweet could be interpreted either way?

Maybe, and things change pretty quickly on this project anyway, so the plan then might not be the same as the plan now. Seems pretty clear to me though.

I don't think anything is changing with the project.   The speed they're moving is so incredible, this has been laid out to the last detail of probably the last 6 months.

Both Hopper and Pad, that is.

There was one mishap, and you can see that a replacement fairing hasn't shown up overnight...  It takes time to execute.  But all the other pieces are arriving JIT, and that's just amazing.

^^^this^^^

I manage a small systems engineering organization in completely different field, and Space X is one of the companies I look to as a model of agile ability in systems engineering.  An equal component to success in development is project management and the hopper is practically a case study in large project orchestration.  The sheer amount of parallel synchronized activity at Boca Chica is breathtaking.

It's not mutually exclusive. You've really mastered development when your changes look like you planned them that way all along.

What items do you think changed?  (other than the nose cone falling over?)

And what caused those items to change?

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 02/14/2019 07:32 am
[

If you look at how they used Grasshoppers 1&2, they started with the basic, well-understood stuff, then added new things like restarting engines in flight, translating via engine gimbaling, & moving on up to hoverslams!

Odds are they’ll take the same path with BFH — start with He or Nitrogen pressurant to start & wring out the engines, including all-new stuff like in-flight restart of a FFSC via sparkplug / torch, then after they have that stuff down, move on to autogenous pressurization.

Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.


Maybe not from the beginning. Eventually, yes, surely they will be testing the pressurization + attitude control system including thrusters, on the hopper, in the “nearly final” configuration. But what’s your explanation for all the big, expensive, high pressure COPVs they mounted on top?

My expectation is that they will use high pressure He to wring out the overall system for Raptor starts / restarts, as well as the cold gas for initial attitude reaction control. Perhaps from the beginning they will have the Raptors provide autogenous pressurization *once started*, just like SSME. But right now I don’t see a methane “hot gas” head tank anywhere on the vehicle to supply either high pressure methane for initial pressurization or for initial attitude reaction control when the engines are shut down. Note, you would also need a high temp one for hot oxygen gas to pressurize that tank as well before the Raptor is started. Again possibly it’s hidden in the bottom. But also possible they may not want to start with that additional complexity when their “hardest challenge” that they need to get a handle on first is reliably starting up and running, and throttling the Raptors under flight conditions.

Besides, what else are the COPVs for?

*modded* great point Humanses Kosmos that 3 bar should be no problem with ambient temperatures heating up cryogenic propellants. Also, reaction vice just attitude control... so no other pressurant gas needed just yet for propellants.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Hominans Kosmos on 02/14/2019 08:51 am

Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.

<snip> 
But what’s your explanation for all the big, expensive, high pressure COPVs they mounted on top? 
<snip> 
Besides, what else are the COPVs for?
 

https://en.wikipedia.org/wiki/Reaction_control_system#/media/File:LM_RCS.jpg
It's for the thrusters, probably.

Ambient temperature + cryogenic propellant in a closed container give you all the pressure you need for engine start-up.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Hominans Kosmos on 02/14/2019 10:17 am
I honestly do not think we are going to see a return of the upper fairing section, atleast not as we knew it. They will probably just cap it off with a shorter version or not at all.  They got their PR picture and are now making ti work. they are even adding leg reinforcements and everything, moving it away from the streamline sleek actual star ship analog and to a functional hopper. which does not need a pretty top anymore and will not resemble what it once was now that the GSE is being added.
That "pretty top" might be important for testing landing characteristics, particularly in the wind. The closer it is to Starship shape, the better the data will be. Better to work the bugs out of your software on a flying water tank than a 200 million dollar full up prototype.

Fairing on/off should be quite a meaningful change in flight characteristics. Didn't the Falcon Heavy booster nosecones versus F9 interstage aerodynamics thing teach us that? Difference will be smaller in the low airspeed part of the flight envelope, however the vehicle is not tiny, wind at vehicle top is going to be a strong factor.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CardBoardBoxProcessor on 02/14/2019 12:42 pm
except this isn't an aerodynamic test model. It was a PR picture and then transition to working flight machine. The extra struts, different underside, different number of engines, lack of movable fins, outside tack race ways, etc etc all make it invalid as an actual aerodynamic tester.  it is as useful at aerodynamics and grasshopper was.  Its simply for Raptor landing calibrations. start up and burn out times, hover testing, stuff like that.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: StuffOfInterest on 02/14/2019 01:23 pm
Regarding the tinfoil hat...err, nose cone...I think it will come back but not before the hopper is closer to completion.  After the mishap with the last one, they probably don't want a replacement sitting around not bolted to the hopper base.  All the work going on right now would prevent installing the top so better to just build it when they are ready for it.  Besides, considering that the first few tests will only be quick up and downs I don't think they need to worry about the top any time soon except for more photos.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/14/2019 01:30 pm
It's not mutually exclusive. You've really mastered development when your changes look like you planned them that way all along.

What items do you think changed?  (other than the nose cone falling over?)

And what caused those items to change?

I don't know of anything specifically changing on this project. I just know that even the best project plans never fully survive contact with reality.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: niwax on 02/14/2019 01:40 pm
Regarding the tinfoil hat...err, nose cone...I think it will come back but not before the hopper is closer to completion.  After the mishap with the last one, they probably don't want a replacement sitting around not bolted to the hopper base.  All the work going on right now would prevent installing the top so better to just build it when they are ready for it.  Besides, considering that the first few tests will only be quick up and downs I don't think they need to worry about the top any time soon except for more photos.

I wouldn't be surprised if they have the first few hops without and then either upgrade to a new hopper or build a larger nose more like the real thing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/14/2019 01:55 pm

Musk already answered this question specifically about the Hopper. It will have autogenous pressurization.

<snip> 
But what’s your explanation for all the big, expensive, high pressure COPVs they mounted on top? 
<snip> 
Besides, what else are the COPVs for?
 

https://en.wikipedia.org/wiki/Reaction_control_system#/media/File:LM_RCS.jpg
It's for the thrusters, probably.

Ambient temperature + cryogenic propellant in a closed container give you all the pressure you need for engine start-up.

- I don't think it will have any RCS at all. Has anyone seen any sign of RCS yet?

- COPVs could be used for purging and rapid engine spin up for starting. We don't know if they use turbine spin up gas but if they do, it would have to be a few hundred psi at least.

- In the final form of Star Ship the RCS will use warm high pressure CH4 and LOX to feed RCS rockets, but neither of these are present on the hopper. Maybe helium is filling in until they make them available.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 02/14/2019 02:37 pm
Data, data, data....

That's what hopper is being built for. That's what all the Pad infrastructure is being built for. Nobody should confuse taking advantage of a good PR moment with the bigger picture. Hopper has an extremely important role to play in SpaceX's quest to reach Moon and Mars. This is not a photoshoot. The upper section (nosecone) isn't going anywhere. It's a critical part of the Hopper design. As the Raptor TVCs / Avionics learn to maneuver this monster while being buffeted by all kinds of wind forces throughout its initial flight regime.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: krsears on 02/14/2019 02:55 pm
IMO, the nosecone is for making the weight closer to the actual weight of the "empty" SS as well as to get a read on the approximate force that wind is going to apply to the profile of the article as it performs the final landing procedures.

I believe that the nosecone is shorter in order to keep the size of the hopper < size of the F9 so that the current licenses can be used for testing.

In summary, I think the nosecone will be reattached for testing.

Kendall
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/14/2019 03:41 pm
except this isn't an aerodynamic test model. It was a PR picture and then transition to working flight machine. The extra struts, different underside, different number of engines, lack of movable fins, outside tack race ways, etc etc all make it invalid as an actual aerodynamic tester.  it is as useful at aerodynamics and grasshopper was.  Its simply for Raptor landing calibrations. start up and burn out times, hover testing, stuff like that.

The hat gets it somewhat closer to the right wind loads, if they want to try landing accurately in a crosswind. Also somewhat closer to the actual angular inertia so that control response is more realistic. It's not going to be perfect for either, though, as it's probably both smaller and lighter than the real thing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: frostbit_canadian on 02/14/2019 03:52 pm
Why does this thread not allow the "Show All" setting to show every post on a single page?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lisa_R4 on 02/14/2019 04:00 pm
Crosswinds aside, would the aerodynamics of the nose cone be important for testing landing with asymmetric thrust, which I'm assuming is implied by engine out capability? Seems like something they'd want to start working out with the Hopper before moving to the higher fidelity prototype.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/14/2019 04:00 pm
Why does this thread not allow the "Show All" setting to show every post on a single page?
Just look at the thread list. That option always goes away at 10 pages.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: IntoTheVoid on 02/14/2019 04:01 pm
Presuming the hat/fairing comes back eventually if not right away, they will need to build a notch into the lower hoop to avoid the wires and pipe blocking the attach point.

Also, noticed a chain hoist at the bottom...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureMartian97 on 02/14/2019 05:02 pm

Also, noticed a chain hoist at the bottom...

Preparing to lift a Raptor maybe?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Tuna-Fish on 02/14/2019 05:11 pm
The hat will be necessary for proper testing later on, but I'd bet that the first time this hops, it just goes up less than a meter and then sets down again. Then next time, they might hover for a bit, or go a tiny bit higher. My point is, even when testing has started, it will take a rather long time and many tests before the testing proceeds to the point where aerodynamics actually matter.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Star One on 02/14/2019 05:16 pm
The hat will be necessary for proper testing later on, but I'd bet that the first time this hops, it just goes up less than a meter and then sets down again. Then next time, they might hover for a bit, or go a tiny bit higher. My point is, even when testing has started, it will take a rather long time and many tests before the testing proceeds to the point where aerodynamics actually matter.


It could be argued that from EM's prospective it is aesthetics that are more important here not aerodynamics.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bogeyman on 02/14/2019 06:35 pm
How about center of mass? Isn‘t that also a factor even when it hops just a couple of feet?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/14/2019 07:02 pm
What do you think this pipe is for?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: matthewkantar on 02/14/2019 07:38 pm
The sets of ninety degree bends are to allow expansion and contraction, whatever flows in them would seem to do so over a wide temperature range. Autogenous pressurization line? I don't think it is a fill line.

Edit: Maybe it is a fill line, terminates outside of tanks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/14/2019 08:40 pm
On the risk of getting laughed out by people with actual knowledge... i guess Methane release/drain/overpressure pipe.

Reason being that i think that boiloff O2 will be vented just next to the rocket, but boiloff Methane will be piped to the flare stack. And i think all fill pipes enter lower and pump up, this seems to come from the top of the dome where gaseous methane will gather.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 02/14/2019 08:51 pm
For those thnking of flying wihtout the nosecone, balance a 2" nail upright on your finger, then balance a 6" nail on your finger. It's easier to control the 6" nail. The height and moment of inertia and CoG are all important. Now put a inch wide bit of paper on the nail and blow on in.

The aero of the entire craft is important.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: flyright on 02/14/2019 09:33 pm
If they do build a new fairing/nose, it looks like they have some newly installed anchor bolts to keep it firmly held down.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: acsawdey on 02/14/2019 09:47 pm
On the risk of getting laughed out by people with actual knowledge... i guess Methane release/drain/overpressure pipe.

Reason being that i think that boiloff O2 will be vented just next to the rocket, but boiloff Methane will be piped to the flare stack. And i think all fill pipes enter lower and pump up, this seems to come from the top of the dome where gaseous methane will gather.

You almost wonder if the craft needs to have a onboard means of flaring excess methane. After the umbilicals disconnect it can't rely on the GSE flare stack. And after landing it has to release the pressure in the fuel tank.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rsdavis9 on 02/14/2019 10:04 pm
On the risk of getting laughed out by people with actual knowledge... i guess Methane release/drain/overpressure pipe.

Reason being that i think that boiloff O2 will be vented just next to the rocket, but boiloff Methane will be piped to the flare stack. And i think all fill pipes enter lower and pump up, this seems to come from the top of the dome where gaseous methane will gather.

You almost wonder if the craft needs to have a onboard means of flaring excess methane. After the umbilicals disconnect it can't rely on the GSE flare stack. And after landing it has to release the pressure in the fuel tank.

Its called rcs thrusters. They have spark ignition. They could be run fuel rich.
Of course now elon says we will have cold gas for SS v1.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: StuffOfInterest on 02/14/2019 10:31 pm
For those thnking of flying wihtout the nosecone, balance a 2" nail upright on your finger, then balance a 6" nail on your finger. It's easier to control the 6" nail. The height and moment of inertia and CoG are all important. Now put a inch wide bit of paper on the nail and blow on in.

The problem with your analogy is the center of gravity.  For a 2" nail the CG is about 1" up.  For a 6" nail the CG is about 3" up.  Having your finger further from the CG makes it easier to adjust as it tips. 

The CG won't move linearly with the hopper as the base is much, much heavier than the top hat.  The entire top hat will probably only move the CG up by a foot or two.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: eriblo on 02/14/2019 11:22 pm
On the risk of getting laughed out by people with actual knowledge... i guess Methane release/drain/overpressure pipe.

Reason being that i think that boiloff O2 will be vented just next to the rocket, but boiloff Methane will be piped to the flare stack. And i think all fill pipes enter lower and pump up, this seems to come from the top of the dome where gaseous methane will gather.
Not a stupid idea, but everything points towards that being the LOX tank... Unless I got my angles mixed up that pipe is connected to the T-pipe "diffuser" on the inside, suggesting gases entering.
I've also seen people wondering how you pressurize before ignition with an autogenous (which requires an extra system) but for the hopper that could just be supplied by GSE.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: IntoTheVoid on 02/14/2019 11:32 pm
Just noticed, and don't recall being mentioned earlier...
It seems they trimmed the cladding at the top root of the clad legs, while the scaffolding was up, so that it no longer extends above the hat/fairing seam. Whether that's because they were generally in the way, or because they blocked the attach for a new hat once the dome went on... argue away.

Pics cropped from the following two posts:
Showing the rectangles running up the Hopper.
Changes on the dome.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: hkultala on 02/15/2019 04:21 am
How about center of mass? Isn‘t that also a factor even when it hops just a couple of feet?

the relation between center of mass and thrust vector does matter, but relation of the center of mass and the center of aerodynamic forces does not matter in these very slow flights.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RobLynn on 02/15/2019 04:35 am
How about center of mass? Isn‘t that also a factor even when it hops just a couple of feet?

the relation between center of mass and thrust vector does matter, but relation of the center of mass and the center of aerodynamic forces does not matter in these very slow flights.

Yes, and the centre of mass could be easily replicated using a lump of concrete supported on a tripod with legs attached to the perimeter of the top of the tank.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/15/2019 04:39 am
It could be argued that from EM's prospective it is aesthetics that are more important here not aerodynamics.
Danger of wandering... but EM himself said, when asked how people could help, that the general public perception of SS was very important.  People care about looks. Especially non engineer types.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Hominans Kosmos on 02/15/2019 05:51 am
How about center of mass? Isn‘t that also a factor even when it hops just a couple of feet?

the relation between center of mass and thrust vector does matter, but relation of the center of mass and the center of aerodynamic forces does not matter in these very slow flights.

Yes, and the centre of mass could be easily replicated using a lump of concrete supported on a tripod with legs attached to the perimeter of the top of the tank.

However, no useful aerodynamic and thermal performance data gained, that way.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 02/15/2019 09:02 am
How about center of mass? Isn‘t that also a factor even when it hops just a couple of feet?

the relation between center of mass and thrust vector does matter, but relation of the center of mass and the center of aerodynamic forces does not matter in these very slow flights.

Yes, and the centre of mass could be easily replicated using a lump of concrete supported on a tripod with legs attached to the perimeter of the top of the tank.

However, no useful aerodynamic and thermal performance data gained, that way.

Both. Use a nosecone, but add the weight up high to simulate the final weight distribution. Make the mass moveable (even in flight?) to simulate different load conditions. Relatively easy to do, gets much more valid results.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 02/15/2019 11:32 am
For those thnking of flying wihtout the nosecone, balance a 2" nail upright on your finger, then balance a 6" nail on your finger. It's easier to control the 6" nail. The height and moment of inertia and CoG are all important. Now put a inch wide bit of paper on the nail and blow on in.

The problem with your analogy is the center of gravity.  For a 2" nail the CG is about 1" up.  For a 6" nail the CG is about 3" up.  Having your finger further from the CG makes it easier to adjust as it tips. 

The CG won't move linearly with the hopper as the base is much, much heavier than the top hat.  The entire top hat will probably only move the CG up by a foot or two.
The cargo version will also be bottom heavy.
it affect drag more first even if slow for an rocket it will probably move at many hundred km/h.

More important an long bottom heavy rocket will fall engines down, even if drag is higer at bottom since drag then sideways is higher. Without the cap it will be far harder to control.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 02/15/2019 12:01 pm
I notice the access ladder on the top of the dome appears to be permanent. Individual rungs are welded on, which is definitely a permanent solution. You don’t need that many rungs with the temp access /safety scaffolding welded on now (you can tell the difference—the permanent rungs are stainless while the temp stuff appears to be painted black or brown)

I find that interesting, this thing really looks more like a “ship” than a rocket.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cheapchips on 02/15/2019 12:37 pm
I wonder if we'll see a hatch in nosecone v2 that lines up with that permanent ladder. It'll be a pain to take off the hat to service all that equipment that's now installed on the dome.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/15/2019 01:54 pm
...access ladder on the top of the dome appears to be permanent. Individual rungs are welded on... safety scaffolding welded on... I find that interesting, this thing really looks more like a “ship” than a rocket.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/15/2019 02:15 pm
Good progress on the "dome" overnight, as shown from BCGal's picture this AM.

A few notes of interest:

1) The T fitting makes me think that's a LOX vent, therefore the LOX tank.

2) They added COPV plumbing

3) The larger diameter line going through the valve and into a dome bulkhead has a thermal expansion / contraction bend on the side of the BFH. I would think this makes it the LOX fill line?

4) Love the handrails

5) All these valves are pressure driven, yet another reason for the COPVs.

Finally - and this again is just my opinion - but I have to say it: There is a ZERO percent chance this thing will fly without the hat. Absolutely zero. To even suggest it shows a disconnect from what SpaceX is, and more specifically, who Elon is. From the beginning I had speculated they are building a mass / shape simulator for hop testing. And of course I still believe that. Not to mention adding some form of protection to the hardware on the dome. But all of that doesn't matter - it's so much more...

Elon is stating (and I am in 100% agreement) that what is happening in Boca Chica represents the very future of spaceflight - human exploration - Mars colonization - Moon returning - space tourism - and arguably the survival of humanity itself (go reread Tim Urban's most excellent blog post if you don't see that).  This is NOT "just another launch vehicle in its development cycle".

This is a statement. A globally-watched tentative first step on the path towards walking off this planet and onto another. This BFH is the very first manifestation of the Starship. Elon's Starship. And he ain't - no way no how - gonna fly it without a hat...

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/15/2019 02:27 pm
There is a ZERO percent chance this thing will fly without the hat. Absolutely zero. To even suggest it shows a disconnect from what SpaceX is, and more specifically, who Elon is.

I hear you but counterpointly, that first tinfairing hat wasn't exactly built for speed and in my opinion would have come apart at anything above a brisk pace.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/15/2019 02:33 pm
There is a ZERO percent chance this thing will fly without the hat. Absolutely zero. To even suggest it shows a disconnect from what SpaceX is, and more specifically, who Elon is.

I hear you but counterpointly, that first tinfairing hat wasn't exactly built for speed and in my opinion would have come apart at anything above a brisk pace.

BFH will move slowly long enough that SSMk1 will be available before fast is needed. 

The rationale is the difference between the Grasshopper and Raptorhopper programs goals.  GH needed to prove out systems for an Experimental F9S1 landing program.  SSMk1 and SHMk1 will require extraordinarily reliable landing systems from their very 1st day.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/15/2019 02:34 pm
There is a ZERO percent chance this thing will fly without the hat. Absolutely zero. To even suggest it shows a disconnect from what SpaceX is, and more specifically, who Elon is.

I hear you but counterpointly, that first tinfairing hat wasn't exactly built for speed and in my opinion would have come apart at anything above a brisk pace.
I'll tell you what - if the BFH flies without a hat then I'll eat my New England Aquarium hat underwater and on camera. BUT if it does fly with a hat, you have to eat a hat of my choosing - and I hope you have a taste for stainless steel, because I know which hat I'm going to pick...  ;D

I'll even sweeten the deal. If it flies without a hat I'll mail you a signed copy of my novel, "Out of Hell's Kitchen",  but if it doesn't then you have to buy five copies of it...  :) :) :)

(^^^ shameless plug ^^^)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/15/2019 02:48 pm
Hey, no eating of flight hardware! :P
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 02/15/2019 04:34 pm
How about the the West Coast exclusive Atlas-Agena with SRV?

Absolutely beautiful and functional SLV. Good pick. There is so much history to uncover and Atlas-Agena/KH-7 is a major unknown. 38 flights in 3 years and gone......

The images attached were printed from 70mm motion picture film cut into 2 x 5 inch dimensions. The color image was from transparency/reversal film.

https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=15393.0;attach=137756;sess=55483

Going through an old thread and found a picture of Atlas-Agena.

My word, the stainless steel+LOX is gorgeous.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: gideonlow on 02/15/2019 05:37 pm
Just noticed, and don't recall being mentioned earlier...
It seems they trimmed the cladding at the top root of the clad legs, while the scaffolding was up, so that it no longer extends above the hat/fairing seam. Whether that's because they were generally in the way, or because they blocked the attach for a new hat once the dome went on... argue away.

My prediction: The new "hat" will include components to (aerodynamically) smooth the transition from the legs, likely including the load bearing attachment points and extending to associated/new reinforcing structure.  This could make it much easier to remove/re-attach/replace.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: berkie on 02/15/2019 06:41 pm
Finally - and this again is just my opinion - but I have to say it: There is a ZERO percent chance this thing will fly without the hat. Absolutely zero.

I understand this is an enthusiast forum and some of the fun is making predictions and seeing how it plays out but I will never understand the willingness of people on here to put absolute predictions into writing. It's a strange game of certainty chicken where both parties just double down until somebody is proven wrong. Thanks for the insight in the rest of your post though.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Semmel on 02/15/2019 07:42 pm
Finally - and this again is just my opinion - but I have to say it: There is a ZERO percent chance this thing will fly without the hat. Absolutely zero.

I understand this is an enthusiast forum and some of the fun is making predictions and seeing how it plays out but I will never understand the willingness of people on here to put absolute predictions into writing. It's a strange game of certainty chicken where both parties just double down until somebody is proven wrong. Thanks for the insight in the rest of your post though.


I think Johnny is right but for different reasons. I dont say it with certainty as he would. But still, the hopper without the nose would have a very strong tendency to flip upside down when the airstream is reversed, meaning when it is coming down. I think the nose must be there to be airodynamically stable. The shiny finish is just SpaceX being SpaceX and make structural element look pretty for practically the same cost as one that would be ugly. So why not? But I also think, the hat must be there. I have been proven wrong before, so no definite statement from me.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AJW on 02/15/2019 08:01 pm
There is a ZERO percent chance this thing will fly without the hat. Absolutely zero. To even suggest it shows a disconnect from what SpaceX is, and more specifically, who Elon is.

I hear you but counterpointly, that first tinfairing hat wasn't exactly built for speed and in my opinion would have come apart at anything above a brisk pace.

At some point the risk assessment of testing with or without the cap will be weighed against the potential benefits of the data gained, not the intangible value of a photo op.  Having a primarily cosmetic cap fail structurally and taking out the entire hopper in hindsight would significantly eclipse not mooring the original cap properly.  Perhaps the high winds were actually a bit of good luck forcing SpaceX to step back and reevaluate the risk/benefits of the cap.  Does the Hopper need to fly with the cap during initial tests?  Absolutely not.  Has Amos-6 taught SpaceX about taking unnecessary risks?  I like to think so.

(And in the spirit of certainty chicken... I call with a recent 140 page patent submission and raise a 460 pager out last fall and only available in hardback)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 02/15/2019 08:05 pm
(And in the spirit of certainty chicken... I call with a recent 140 page patent submission and raise a 460 pager out last fall and only available in hardback)
Is this a SpaceX patent on Starship components?  Could you elaborate a bit?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/15/2019 09:47 pm
If they follow the model of one GSE port assembly being the LOX side and one GSE port assembly being the Methane side, we might be lucky and see them paint/colour code both sides so we can tell which is which.

I still think the shorter, higher diameter pipes going inside in a sharp bend right over the GSE ports are the fill pipes. Filling bottom up. And the 2 large diameter pipes coming out of the dome top seem to be for gas drain - O2 terminating up there for direct venting, Methane pipe going back down to Methane side GSE port for connecting with the flare stack.

Hidden inside the Hopper itself are the LOX / Liquid Methane pipes bringing the stuff down to the engines, but also up from the fill pipes that therefore both do not need to run up to the respective tank levels at the outside. And i do not have the slightest clue if the Hopper has header tanks inside the tanks, but we did not see any go in so i guess not.

The Helium/N2/COPV pipes are much lower diameter.

How the autogenous pressurization system, if it exists, and the RCS thrusters, if they exist, are piped up is another bit i have no clue about.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ngkiwi on 02/16/2019 12:15 am

Quick question and offish topic, why does CH4 have to be flared off and no other commonly used rocket fuel does?  The Delta (heavy?), lights a match and all the surplus H2 burns up the side of the rocket
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JBF on 02/16/2019 01:09 am

Quick question and offish topic, why does CH4 have to be flared off and no other commonly used rocket fuel does?  The Delta (heavy?), lights a match and all the surplus H2 burns up the side of the rocket

NASA uses flare stacks for hydrogen.  see https://www.nasa.gov/sites/default/files/thumbnails/image/ksc-20161128-lc39b.jpg
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/16/2019 03:35 am

Quick question and offish topic, why does CH4 have to be flared off and no other commonly used rocket fuel does?  The Delta (heavy?), lights a match and all the surplus H2 burns up the side of the rocket

NASA uses flare stacks for hydrogen.  see https://www.nasa.gov/sites/default/files/thumbnails/image/ksc-20161128-lc39b.jpg

It's also no big deal to release H2 that's diluted enough to be non explosive, while Methane is a particularly nasty greenhouse gas.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/16/2019 03:46 am
It's a valid question though, why isn't the CH4 reliquified? They worked the trades and flaring it is cheaper and more efficient, but it makes no sense to me. (That's because I didn't work the trades and am going on gut).

How much are the optics of not flaring it off worth? Flaring it generates greenhouse gases.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/16/2019 06:03 am
It's a valid question though, why isn't the CH4 reliquified? They worked the trades and flaring it is cheaper and more efficient, but it makes no sense to me. (That's because I didn't work the trades and am going on gut).

How much are the optics of not flaring it off worth? Flaring it generates greenhouse gases.
With subcooled methane there's probably not enough vent gas to justify all the re-liquification gear they'd need. And it might not be pure enough to reuse as fuel without re-refining.
 That study is fairly meaningless because the natural gas they flare in huge amounts isn't pure Methane by a long shot. There's none of the sulfur that causes most of the problems, and the nitrogen oxides can be controlled by the way you flare.
 The study actually has absolutely no numbers comparing flaring versus methane release. Just the usual "Acid rain" cliches.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: freddo411 on 02/16/2019 07:20 am

Unless we are discussing building metropolitan scale power plants, I find it tiresome to measure the value of things by relative greenhouse gas effects.   It's not a useful metric.   It's all in the noise and it's holding smart people back from spending brain cycles on issues that make sense.

Insert joke about McGregor cows here.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AndyH on 02/16/2019 07:44 am

Unless we are discussing building metropolitan scale power plants, I find it tiresome to measure the value of things by relative greenhouse gas effects.   It's not a useful metric.   
It's only a useful metric if we think that it's important for humans to be around to build things like rockets, and endeavor to become multi planetary before our food sources become extinct.

Nomad's right - it's better to burn the methane.  Once burned, it becomes an additional source of fossil carbon in the atmosphere.  Unburned, it does 25-30* times more damage as a greenhouse gas until it degrades into CO2 and...becomes an additional source of fossil carbon in the atmosphere.

edit...or 85 times.  https://www.edf.org/climate/methane-other-important-greenhouse-gas (https://www.edf.org/climate/methane-other-important-greenhouse-gas)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 02/16/2019 08:23 am
Can we move to a more relevant topic? Thousands of SSH’s worth of methane released into the atmosphere don’t even touch a single volcanic eruption like anak krakatau, and there are hundreds of eruptions a year. So let’s get back to BFH.

Elon tweeted that they would put header tanks in SS, but in a “simpler configuration.” Any need to try this on BFH?

Would that configuration just be an additional set of bulkheads making the two part tank into a four part tank? If so, that might be more or less weight than a smaller set of header tanks?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/16/2019 09:21 am
I still think the shorter, higher diameter pipes going inside in a sharp bend right over the GSE ports are the fill pipes. Filling bottom up.

Seems it is so. The question remains about two external pipes rising from GSE connectors to the top of dome (LOX?) and to the entry point near the lower hatch (LM?). Could it be for replenishing tanks after main filling lines are closed?

Fragments from bocachicagal's photos:
https://forum.nasaspaceflight.com/index.php?topic=47120.msg1911246#msg1911246
https://forum.nasaspaceflight.com/index.php?topic=47120.msg1911415#msg1911415
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cmoorelife on 02/16/2019 11:45 am
How close is the site to what was proposed?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/16/2019 11:54 am
The question remains about two external pipes rising from GSE connectors to the top of dome (LOX?) and to the entry point near the lower hatch (LM?). Could it be for replenishing tanks after main filling lines are closed?

Possible. If my guess about the line up to the very top being CH4 gas drain is correct, the port sides would be exactly the opposite way than you labeled them. But your idea would explain why there are 2 medium diameter pipes going up the outer sides.

How is topping off normally handled? Do they close the main filling lines and use secondary lines in other rockets?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/16/2019 12:35 pm
Ultimately the re-liquification hardware is going to be right on SS for ISRU, so a more robust non-flight version seems to be a no brainier.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/16/2019 01:00 pm
How is topping off normally handled? Do they close the main filling lines and use secondary lines in other rockets?

Probably they use one RP-1 pipe and one LOX pipe on Falcon 9. But they could have some reasons to change it on the BFH. For instance, to use powerful pumps for the fast fueling and ordinary pumps to maintain fuel/oxidizer levels.

Or maybe these smaller pipes will be used for separate filling of header tanks?

As for the port labels, I assume the LOX tank is above the LM tank, in accordance to Elon's chart:
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rakaydos on 02/16/2019 01:32 pm
Re: Simpler header tank layout for starship.

The only simpler configuration I can think of is two tanks, one on either side of the pipe from the upper tank.
Or perhaps 4 tanks, for redundancy, circling the upper tank pipe. Anyone got other ideas?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: launchwatcher on 02/16/2019 01:35 pm
Nomad's right - it's better to burn the methane.  Once burned, it becomes an additional source of fossil carbon in the atmosphere.  Unburned, it does 25-30* times more damage as a greenhouse gas until it degrades into CO2 and...becomes an additional source of fossil carbon in the atmosphere.

edit...or 85 times.  https://www.edf.org/climate/methane-other-important-greenhouse-gas (https://www.edf.org/climate/methane-other-important-greenhouse-gas)
The relationship between the two isn't linear because atmospheric methane slowly decomposes into water and CO2).   I've seen a warming factor of 25-30x cited for a 100-year timespan, 85x-100x for a 20-year timespan, but at either value it's clear that you're better off flaring it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/16/2019 02:28 pm
Re: Simpler header tank layout for starship.

The only simpler configuration I can think of is two tanks, one on either side of the pipe from the upper tank.
Or perhaps 4 tanks, for redundancy, circling the upper tank pipe. Anyone got other ideas?

Two concentric tubes probably?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/16/2019 02:57 pm
So trying to shoehorn this thing into a familiar fruit (apples to apples), by my simple math, when the BFH finally lights her three Raptors it will be roughly the equivalent of a Falcon7 - just trying to provide Nomadd and BCGal an idea of the show they’ll get.
And you guys live about 1.7 miles from the pad, right? 1.3MM lbs of thrust. Oh boy!

I was at the QM-1 test fire of one of the SLS five segment boosters in Utah a few years ago, at three miles away it was pretty damn impressive. Granted that sucker had almost three times the thrust, but still - you’re in for quite the show!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 02/16/2019 03:00 pm
Ultimately the re-liquification hardware is going to be right on SS for ISRU, so a more robust non-flight version seems to be a no brainier.

And if you’re going to have to use liquefaction hardware on Mars it might well be useable as a means to chill propellants in flight if there's excess beyond what will fit into the header tanks on the journey between Earth and Mars. And also as a means to sub cool the methane before re-entry. Bit of an extra chill factor might not go amiss, although in the grand scheme of things probably not that significant, but if you can do it why not.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/16/2019 03:13 pm
So trying to shoehorn this thing into a familiar fruit (apples to apples), by my simple math, when the BFH finally lights her three Raptors it will be roughly the equivalent of a Falcon7 - just trying to provide Nomadd and BCGal an idea of the show they’ll get.
And you guys live about 1.7 miles from the pad, right? 1.3MM lbs of thrust. Oh boy!

I was at the QM-1 test fire of one of the SLS five segment boosters in Utah a few years ago, at three miles away it was pretty damn impressive. Granted that sucker had almost three times the thrust, but still - you’re in for quite the show!
I'm replacing my Woodstock era windows with tempered glass. I keep waiting for SpaceX to come by and assist, but nothing yet.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/16/2019 03:18 pm
So trying to shoehorn this thing into a familiar fruit (apples to apples), by my simple math, when the BFH finally lights her three Raptors it will be roughly the equivalent of a Falcon7 - just trying to provide Nomadd and BCGal an idea of the show they’ll get.
And you guys live about 1.7 miles from the pad, right? 1.3MM lbs of thrust. Oh boy!

I was at the QM-1 test fire of one of the SLS five segment boosters in Utah a few years ago, at three miles away it was pretty damn impressive. Granted that sucker had almost three times the thrust, but still - you’re in for quite the show!
I'm replacing my Woodstock era windows with tempered glass. I keep waiting for SpaceX to come by and assist, but nothing yet.
You’re ruining my mental image of your home. I pictured it something analogous to places I visited while mountain biking in Peru in 1987 (ignore my buddy and I choking each other out in that on picture...)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 02/16/2019 03:25 pm
I'm replacing my Woodstock era windows with tempered glass. I keep waiting for SpaceX to come by and assist, but nothing yet.
I used to think that Broken Windows Policing meant the Police would come by and help replace your broken windows.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Niavok on 02/16/2019 03:34 pm
The question remains about two external pipes rising from GSE connectors to the top of dome (LOX?) and to the entry point near the lower hatch (LM?). Could it be for replenishing tanks after main filling lines are closed?

Both pipe seem robust and connected to the very top of each tank (https://pbs.twimg.com/media/DzaxvvRVsAAKU0L.jpg:large (https://pbs.twimg.com/media/DzaxvvRVsAAKU0L.jpg:large)). To me, it look like pipe for the autogenous pressurization so they will contain warm gas when the engines are running but they can be very cold during fueling, by conduction. As it's the only warm part of the rocket (except the engine) it may explain the need of dilatation corners for the thermal expansion.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/16/2019 03:48 pm
Re: Simpler header tank layout for starship.

The only simpler configuration I can think of is two tanks, one on either side of the pipe from the upper tank.
Or perhaps 4 tanks, for redundancy, circling the upper tank pipe. Anyone got other ideas?

- One spherical header tank in the main LOX tank with a single propellant line (double walled for safety) down through the CH4 tank exiting out the bottom of the CH4 tank at its center.

- One toroidal header tank in the CH4 main tank with 6 down lines arranged around the bottom of the toroidal tank exiting out the bottom of the CH4 tank around its center.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/16/2019 04:01 pm
To me, it look like pipe for the autogenous pressurization
Still your hypothesis doesn't explain why these pipes are connected to GSE ports...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Niavok on 02/16/2019 04:26 pm
To me, it look like pipe for the autogenous pressurization
Still your hypothesis doesn't explain why these pipes are connected to GSE ports...

Hum ... maybe there are connected to both the GSE ports and the engines. Just before engine startup, the tank may need some external initial pressurization and the GSE can provide some gazeous CH4/O2 with these ports (if the CH4/02 are not at boiling temperature yet, the gazeous CH4/O2 will slowly condensate, reducing the pressure). As soon as the engines start, the GSE will disconnect to let the engines take care about the pressurization. Sound possible ?

About the GSE connection, will it be a umbilical kind connection allowing to load or unload the BFH at distance or someone will need to approach the fueled BFH in case of scrub ? (how was it done with the grasshopper ?)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 02/16/2019 05:01 pm
I was just wondering why much of the dome was not dressed out on the ground then lifted and welded in place.  It seams like it would have been easier and safer.  Perhaps some components were not available in time and they were just trying to maintain schedule.  If it was schedule driven, it would be very understandable.  If we get to see the next vehicle being constructed it will be interesting to see if the sequence of events is modified.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/16/2019 05:38 pm
To me, it look like pipe for the autogenous pressurization
Still your hypothesis doesn't explain why these pipes are connected to GSE ports...

Hum ... maybe there are connected to both the GSE ports and the engines. Just before engine startup, the tank may need some external initial pressurization and the GSE can provide some gazeous CH4/O2 with these ports (if the CH4/02 are not at boiling temperature yet, the gazeous CH4/O2 will slowly condensate, reducing the pressure). As soon as the engines start, the GSE will disconnect to let the engines take care about the pressurization. Sound possible ?

Sounds possible.

So, we have some assumptions on these pipes:
1) secondary fill lines for the main tanks,
2) fill lines for the header tanks,
3) lines for the autogenous pressurization,
4) lines for gaseous methane drain to the flare stack.

Now we should wait the correct answer.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 02/16/2019 07:30 pm
Re: Simpler header tank layout for starship.

The only simpler configuration I can think of is two tanks, one on either side of the pipe from the upper tank.
Or perhaps 4 tanks, for redundancy, circling the upper tank pipe. Anyone got other ideas?

- One spherical header tank in the main LOX tank with a single propellant line (double walled for safety) down through the CH4 tank exiting out the bottom of the CH4 tank at its center.

- One toroidal header tank in the CH4 main tank with 6 down lines arranged around the bottom of the toroidal tank exiting out the bottom of the CH4 tank around its center.

I like the spherical LOX header but the toroidal methane tank sounds complex. Especially with 6 downcomers. Why not just another offset sphere or cylinder with a single downcomer? If it’s right next to the LOX downcomer it should be close enough to keep center of mass relatively close to the middle.

Alternatively you could do two vertical cylinders inside the methane tank, just beside the LOX downcomer, one for LOX, the other methane, with direct drains to the main manifolds.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 02/16/2019 07:52 pm
Re: Simpler header tank layout for starship.

The only simpler configuration I can think of is two tanks, one on either side of the pipe from the upper tank.
Or perhaps 4 tanks, for redundancy, circling the upper tank pipe. Anyone got other ideas?

- One spherical header tank in the main LOX tank with a single propellant line (double walled for safety) down through the CH4 tank exiting out the bottom of the CH4 tank at its center.

- One toroidal header tank in the CH4 main tank with 6 down lines arranged around the bottom of the toroidal tank exiting out the bottom of the CH4 tank around its center.

I like the spherical LOX header but the toroidal methane tank sounds complex. Especially with 6 downcomers. Why not just another offset sphere or cylinder with a single downcomer? If it’s right next to the LOX downcomer it should be close enough to keep center of mass relatively close to the middle.

Alternatively you could do two vertical cylinders inside the methane tank, just beside the LOX downcomer, one for LOX, the other methane, with direct drains to the main manifolds.

- Two CH4 header tanks on either side of the downcomer would work as well. Then each CH4 header tank would only need to feed 3 engine section manifolds.

- I am assuming 6 engine segments each containing 5 engines with one in the middle.

- The Toroidal tank would simplify the manifolding but complicate the tank. Could be either or something completely different. Who knows? Wait, SpaceX knows.

- Header tanks will likely go back to spherical since they are most likely going to be made from Stainless Steel and not Carbon fibre composite.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/16/2019 08:15 pm
Nomad's right - it's better to burn the methane.  Once burned, it becomes an additional source of fossil carbon in the atmosphere.  Unburned, it does 25-30* times more damage as a greenhouse gas until it degrades into CO2 and...becomes an additional source of fossil carbon in the atmosphere.

edit...or 85 times.  https://www.edf.org/climate/methane-other-important-greenhouse-gas (https://www.edf.org/climate/methane-other-important-greenhouse-gas)
The relationship between the two isn't linear because atmospheric methane slowly decomposes into water and CO2).   I've seen a warming factor of 25-30x cited for a 100-year timespan, 85x-100x for a 20-year timespan, but at either value it's clear that you're better off flaring it.

better off flaring than venting, for sure (also less potential fire hazard. My point about not flaring wasn't about how much greenhouse gas actually is emitted, but rather the optics of it. Sometimes really really irrelevant numbers get blown way out of proportion in the media.... Elon has said he wants everyone on his side (not in so many words but he did). if you argue that the numbers are really really small, you already missed my point. 

Reliquefaction may not be cost efficient but it's needful eventually, on Mars. Maybe they can add it later but flaring is quick and easy.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 02/16/2019 08:29 pm
Reliquefaction may not be cost efficient but it's needful eventually, on Mars. Maybe they can add it later but flaring is quick and easy.
By the same token, it might make sense to do ISRU at Boca, to establish that it works and that methane produced and burned/leaked/flared does not represent a net increase in methane  in the atmosphere.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 02/16/2019 08:35 pm
Reliquefaction may not be cost efficient but it's needful eventually, on Mars. Maybe they can add it later but flaring is quick and easy.
By the same token, it might make sense to do ISRU at Boca, to establish that it works and that methane produced and burned/leaked/flared does not represent a net increase in methane on in the atmosphere.

I can't see any ISRU happening at Boca anytime soon. The whole methane release with respect to the hopper (or the Starship/Superheavy for that matter) is a non-issue due to its minuscule scale.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/16/2019 08:51 pm
 There could be a non routine reason for the flare too. If a pump or something fails while defueling, or they can't maintain a liquid state for any reason, they might have to get rid of a lot of methane fast.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 02/16/2019 10:08 pm
There could be a non routine reason for the flare too. If a pump or something fails while defueling, or they can't maintain a liquid state for any reason, they might have to get rid of a lot of methane fast.

Sure, but still utterly miniscule from a world greenhouse gas perspective.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 02/16/2019 11:02 pm
There could be a non routine reason for the flare too. If a pump or something fails while defueling, or they can't maintain a liquid state for any reason, they might have to get rid of a lot of methane fast.

Sure, but still utterly miniscule from a world greenhouse gas perspective.
Yes, minuscule until you are launching many hundreds of rockets per year.  But that may not be the perception of the public.  The point was that Elon is concerned with public opinion.  Also, demonstrating ISRU would educate people about the Mars mission and the requirement to make fuel.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/16/2019 11:12 pm
There could be a non routine reason for the flare too. If a pump or something fails while defueling, or they can't maintain a liquid state for any reason, they might have to get rid of a lot of methane fast.

Sure, but still utterly miniscule from a world greenhouse gas perspective.
Sorry - and not to take away from this thread, but it’s this kind of mindset that is so upsetting.

Do the best you can - regardless of the percentage of benefit it’s perceived to be. We all need to be responsible caretakers of our home.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 02/16/2019 11:38 pm
There could be a non routine reason for the flare too. If a pump or something fails while defueling, or they can't maintain a liquid state for any reason, they might have to get rid of a lot of methane fast.

Sure, but still utterly miniscule from a world greenhouse gas perspective.
Sorry - and not to take away from this thread, but it’s this kind of mindset that is so upsetting.

Do the best you can - regardless of the percentage of benefit it’s perceived to be. We all need to be responsible caretakers of our home.

I cannot advocate for hamstringing the West with excessive costs for minimal benefits while everyone else continues on giving less than zero care about the damage they're doing with rapid and unrepentant industrialization with primitive and highly polluting industrial activity.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 02/17/2019 01:08 am
Some very good points. I would agree we should all do our bit, but some bits are easier to do than others and rockets for Mars that need to use methane are especially problematic. It might be beneficial to consider some form of ISRU generating methane and consuming CO2 as good public relations (that would actually help greenhouse gas emissions in a small way) but suspect it would be challenging.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 02/17/2019 01:34 am
Finally - and this again is just my opinion - but I have to say it: There is a ZERO percent chance this thing will fly without the hat. Absolutely zero.

I understand this is an enthusiast forum and some of the fun is making predictions and seeing how it plays out but I will never understand the willingness of people on here to put absolute predictions into writing. It's a strange game of certainty chicken where both parties just double down until somebody is proven wrong. Thanks for the insight in the rest of your post though.


I think Johnny is right but for different reasons. I dont say it with certainty as he would. But still, the hopper without the nose would have a very strong tendency to flip upside down when the airstream is reversed, meaning when it is coming down. I think the nose must be there to be airodynamically stable. The shiny finish is just SpaceX being SpaceX and make structural element look pretty for practically the same cost as one that would be ugly. So why not? But I also think, the hat must be there. I have been proven wrong before, so no definite statement from me.
Yes, the hopper is bottom heavy but also has most of its drag in the bottom part.
If you tip it 45 degree sideways drag will not increase a lot. This changes a lot with the hat.

Yes you also reduces air resistance going up. but this is an minor thing and you could do with an shorter hat.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: mme on 02/17/2019 01:58 am
Musk has already said that they will eventually produce methane to become carbon neutral. To do that you need a lot of carbon neutral power or it's a charade. SpaceX needs to get this beast flying, I am confident they will shift to carbon neutral production. I agree they will need to address it publicly at some point because people are not naturally numerate.

<rant>
As for "hamstringing the west" - I lived in a developing nation for a year and to put the onus on them to clean up first and faster than the developed world is ridiculous. Life is much, much, much harder in the developing world and we've profited mightily off of it. And even though China has over 4 times our population it only produces twice the greenhouse gasses. India also has over 4 times the US population and produces 1/4 of the greenhouse gasses. The European Union has 1.5 times the population of the US and produces about 2/3 of the greenhouse gasses.

We need to seriously invest in our infrastructure anyway. We can invest in the future or we can invest in the past. Both cost money, it just goes to different people.
</rant>
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AndyH on 02/17/2019 02:05 am
I cannot advocate for hamstringing the West with excessive costs for minimal benefits while everyone else continues on giving less than zero care about the damage they're doing with rapid and unrepentant industrialization with primitive and highly polluting industrial activity.
Respectfully, absolutely nothing about this conversation has anything to do with 'hamstringing' anyone for any reason.

I personally find it useful to remember that 1. the west (and especially the USA) was and continues to be the primary source of pollutants overall and greenhouse gasses in particular since at least the industrial revolution, and  2. while some might feel more comfortable ignoring the US's...contribution...to the problem and point fingers at the rising East, they're forgetting for whom most of those things are being manufactured.  In other words, the west broke it and that means it's up to us to fix it.

I honor the folks here that understand the above, and also grok that SpaceX and her sister companies march to a different drummer.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 02/17/2019 02:55 am
For those that wish to discuss Carbon Footprints, can you please move to a splinter thread?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AJW on 02/17/2019 03:18 am
I'm replacing my Woodstock era windows with tempered glass. I keep waiting for SpaceX to come by and assist, but nothing yet.

On the topic of living near launch sites, my friend in Titusville didn't mind the noise from the launches, but she hated how her old windows would rattle.  On her 50's era home, the caulk in the windows would dry out and loosen and the glass panes would vibrate and make a horrible noise during launches.   She had a regular windows repair guy who would come out and re-caulk her windows whenever the rattling got too bad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 02/17/2019 05:29 am
For those that wish to discuss Carbon Footprints, can you please move to a splinter thread?

I don't think there's any way to keep that subject sufficiently on the topic of spaceflight to have a thread for it on this forum.

But for what's still on topic, access to energy is everything; without energy, you can't produce refined fuels. Without energy, you can't transport advanced industrial products across the country. Without energy, you can't hope to synthesize methane from carbon neutral sources. Worst of all, without abundant energy, you can't hope to chill and condense gasses into liquids, which is a very energy intensive process. Capturing methane from boiloff and re-condensing it probably represents a net loss of energy reserves and increased CO2 production over flaring it off.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/17/2019 07:45 am
To turn this discussion more close to the topic. Probably we can see the vent for the methane on the last bocachicagal's photos (upper pipe):
https://forum.nasaspaceflight.com/index.php?topic=47120.msg1912089#msg1912089
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris Bergin on 02/17/2019 01:05 pm
Yeah, back on topic guys and gals. We never had methane concerns being noted on the McGregor thread.

#RocketCows ;)

Hopper. Talk about Hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: maryalice on 02/17/2019 06:19 pm
….is a Hopper a Bullfrog?......then what about instead of grasshoppa,,bullfrog?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: alang on 02/17/2019 08:12 pm
I'm replacing my Woodstock era windows with tempered glass. I keep waiting for SpaceX to come by and assist, but nothing yet.

On the topic of living near launch sites, my friend in Titusville didn't mind the noise from the launches, but she hated how her old windows would rattle.  On her 50's era home, the caulk in the windows would dry out and loosen and the glass panes would vibrate and make a horrible noise during launches.   She had a regular windows repair guy who would come out and re-caulk her windows whenever the rattling got too bad.

I once asked what the practice is in earthquake zones. I still don't know.
Advanced economies like Japan and California must have to deal with this issue regularly. I wonder what solutions they have arrived at. Perhaps they have casement double/triple glazing like cold climates with different kind of fixing than putty/caulk.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 02/18/2019 12:42 pm
Those square penetrations for the cable/piping runs appear to have no provision for installing any sort of liquid seal, so must be entering a 'dry' space rather than directly into a tank. Either Starhopper has much shorter tanks than assumed (with them sitting 'up high' rather than 'down low'), or it lacks the assumed common bulkhead and has a circumferential 'dead space' between two discrete tanks.

(Image edited from BocaChicaGal's post here (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1911415#msg1911415))
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: StuffOfInterest on 02/18/2019 12:58 pm
Those square penetrations for the cable/piping runs appear to have no provision for installing any sort of liquid seal, so must be entering a 'dry' space rather than directly into a tank. Either Starhopper has much shorter tanks than assumed (with them sitting 'up high' rather than 'down low'), or it lacks the assumed common bulkhead and has a circumferential 'dead space' between two discrete tanks.

I would wager on smaller tanks mounted up high.  First, you don't need the entire base filled with fuel and oxidizer for the type of hop tests that will be occurring.  Second, putting the tanks up high will move the center of mass higher to give a better simulation of the handling characteristics of Starship.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SPadre on 02/18/2019 03:04 pm
Took a kid and his family who are visiting South Padre Island to Boca Chica a couple days ago, should have seen his face when he saw Hopper! His mom said he was missing out on his class participating in the Challenger Learning Center Mars Mission, so I said well I have an idea, lets take him to the real Mars rocket and he can skype and join the class from there! Funny little fella, hope you enjoy this video!

https://www.youtube.com/watch?v=Bl5Tfwmhk0Y
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WTF on 02/18/2019 04:25 pm
" ...  much shorter tanks ..."  and " ... or it lacks the assumed common bulkhead and has a circumferential 'dead space' between two discrete tanks. ..."

I think both of you ( edzieba and StuffOfInterest) are on something.

The Phase One Hopper ... simplicity and speed of fabrication seems to be at the top of the to do list,

Perhaps both header tanks are mounted above and to the left and right of the three raptors ... makes for some simplified piping to the three raptors.

And an idle suggestion ... run the piping from the main LOX tank to the LOX header tank inside the fin that does not move ... call it the dorsal fin. Avoids complicating the structure of the main CH4 tank.

And a quite idle comment. I have quite a unique experience in piping.  Back in the day,  I set fire to my toilet.

Any feedback welcome by the NSF community.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/18/2019 05:09 pm
Those square penetrations for the cable/piping runs appear to have no provision for installing any sort of liquid seal, so must be entering a 'dry' space rather than directly into a tank. Either Starhopper has much shorter tanks than assumed (with them sitting 'up high' rather than 'down low'), or it lacks the assumed common bulkhead and has a circumferential 'dead space' between two discrete tanks.

(Image edited from BocaChicaGal's post here (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1911415#msg1911415))

Actually your diagram shows the LOX + methane tanks total height is ~5.7m and distance between lowest point of the methane tank to lower edge of the hopper to be ~3.3m, this is pretty close to my previous estimate here (https://forum.nasaspaceflight.com/index.php?topic=47113.msg1905446#msg1905446): LOX tank height 2.4m, methane tank height 3.7m, total tanks height 6.1m, distance between lowest point of the methane tank to lower edge of the hopper 3.3m. My estimate assumed common bulkhead, total propellant load would be 454t.

Rough rule of thumb for my estimate: top half of the hopper height (without top dome) is LOX + methane tank, the lower half is roughly equally divided between lower dome and engine compartment.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Alias on 02/18/2019 06:21 pm
 ??? first time i've ever heard of that happening , how did you do that?
" ...  much shorter tanks ..."  and " ... or it lacks the assumed common bulkhead and has a circumferential 'dead space' between two discrete tanks. ..."

I think both of you ( edzieba and StuffOfInterest) are on something.

The Phase One Hopper ... simplicity and speed of fabrication seems to be at the top of the to do list,

Perhaps both header tanks are mounted above and to the left and right of the three raptors ... makes for some simplified piping to the three raptors.

And an idle suggestion ... run the piping from the main LOX tank to the LOX header tank inside the fin that does not move ... call it the dorsal fin. Avoids complicating the structure of the main CH4 tank.

And a quite idle comment. I have quite a unique experience in piping.  Back in the day,  I set fire to my toilet.

Any feedback welcome by the NSF community.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: freddo411 on 02/18/2019 08:25 pm

And a quite idle comment. I have quite a unique experience in piping.  Back in the day,  I set fire to my toilet.

Any feedback welcome by the NSF community.

Seems like a non-optimal toilet design and/or feature.   
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WTF on 02/18/2019 09:00 pm
Exceeded design parameters of the hardware  ... some elaboration forthcoming on the party thread.

Moving back to the topic of Phase 1 Big Falcon Hopper (BFH, I note a scissors jack in a couple of photos at the base of the Hopper ... Appears its platform is deployed past the lower edge of the hopper. Perhaps indicating there is substantial space between the main CH4 tank and bottom of the Hopper ... perhaps '3.1 meters' (thank you SU27k).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: psherriffs on 02/18/2019 09:06 pm
WTF: seems your experience with plumbing is similar to my own. Has anyone made a diagram(s) of how the tanks might be arranged inside? I have a hard time picturing it. At first I thought one of them might be going in the nose section.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MKremer on 02/18/2019 09:11 pm
Moving back to the topic of Phase 1 Big Falcon Hopper (BFH, I note a scissors jack in a couple of photos at the base of the Hopper ... Appears its platform is deployed past the lower edge of the hopper. Perhaps indicating there is substantial space between the main CH4 tank and bottom of the Hopper ... perhaps '3.1 meters' (thank you SU27k).
It's too bad we won't get to see the thrust structure taking shape underneath there.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WTF on 02/18/2019 10:44 pm
" ... the thrust structure taking shape underneath there. ..."

In my humble opinion ... as humble as anyone who has ever set a toilet afire, I offer the following speculation regarding the configuration of the tankage:

From top to bottom of the Phase 1 Hopper ...
Main LOX tank with a couple of COPV tanks on top, nothing substantial in the 'Hat"
Main CH4 tank underneath, perhaps common bulkhead between the two, perhaps not.
Both header tanks next ... one on each side of the line of three Raptors.
The three Raptors are in line. The line is through the center of the Hopper ... central Raptor gymbals.

Questions  follow:

How does SpaceX reconcile a triangular fin/leg structure and cylindrical Hopper with three Raptors that are in line?
I'll most certainly defer to the NSF community on this detail.

How does the LOX flow from the main LOX tank to the LOX header tank?
My speculation is thru the 'dorsal' fin. Which does not move  ... the integrity of the CH4 tank is not compromised.
This is assuming there is no common bulkhead between the main tanks.

RCS and or the movement of two of the fins ?
Will either be implemented during Phase 1 testing ?
Well under 200 meters height in Phase 1 ...and Grasshopper did neither throughout its entire testing program, relying on gymbaling.Yet there are those pipes added those fins, one to each. Control mechanism?

I'll leave it at this, comments are welcome and undoubtedly needed ... I might go do a FRR on my toilet.




Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/18/2019 11:25 pm
Just a couple pics from today.

Are they now making the dome top shiny? Why would they do that? Hatless Hopping after all? Any functional reason to do this?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: flyright on 02/18/2019 11:37 pm
Just a couple pics from today.

Are they now making the dome top shiny? Why would they do that? Hatless Hopping after all? Any functional reason to do this?

Insulation?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 02/18/2019 11:52 pm
I'm confused. Is that two tanks or one?

What happened to the middle bit with the portholes? Did it get trashed with the "fairing"?

Wasn't that the second tank? That goes over the dome, right?

They've gotta make another one of those before this thing will fly, don't they?

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: 50_Caliber on 02/19/2019 12:58 am
Just a couple pics from today.

Are they now making the dome top shiny? Why would they do that? Hatless Hopping after all? Any functional reason to do this?

Looks more like a reflective adhesive, not the stainless steel plates on the hull.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Alias on 02/19/2019 01:17 am
I'm confused. Is that two tanks or one?

What happened to the middle bit with the portholes? Did it get trashed with the "fairing"?

Wasn't that the second tank? That goes over the dome, right?

They've gotta make another one of those before this thing will fly, don't they?
two tanks you can see the bulkhead through the lower access here, the portholes were on the faring edzieba missed the bulkhead on the diagram he posted
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/19/2019 01:22 am
I'm confused. Is that two tanks or one?

What happened to the middle bit with the portholes? Did it get trashed with the "fairing"?

Wasn't that the second tank? That goes over the dome, right?

They've gotta make another one of those before this thing will fly, don't they?


2
 yes
 no
 no
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 02/19/2019 01:24 am
Whew!  ;D

LOX on the top or the bottom?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Alias on 02/19/2019 01:36 am
top
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Semmel on 02/19/2019 04:40 am
top

How do you know?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Alias on 02/19/2019 01:26 pm
read the engineering thread
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Semmel on 02/19/2019 02:22 pm
When you hit 'quote' on the post you want to link, you can copy the text there and paste it into the answer of this thread. That way, you can directly reference the statement you want to reference.

And for being on topic, I know that the Starship has its LOX tank on top in the last design, same as SuperHeavy. But I dont remember a statement that this applies to the hopper as well, or where we have deduced that from images or other evidence. The engineering thread is long, so please link to the place we need to look or this information.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/19/2019 03:06 pm
Germaine to the Phase 1 BFH, I’d think LOX is on top because that T fitting on top of the dome looks like a vent and though I am at a loss as to how methane is (safely) vented, it would strike me as a LOX vent. My guess (because the T has protective covers over the ends, implying that the plumbing isn’t complete) is that there will be two lines run from  the T out to the sides of the hat once installed.

I’m a little concerned about the reflective sheets being bonded to the dome. As in, they are very thin so don’t think it’s insulation, but why pretty it up unless it’s not getting a hat...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 02/19/2019 03:40 pm
Germaine to the Phase 1 BFH, I’d think LOX is on top because that T fitting on top of the dome looks like a vent and though I am at a loss as to how methane is (safely) vented, it would strike me as a LOX vent. My guess (because the T has protective covers over the ends, implying that the plumbing isn’t complete) is that there will be two lines run from  the T out to the sides of the hat once installed.

I’m a little concerned about the reflective sheets being bonded to the dome. As in, they are very thin so don’t think it’s insulation, but why pretty it up unless it’s not getting a hat...

John... always love your insights and experience... my only guess is that the reflective Mylar film or possibly Kapton film would be for IR reflectance [like the foundry guy's protective gear] and possible static build-up mitigation? just a WAG!

Source Reference: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750006837.pdf (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750006837.pdf)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 02/19/2019 03:52 pm
Germaine to the Phase 1 BFH, I’d think LOX is on top because that T fitting on top of the dome looks like a vent and though I am at a loss as to how methane is (safely) vented, it would strike me as a LOX vent. My guess (because the T has protective covers over the ends, implying that the plumbing isn’t complete) is that there will be two lines run from  the T out to the sides of the hat once installed.

I’m a little concerned about the reflective sheets being bonded to the dome. As in, they are very thin so don’t think it’s insulation, but why pretty it up unless it’s not getting a hat...

One more possible explanation of the tee.
    As you are where, venting can occur when a spring loaded relief valve vents due to exceeding a preset pressure or a when a valve is commanded to open manually or remotely.  In both cases the thrust level produced in line with the pipe is relatively low and would not require a tee just an inline elbow.
    However, if there is any concern of a relief valve freezing or valve failing to actuate, a burst disc may be installed to prevent a catastrophic over pressurization.  The function of the burst disc is virtual instantaneous and Will result in a very high thrust load.  It is common practice to install a tee downstream of the disc to neutralize this load.  I too looked closely at the tee and can see a flange set that may house a burst disc assembly.  In any event. I agree that both sides of the tee will be needed to be plumbed overboard.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 02/19/2019 04:28 pm
I’m a little concerned about the reflective sheets being bonded to the dome. As in, they are very thin so don’t think it’s insulation, but why pretty it up unless it’s not getting a hat...

Why concern?  I'd think the hat would be made if there's time.  I've been assuming there's a lot of that with raptor testing still on-going, but if there's no hat, then surely that's good news wrt schedule? 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 02/19/2019 07:55 pm
Something new on the unfinished fin. Another overcast drizzly day here.

From BCG's latest pic of new gizmo's on the unfinished leg...

Looks to be a plate in which the landing gear will be attached... at least the shock absorber will receive pneumatic pressuerization... Expect a COPV to be tucked in behind that leg and fairing...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/19/2019 11:35 pm
I’m a little concerned about the reflective sheets being bonded to the dome. As in, they are very thin so don’t think it’s insulation, but why pretty it up unless it’s not getting a hat...

operation chrome dome on the hard head of the R2 unit
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rsdavis9 on 02/19/2019 11:56 pm
I’m a little concerned about the reflective sheets being bonded to the dome. As in, they are very thin so don’t think it’s insulation, but why pretty it up unless it’s not getting a hat...

operation chrome dome on the hard head of the R2 unit
reflect some of that hot Texas sun?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/20/2019 12:32 am
Something new on the unfinished fin. Another overcast drizzly day here.

Let's take a step back and look at those legs again.  What are they?  Heavy walled stainless steel cylinders capped at both ends.  Six large ones and six smaller brace tubes.  If some designer were enterprising they could use any of them as pressure vessels to hold pressurized gasses.  Probably not into the thousands of psi but likely at least in the high hundreds of psi.  Where do you need pressurized gasses?  Spinning up turbines perhaps?  Pressurizing tanks before Raptors get it done (either in the seconds before or on test flights before autogenous is hooked up), thrusters.  And how many tanks of various gasses have we seen onsite? (many)   Those two COPVs riding on top of R2s head may serve a specific purpose that requires very high pressure but their volume is no match for that of the leg tubes.  And using the leg tubes for pressure vessels comes at an even better price than no cost at all as the landing loads will be compressive (for the longer ones at least) and the pressure loads will be tensile, somewhat offsetting.

Now I direct your attention to BCG's picture herein zoomed to the area of interest.  Notice the tube extending to the right currently capped with red.  To my eye (its debatable) it ends about 2 tube diameters from the inner leg.  It wouldn't take much to flex that tube over out of the way while you drill a hole there and weld in a tube fitting.  What do you suppose?

So you've got a panel with six ports.  What could you do with that.  My guess(es) - Three of them to three tank chambers (one of the large tanks partitioned into two) in which case each of the three ports would have a connect fitting and a shutoff valve and three of them for pressure gauges / sensors.  Or maybe three of them to have connect fittings and the other three shutoff valves.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bogeyman on 02/20/2019 04:15 am
Maybe it has to do with the shock absorbing system for the legs?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: mattstep on 02/20/2019 04:25 am
Something new on the unfinished fin. Another overcast drizzly day here.

My guess is a mount for a camera or other instrumentation. Seems too flimsy to be part of a shock absorbing system.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SDSmith on 02/20/2019 09:43 am
Something new on the unfinished fin. Another overcast drizzly day here.

My guess is a mount for a camera or other instrumentation. Seems too flimsy to be part of a shock absorbing system.
They haven't added the ignition key yet.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/20/2019 10:17 am
Okay, so I’m loving this new development (of the panel mount plate welded to the top tube of the back leg). I’m not going to speculate, but just point out.

- small diameter HP lines. AND THEY BOTH APPEAR TO CONNECT DIRECTLY INTO THE BOTTOM TUBE!

Many more observations but no time. However that single point seems to be of incredible interest (to me).

Image lightened and area of interest circled.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Peter.Colin on 02/20/2019 11:54 am
So there are two “oval holes”, which most likely function as acces holes for the men working inside the tanks.
One is one the upper LOX tank, and one in the lower methane tank.
Whitout those manholes there is no way to enter the tanks and connect a new camera or add a new pipe or something.

If you look closely you can see the common bulkhead in the lower methane tank manhole (see first pic).

The two lines with a kink in them probably come from the raptor-engines (lox turbopump and engine bell) and are for autogenous pressurization of the two tanks
The kink in them is probably to accommodate for thermal expansion.
What’s interesting is that the pipe for autogenious methane pressure, is entering the methane tank totally at the top of the rim of this common bulkhead.

Edit: added some text in the pics
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/20/2019 12:25 pm
If you look closely you can see the common bulkhead in the lower methane tank manhole (see first pic).
From this one picture you can't rule out that the common bulkhead your seeing is just shadow play from the light source and curve of the manhole.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Niavok on 02/20/2019 01:57 pm
From the last pics, the small pipes could be the COPV's helium fill line. But why put it on the leg ?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/20/2019 03:55 pm
A pic of the same area. This pic was taken this morning.

The tubes just took a different turn.

Are we sure we as a forum are ready to sign off on zip ties being used for this?  Perhaps we should hold out for more secure securing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NH22077 on 02/20/2019 04:23 pm
A pic of the same area. This pic was taken this morning.

The tubes just took a different turn.

Are we sure we as a forum are ready to sign off on zip ties being used for this?  Perhaps we should hold out for more secure securing.

The flat edges of the brackets will cut through the zip ties due to launch vibration.
They should last a few launches, but I wouldn't use them on a production SS.

Ned 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris_Pi on 02/20/2019 06:27 pm

The flat edges of the brackets will cut through the zip ties due to launch vibration.
They should last a few launches, but I wouldn't use them on a production SS.

Ned

Possibly the plastic ones are temporary until all the piping is installed? From some photos F9 has stainless steel zipties through D-rings around the flexible engine boots. Those would hold up much better but must be a pain to cut if something needs to be moved around.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 02/20/2019 09:00 pm
NASA and JPL have flown lots of zip ties to Mars already, just sayin'... :-)

(Ok, not quite, but they tie up wire bundles on their rovers in quite a similar way.)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/20/2019 09:52 pm

The flat edges of the brackets will cut through the zip ties due to launch vibration.
They should last a few launches, but I wouldn't use them on a production SS.

Ned

Possibly the plastic ones are temporary until all the piping is installed? From some photos F9 has stainless steel zipties through D-rings around the flexible engine boots. Those would hold up much better but must be a pain to cut if something needs to be moved around.
Many years of running cables on ships, and coated stainless ties would be my guess once all the lines are in.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Zpoxy on 02/21/2019 12:09 am

The flat edges of the brackets will cut through the zip ties due to launch vibration.
They should last a few launches, but I wouldn't use them on a production SS.

Ned

Possibly the plastic ones are temporary until all the piping is installed? From some photos F9 has stainless steel zipties through D-rings around the flexible engine boots. Those would hold up much better but must be a pain to cut if something needs to be moved around.

Used plastic zip ties all the time in the space shuttle payload bay wire trays, no problem with vibration. I don't think I ever saw a broken one after a flight.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/21/2019 12:25 am
There's a big difference between wires and hydraulic/pneumatic lines.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bubbinski on 02/21/2019 12:38 am
Say, is there any word about how the nosecone repairs are going?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureSpaceTourist on 02/21/2019 08:56 am
Say, is there any word about how the nosecone repairs are going?

This may be a clue:

https://twitter.com/RogerLewisHolt/status/1098498277006286848

Quote
Cadwell the manufacturer of Water Storage Tanks just made a delivery at Boca Chica. This could be new stainless steel panels for the new nose cone being delivered! @John_Gardi
Credit📷Maria Pointer
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SPadre on 02/21/2019 12:59 pm
Updates from Boca Chica

https://www.youtube.com/watch?v=xIazoCEfF6k
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cheapchips on 02/21/2019 02:43 pm

The rods that just went into the concrete base were presumably from the Cadwell delivery this morning?  I'm expecting the nosecone to happen pretty rapidly based on last time.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/21/2019 03:07 pm
Updates from Boca Chica

https://www.youtube.com/watch?v=xIazoCEfF6k
From the video you can see they’ve made good progress plumbing the GSE attach points.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/21/2019 04:55 pm
I like that work platform... Every Texan has a pickup truck right?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/21/2019 05:31 pm
Updates from Boca Chica
From the video you can see they’ve made good progress plumbing the GSE attach points.

I would also hesitantly say that the tall metal thing between the two GSE terminators is the rainbird I said was going to terminate the water line run to the pad area. However can't say it with too much confidence.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Inoeth on 02/21/2019 05:38 pm
with the latest pics of the Caldwell truck and the metal rods being (re?)installed on the cement mount where hopper was first built, i'd say we're only a few days to perhaps a week or two at most before we see a new fairing...

At this point i'm thinking we'll see Hopper fly sometime in April at the earliest (perhaps that's too optimistic) or more likely May or even June... it really is interesting to see which will actually be ready first- the Raptor engines which have to be built and tested, the finishing of the hopper vehicle (eventually installing said engines) and the finishing of the actual launch pad... all of which are clearly progressing at a rapid pace.

I really hope we get a new Austin Barnard drone footage of the launch pad soon..
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: spacenut on 02/21/2019 05:44 pm
I like that work platform... Every Texan has a pickup truck right?

Either that or a horse. 

Does flying Hopper later than they wanted, mean flying the Starship prototype later than June?  Hopper has to completed hops and testing before they can fly Starship right?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 02/21/2019 08:16 pm
So they are going to build another nose cone and this time hold it (bolt it?) in place to safe it from the wind. Then if they need to remove it from the engine section maybe they can store it on the concrete base.

Could also be in preparation for lifting the Hopper back on the jig, lifted up a bit, so the footpads can be installed.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/21/2019 08:32 pm
Based on the pictures of the new fairing pieces on the update thread, looks like they are built and welded very differently.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/21/2019 08:39 pm
So according to the new pics from BCGal, the hat is frame-less. Much thicker stock and zero internal frame. At least, at the section level. Maybe internal strength member will be added when sections are joined, but this looks like a much sturdier build and once all joined should provide good shape holding support.


One thing to be said, SpaceX certainly seems to always learn and iterate whenever possible...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 02/21/2019 08:41 pm
Those new fairing sections look almost like the way you'd build a flight tank, except for some internal stiffeners.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MKremer on 02/21/2019 08:54 pm
So according to the new pics from BCGal, the hat is frame-less. Much thicker stock and zero internal frame. 
And pre-polished!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 02/21/2019 09:07 pm
Now THAT looks much better. I was getting seriously annoyed with the crinkly tin-foil look that made the Hopper appear a bit ridiculous and not awe-inspiring as it ought to.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/21/2019 09:18 pm
Fans: You need a better hold down system for your nosecone SpaceX!
SpaceX: No, we have so much room for mass growth, we will just build a sturdier nosecone.

At this point it really looks like pad and Hopper will beat the Raptors in terms of readyness. :D

[/edit] Oh and btw, looking at those nice, smooth, sturdy but not too thick evenly shaped sections... it sure looks more and more like a production Starship CAN be built at launch site from road transportable segments. Cause those ARE road transportable segments.

I would not even be surprised if they took the nosecone bits that were under preparation for the orbital test Starship and pulled them forward for the Hopper after losing Nose1. <- ( wild uninformed speculation ) [/edit]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Inoeth on 02/21/2019 09:47 pm
i don't know if the pad and hopper will beat the raptors or not...

Elon on Twitter earlier today say that they've tested the first Raptor to the point of mildly damaging it but plenty to be fixed/reused and that they're almost done building the second raptor which has already incorporated improvements... That to me says that they can build these engines in just a couple weeks... i'm sure they'll finish the second engine, test it a bit and then build the third engine with even more improvements... that to me says they could be done with the first three engines in perhaps a month or so from now... which could very well be right on time to be ready for the pad and hopper...

That being said, it's entirely possible they'll test the heak out these first couple engines and build new ones that'll actually fly on the hopper... tho it's equally possible and perhaps more likely that these first engines will end up on the hopper... The good news is that once they're happy with the engines, it's less than a day's drive from McGreggor to Boca Chica.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 02/21/2019 11:33 pm
Well they COULD fly the Hoppah with just one engine at first
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/21/2019 11:47 pm
Well they COULD fly the Hoppah with just one engine at first
They will.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 02/22/2019 01:34 am
Those new fairing sections look almost like the way you'd build a flight tank, except for some internal stiffeners.

[/edit] Oh and btw, looking at those nice, smooth, sturdy but not too thick evenly shaped sections... it sure looks more and more like a production Starship CAN be built at launch site from road transportable segments. Cause those ARE road transportable segments.

I would not even be surprised if they took the nosecone bits that were under preparation for the orbital test Starship and pulled them forward for the Hopper after losing Nose1. <- ( wild uninformed speculation ) [/edit]

Do we actually know this new "fairing" is for the hopper? Couldn't this be the start of the orbital prototype construction?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/22/2019 01:57 am
Do we actually know this new "fairing" is for the hopper? Couldn't this be the start of the orbital prototype construction?

Well, what do you think it more likely? The hopper isn't even finished, so why would they bring in parts of the next one?

I suppose it could also be for the third prototype, or fourth...  ;D No, Occams razor applies here.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Zed_Noir on 02/22/2019 02:14 am
Something just occur to me. Does the workers from Caldwell have to be vetted for ITAR? Since they are more or less building a sub-orbital rocket.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Robotbeat on 02/22/2019 02:18 am
Something just occur to me. Does the workers from Caldwell have to be vetted for ITAR? Since they are more or less building a sub-orbital rocket.
ITAR just means no exporting of stuff to non-citizens. Doesn't mean extra vetting beyond citizenship.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/22/2019 01:28 pm
While we wait for the next batch of amazing images and video to pour over, I thought I’d share a story that’s making the news today - though it’s one that’s been out for some time. It’s making the rounds now because of the China trade spat.

How Caldwell saved the Apple Mac Pro (paraphrased)...

https://www.google.com/amp/s/appleinsider.com/articles/19/01/28/a-custom-screw-was-the-bottleneck-in-us-mac-pro-production/amp/


I am assuming not the same Caldwell???  Or are they that big a conglomerate?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/22/2019 01:44 pm
While we wait for the next batch of amazing images and video to pour over, I thought I’d share a story that’s making the news today - though it’s one that’s been out for some time. It’s making the rounds now because of the China trade spat.

How Caldwell saved the Apple Mac Pro (paraphrased)...

https://www.google.com/amp/s/appleinsider.com/articles/19/01/28/a-custom-screw-was-the-bottleneck-in-us-mac-pro-production/amp/ (https://www.google.com/amp/s/appleinsider.com/articles/19/01/28/a-custom-screw-was-the-bottleneck-in-us-mac-pro-production/amp/)


I am assuming not the same Caldwell???  Or are they that big a conglomerate?
Ugh - different Caldwell. I am so peeved at myself I removed my post. I thought I had fact checked the company when I first read the story a few months ago. Never mind - carry on...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ngkiwi on 02/22/2019 06:23 pm
Well they COULD fly the Hoppah with just one engine at first
They will.


And tongue in cheek: Fly on one engine to McGregor and pick up the oher two straight off the test bed :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/22/2019 07:12 pm
Do we actually know this new "fairing" is for the hopper? Couldn't this be the start of the orbital prototype construction?

Well, what do you think it more likely? The hopper isn't even finished, so why would they bring in parts of the next one?

Because they have already a flying article to test Raptors in various operating regimes of flight and landing. This is the 'Starhopper'. It can make its job without fairing at all. (I've read arguments for the fairing - 'aerodynamics studies' - but I can't accept them for the low velocities of the proposed hopper tests.)

Now they could start build the 'Starship' prototype.

We are building the Starship prototypes locally at our launch site in Texas
https://twitter.com/elonmusk/status/1085679367374524417
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Norm38 on 02/22/2019 07:24 pm
Do they have room to build two at once?
And wouldn't they want to finish the first and get a sense of it (lessons learned etc) before starting the second?  Else they can't effectively iterate.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DJPledger on 02/22/2019 07:34 pm
Perhaps Raptor being able to generate more thrust than expected has given more mass margin for BFH allowing them to make the new fairing with thicker stainless steel for extra sturdiness. Just make sure that all the measures have been put in place to avoid the new fairing from getting blown over.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/22/2019 07:37 pm
Looking at BCGal's photos from today it looks like they're stacking containers for a wind break like they did when they first started building the "water tank" way back...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/22/2019 07:55 pm
I title this one, “Irony”...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: launchwatcher on 02/22/2019 08:15 pm
I title this one, “Irony”...
Looks like a Davis Vantage Pro2 automated weather station.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 02/22/2019 08:29 pm
Do they have room to build two at once?
And wouldn't they want to finish the first and get a sense of it (lessons learned etc) before starting the second?  Else they can't effectively iterate.

I assume this is a new top-hat.  That said, there's a pretty strong argument for building the full-up flight article sooner rather than later.  SpaceX itself said it already has "sufficient" experience building the booster, and the hopper's low-altitude flights are firmly in the booster-knowledge space.  The risk exists in those things that they've never done before:  flapperons, sweaty steel, in-space refueling, etc.  None of that is being tested with the first article.  If you're in a hurry, you go straight to testing the bits you're least sure of.  That's where the iteration will take place.  Presumably what you learn from the hopper is how the engines interact with the ground during landing, throttle responsiveness, etc.  I don't think you get a lot of hardware feedback from the hopper, it seems mostly for control software?

I would not be surprised if they strap on the dev engines to the hopper for a couple of go-arounds and start building a flight article in parallel.  Raptor engines come in, a couple more hopper tests and software tweaking, then straight to the flight article.

I don't think that's what is happening, but at this point, very little would surprise me.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/22/2019 08:38 pm
The camera hanging from the tent wall appears to have an odd angle if it is just a security cam. Is SpaceX preparing to give us a better Hopper construction live webcast angle? :D

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/22/2019 09:18 pm
The camera hanging from the tent wall appears to have an odd angle if it is just a security cam. Is SpaceX preparing to give us a better Hopper construction live webcast angle? :D

They're going to point it at my house.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DigitalMan on 02/22/2019 09:43 pm
The camera hanging from the tent wall appears to have an odd angle if it is just a security cam. Is SpaceX preparing to give us a better Hopper construction live webcast angle? :D

They're going to point it at my house.

I suggest get a nice BBQ going to make them jealous.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: uncas on 02/22/2019 09:54 pm
The camera hanging from the tent wall appears to have an odd angle if it is just a security cam. Is SpaceX preparing to give us a better Hopper construction live webcast angle? :D

They're going to point it at my house.
Turnabout's fair play, eh?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 02/22/2019 11:40 pm
What's the deal with the new cheese graters on the hopper legs?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: tyrred on 02/23/2019 09:24 am
What's the deal with the new cheese graters on the hopper legs?

(west world fan on)
It doesn't look like anything to me.
(west world fan off)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 02/23/2019 10:20 am
What's the deal with the new cheese graters on the hopper legs?

As some proposed higher up in the thread, appears to be mounting plates for gauges/valves for some pressurant into or near the legs, likely for the landing shock absorbers.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/23/2019 10:28 am
What's the deal with the new cheese graters on the hopper legs?

As some proposed higher up in the thread, appears to be mounting plates for gauges/valves for some pressurant into or near the legs, likely for the landing shock absorbers.
No - ZChris13 isn’t referring to the bulkhead panel on the back leg with the plumbing running to it, he’s referring to the things that have been attached to the lower tube of all the legs. I’ve circled them in the image below.

And I for one have no idea, and I love it! It’s an odd development.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/23/2019 11:48 am
[guess] Mounting points. Those are bolt holes, a clamp goes round, bolts go through. The clamp holds a flexible/swinging part of the shock absorbing feet. [/guess]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/23/2019 01:03 pm
[guess] Mounting points. Those are bolt holes, a clamp goes round, bolts go through. The clamp holds a flexible/swinging part of the shock absorbing feet. [/guess]
If so, what size bolts do you think fit in there?  And how thick is that plate?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/23/2019 01:14 pm
Oof you ask me to measure thickness from photos? :D Well based on the worker next to it, id say maybe half inch for the plate thickness + the tube thickness of i dont know, half or quarter inch? Bolt diameter like an inch maybe?

But i realized that unless there are threads already cut in those holes my idea is stupid anyways - there is no way to put on a nut from inside the leg cyclinder/tube.  ::)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/23/2019 01:22 pm
Oof you ask me to measure thickness from photos? :D Well based on the worker next to it, id say maybe half inch for the plate thickness + the tube thickness of i dont know, half or quarter inch? Bolt diameter like an inch maybe?

But i realized that unless there are threads already cut in those holes my idea is stupid anyways - there is no way to put on a nut from inside the leg cyclinder/tube.  ::)
I meant they look gigantic to me.

That plate is 3' long?  Distance between holes is 6"?  So at least 1" diameter if not 2"?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 02/23/2019 01:40 pm
Do they have room to build two at once?
And wouldn't they want to finish the first and get a sense of it (lessons learned etc) before starting the second?  Else they can't effectively iterate.

I assume this is a new top-hat.  That said, there's a pretty strong argument for building the full-up flight article sooner rather than later.  SpaceX itself said it already has "sufficient" experience building the booster, and the hopper's low-altitude flights are firmly in the booster-knowledge space.  The risk exists in those things that they've never done before:  flapperons, sweaty steel, in-space refueling, etc.  None of that is being tested with the first article.  If you're in a hurry, you go straight to testing the bits you're least sure of.  That's where the iteration will take place.  Presumably what you learn from the hopper is how the engines interact with the ground during landing, throttle responsiveness, etc.  I don't think you get a lot of hardware feedback from the hopper, it seems mostly for control software?

I would not be surprised if they strap on the dev engines to the hopper for a couple of go-arounds and start building a flight article in parallel.  Raptor engines come in, a couple more hopper tests and software tweaking, then straight to the flight article.

I don't think that's what is happening, but at this point, very little would surprise me.
They are building an full feature starship in California. This will do suborbital tests and also orbital ones down the line.
The hopper is an shortcut for testing landings. Starship has much less drag on top than falcon 9 first stage and engine is new so it will handle totally different.  Guess they will also do engine out testing on it.
If core engine fails it will have to land on two of the side engines.

They build the hopper in Texas using lots of hired resources, the real deal require lots more quality and its also an far more valuable asset.
They could even rebuild the hopper to test first stage landings by modifying the fairing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/23/2019 01:48 pm
[guess] Mounting points. Those are bolt holes, a clamp goes round, bolts go through. The clamp holds a flexible/swinging part of the shock absorbing feet. [/guess]
If so, what size bolts do you think fit in there?  And how thick is that plate?
Highly doubt that’s a bolt plate. The holes would have to be tapped because don’t think there’s a way to get someone down the tube with corresponding nuts.

It’s a real mystery - could it be for venting? Could the use the legs to direct out vent gasses? Pretty unorthodox.

Good thing is, like the weather here in Boston, just wait a day and everything changes...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/23/2019 01:56 pm
[guess] Mounting points. Those are bolt holes, a clamp goes round, bolts go through. The clamp holds a flexible/swinging part of the shock absorbing feet. [/guess]
If so, what size bolts do you think fit in there?  And how thick is that plate?
Highly doubt that’s a bolt plate. The holes would have to be tapped because don’t think there’s a way to get someone down the tube with corresponding nuts.

It’s a real mystery - could it be for venting? Could the use the legs to direct out vent gasses? Pretty unorthodox.

Good thing is, like the weather here in Boston, just wait a day and everything changes...
Agreed.  It's really odd. The hole diameters are too large.

Oooh!  An LED array fixture to make it look cool!

That's all I got.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/23/2019 01:57 pm
[guess] Mounting points. Those are bolt holes, a clamp goes round, bolts go through. The clamp holds a flexible/swinging part of the shock absorbing feet. [/guess]
If so, what size bolts do you think fit in there?  And how thick is that plate?
Highly doubt that’s a bolt plate. The holes would have to be tapped because don’t think there’s a way to get someone down the tube with corresponding nuts.

It’s a real mystery - could it be for venting? Could the use the legs to direct out vent gasses? Pretty unorthodox.

Good thing is, like the weather here in Boston, just wait a day and everything changes...
Agreed.  It's really odd. The hole diameters are too large.

Oooh!  An LED array fixture to make it look cool!

That's all I got.
To me they look like diffusers. Air intakes to ventilate engine space?

Edit to add: recall that unlike the top tubes, which are welded to the outside of the water tank, the bottom tubes run inside via a notch cut through the tanks wall.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/23/2019 02:00 pm
[guess] Mounting points. Those are bolt holes, a clamp goes round, bolts go through. The clamp holds a flexible/swinging part of the shock absorbing feet. [/guess]
If so, what size bolts do you think fit in there?  And how thick is that plate?
Highly doubt that’s a bolt plate. The holes would have to be tapped because don’t think there’s a way to get someone down the tube with corresponding nuts.

It’s a real mystery - could it be for venting? Could the use the legs to direct out vent gasses? Pretty unorthodox.

Good thing is, like the weather here in Boston, just wait a day and everything changes...
Agreed.  It's really odd. The hole diameters are too large.

Oooh!  An LED array fixture to make it look cool!

That's all I got.
To me they look like diffusers. Air intakes to ventilate engine space?
Interesting.  Something to do with the bottom leg tube being a pressure reservoir?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/23/2019 02:04 pm
It’s an odd development.

To my guessing eyes it seems to not be a thick metal plate but rather a thin metal plate with holes which is wrapped / sitting on top of some black spacer stuff.  Maybe stainless sheet the thickness of the new nose fairing (or maybe that's stretchpossibly hopper 2 being built) wrapped over thermal insulation.  Perhaps because on the real thing they're concerned about the bottom ends of the fins receiving too much heat from he raptors (envision the smoke coming off the legs of grasshopper) so they want to test their proposed heat protection.  I see the holes as being black not because they're deep holes but because we're looking through the metal sheet to see the black spacer stuff.

Now stretchguessing a bunch more, what if that black stuff is some kind of high temperature wool which would be soaked with liquid meth and the holes are for release of boiled off meth and this is the first view of their version of transpiration cooling.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/23/2019 02:07 pm
It’s an odd development.

To my guessing eyes it seems to not be a thick metal plate but rather a thin metal plate with holes which is wrapped / sitting on top of some black spacer stuff.  Maybe stainless sheet the thickness of the new nose fairing (or maybe that's stretchpossibly hopper 2 being built) wrapped over thermal insulation.  Perhaps because on the real thing they're concerned about the bottom ends of the fins receiving too much heat from he raptors (envision the smoke coming off the legs of grasshopper) so they want to test their proposed heat protection.  I see the holes as being black not because they're deep holes but because we're looking through the metal sheet to see the black spacer stuff.

Now stretchguessing a bunch more, what if that black stuff is some kind of high temperature wool which would be soaked with liquid meth and the holes are for release of boiled off meth and this is the first view of their version of transpiration cooling.
Well, if so I hope the give Nomadd and BCGal a lot of narcan...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/23/2019 02:10 pm
To me they look like diffusers. Air intakes to ventilate engine space?

Edit to add: recall that unlike the top tubes, which are welded to the outside of the water tank, the bottom tubes run inside via a notch cut through the tanks wall.

Add to that thought - IIRC, the bottom tubes when we saw them being brought to the hopper pot were much longer than just the length to get to the walls of the hopper pot, closer to being long enough to meet in the middle IIRC.  Anyone using this post for constructive purposes would be wise to go back and confirm.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/23/2019 02:30 pm
[guess] Mounting points. Those are bolt holes, a clamp goes round, bolts go through. The clamp holds a flexible/swinging part of the shock absorbing feet. [/guess]
If so, what size bolts do you think fit in there?  And how thick is that plate?
Highly doubt that’s a bolt plate. The holes would have to be tapped because don’t think there’s a way to get someone down the tube with corresponding nuts.

It’s a real mystery - could it be for venting? Could the use the legs to direct out vent gasses? Pretty unorthodox.

Good thing is, like the weather here in Boston, just wait a day and everything changes...
They could be templates for drilling the legs. The legs could have something already mounted inside or could be accessible to a skinny mechanic inside. They could be an inch thick and the holes threaded. Hard to rule anything out for a group that doesn't know how to follow the rules.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/23/2019 02:38 pm
Something to assess how much flung rock damage the legs will see?   Tesla ultrasonic sensors in every hole?  Improbable.  Stretching & head scratching.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 02/23/2019 03:44 pm
They are building an full feature starship in California. This will do suborbital tests and also orbital ones down the line.

I know we've been led to believe that, but there's no way to get the thing from Hawthorne to Texas except in pieces.  So, if we continue to believe that's the plan (and remember, during dear moon we all continued to believe in giant pieces of carbon fiber), then we have to expect delivery, and ... "some assembly required" at BC or nearby

I don't think that's what is happening, but at this point, very little would surprise me.

My actual supposition at this point is that they're going to build the top using the same welding/techniques they intend to use to assemble the pieces arriving from CA.  Perhaps they're testing non-enclosed construction.  It's possible that this version will be sturdy enough to reuse on suborbital tests (but unlikely to include transpiration layer).  Suborbital tester verifies flapperons and raptor reflight, may include transpiration on tank half of Starship, but may not.  I assume there's a parallel effort underway to verify, optimize, and test various sweating techniques (big holes, little holes, exhaust only on one side or the other, etc).  All in conjunction with different landing profiles.

In which case, I guess I believe a third version is built with more complete capabilities -- possibly reusing thrust structure and some, if not all, the original raptors of the suborbital test article.

The entertaining thing here is the degree to which most of my guessing is completely wrong, so, like I said, nothing would surprise me.  Maybe they're already constructing the suborbital article under the tent.  After all, given what we can see, what in heaven's name is going on in there?

Quote
The hopper is an shortcut for testing landings. Starship has much less drag on top than falcon 9 first stage and engine is new so it will handle totally different.  Guess they will also do engine out testing on it.

Of all the things the team has to model, low-altitude, low-speed flight has got to be the simplest.  So, I assume they will test all of this, but I also assume it won't be much work to dial everything in.  Except anything to do with engines -- start / stop / fail modes likely have crazy transients.  No re-contacting stages please....
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/23/2019 05:53 pm
Saw them move some more stainless panels. We are going higher.

From these photos, some observations...

- Looks like the same SS sheet stock they used for the leg panels, with the same peel off protector. Wonder if its the same gauge.

- I like how, on the backside, they welded on the tabs that then have the yellow alignment jigs, and how they use basically a spud wrench to lock the jig in place. It would appear that once the panel is lowered onto the top of the lower section they flip the yellow jig, spot weld a tab to the lower section where the hole in the jig is, and then drop a second spud wrench into place to lock it in and hold the two sections together...

BocaChicaGal - can you see of they've done any additional work to those multi-holed plates they attached to the lower tube of the legs?

And again, thanks!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 02/23/2019 06:05 pm
Transpiration cooling test plates?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 02/23/2019 06:55 pm
Saw them move some more stainless panels. We are going higher.

From these photos, some observations...

- Looks like the same SS sheet stock they used for the leg panels, with the same peel off protector. Wonder if its the same gauge.

- I like how, on the backside, they welded on the tabs that then have the yellow alignment jigs, and how they use basically a spud wrench to lock the jig in place. It would appear that once the panel is lowered onto the top of the lower section they flip the yellow jig, spot weld a tab to the lower section where the hole in the jig is, and then drop a second spud wrench into place to lock it in and hold the two sections together...

BocaChicaGal - can you see of they've done any additional work to those multi-holed plates they attached to the lower tube of the legs?

And again, thanks!
I will go check it out.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: groundbound on 02/23/2019 07:00 pm
Transpiration cooling test plates?

My first reaction seeing those was that they were the world's largest hose clamps. I don't see how compression in that location would be useful though.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 02/23/2019 07:22 pm
Saw them move some more stainless panels. We are going higher.

From these photos, some observations...

- Looks like the same SS sheet stock they used for the leg panels, with the same peel off protector. Wonder if its the same gauge.

- I like how, on the backside, they welded on the tabs that then have the yellow alignment jigs, and how they use basically a spud wrench to lock the jig in place. It would appear that once the panel is lowered onto the top of the lower section they flip the yellow jig, spot weld a tab to the lower section where the hole in the jig is, and then drop a second spud wrench into place to lock it in and hold the two sections together...

BocaChicaGal - can you see of they've done any additional work to those multi-holed plates they attached to the lower tube of the legs?

And again, thanks!
I will go check it out.
Nothing additional.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AnalogMan on 02/23/2019 07:22 pm
Transpiration cooling test plates?

My first reaction seeing those was that they were the world's largest hose clamps. I don't see how compression in that location would be useful though.

It does look like they are two layers bonded together (as previously noted).

My wild guesses:

• Vibration isolation pads for supporting other equipment?
• Vibration damping pads (even less likely given the mass of the leg tubes)

(Holes to avoid trapping air?)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 02/23/2019 08:03 pm
Transpiration cooling test plates?

My first reaction seeing those was that they were the world's largest hose clamps. I don't see how compression in that location would be useful though.

It does look like they are two layers bonded together (as previously noted).

My wild guesses:

• Vibration isolation pads for supporting other equipment?
• Vibration damping pads (even less likely given the mass of the leg tubes)

(Holes to avoid trapping air?)

Seems to me that these plates may just be locking mechanisms for the landing feet - where the landing feet atachments would have matching plates with protruding elements that would attach and lock into the holes to keep the plates in place.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 02/23/2019 10:36 pm
Looks like two shock absorbing leg assemblies.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/23/2019 10:48 pm
Looks like two shock absorbing leg assemblies.
Absolutely not - this is a construction tool that’s been used many times. Crop included for reference...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 02/23/2019 10:54 pm
The latest Hopper photo updates show an unusual item on site. One person has suggested that it's a welding rig, but I have no idea.

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1914582#msg1914582
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OneSpeed on 02/23/2019 11:06 pm
To my guessing eyes it seems to not be a thick metal plate but rather a thin metal plate with holes which is wrapped / sitting on top of some black spacer stuff.

Perhaps they are load spreaders for hawsers? The shape of the plate allows for a small range in the angle of incidence of the hawser, and doesn't continue under the leg where the hawser would not be in contact. Also, there are two plates forming a rough hawse hole between the legs. Once the StarHopper is moved to the launch pad, and the new nose cone is attached, they'll be keen to keep it securely tied down.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 02/23/2019 11:08 pm
To my guessing eyes it seems to not be a thick metal plate but rather a thin metal plate with holes which is wrapped / sitting on top of some black spacer stuff.

Perhaps they are load spreaders for hawsers? Once the StarHopper is moved to the launch pad, and the new nose cone is attached, they'll be keen to keep it securely tied down.

It looks more like skin reinforcement for pending hole drilling in the primary leg strut to me, but who knows? My predictions for this entire thing have been terribly inaccurate.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 02/23/2019 11:29 pm
Looks like two shock absorbing leg assemblies.
Absolutely not - this is a construction tool that’s been used many times.
What does it do?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cinder on 02/24/2019 12:08 am
Perhaps something can be inferred from the divergence of those lines of holes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 02/24/2019 12:21 am
Inspecting both photos with good zoom, it appears that the "Hole Plates" are quite heavy. I am guessing 1 to 1-1/2 inches thick and solid stainless. They appear to be full perimeter fillet welded and are definitely permanent.

From one of the holes, threads appear to be visible and I expect that all of the holes are tapped.

I would say that they are mounting plates. possibly for the shock absorber foot pads.. whatever they intend to use. :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ejb749 on 02/24/2019 12:35 am
Looks like two shock absorbing leg assemblies.
Absolutely not - this is a construction tool that’s been used many times. Crop included for reference...
The answer is in L2.  It's nothing to do with shock absorbing. 
There is enough evidence in the photos to figure it out.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DaddyBee on 02/24/2019 12:45 am
Today they uncovered this. I managed to get a couple pics but they are not the best. What is it?
It (they) look like 3G vertical welders used for doing horizontal welds on large tanks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/24/2019 01:17 am
It's an storage tank welding machine.
https://youtu.be/WXOgHqGULCk
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JBF on 02/24/2019 02:51 am
It's an storage tank welding machine.
https://www.youtube.com/watch?v=WXOgHqGULCk
Watching this video they zoom in a couple times on the weld itself. Is that considered a good quality weld?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MKremer on 02/24/2019 02:52 am

Perhaps they are load spreaders for hawsers? The shape of the plate allows for a small range in the angle of incidence of the hawser, and doesn't continue under the leg where the hawser would not be in contact. Also, there are two plates forming a rough hawse hole between the legs. Once the StarHopper is moved to the launch pad, and the new nose cone is attached, they'll be keen to keep it securely tied down.

That is more or less what I was thinking, that they are doublers to distribute force or load more equally to the lower leg.

I guess they could use it as a tiedown, but I figured it is more to  act as a gusset for additional vertical reinforcement.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 02/24/2019 03:18 am
It's an storage tank welding machine.
https://www.youtube.com/watch?v=WXOgHqGULCk
Watching this video they zoom in a couple times on the weld itself. Is that considered a good quality weld?

From my googling, very good - it'll pass x-ray inspection.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/24/2019 05:05 am

Perhaps they are load spreaders for hawsers? The shape of the plate allows for a small range in the angle of incidence of the hawser, and doesn't continue under the leg where the hawser would not be in contact. Also, there are two plates forming a rough hawse hole between the legs. Once the StarHopper is moved to the launch pad, and the new nose cone is attached, they'll be keen to keep it securely tied down.

That is more or less what I was thinking, that they are doublers to distribute force or load more equally to the lower leg.

I guess they could use it as a tiedown, but I figured it is more to  act as a gusset for additional vertical reinforcement.

Sounds ok since we know something interesting is going to happen at the leg tips...

But that arrangement of non-planar holes is so....  unboltable...
I'd have expected this plate to have boxed edges, and the box faces (Being perpendicular to each other) have the bolt patterns.

However, I have zero doubt that if this an attachment plate, the mating part will fit just fine. :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 02/24/2019 05:55 am
ITAR just means no exporting of stuff to non-citizens. Doesn't mean extra vetting beyond citizenship.

There is a blacklist...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/24/2019 08:33 am
Okay, so I’ve been reading up on SAW (submerged arc welding), flux recovery belts, girth welders in general, and all that goes into that rabbit hole.

A few points...

- The unit on-site is a double sided version, so will weld both the inside and the outside (horizontal seam) at the same time.

- The minimum diameter the unit can be used is someplace between 15 and 20 feet. So when the hat tapers beyond that cutoff it can’t be used. However, recalling the V1 hat, the shape held pretty close to a 9 meter diameter until perhaps the upper third or even quarter. I expect this top part of the hat is being constructed inside the tent and will emerge as a complete unit.

So here’s the timeline:

- Bottom section (S1) and second section (S2) are girth welded together on the ground

- (potential intermediate step) Interface section built on concrete base. This section provides proper attachment mechanism to the BFH base section. It can be test fitted to the base and adjusted as needed.

- These two completed sections are picked up an put on concrete base (or onto the Interface section which is on the concrete base)

- S3 is girth welded.

-S4-? likewise

- Nosecone emerges from tent and hand welded to top

- Nosecone has lifting attachment on top to allow entire assembly to be lifted off concrete base and placed on the BFH base when appropriate
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/24/2019 09:22 am
About plates with holes (the second photo):
https://forum.nasaspaceflight.com/index.php?topic=47120.msg1914542#msg1914542

It looks more like skin reinforcement for pending hole drilling in the primary leg strut to me

Agreed. Here is my suggestion, for what these holes could be.

Suppose they use pneumatic shock absorbers. Then the piston moving up (red arrow) will create a vacuum under it. Holes are needed to ensure air flow into this area.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 02/24/2019 09:27 am
Is that considered a good quality weld?
it's a machine weld, so it's even more impossible to tell if it's a good weld from the surface than a regular weld
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 02/24/2019 02:40 pm
About plates with holes (the second photo):
https://forum.nasaspaceflight.com/index.php?topic=47120.msg1914542#msg1914542

It looks more like skin reinforcement for pending hole drilling in the primary leg strut to me

Agreed. Here is my suggestion, for what these holes could be.

Suppose they use pneumatic shock absorbers. Then the piston moving up (red arrow) will create a vacuum under it. Holes are needed to ensure air flow into this area.

I think that is possibly the reason. But it also means that the piston cannot travel below the lower joint as that would decompress the system.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 02/24/2019 03:53 pm
Okay, so I’ve been reading up on SAW (submerged arc welding), flux recovery belts, girth welders in general, and all that goes into that rabbit hole.

[...]

- The unit on-site is a double sided version, so will weld both the inside and the outside (horizontal seam) at the same time.

Did your research provide any clues as to how the double-walled transpiration-capable side is likely to be constructed?  As I said earlier, I don't necessarily expect that this version, but if this is the technique they intend to use for mark.2, I'd have thought they'd think about that.  I'm curious as to whether they'll build the double-walled sections in Hawthorne and cart them out here, or whether the entire construction is likely to be done here, one layer at a time. 

Quote
- The minimum diameter the unit can be used is someplace between 15 and 20 feet. So when the hat tapers beyond that cutoff it can’t be used. However, recalling the V1 hat, the shape held pretty close to a 9 meter diameter until perhaps the upper third or even quarter.

I think it's better than you remember, though 15-20 ft is a big error bar.  Also, the hopper was shorter than the SS will be, so the SS will probably see even better use of this technique.  I'm seeing about 4/5ths of the bit that's been lost has a diameter larger than 5m, and a smidge over 3/4ths larger than 6m.  That's a quite rough estimate (ruler, not pixel peeping) from: https://forum.nasaspaceflight.com/index.php?topic=47120.msg1898820#msg1898820

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: oldAtlas_Eguy on 02/24/2019 07:49 pm
Is that considered a good quality weld?
it's a machine weld, so it's even more impossible to tell if it's a good weld from the surface than a regular weld
Welders of this type when calibrated produce extremely reproducible welds of a specific quality. To calibrate for high quality requires a calibration using the specific serial number of the source metals to be welded by having the welder weld test tabs that are then examined by a lab set-up until the calibration results in the required weld quality. Once calibrated the welder welds only those whose metals are the the exact SN in the exact order that the calibration was done. Change the the SN or the order requires a recalibration.

This methodology produces such highly repeatable high quality welds that the finished weld products are rarely even examined. On SS and SH welds are likely to be examined for proper
placement more than for quality.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/24/2019 10:16 pm
So this image was posted on twitter by user @CowboyDanPaasch - who is also on this forum. Want to get a bit of back story about where it was taken, etc, but still - that's one big track...

https://twitter.com/CowboyDanPaasch/status/1099802538780561409
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: GregTheGrumpy on 02/24/2019 11:02 pm
Dan indicates that it was from FB Boca Chica (to you I think).  I found a SpaceX Boca Chica Group on FB.  I'm none too good navigating facebook, but I did find a post Alex Balderas shared from Marc Crain (3:21 pm).  Tried going there but I can't find the pic on Marc's page (hardly ever find what I'm looking for on FB).  Anyway Marc says "I passed two of these crawler tracks around Sarita headed south to Space X .. The launch crawler will have 4 of them" and a later comment says "Marc Crain was told by the driver".  I don't know if I should post a screen capture (or even how).  I couldn't find a direct link to the thing either.
-g
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/24/2019 11:14 pm
Dan indicates that it was from FB Boca Chica (to you I think).  I found a SpaceX Boca Chica Group on FB.  I'm none too good navigating facebook, but I did find a post Alex Balderas shared from Marc Crain (3:21 pm).  Tried going there but I can't find the pic on Marc's page (hardly ever find what I'm looking for on FB).  Anyway Marc says "I passed two of these crawler tracks around Sarita headed south to Space X .. The launch crawler will have 4 of them" and a later comment says "Marc Crain was told by the driver".  I don't know if I should post a screen capture (or even how).  I couldn't find a direct link to the thing either.
-g
You are correct on all counts. Not really confident that this track is for SpaceX, but this thing will be kinda hard to hide, so we’ll know one way or the other soon enough!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/24/2019 11:40 pm
Dan indicates that it was from FB Boca Chica (to you I think).  I found a SpaceX Boca Chica Group on FB.  I'm none too good navigating facebook, but I did find a post Alex Balderas shared from Marc Crain (3:21 pm).  Tried going there but I can't find the pic on Marc's page (hardly ever find what I'm looking for on FB).  Anyway Marc says "I passed two of these crawler tracks around Sarita headed south to Space X .. The launch crawler will have 4 of them" and a later comment says "Marc Crain was told by the driver".  I don't know if I should post a screen capture (or even how).  I couldn't find a direct link to the thing either.
-g
You are correct on all counts. Not really confident that this track is for SpaceX, but this thing will be kinda hard to hide, so we’ll know one way or the other soon enough!

Google says 2 hours' drive... 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CardBoardBoxProcessor on 02/25/2019 12:35 am
So do we supposed they will be stir welding on the actual ship or using these automatic welders
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/25/2019 12:36 am
 Dock cranes can use those tracks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/25/2019 12:42 am
Dock cranes can use those tracks.
Yeah, I personally don’t see a reasonable, justifiable use for such massive tracks. There’s far simpler and to be honest, more practical solutions out there that can handle moving a fully built BFH to and from the BC site without having to resort to a massive crawler.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 02/25/2019 12:55 am
Dock cranes can use those tracks.
Yeah, I personally don’t see a reasonable, justifiable use for such massive tracks. There’s far simpler and to be honest, more practical solutions out there that can handle moving a fully built BFH to and from the BC site without having to resort to a massive crawler.

Agreed...  Someone may be building a very large crawler crane somewhere, but if it's SpaceX in BocaChica, I don't think it's for moving the hopper around.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 02/25/2019 12:58 am
Agreed...  Someone may be building a very large crawler crane somewhere, but if it's SpaceX in BocaChica, I don't think it's for moving the hopper around.
What about for moving the SH?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/25/2019 01:06 am
Agreed...  Someone may be building a very large crawler crane somewhere, but if it's SpaceX in BocaChica, I don't think it's for moving the hopper around.
What about for moving the SH?
You’d want something that could reasonably get under the BFH and lift it up off its legs. There are building moving machines that are low, relatively narrow at the wheelbase, and use wheels and not road destroying tracks to move. These have been suggested many times over the past few months.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/25/2019 01:57 am
 Moving up and down that ramp at the pad might be different than going down the road. Pulling 80 or 90 tons up a gravel ramp with a few driven rubber tires could be interesting.
 It's not getting paved, by the way.
 A crawler for the megacrane would be fun.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RobLynn on 02/25/2019 03:00 am
Dock cranes can use those tracks.
Yeah, I personally don’t see a reasonable, justifiable use for such massive tracks. There’s far simpler and to be honest, more practical solutions out there that can handle moving a fully built BFH to and from the BC site without having to resort to a massive crawler.

Agreed...  Someone may be building a very large crawler crane somewhere, but if it's SpaceX in BocaChica, I don't think it's for moving the hopper around.

They eventually need a crane that can lift up to 200 tonnes to 120m height to stack a fully payload laden SS on the SH.
They would probably like a crane that can back out of the way of the launch and landing pads during testing
They possibly want a crane that can make it possible to do some suspended hover/landing testing.
They need means to transport big unwieldy SH and SS and Hopper from construction facility to site and probably lift them from horizontal to vertical.

A second hand Leibherr LR1600-2 crane with 120m boom and 600 tonne capacity costs about $2.5million.  That's not a lot of capital - they have great resale value, so really only cost a few $100k per year to own - relative peanuts using off-the-shelf equipment like this compared to bespoke engineering.

They can probably take off a lot of the counterweights for the work they are doing to make them better for using as a transport crawler without having to build expensive transport trailers for SS and SH, and they can also afford to have one at the launch site and one at the construction site as the program gets busier.  Two of them provides redundancy, faster ability to pack up for hurricanes, and might give more options for captive hover testing too.

They could also provide a nice easy way of bringing heavy or bulky stuff in from a beached barge near the launch site (like SH or SS if constructed elsewhere in Texas).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MKremer on 02/25/2019 03:10 am

You’d want something that could reasonably get under the BFH and lift it up off its legs. There are building moving machines that are low, relatively narrow at the wheelbase, and use wheels and not road destroying tracks to move. These have been suggested many times over the past few months.
True, but they have yet to cut off the lifting lugs at the top of the legs, so I suppose they'll keep us guessing for a while longer.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 02/25/2019 06:00 am
They eventually need a crane that can lift up to 200 tonnes to 120m height to stack a fully payload laden SS on the SH.
They would probably like a crane that can back out of the way of the launch and landing pads during testing
They possibly want a crane that can make it possible to do some suspended hover/landing testing.
They need means to transport big unwieldy SH and SS and Hopper from construction facility to site and probably lift them from horizontal to vertical.

A second hand Leibherr LR1600-2 crane with 120m boom and 600 tonne capacity costs about $2.5million.  That's not a lot of capital - they have great resale value, so really only cost a few $100k per year to own - relative peanuts using off-the-shelf equipment like this compared to bespoke engineering.

They can probably take off a lot of the counterweights for the work they are doing to make them better for using as a transport crawler without having to build expensive transport trailers for SS and SH, and they can also afford to have one at the launch site and one at the construction site as the program gets busier.  Two of them provides redundancy, faster ability to pack up for hurricanes, and might give more options for captive hover testing too.

They could also provide a nice easy way of bringing heavy or bulky stuff in from a beached barge near the launch site (like SH or SS if constructed elsewhere in Texas).

Massive crane incoming: https://www.reddit.com/r/SpaceXLounge/comments/aue7az/just_saw_this_on_a_spacex_fan_facebook_pagenot/

Somebody suggested a Liebherr LR 11350:

https://www.youtube.com/watch?v=9KUJfhFMsTU

or a Liebherr LR 11000:

https://youtu.be/0IuduorZHXo
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 02/25/2019 08:42 am
Massive crane incoming: https://www.reddit.com/r/SpaceXLounge/comments/aue7az/just_saw_this_on_a_spacex_fan_facebook_pagenot/

Somebody suggested a Liebherr LR 11350

or a Liebherr LR 11000

The smallest Liebherr crawler crane I see with that track arrangement is the LR 1350/1, which is a 350 ton crane. They only get bigger from there.

https://www.liebherr.com/en/usa/products/mobile-and-crawler-cranes/crawler-cranes/lr-crawler-cranes/lr-crawler-cranes.html?page=1
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 02/25/2019 12:39 pm
Dock cranes can use those tracks.
Yeah, I personally don’t see a reasonable, justifiable use for such massive tracks. There’s far simpler and to be honest, more practical solutions out there that can handle moving a fully built BFH to and from the BC site without having to resort to a massive crawler.

Agreed...  Someone may be building a very large crawler crane somewhere, but if it's SpaceX in BocaChica, I don't think it's for moving the hopper around.

They eventually need a crane that can lift up to 200 tonnes to 120m height to stack a fully payload laden SS on the SH.
They would probably like a crane that can back out of the way of the launch and landing pads during testing
They possibly want a crane that can make it possible to do some suspended hover/landing testing.
They need means to transport big unwieldy SH and SS and Hopper from construction facility to site and probably lift them from horizontal to vertical.

A second hand Leibherr LR1600-2 crane with 120m boom and 600 tonne capacity costs about $2.5million.  That's not a lot of capital - they have great resale value, so really only cost a few $100k per year to own - relative peanuts using off-the-shelf equipment like this compared to bespoke engineering.

They can probably take off a lot of the counterweights for the work they are doing to make them better for using as a transport crawler without having to build expensive transport trailers for SS and SH, and they can also afford to have one at the launch site and one at the construction site as the program gets busier.  Two of them provides redundancy, faster ability to pack up for hurricanes, and might give more options for captive hover testing too.

They could also provide a nice easy way of bringing heavy or bulky stuff in from a beached barge near the launch site (like SH or SS if constructed elsewhere in Texas).

I wish I had worked for a company where $2.5 million for a single piece of equipment was not a lot of money.  Justifying capital expenditures was always a challenge.  BTW, $100,000 year to own is even less than the cost of money
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/25/2019 01:31 pm
No expertism here but it seems that a crane would be only slightly useful in moving the gadget over distances greater than its swing radius.  They move very slowly, all the images I've seen seem to have them on prepared surfaces, concrete or railroad ties (not moving over km distances of ground), and it seems you could put an eye out with the swinging pendulum dynamics of a hopper hanging from a long line below a long boom on a moving vehicle.  So then my thinking goes along the line of... The existing crane is tall enough to place the tinfoil hat but can it handle the weight of the new tinfoil hat also?  Or maybe 4 tracks go under a simple platform such as a Marmac that would have a tower and on top of that tower the Wisconsin hammerhead crane.  I dunno, just thinking out loud.

Hmm, something to walk the next generation SS/SH out to a floating barge to get it to an offshore launch site?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 02/25/2019 01:56 pm
No expertism here but it seems that a crane would be only slightly useful in moving the gadget over distances greater than its swing radius.  They move very slowly, all the images I've seen seem to have them on prepared surfaces, concrete or railroad ties (not moving over km distances of ground), and it seems you could put an eye out with the swinging pendulum dynamics of a hopper hanging from a long line below a long boom on a moving vehicle.  So then my thinking goes along the line of... The existing crane is tall enough to place the tinfoil hat but can it handle the weight of the new tinfoil hat also?  Or maybe 4 tracks go under a simple platform such as a Marmac that would have a tower and on top of that tower the Wisconsin hammerhead crane.  I dunno, just thinking out loud.

Hmm, something to walk the next generation SS/SH out to a floating barge to get it to an offshore launch site?

Pick up cargo, swing round 180, drop cargo, move crane round cargo, pick up cargo, swing round 180, drop cargo. Repeat until at launch site.

Avoids moving crane whilst carrying cargo, but a bit slow. I pressume they can move faster when not carrying anything.

You don't need a crawler, but need a prepared track. Probably easier just to build/buy a crawler.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 02/25/2019 02:00 pm
This morning they are using the welding machine.

https://youtu.be/vzIAXZ1Wjss
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: geza on 02/25/2019 02:59 pm
They eventually need a crane that can lift up to 200 tonnes to 120m height to stack a fully payload laden SS on the SH.
They would probably like a crane that can back out of the way of the launch and landing pads during testing
They possibly want a crane that can make it possible to do some suspended hover/landing testing.
They need means to transport big unwieldy SH and SS and Hopper from construction facility to site and probably lift them from horizontal to vertical.

A second hand Leibherr LR1600-2 crane with 120m boom and 600 tonne capacity costs about $2.5million.  That's not a lot of capital - they have great resale value, so really only cost a few $100k per year to own - relative peanuts using off-the-shelf equipment like this compared to bespoke engineering.
It is good to know that crane with this specification does exist on this price, even if it is not useful for transporting. I am still worrying about e.g. lifting SS to the top of SH. How swing and roll can be controlled for mating the two elements with the needed precision?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 02/25/2019 03:09 pm
No expertism here but it seems that a crane would be only slightly useful in moving the gadget over distances greater than its swing radius.  They move very slowly, all the images I've seen seem to have them on prepared surfaces, concrete or railroad ties (not moving over km distances of ground), and it seems you could put an eye out with the swinging pendulum dynamics of a hopper hanging from a long line below a long boom on a moving vehicle.  So then my thinking goes along the line of... The existing crane is tall enough to place the tinfoil hat but can it handle the weight of the new tinfoil hat also?  Or maybe 4 tracks go under a simple platform such as a Marmac that would have a tower and on top of that tower the Wisconsin hammerhead crane.  I dunno, just thinking out loud.

Hmm, something to walk the next generation SS/SH out to a floating barge to get it to an offshore launch site?

Or they might just be using it for ordinary construction purposes. The oil and gas industry is a heavy user of these kinds of cranes, and there's a lot of overlap with launch vehicle support infrastructure.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/25/2019 04:14 pm
How swing and roll can be controlled for mating the two elements with the needed precision?
cold gas RCS.

mostly jokingly.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 02/25/2019 05:04 pm
"Aerial photo taken today 02/24 , will post more later." (https://www.facebook.com/photo.php?fbid=806674559694705&set=gm.2249986125319838&type=3&theater&ifg=1)
from Mauricio Atilano @ ‎SpaceX Boca Chica Group on Facebook

I know I'm late, but I am loving the new tinfoil hat fairing they're building. <3
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThereIWas3 on 02/25/2019 06:28 pm
I am still worrying about e.g. lifting SS to the top of SH. How swing and roll can be controlled for mating the two elements with the needed precision?

Maybe alignment sensors and cameras around the inside of one piece or the other, or both.  Or maybe mechanized grabbers so you only need to get close.  A permanent part of the instrumentation.   There has to be a way to control rotation about the long axis as well, so this is not going to be a simple cable suspension.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: kenny008 on 02/25/2019 06:44 pm
I’m not a crane expert by any means, but this is pretty much solved in industry. Things are lifted and aligned all the time in the field. Watch them build a wind turbine tower and place the turbine and blades into place. While we may not know how to do it, lifting experts have the skills.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RobLynn on 02/25/2019 06:47 pm
I wish I had worked for a company where $2.5 million for a single piece of equipment was not a lot of money.  Justifying capital expenditures was always a challenge.  BTW, $100,000 year to own is even less than the cost of money

I said a few 100k per year.  There are no end of companies and individuals that can finance and rent the crane at %10-20% ROI if SpaceX can't or don't want to borrow the money themselves.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/25/2019 09:06 pm
First photo here:
https://forum.nasaspaceflight.com/index.php?topic=47120.msg1915182#msg1915182
captured by bocachicagal: Some more reflective sheets going onto the dome.

It's a rather strange job if they're going to cover the 'water tank' with the new fairing. Isn't it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lisa_R4 on 02/25/2019 09:22 pm
It's a rather strange job if they're going to cover the 'water tank' with the new fairing. Isn't it?

It seems strange if they aren't replacing the fairing, too. I can't see much aesthetic value to making the top shiny with all the plumbing up there. My best guess is thermal insulation but that doesn't sit right with me either.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cppetrie on 02/25/2019 09:42 pm
It's a rather strange job if they're going to cover the 'water tank' with the new fairing. Isn't it?

It seems strange if they aren't replacing the fairing, too. I can't see much aesthetic value to making the top shiny with all the plumbing up there. My best guess is thermal insulation but that doesn't sit right with me either.
Perhaps they are planning to pass hot gas plumbing for autogenous pressurization over that area and want to reduce heat flux to tank. Don’t care for that rationale but it’s a thought.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 02/25/2019 09:55 pm
This pic was taken later this afternoon.
I know nothing about welds, but I assume someone here does: there seems to be a big difference between the two circumferential welds on the new tinfoil hat, with the upper looking "clean" and uniform, whereas the lower one looks "dirtier" and less uniform. Which represents the weld done by the automatic tank welding machine? I think it's the lower one. Some previous comments suggest these machines make uniform and quality welds (if calibrated properly), so is there anything we can say about the quality of this weld we see here?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/25/2019 10:01 pm
This pic was taken later this afternoon.
I know nothing about welds, but I assume someone here does: there seems to be a big difference between the two circumferential welds on the new tinfoil hat, with the upper looking "clean" and uniform, whereas the lower one looks "dirtier" and less uniform. Which represents the weld done by the automatic tank welding machine? I think it's the lower one. Some previous comments suggest these machines make uniform and quality welds (if calibrated properly), so is there anything we can say about the quality of this weld we see here?
The sheets were already assembled two sections high when they came, so the upper weld was done at the fabricator and the lower at the site.
 There's more to it than quality. The bigger, spread out welds can act as miniature doublers. The skinnier welds could have doublers reinforcing the joint inside.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jak Kennedy on 02/25/2019 10:06 pm
No expertism here but it seems that a crane would be only slightly useful in moving the gadget over distances greater than its swing radius.  They move very slowly, all the images I've seen seem to have them on prepared surfaces, concrete or railroad ties (not moving over km distances of ground), and it seems you could put an eye out with the swinging pendulum dynamics of a hopper hanging from a long line below a long boom on a moving vehicle.  So then my thinking goes along the line of... The existing crane is tall enough to place the tinfoil hat but can it handle the weight of the new tinfoil hat also?  Or maybe 4 tracks go under a simple platform such as a Marmac that would have a tower and on top of that tower the Wisconsin hammerhead crane.  I dunno, just thinking out loud.

Hmm, something to walk the next generation SS/SH out to a floating barge to get it to an offshore launch site?

Pick up cargo, swing round 180, drop cargo, move crane round cargo, pick up cargo, swing round 180, drop cargo. Repeat until at launch site.

Avoids moving crane whilst carrying cargo, but a bit slow. I pressume they can move faster when not carrying anything.

You don't need a crawler, but need a prepared track. Probably easier just to build/buy a crawler.

Why not just transport them horizontally then use a crane to lift vertically and stack? Or has this been discussed? (Probably)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: billh on 02/25/2019 10:07 pm
This looks like it would have been a nice photo op!

(credit:  detail from RGV Aerial Photography photo)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: masterxel on 02/26/2019 12:30 am
It's a rather strange job if they're going to cover the 'water tank' with the new fairing. Isn't it?

It seems strange if they aren't replacing the fairing, too. I can't see much aesthetic value to making the top shiny with all the plumbing up there. My best guess is thermal insulation but that doesn't sit right with me either.
Perhaps they are planning to pass hot gas plumbing for autogenous pressurization over that area and want to reduce heat flux to tank. Don’t care for that rationale but it’s a thought.

I think I have an idea for covering the dome top that I haven't seen here before. They are testing thermal protection because cargo mission Starship will launch with the tinfoil hat but land without it.

The completed Starship is a reusable second stage, carrying a deployable payload for cargo missions.

Deploying a payload involves ejecting the fairing (tinfoil hat) and then reusability implies landing the Starship without the hat, so the exposed structure that remains needs thermal protection.

For the purpose of hopper they could either do a test involving ejecting the fairing or just launch without the hat.

The exposed plumbing contradicts this but maybe we'll see a mini shiny hat for that.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: lonestriker on 02/26/2019 12:35 am
It's a rather strange job if they're going to cover the 'water tank' with the new fairing. Isn't it?

It seems strange if they aren't replacing the fairing, too. I can't see much aesthetic value to making the top shiny with all the plumbing up there. My best guess is thermal insulation but that doesn't sit right with me either.
Perhaps they are planning to pass hot gas plumbing for autogenous pressurization over that area and want to reduce heat flux to tank. Don’t care for that rationale but it’s a thought.

I think I have an idea for covering the dome top that I haven't seen here before. They are testing thermal protection because cargo mission Starship will launch with the tinfoil hat but land without it.

The completed Starship is a reusable second stage, carrying a deployable payload for cargo missions.

Deploying a payload involves ejecting the fairing (tinfoil hat) and then reusability implies landing the Starship without the hat, so the exposed structure that remains needs thermal protection.

For the purpose of hopper they could either do a test involving ejecting the fairing or just launch without the hat.

The exposed plumbing contradicts this but maybe we'll see a mini shiny hat for that.

There are no throw-away components for SS/SH that have been announced.  The whole point of SS/SH is complete reusability.  Where did you get information on the "faring" being discarded?  That would be (bad) news to everyone.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RobLynn on 02/26/2019 12:36 am
I think I have an idea for covering the dome top that I haven't seen here before. They are testing thermal protection because cargo mission Starship will launch with the tinfoil hat but land without it.

That would entirely wreck the re-entry centre of mass / lateral centre of pressure balance, so highly unlikely.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/26/2019 12:37 am
I think I have an idea for covering the dome top that I haven't seen here before. They are testing thermal protection because cargo mission Starship will launch with the tinfoil hat but land without it.

No, they would not do that. It makes no sense. This is the HOPPER. Do not assume any engineering decisions for Orbital Starship models from this.

Any insulation added on the Hopper is simply to help keep propellants in cryogenic form longer.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: TomH on 02/26/2019 01:03 am
...Starship will launch with the tinfoil hat but land without it....Deploying a payload involves ejecting the fairing... reusability implies landing the Starship without the hat...

This is incorrect. Starship has no fairing. Everything is completely reusable. This has been the plan since the very first ITS iteration was revealed several years ago.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 02/26/2019 01:33 am
This pic was taken later this afternoon.
I know nothing about welds, but I assume someone here does: there seems to be a big difference between the two circumferential welds on the new tinfoil hat, with the upper looking "clean" and uniform, whereas the lower one looks "dirtier" and less uniform. Which represents the weld done by the automatic tank welding machine? I think it's the lower one. Some previous comments suggest these machines make uniform and quality welds (if calibrated properly), so is there anything we can say about the quality of this weld we see here?
the biggest difference between the top and the bottom welds is that the new (bottom) weld hasn't been cleaned and shows all sorts of cosmetic discolorations of the weldment. Steel, especially stainless, turns all sorts of amazing colors when it gets hot. the bead looks fine, and you cannot tell what is happening on the inside of a weld from the outside, even less so on a machine weld
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Zed_Noir on 02/26/2019 02:06 am
My guess for putting the shiny stuff on top of the tank is that there are people working inside those tanks and SX don't want anyone roasted in there from the sun. So SX is putting some temporary reflecting stuff on top of the tank to reduced heating from the sun.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MickQ on 02/26/2019 04:59 am
A temporary sun shade spaced slightly above the dome top would be much more effective.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Star One on 02/26/2019 03:34 pm
...Starship will launch with the tinfoil hat but land without it....Deploying a payload involves ejecting the fairing... reusability implies landing the Starship without the hat...

This is incorrect. Starship has no fairing. Everything is completely reusable. This has been the plan since the very first ITS iteration was revealed several years ago.

Why would anyone even get the idea that the Starship was anything other one complete item. It seems some still can’t grasp the idea that it is closer to an aircraft in this respect than a traditional launcher.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NH22077 on 02/26/2019 04:24 pm

I think I have an idea for covering the dome top that I haven't seen here before. They are testing thermal protection because cargo mission Starship will launch with the tinfoil hat but land without it.

The completed Starship is a reusable second stage, carrying a deployable payload for cargo missions.

Deploying a payload involves ejecting the fairing (tinfoil hat) and then reusability implies landing the Starship without the hat, so the exposed structure that remains needs thermal protection.

For the purpose of hopper they could either do a test involving ejecting the fairing or just launch without the hat.

The exposed plumbing contradicts this but maybe we'll see a mini shiny hat for that.

As already stated the fairing will never be expended. Besides this is a hop test vehicle for VTOVL testing & will never reach orbit.
  Here is a pic of the BFR satalite deploying version, to give you a visual of the right the idea. It will have canards & 3 fins though.

Ned

PS: I don't know who to credit the photo to.
Edit, clarity.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 02/26/2019 05:06 pm
Some deliveries were made inside the fairing this morning.

Parts for scaffolding, I think.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/26/2019 05:48 pm
This was brought in from the big dish area and parked by the Hopper.
That's a rather odd sign, "do not take parts".
 ???
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nehkara on 02/26/2019 06:00 pm
This was brought in from the big dish area and parked by the Hopper.
That's a rather odd sign, "do not take parts".
 ???

This was brought in from the big dish area and parked by the Hopper.

"Do Not Take Parts"
"Needed for Hopper Vehicle _______"

I can't make out the last word.  Anyone else have any guesses?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/26/2019 06:05 pm
I also think there will be no expendable fairing for airodynamic / reentry reasons.

However if there was one, out of stainless steel you could probably make it dirt cheap.

( If e.g. Falcon Heavy is indeed volume limited, not weight limited, and ignoring the airodynamic problems of a wider fairing, a 7m diameter stainless steel fairing might make sense in terms of $$$, where a carbon fiber version would not. )
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 02/26/2019 06:09 pm
This was brought in from the big dish area and parked by the Hopper.
That's a rather odd sign, "do not take parts".
 ???

This was brought in from the big dish area and parked by the Hopper.

"Do Not Take Parts"
"Needed for Hopper Vehicle _______"

I can't make out the last word.  Anyone else have any guesses?

Needed for Hopper Vehicle Checkout
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: toren on 02/26/2019 06:16 pm
This was brought in from the big dish area and parked by the Hopper.
That's a rather odd sign, "do not take parts".
 ???

Seems like 'midnight engineering' might be alive and well with the SX pad rats and their contractors...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/26/2019 06:23 pm
What do we suppose is up with this?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/26/2019 08:41 pm
Looks like the foundation for a small (or tall) building - or a helipad?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 02/26/2019 08:44 pm
did a contrast stretch on this pic from BCG.

Look at the signs on the left side of panel of gauges. Bottom spool says ... Stage SEP....  :o
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 02/26/2019 08:50 pm
This was brought in from the big dish area and parked by the Hopper.
That's a rather odd sign, "do not take parts".
 ???

This was brought in from the big dish area and parked by the Hopper.

"Do Not Take Parts"
"Needed for Hopper Vehicle _______"

I can't make out the last word.  Anyone else have any guesses?

Needed for Hopper Vehicle Checkout

I was thinking "needed for hopper vehicle prechecks"
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 02/26/2019 09:04 pm
This was brought in from the big dish area and parked by the Hopper.
That's a rather odd sign, "do not take parts".
 ???
Seriously? You see stuff like that in large manufacturing facilities all the time. People raid other areas to get thier tasks done. Especially if procurement is a pain.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/26/2019 09:24 pm
This was brought in from the big dish area and parked by the Hopper.
That's a rather odd sign, "do not take parts".
 ???

This was brought in from the big dish area and parked by the Hopper.

"Do Not Take Parts"
"Needed for Hopper Vehicle _______"

I can't make out the last word.  Anyone else have any guesses?

Needed for Hopper Vehicle Checkout

I was thinking "needed for hopper vehicle prechecks"
Checkout
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kansan52 on 02/26/2019 10:04 pm
Does a sign like like actually stop 'DIYers'?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 02/26/2019 11:09 pm
This was brought in from the big dish area and parked by the Hopper.
That's a rather odd sign, "do not take parts".
 ???
roughly translated, it means "please do not cannibalize this useless and expensive looking contraption to make useful tools, it is both expensive and very useful"
Gauges have amazing utility, enough so that you frequently don't want to leave them attached to the same test stand for long periods of time. Same goes for all of the valves.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bogeyman on 02/27/2019 04:16 am
Looks like ohne of these demonstrator mockups in tech schools....
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 02/27/2019 12:59 pm
RE exposed top re-entry:

1) A detachable upper fairing does not mean a disposable fairing. SpaceX are already trying to recover Falcon's fairing, after all. A simple pop-the-top mechanism is simpler, cheaper, and allows for more payload volume and easier payload deployment than any sort of door mechanism and deployment structure needed for a reattachable upper section. The idea is not inherently silly and has merit for quick deployment of SS/SH as a Big Dumb Cargo Launcher.

2) The point is moot for the hopper: it's never going to get even vaguely close to re-entry velocities, so is not going to be testing any re-entry shielding. Any shielding on it is going to be for aerodynamics, cosmetics, or for ground factors (e.g. insulation).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Eylrid on 02/27/2019 03:41 pm
RE exposed top re-entry:

1) A detachable upper fairing does not mean a disposable fairing. SpaceX are already trying to recover Falcon's fairing, after all. A simple pop-the-top mechanism is simpler, cheaper, and allows for more payload volume and easier payload deployment than any sort of door mechanism and deployment structure needed for a reattachable upper section. The idea is not inherently silly and has merit for quick deployment of SS/SH as a Big Dumb Cargo Launcher.

2) The point is moot for the hopper: it's never going to get even vaguely close to re-entry velocities, so is not going to be testing any re-entry shielding. Any shielding on it is going to be for aerodynamics, cosmetics, or for ground factors (e.g. insulation).

Is it, though? They have been struggling with catching fairings. They haven't even succeeded at it with helicopter drop tests. Catching fairings comes with the expense of the boat and extra time to bring the fairing back and reintegrate it. With Falcon 9 they have to try catching the fairings because they have no other way to bring them back. But for Starship they don't have to mess with that. It goes against their Starship design philosophy: Bring the the whole ship back in one piece so they can immediately and cheaply reuse it.

As for payload volume, Starship will have significantly more payload volume than any rocket currently launching, with or without payload bay doors.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 02/27/2019 04:01 pm
RE exposed top re-entry:

1) A detachable upper fairing does not mean a disposable fairing. SpaceX are already trying to recover Falcon's fairing, after all. A simple pop-the-top mechanism is simpler, cheaper, and allows for more payload volume and easier payload deployment than any sort of door mechanism and deployment structure needed for a reattachable upper section. The idea is not inherently silly and has merit for quick deployment of SS/SH as a Big Dumb Cargo Launcher.

2) The point is moot for the hopper: it's never going to get even vaguely close to re-entry velocities, so is not going to be testing any re-entry shielding. Any shielding on it is going to be for aerodynamics, cosmetics, or for ground factors (e.g. insulation).

Is it, though? They have been struggling with catching fairings. They haven't even succeeded at it with helicopter drop tests. Catching fairings comes with the expense of the boat and extra time to bring the fairing back and reintegrate it. With Falcon 9 they have to try catching the fairings because they have no other way to bring them back. But for Starship they don't have to mess with that. It goes against their Starship design philosophy: Bring the the whole ship back in one piece so they can immediately and cheaply reuse it.

As for payload volume, Starship will have significantly more payload volume than any rocket currently launching, with or without payload bay doors.
And with reusability, fast turn-around and in orbit refueling building with subassemblies is a reasonably alternative to monolithic payloads in most cases. I bet it would be spacex themselves that move to a 12m ITS before any paying customer requested a larger payload.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: alhenry1231 on 02/27/2019 04:08 pm
Here is an approximate figure on fairing thickness.
Assuming gloved hand is 4.25" [107.95] wide
thickness is close to 6mm or .25"

parallel lines .375" [9.5] is far wider than the material.
I would guess close to .25" [6] or less.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: eriblo on 02/27/2019 05:46 pm
Here is an approximate figure on fairing thickness.
Assuming gloved hand is 4.25" [107.95] wide
thickness is close to 6mm or .25"

parallel lines .375" [9.5] is far wider than the material.
I would guess close to .25" [6] or less.
My analysis assuming standard stainless steel sizes:
I get the most likely standard sheet size to be 5 ft x 12 ft by comparing to guard rails and workers and noting that 8*12 ft = 29.3 m which is close to the nominal circumference at 9 m*pi = 28.3 m. Trimming each sheet by 12.3 cm would match a 9 m diameter. 2 x 5 ft sheet width also seems to be the maximum for the automatic girth welder if it is unmodified.

The spreader they are using with the crane is marked 4 tons,so I assume this is total rated load. This spreader was used to lift 4 of the big "quarter panels" consisting of 2 x 2 pre-welded sheets, i.e. 16 sheets, at once. The stainless steel grade is unknown but it seems that most are > 7.9 t/m^3. Assuming they keep the weight limit the maximum allowable thickness would then be:

4 tons/(16*5 ft*12 ft*7.9 t/m^3) = 5.2 mm (5.3 mm for trimmed sheets), so the maximum standard thickness with all of these assumptions is 3/16 inch (7 gauge, ~4.8 mm).

(That's enough freedom units for one day...  ::) )
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Star One on 02/27/2019 05:52 pm
RE exposed top re-entry:

1) A detachable upper fairing does not mean a disposable fairing. SpaceX are already trying to recover Falcon's fairing, after all. A simple pop-the-top mechanism is simpler, cheaper, and allows for more payload volume and easier payload deployment than any sort of door mechanism and deployment structure needed for a reattachable upper section. The idea is not inherently silly and has merit for quick deployment of SS/SH as a Big Dumb Cargo Launcher.

2) The point is moot for the hopper: it's never going to get even vaguely close to re-entry velocities, so is not going to be testing any re-entry shielding. Any shielding on it is going to be for aerodynamics, cosmetics, or for ground factors (e.g. insulation).

Why introduce complexity into a simple design, the whole point of Starship is to keep things simple and your suggestion is completely opposite to this.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NH22077 on 02/27/2019 05:53 pm
Here is an approximate figure on fairing thickness.
Assuming gloved hand is 4.25" [107.95] wide
thickness is close to 6mm or .25"

parallel lines .375" [9.5] is far wider than the material.
I would guess close to .25" [6] or less.
My analysis assuming standard stainless steel sizes:
I get the most likely standard sheet size to be 5 ft x 12 ft by comparing to guard rails and workers and noting that 8*12 ft = 29.3 m which is close to the nominal circumference at 9 m*pi = 28.3 m. Trimming each sheet by 12.3 cm would match a 9 m diameter. 2 x 5 ft sheet width also seems to be the maximum for the automatic girth welder if it is unmodified.

The spreader they are using with the crane is marked 4 tons,so I assume this is total rated load. This spreader was used to lift 4 of the big "quarter panels" consisting of 2 x 2 pre-welded sheets, i.e. 16 sheets, at once. The stainless steel grade is unknown but it seems that most are > 7.9 t/m^3. Assuming they keep the weight limit the maximum allowable thickness would then be:

4 tons/(16*5 ft*12 ft*7.9 t/m^3) = 5.2 mm (5.3 mm for trimmed sheets), so the maximum standard thickness with all of these assumptions is 3/16 inch (7 gauge, ~4.8 mm).

(That's enough freedom units for one day...  ::) )

Someone posted a link to the corporate website for the machine and it states that minimum metal thickness is 3/8 of an inch. I just searched the threads I've been reading. And haven't found the link yet. Will update if I do.

Ned
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 02/27/2019 06:04 pm
Here is an approximate figure on fairing thickness.
Assuming gloved hand is 4.25" [107.95] wide
thickness is close to 6mm or .25"

parallel lines .375" [9.5] is far wider than the material.
I would guess close to .25" [6] or less.
My analysis assuming standard stainless steel sizes:
I get the most likely standard sheet size to be 5 ft x 12 ft by comparing to guard rails and workers and noting that 8*12 ft = 29.3 m which is close to the nominal circumference at 9 m*pi = 28.3 m. Trimming each sheet by 12.3 cm would match a 9 m diameter. 2 x 5 ft sheet width also seems to be the maximum for the automatic girth welder if it is unmodified.

The spreader they are using with the crane is marked 4 tons,so I assume this is total rated load. This spreader was used to lift 4 of the big "quarter panels" consisting of 2 x 2 pre-welded sheets, i.e. 16 sheets, at once. The stainless steel grade is unknown but it seems that most are > 7.9 t/m^3. Assuming they keep the weight limit the maximum allowable thickness would then be:

4 tons/(16*5 ft*12 ft*7.9 t/m^3) = 5.2 mm (5.3 mm for trimmed sheets), so the maximum standard thickness with all of these assumptions is 3/16 inch (7 gauge, ~4.8 mm).

(That's enough freedom units for one day...  ::) )

Someone posted a link to the corporate website for the machine and it states that minimum metal thickness is 3/8 of an inch. I just searched the threads I've been reading. And haven't found the link yet. Will update if I do.

Ned

I think this is what you're looking for?

reddit user ThatOlJanxSpirit found this welding machine company's website: http://ransomecompany.com/

Their 3 O'CLOCK TANK WELDER GIRTH WELD SEAMERS is similar to the one currently being used in Boca Chica hopper site for the new "fairing":

Quote
3 O'CLOCK TANK WELDER GIRTH WELD SEAMERS - AUTOMATIC VESSEL WELDING
Cut in-field welding time for storage tanks by up to 40%. The Ransome Automatic 3 oclock Girth Welder (AGW) performs x-ray quality horizontal welds up to 20 times faster than standard manual techniques. Operating at speeds from four to 105 inches per minute, the AGW can handle plates as thick as 1 ¾" and tank diameters from the largest to as small as 30’. It is available as a single or dual mobile welding station completely equipped with welding heads, all controls, flux support belts and flux recovery units.

The AGW straddles the tank shell plates, riding on serrated steel drive wheels that can be adjusted for tank diameter. The adjustable A-frame telescopes manually to handle six- to 10-feet high steel plates.

The AGW’s operator platform is a sturdy and solid work station with guard rails and all-weather curtains for operator safety and comfort. Ransome’s double platform is fully equipped with its own direction and speed controls. An access ladder allows movement to the primary flux separator tank and to the side of the dual unit.

Ergonomically designed for convenience, accessibility and efficiency, the AGW includes the Lincoln NA-3 solid state control and welding head fitted with nozzles, wire feed rolls, strengtheners and 50 lb. wire reels for either single or twin-arc wire. The submerged arc flux belt mechanism ensures retention of the flux at the joint for efficient recycling.

So minimal speed 0.1m per minute, maximum thickness is 44.45mm, minimal tank diameter 9.1m, plate height 1.8~3.0m. Is there any showstopper preventing SpaceX from using something like this to weld early Starship/SuperHeavy tanks?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: eriblo on 02/27/2019 06:26 pm
[...]

Someone posted a link to the corporate website for the machine and it states that minimum metal thickness is 3/8 of an inch. I just searched the threads I've been reading. And haven't found the link yet. Will update if I do.

Ned
I think this is what you're looking for?

reddit user ThatOlJanxSpirit found this welding machine company's website: http://ransomecompany.com/

[...]

I haven't been able to find a minimum for the Ransome AGW-2, although the maximum is 1 ¾"  (or 2" according to some sources). However, their single sided light weight AGW-LW (https://www.koike.com/documents/Product-Brochures/Welding/TANKFABRICATION_POS_ENG_WEB.pdf) (WARNING: PDF) goes down to 3/16" so I think it's possible with the right settings. The limit might be the walls ability to support the weight of the welder in which case the relatively small diameter helps.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: alhenry1231 on 02/27/2019 07:20 pm
For the plate to be .375" [9.5] the gloved hand would need to be 6.375" [162] wide

my hand width for reference 3.5" [89] un-gloved.

I think its less than .375" [9.5]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ejb749 on 02/27/2019 08:13 pm
Here's a comparison on the progress on Hat V2.0 vs the original.  The new section is in the red box.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Zed_Noir on 02/27/2019 08:29 pm
Have a idea for an interim upper stage with the current Hopper configuration.

After the Hopper finishes the low altitude flight test. Is it worthwhile to refitted it with a flight capable payload fairing/nose cone that can survive orbital launch? Maybe carrying up a few smallsats and many cubesats to LEO as the Inaugural Super Heavy upper stage. Something to tested the Raptor SL engines' vacuum performance with redundant hardware.

Putting a real Starship of some type on the inaugural Super Heavy flight seems like a bad idea. Expending the redundant Hopper as a flight test unit appears to be a cheap alternative.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 02/27/2019 09:01 pm
Just "no".
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/27/2019 09:10 pm
Putting a real Starship of some type on the inaugural Super Heavy flight seems like a bad idea. Expending the redundant Hopper as a flight test unit appears to be a cheap alternative.

What would it accomplish? It doesn't have anywhere NEAR the performance to make orbit.

The SuperHeavy/Starship is a fully reusable system, where the parts will tested separately before being flown together. (And Starship will see a lot more test flights)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 02/27/2019 09:26 pm
Here's a comparison on the progress on Hat V2.0 vs the original.  The new section is in the red box.
I think you're red box is one 1/2 section too low. For the new hat, each full section is two panels high, so there are six panels vertical in total. The image in the red box has cropped off the majority of the bottom panel. Therefore there should be one more section (again, comprised of two panels in height) before it begins to taper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 02/27/2019 09:35 pm
I am willing to bet 2 internet bananas that a cone cap section is already waiting in the tent.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kansan52 on 02/27/2019 10:32 pm
How does that 'internet banana bet' work? Because I am positive the old cap is still laying there while SX figures if selling as scrap or reusing is best.

Of course, with my record of guessing, it probably is sitting there waiting for the insurance adjuster.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: uhuznaa on 02/27/2019 10:43 pm
To be honest I fear they will just try to launch the thing from A to B. Everything else would be pretending.

It really looks like that. Why prepare the surface beneath a stage you want to drive away first? They're crazy, yes. You need to be crazy to even try anything like that.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/27/2019 11:45 pm
To be honest I fear they will just try to launch the thing from A to B. Everything else would be pretending.

Pretending? Really?  ::)

It really looks like that. Why prepare the surface beneath a stage you want to drive away first? They're crazy, yes. You need to be crazy to even try anything like that.

Because no one wants to work in sand/mud. And they need a flat surface. Of course they will move it - have you missed the road they are building to it? Just spend a few minutes thinking about it and you'll see that they propellant and launch infrastructure is being built ... at the launch place.

A concrete foundation does not equal launch spot. You are the crazy one.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/28/2019 01:29 am
Putting a real Starship of some type on the inaugural Super Heavy flight seems like a bad idea. Expending the redundant Hopper as a flight test unit appears to be a cheap alternative.

Why?  By the time an Upper Stage is ready to be mated to Super Heavy, it will have been sufficiently proven through Static Fires and a robust Booster Hopping and Landing testing regime.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Boer on 02/28/2019 05:32 am
Hi, I am new to the forum.

What if the segments they are welding are not a new Starhip hat, but a Superheavy representative? The booster needs landing testing too right?

With both a Starship and Superheavy top they can switch en test both.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/28/2019 05:39 am
How does that 'internet banana bet' work? Because I am positive the old cap is still laying there while SX figures if selling as scrap or reusing is best.

Of course, with my record of guessing, it probably is sitting there waiting for the insurance adjuster.
It was hauled away in scrap trucks a while ago. Mostly.

Hi, I am new to the forum.

What if the segments they are welding are not a new Starhip hat, but a Superheavy representative? The booster needs landing testing too right?

With both a Starship and Superheavy top they can switch en test both.
It's way too light for that. Heavier than the original, but you can still see it shaking in the wind.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bogeyman on 02/28/2019 05:53 am
Hi, I am new to the forum.

What if the segments they are welding are not a new Starhip hat, but a Superheavy representative? The booster needs landing testing too right?

With both a Starship and Superheavy top they can switch en test both.
Hi and welcome to the forum.
No, that thing is going to be the tip for the hopper. They had another one already on it but it got blewn over by a storm. The one they are building right now is the replacement for the broken one.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 02/28/2019 06:35 am
Hi, I am new to the forum.

What if the segments they are welding are not a new Starhip hat, but a Superheavy representative? The booster needs landing testing too right?

With both a Starship and Superheavy top they can switch en test both.
Hi and welcome to the forum.
No, that thing is going to be the tip for the hopper. They had another one already on it but it got blewn over by a storm. The one they are building right now is the replacement for the broken one.
It's possible that they're building an actual for real orbital Starship, but I doubt it. Probably just another, better, tinfoil hat.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: born01930 on 02/28/2019 11:03 am
The old tinfoil hat started to taper by the time it reached the height of the new shiny cylinder. Maybe Boer is on to something. Also that may be why they are making the hopper dome shiny...for esthetics
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 02/28/2019 12:01 pm
The old alufoil-wrapped cardboard hat didn't stand quite as tall as the planned Starship. Maybe this time SpaceX decided to do a proper job and approximate the Starship outer mold line with their v. 2.0.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 02/28/2019 12:53 pm
The old tinfoil hat started to taper by the time it reached the height of the new shiny cylinder. Maybe Boer is on to something. Also that may be why they are making the hopper dome shiny...for esthetics

Yes. The more reflective sheets on the dome, the less chance to see the fairing v.2 on the hopper v.1  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RocketGoBoom on 02/28/2019 01:02 pm
Elon should have called it the "Centennium Falcon".

When people ask, "Why did you call it the Centennium Falcon?"

Elon would say, "We are not yet ready to build the Millennium Falcon."
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 02/28/2019 02:50 pm
have been added to the dome.

So about that blue trapezoid of stuff being added to the dome, again I pull out these pictures of how it looks like this is shaping up
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/28/2019 03:13 pm
have been added to the dome.

So about that blue trapezoid of stuff being added to the dome, again I pull out these pictures of how it looks like this is shaping up
It's not blue. The sky is.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ejb749 on 02/28/2019 03:41 pm
I think you're red box is one 1/2 section too low. For the new hat, each full section is two panels high, so there are six panels vertical in total. The image in the red box has cropped off the majority of the bottom panel. Therefore there should be one more section (again, comprised of two panels in height) before it begins to taper.
The V1 hat is on top of the concrete base, and the V2 hat is not.  Also, the bottom of the V2 hat isn't in the picture, so I estimated about where it would be.

Nomadd, could you get a shot of the entire V2 hat from the ground up? (...when the fog clears)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 02/28/2019 04:10 pm
I think you're red box is one 1/2 section too low. For the new hat, each full section is two panels high, so there are six panels vertical in total. The image in the red box has cropped off the majority of the bottom panel. Therefore there should be one more section (again, comprised of two panels in height) before it begins to taper.
The V1 hat is on top of the concrete base, and the V2 hat is not.  Also, the bottom of the V2 hat isn't in the picture, so I estimated about where it would be.

Nomadd, could you get a shot of the entire V2 hat from the ground up? (...when the fog clears)
The one Bocachicagal got is the closest. Too many obstructions for a clear shot. You can see the bottom of the six sections, which is the same height as the other five.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kansan52 on 02/28/2019 04:25 pm

 It was hauled away in scrap trucks a while ago. Mostly.


Thanks!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Zed_Noir on 02/28/2019 04:43 pm
Putting a real Starship of some type on the inaugural Super Heavy flight seems like a bad idea. Expending the redundant Hopper as a flight test unit appears to be a cheap alternative.

Why?  By the time an Upper Stage is ready to be mated to Super Heavy, it will have been sufficiently proven through Static Fires and a robust Booster Hopping and Landing testing regime.

It is a cheap way of testing the Raptor SL engines in vacuum in at least a sub-orbital flight before the inaugural orbital Starship flight. Since AFAIK there is no vacuum test facility to test fire the Raptor engines.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ejb749 on 02/28/2019 04:45 pm
Quote
The one Bocachicagal got is the closest. Too many obstructions for a clear shot. You can see the bottom of the six sections, which is the same height as the other five.
That's the one I used.  I just overlaid your L2 picture from 02/27/2019 03:43 pm where you can see the bottom, and it matches pretty well. So I think the first overlay is very close.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 02/28/2019 04:51 pm
Putting a real Starship of some type on the inaugural Super Heavy flight seems like a bad idea. Expending the redundant Hopper as a flight test unit appears to be a cheap alternative.

Why?  By the time an Upper Stage is ready to be mated to Super Heavy, it will have been sufficiently proven through Static Fires and a robust Booster Hopping and Landing testing regime.

It is a cheap way of testing the Raptor SL engines in vacuum in at least a sub-orbital flight before the inaugural orbital Starship flight. Since AFAIK there is no vacuum test facility to test fire the Raptor engines.

Starship does that before mating.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Zed_Noir on 02/28/2019 05:08 pm
Putting a real Starship of some type on the inaugural Super Heavy flight seems like a bad idea. Expending the redundant Hopper as a flight test unit appears to be a cheap alternative.

Why?  By the time an Upper Stage is ready to be mated to Super Heavy, it will have been sufficiently proven through Static Fires and a robust Booster Hopping and Landing testing regime.

It is a cheap way of testing the Raptor SL engines in vacuum in at least a sub-orbital flight before the inaugural orbital Starship flight. Since AFAIK there is no vacuum test facility to test fire the Raptor engines.

Starship does that before mating.

Starship doing a near SSTO launch without the Raptor SL engines being vacuum test fired previously seems like rolling the dice unnecessarily with expensive hardware. IMO
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/28/2019 05:11 pm
Starship doing a near SSTO launch without the Raptor SL engines being vacuum test fired previously seems like rolling the dice unnecessarily with expensive hardware. IMO

This is bordering on concern trolling. SL engines operating in Vacuum is not a mystery. Every SL engine eventually runs in vacuum as it rises above the atmosphere. SpaceX developed several Merlin variants (SL and Vacuum) without a vacuum test stand or the need to lob an engine up in space just to test if it will run period.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Negan on 02/28/2019 05:15 pm
There's only one way to test staging.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 02/28/2019 05:29 pm
Starship doing a near SSTO launch without the Raptor SL engines being vacuum test fired previously seems like rolling the dice unnecessarily with expensive hardware. IMO

This is bordering on concern trolling. SL engines operating in Vacuum is not a mystery. Every SL engine eventually runs in vacuum as it rises above the atmosphere. SpaceX developed several Merlin variants (SL and Vacuum) without a vacuum test stand or the need to lob an engine up in space just to test if it will run period.

Agree about the SL engines in vacuum (not an issue), but if the entire vacuum nozzle is regeneratively cooled, isn't that something that needs testing? Perhaps they just need to know the flow rates and everything (which could be tested without vacuum), but I'd imagine one would want to test the entire setup. What do I know, I'm no rocket scientist.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: matthewkantar on 02/28/2019 05:29 pm
There's only one way to test staging.

Not completely true, there was a SpaceX video, I think called “cool stuff,” of a test stand for validating the center-push staging mechanism. It featured a large counterweight to simulate zero gee. The video showed a Twomp! Painted on the counterweight.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: abaddon on 02/28/2019 05:40 pm
There's only one way to test staging.

Not completely true, there was a SpaceX video, I think called “cool stuff,” of a test stand for validating the center-push staging mechanism. It featured a large counterweight to simulate zero gee. The video showed a Twomp! Painted on the counterweight.
Right, this feature is unique to SpaceX (that I know of) since they use pushers instead of frangible bolts.  (I guess you could still test stage separation with frangible bolts but you'd have to replace the hardware).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Negan on 02/28/2019 05:53 pm
There's only one way to test staging.

Not completely true, there was a SpaceX video, I think called “cool stuff,” of a test stand for validating the center-push staging mechanism. It featured a large counterweight to simulate zero gee. The video showed a Twomp! Painted on the counterweight.

Had they even landed their first booster at that point?

Edit: They will have a cheap launch cost (which must be true if they're to do many Super Heavy hop tests), and a cheap way to build flight worthy test setups (already proven by Hopper). They might not be satisfied with the same testing regime that systems on an expendable F9 went through.

Edit: It's interesting that the second F1 flight failed because of a staging problem. Knowing this, the idea they would risk a full up SS on the first full stack flight is absurd.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 02/28/2019 06:23 pm
Starship doing a near SSTO launch without the Raptor SL engines being vacuum test fired previously seems like rolling the dice unnecessarily with expensive hardware. IMO

This is bordering on concern trolling. SL engines operating in Vacuum is not a mystery. Every SL engine eventually runs in vacuum as it rises above the atmosphere. SpaceX developed several Merlin variants (SL and Vacuum) without a vacuum test stand or the need to lob an engine up in space just to test if it will run period.

Agree about the SL engines in vacuum (not an issue), but if the entire vacuum nozzle is regeneratively cooled, isn't that something that needs testing? Perhaps they just need to know the flow rates and everything (which could be tested without vacuum), but I'd imagine one would want to test the entire setup. What do I know, I'm no rocket scientist.

This is drifting off topic, but they deferred a vacuum version of Raptor (with a cooled vacuum nozzle) to a later version of the system.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: StuffOfInterest on 03/01/2019 02:26 pm
Hi, I am new to the forum.

What if the segments they are welding are not a new Starhip hat, but a Superheavy representative? The booster needs landing testing too right?

With both a Starship and Superheavy top they can switch en test both.
It's way too light for that. Heavier than the original, but you can still see it shaking in the wind.

I still wonder if there will be some cable tensioners inside of the top hat eventually.  Even three crossing at 60-deg angles and repeated every 10' or so vertically would provide a lot of stiffness to the structure without adding too much weight.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/01/2019 02:45 pm
Hi, I am new to the forum.

What if the segments they are welding are not a new Starhip hat, but a Superheavy representative? The booster needs landing testing too right?

With both a Starship and Superheavy top they can switch en test both.
It's way too light for that. Heavier than the original, but you can still see it shaking in the wind.

I still wonder if there will be some cable tensioners inside of the top hat eventually.  Even three crossing at 60-deg angles and repeated every 10' or so vertically would provide a lot of stiffness to the structure without adding too much weight.
That's what I guessed they'd do to the original when the storm was on it's way. It seemed way too flexible for those winds.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Negan on 03/01/2019 03:35 pm
That staging failure was 70 launches ago.  I think by now they've pretty much worked out any kinks in their staging system, such that they should have high confidence with it on the new architecture.  They're not treading entirely unknown ground, here.

They are not on entirely known ground either. As this forum points out a lot, there can always be unknown unknowns. It is very perplexing to me why there is so much resistance to the idea. Especially when such a test article would be fairly inexpensive to make and launch, and they would be trying to prevent an issue they have first hand experience with.

Edit: Really the only argument people can make in this case is that staging issues on new launch systems don't happen, and that would be totally false.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SPadre on 03/01/2019 04:14 pm
SpaceX fans, join in today at 3pm CST for a fun "live stream / live chat" session live on location at SpaceX Boca Chica Starship Hopper! The fog has been relentless here, sorry, its definitely unprecedented and with yet another major cold front arriving next week it may not be over yet.

The stream will go live on our youtube channel at 3pm, hope you enjoy! No talking heads or professional equipment, just raw streaming from Iphone XS Max and a chance for everyone to chat live while seeing the up close current status of the FogHopper.

https://www.youtube.com/channel/UCDkP5NWUhfHXZNhcGr2G2pQ
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/01/2019 05:46 pm
That staging failure was 70 launches ago.  I think by now they've pretty much worked out any kinks in their staging system, such that they should have high confidence with it on the new architecture.  They're not treading entirely unknown ground, here.

They are not on entirely known ground either. As this forum points out a lot, there can always be unknown unknowns. It is very perplexing to me why there is so much resistance to the idea. Especially when such a test article would be fairly inexpensive to make and launch, and they would be trying to prevent an issue they have first hand experience with.

Edit: Really the only argument people can make in this case is that staging issues on new launch systems don't happen, and that would be totally false.

I'm not sure what your point is though. Stage testing CAN be tested on the ground, SpaceX does it at McGregor, so your claim ("There's only one way to test staging") is demonstrably false.
 
I might regret asking this, but I don't want to assume concern trolling - but what is your concern exactly? Why is staging something that should keep SpaceXers up at night compared to other issues?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JonathanD on 03/01/2019 06:32 pm
If there were a list of things that SpaceX would be worried about with this architecture, I'm pretty confident in saying that staging would be near the bottom.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Negan on 03/01/2019 07:14 pm
I'm not sure what your point is though. Stage testing CAN be tested on the ground, SpaceX does it at McGregor, so your claim ("There's only one way to test staging") is demonstrably false.

I was told my statement wasn't completely true so to me that sounded like the McGregor testing doesn't cover all flight variables. Does it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: abaddon on 03/01/2019 07:27 pm
I was told my statement wasn't completely true so to me that sounded like the McGregor testing doesn't cover all flight variables. Does it?
Nothing covers all flight variables other than flying... a lot.  In fact, you could argue that you don't cover all flight variables a vehicle will see in service until the vehicle is retired.

The fact remains that staging is among the best understood and least risky parts of what SpaceX are doing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Negan on 03/01/2019 07:35 pm
The fact remains that staging is among the best understood and least risky parts of what SpaceX are doing.

Than why the heck was one of the first failures that they encountered due to a staging issue?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/01/2019 07:40 pm
The fact remains that staging is among the best understood and least risky parts of what SpaceX are doing.

Than why the heck was one of the first failures that they encountered due to a staging issue?

It wasn't a "staging failure" per se. The separation worked. But the timing was off since the Merlin engine had residual thrust and recontacted the upper stage. One part of the fix was to delay staging another second or two after MECO.

And ^%& happens. Sometimes you test something pretty thoroughly but miss one aspect that comes back to bite you. But SpaceX staging process has been extremely reliable ever since.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Negan on 03/01/2019 07:45 pm
And ^%& happens. Sometimes you test something pretty thoroughly but miss one aspect that comes back to bite you.

So why not just do a cheap flight test before risking a full up SS?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JonathanD on 03/01/2019 07:49 pm
So why not just do a cheap flight test before risking a full up SS?

1) You're never going to be able to exactly replicate it

2) They want to get to Mars in our lifetime
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: abaddon on 03/01/2019 07:52 pm
So why not just do a cheap flight test before risking a full up SS?

1) You're never going to be able to exactly replicate it

2) They want to get to Mars in our lifetime
3) What is this "cheap test flight" that tests Starship staging from the Super Heavy without actually being Starship staging from the Super Heavy?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BunkerTheHusky on 03/01/2019 07:55 pm
This is a new section they have started today.  ;D

New section? As in a new segment of the top hat about to be welded on, or a new construction for something else?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Negan on 03/01/2019 07:58 pm
So why not just do a cheap flight test before risking a full up SS?

1) You're never going to be able to exactly replicate it

2) They want to get to Mars in our lifetime
3) What is this "cheap test flight" that tests Starship staging from the Super Heavy without actually being Starship staging from the Super Heavy?

Anything that can give additional useful data than what the ground tests could.

Edit: Considering the water tower verses hopper debate, I'm skeptical of someone telling me the only way to test flight separation is with a actual SS.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/01/2019 07:59 pm
And ^%& happens. Sometimes you test something pretty thoroughly but miss one aspect that comes back to bite you.

So why not just do a cheap flight test before risking a full up SS?

Sigh... How many "cheap flight tests" do you propose to ease your mind about this? And the next issue you are concerned about... and so on. This is not the 50's and 60's anymore.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Negan on 03/01/2019 08:10 pm
And ^%& happens. Sometimes you test something pretty thoroughly but miss one aspect that comes back to bite you.

So why not just do a cheap flight test before risking a full up SS?

Sigh... How many "cheap flight tests" do you propose to ease your mind about this? And the next issue you are concerned about... and so on. This is not the 50's and 60's anymore.

Only one test was proposed. Who's being the concern troll now?

Edit: The F1 failure happened in 2007.

Edit: And the Soyuz MS-10 failure happened 10/2018. Very low risk huh? Soyuz FG 64 successful flights before its first failure.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 03/01/2019 08:22 pm
So why not just do a cheap flight test before risking a full up SS?

1) You're never going to be able to exactly replicate it

2) They want to get to Mars in our lifetime
3) What is this "cheap test flight" that tests Starship staging from the Super Heavy without actually being Starship staging from the Super Heavy?
This, note that starship is way easier than Falcon 9 since starship will have no interstage but an skirt covering the upper stage engines.

You have the option to use shaped charges as an fallback if the hydraulic separation fails.  For an manned or high profile mission this makes sense even if you loose super heavy and armoring for this will just cost a few hundred kg on first stage.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/01/2019 08:29 pm
And ^%& happens. Sometimes you test something pretty thoroughly but miss one aspect that comes back to bite you.

So why not just do a cheap flight test before risking a full up SS?

Sigh... How many "cheap flight tests" do you propose to ease your mind about this? And the next issue you are concerned about... and so on. This is not the 50's and 60's anymore.

Only one test was proposed. Who's being the concern troll now?
?? I'm not the one proposing near useless test flights to verify very low risk technologies. The point is that IF indeed staging is your threshold for "gotta do a throw away flight test", then there are several much more challenging technologies that will be involved. Are you going to suggest throw away test articles for those as well?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: zodiacchris on 03/01/2019 08:41 pm
Guys, this thread is about the hopper development not about future flight testing of Booster and Starship. So please settle, and if you absolutely must argue about unlikely fringe ideas take it somewhere else. I for one do not care to read all that pointless arguing when I‘m interested in the Hopper DEVELOPMENT.

Thank you 🙏
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 03/01/2019 08:41 pm
This is a new section they have started today.  ;D

New section? As in a new segment of the top hat about to be welded on, or a new construction for something else?

The former I believe. But nothing certain
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Negan on 03/01/2019 08:45 pm
Unlikely fringe ideas

Sort of exactly like how Hopper was made.  :P
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 03/01/2019 08:57 pm
This is a new section they have started today.  ;D

New section? As in a new segment of the top hat about to be welded on, or a new construction for something else?

The former I believe. But nothing certain

A new section of the fairing/nosecone. It is being assembled on a pad behind the containers that were recently delivered.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Pallen on 03/02/2019 02:36 am
It does not look like shiny S. Steel unless it is just optical.   It couldn't be the start of a... naw couldn't be.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/02/2019 03:05 am
This is a new section they have started today.  ;D

New section? As in a new segment of the top hat about to be welded on, or a new construction for something else?

The former I believe. But nothing certain
A new section of the fairing/nosecone. It is being assembled on a pad behind the containers that were recently delivered.

Do you mean this location (in red circle)?

If so this could be huge, we may be seeing the start of SuperHeavy prototype.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Metalskin on 03/02/2019 04:23 am
This is a new section they have started today.  ;D

New section? As in a new segment of the top hat about to be welded on, or a new construction for something else?

The former I believe. But nothing certain
A new section of the fairing/nosecone. It is being assembled on a pad behind the containers that were recently delivered.

Do you mean this location (in red circle)?

If so this could be huge, we may be seeing the start of SuperHeavy prototype.

You can see a green container with a red container on top of it in the reflection, with some further red containers next to those two. The only matching location appears to be the concrete pad that you circled.

It's confusing, because the zoom lens has compressed the distances so much.  Until your comment, I thought it was over near the hopper.

~edit~

If my assumptions are correct, then bocachicagal must have taken the pic from between middle top and top right of your pic with the circle in it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/02/2019 04:24 am
It does not look like shiny S. Steel unless it is just optical.   It couldn't be the start of a... naw couldn't be.
It comes with a film they have to peel off.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 03/02/2019 04:49 am
If my assumptions are correct, then bocachicagal must have taken the pic from between middle top and top right of your pic with the circle in it?
I've seen a flyover pic where there is a stainless steel cylinder being assembled in that place
I don't know when it was from
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/02/2019 07:51 am
You can see a green container with a red container on top of it in the reflection, with some further red containers next to those two. The only matching location appears to be the concrete pad that you circled.

Thank you for pointing this out, I didn't even realize it's reflection, I thought it's a real container distorted by lens. This reflective stuff really messes with perception, now I can see the section clearly.

Quote
If my assumptions are correct, then bocachicagal must have taken the pic from between middle top and top right of your pic with the circle in it?

Right, here's my guess of where she took the photo from.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 03/02/2019 08:13 am
L2 may be a wonderful place for more information. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/02/2019 08:24 am
L2 may be a wonderful place for more information. 
Yes. Go into the light.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Star One on 03/02/2019 08:27 am
Guys, this thread is about the hopper development not about future flight testing of Booster and Starship. So please settle, and if you absolutely must argue about unlikely fringe ideas take it somewhere else. I for one do not care to read all that pointless arguing when I‘m interested in the Hopper DEVELOPMENT.

Thank you

Why not direct your complaint at those coming in here and concern trolling, so that reliable posters like Lars-J has to waste time answering?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/02/2019 05:26 pm
Closing up the upper bulkhead access port.

Wohoo! Interior work finished!

But how does the guy who fastens the bolts from the inside get out?  ???
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/02/2019 05:29 pm
Closing up the upper bulkhead access port.

Wohoo! Interior work finished!

But how does the guy who fastens the bolts from the inside get out?  ???
Hatch has threaded lugs welded to backside. Notice hatch inserted through hole and the bolted together. This is good from a pressure perspective too.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: TheEmbeddedGuy on 03/02/2019 07:33 pm
Now we know why it was oval shaped.
Everyone has called it an 'access port', did we ever see it used for anything but ventilation?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HeartofGold2030 on 03/02/2019 07:41 pm
Now we know why it was oval shaped.
Everyone has called it an 'access port', did we ever see it used for anything but ventilation?

People are calling it an access port because that's exactly what it is, there are many pictures of people climbing inside the vehicle through it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: brlavalamp on 03/03/2019 03:33 am
It does not look like shiny S. Steel unless it is just optical.   It couldn't be the start of a... naw couldn't be.
It comes with a film they have to peel off.

I believe the stainless steel does not look shiny in this photo because it is covered in dew, which is diffusing the reflections.  Here is a crop that clearly shows both drops of water along the bottom edge of the section and also droplet trails running down the welded sheets.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/03/2019 03:43 am
Closing up the upper bulkhead access port.

Wohoo! Interior work finished!

But how does the guy who fastens the bolts from the inside get out?  ???
Hatch has threaded lugs welded to backside. Notice hatch inserted through hole and the bolted together. This is good from a pressure perspective too.
Always good to have pressure making the seal instead of trying to blow it out.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Barrie on 03/03/2019 10:44 am
Not sure what the yellow crane is lifting

https://twitter.com/janeidyeve/status/1102028806158778368

Telescopic mast?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Zardar on 03/03/2019 11:28 am
Telescopic mast?

Nope, that piece of truss is just part of the (yellow) crane.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/03/2019 02:31 pm
So, after the both hatches are closed and the the blue stand (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1915440#msg1915440) is delivered, we should expect the first tests of the hopper - checking tanks for leaks. I predict these tests will undergo next week.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/03/2019 06:39 pm
This afternoon they lowering and attaching these sections along the top inside edge of the fairing. The lower bulkhead access port has now been closed.
That looks to be wither a stiffening member or a mounting flange for attaching the hat to the base. I'm trying to work out a attaching method that utilizes the steel angle brackets that have recently showed up on the concrete jig. I suppose if threaded rod was welded to the top of the dome on the BFH base, then these steel angle brackets could be bolted to them after the hat is put in place, with the bottom of the brackets snugging down against the "mounting flange" we see going into the hat section.

In order to do that I expect to see a manhole installed on the back side of the hat at some point...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Spindog on 03/03/2019 06:54 pm
Have we seen any part of the cone sections for the new faring yet? I presume that work may be going on inside the tent.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Zardar on 03/03/2019 08:14 pm

In order to do that I expect to see a manhole installed on the back side of the hat at some point...

I am also expecting some sort of access port - and it will line up with the welded ladder rungs on the top of the dome.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/03/2019 11:59 pm
What’s being constructed by the shipping containers out back?!

Aha, now the world is ready to deal with the question I asked 5 days ago.  Those containers are stacked as a wind break around a pad the same way that they were for the original build in November / December, that's why I asked.

https://forum.nasaspaceflight.com/index.php?topic=47301.msg1915456#msg1915456 (https://forum.nasaspaceflight.com/index.php?topic=47301.msg1915456#msg1915456)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/04/2019 12:14 am
What’s being constructed by the shipping containers out back?!

Aha, now the world is ready to deal with the question I asked 5 days ago.  Those containers are stacked as a wind break around a pad the same way that they were for the original build in November / December, that's why I asked.

https://forum.nasaspaceflight.com/index.php?topic=47301.msg1915456#msg1915456 (https://forum.nasaspaceflight.com/index.php?topic=47301.msg1915456#msg1915456)

Well it's been a head-scratcher ever since we spotted the empty square pad a couple of weeks ago.

There's plenty of room in the main area for a small side project.  Why is this thing being built so far out of the way?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/04/2019 01:02 am
They parked a Helium(?) trailer near the hopper, looks like they're ready to pressure test the tanks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RobLynn on 03/04/2019 01:39 am
They parked a Helium(?) trailer near the hopper, looks like they're ready to pressure test the tanks.

I doubt they would pressure test with helium, much more likely to do it using far safer incompressible water.  The helium would be for leak detection using only very low pressure.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BrianPeterson on 03/04/2019 02:28 am
Those containers are stacked as a wind break around a pad the same way that they were for the original build in November / December, that's why I asked.

https://forum.nasaspaceflight.com/index.php?topic=47301.msg1915456#msg1915456 (https://forum.nasaspaceflight.com/index.php?topic=47301.msg1915456#msg1915456)

Long time lurker. But going through RGVAriealPhotography's twitter feed I noticed this interesting detail today.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThereIWas3 on 03/04/2019 02:41 am
There's plenty of room in the main area for a small side project.  Why is this thing being built so far out of the way?

Perhaps to leave room back in the main area for something else, or so that the big cranes have room to move about.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/04/2019 02:54 am
There's plenty of room in the main area for a small side project.  Why is this thing being built so far out of the way?

Perhaps to leave room back in the main area for something else, or so that the big cranes have room to move about.

I know, but this is such a tiny pad, and they already have the tent there as a wind breaker.... 

Instead they went of to a place that's disconnected from the main work area, built a wind breaker out of containers... and if these two structures are related, they'll have to haul it back to the main area anyway...

But if it's a different thing - is it the next prototype?  Seems a bit... modest...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Coastal Ron on 03/04/2019 03:26 am
There's plenty of room in the main area for a small side project.  Why is this thing being built so far out of the way?

Perhaps to leave room back in the main area for something else, or so that the big cranes have room to move about.

I know, but this is such a tiny pad, and they already have the tent there as a wind breaker....

Instead they went of to a place that's disconnected from the main work area, built a wind breaker out of containers... and if these two structures are related, they'll have to haul it back to the main area anyway...

I think we'll know soon, but how about this for a guess:

They are working on the lower half of the nosecone over at the main pad, but this "remote" assembly area might be for the upper half - maybe because they need to work on the curved section of the nosecone closer to the ground?

If so then soon we should start seeing some structural scaffolding going up inside the ring of this remote assembly area.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 03/04/2019 03:35 am
Regarding the Helium tank near the hopper.

Helium is used extensively in welding of 300 series alloys in some applications. This is
particularly true with heavier gauge metals and when welding seams. It allows higher heat welds than argon does. It may be that they are using that for internal welding or finishing welds on the internal seams.

Another possibility is using helium for inert gas purging of internal and external stainless piping while welding. It may for some reason be preferred over the more commonly used argon in an application.

Yet another possibility is that they are using it as the actuating gas for various systems. pneumatically operated valves comes to mind. Since those components would be located in a cryogenic environment, they need an actuating gas that wont liquefy at super cooled LOX or LCH4 temperatures. We know that spaceX does use helium as an actuator gas in Falcon 9 applications such as extending the landing leg cylinders.

These are just possibilities that come to mind.

Best Wishes all, thanks for the good reading!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/04/2019 03:46 am
There's plenty of room in the main area for a small side project.  Why is this thing being built so far out of the way?

Perhaps to leave room back in the main area for something else, or so that the big cranes have room to move about.

I know, but this is such a tiny pad, and they already have the tent there as a wind breaker....

Instead they went of to a place that's disconnected from the main work area, built a wind breaker out of containers... and if these two structures are related, they'll have to haul it back to the main area anyway...

I think we'll know soon, but how about this for a guess:

They are working on the lower half of the nosecone over at the main pad, but this "remote" assembly area might be for the upper half - maybe because they need to work on the curved section of the nosecone closer to the ground?

If so then soon we should start seeing some structural scaffolding going up inside the ring of this remote assembly area.
Maybe it's a process dev explorer, that's never going to merge with the main assembly?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Negan on 03/04/2019 05:14 am
There's plenty of room in the main area for a small side project.  Why is this thing being built so far out of the way?

Perhaps to leave room back in the main area for something else, or so that the big cranes have room to move about.

I know, but this is such a tiny pad, and they already have the tent there as a wind breaker....

Instead they went of to a place that's disconnected from the main work area, built a wind breaker out of containers... and if these two structures are related, they'll have to haul it back to the main area anyway...

I think we'll know soon, but how about this for a guess:

They are working on the lower half of the nosecone over at the main pad, but this "remote" assembly area might be for the upper half - maybe because they need to work on the curved section of the nosecone closer to the ground?

If so then soon we should start seeing some structural scaffolding going up inside the ring of this remote assembly area.
Maybe it's a process dev explorer, that's never going to merge with the main assembly?

Maybe it's a boilerplate for the first Super Heavy launch.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Coastal Ron on 03/04/2019 06:00 am
Maybe it's a boilerplate for the first Super Heavy launch.

Musk stated that Super Heavy test version wouldn't start being built until at least Spring, and we're still in Winter. So while there are many things it could be, I'm not thinking it's Super Heavy related.

I think we'll know within a weeks time though...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/04/2019 08:48 am
But if it's a different thing - is it the next prototype?  Seems a bit... modest...

Well, the hopper started pretty modest too, many people (including me) thought it was a water tower...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: stioks on 03/04/2019 09:25 am

I think we'll know soon, but how about this for a guess:

They are working on the lower half of the nosecone over at the main pad, but this "remote" assembly area might be for the upper half - maybe because they need to work on the curved section of the nosecone closer to the ground?

If so then soon we should start seeing some structural scaffolding going up inside the ring of this remote assembly area.

I also think they will built the fairing in two halves and will assemble them as soon as the bottom engine/tank section is complete. Until then they will stay separated in order to minimize the risk of high winds destroying them.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/04/2019 11:40 am
Well the concrete cylinder has new bits on it that look like very sturdy holddowns. So they might assemble the nosecond on it again without having to worry about another blowover event.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: KSHavre on 03/04/2019 02:32 pm

I think we'll know soon, but how about this for a guess:

They are working on the lower half of the nosecone over at the main pad, but this "remote" assembly area might be for the upper half - maybe because they need to work on the curved section of the nosecone closer to the ground?

If so then soon we should start seeing some structural scaffolding going up inside the ring of this remote assembly area.

I also think they will built the fairing in two halves and will assemble them as soon as the bottom engine/tank section is complete. Until then they will stay separated in order to minimize the risk of high winds destroying them.

If I remember right, they built the last fairing in 2 pieces; the straight piece as one section and the curved bit as another, then assemble on a still day. Get each part right, use smaller cranes (safety?), easier wind protection; it just makes sense. EDIT: deleted redundant text
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/04/2019 02:35 pm

I think we'll know soon, but how about this for a guess:

They are working on the lower half of the nosecone over at the main pad, but this "remote" assembly area might be for the upper half - maybe because they need to work on the curved section of the nosecone closer to the ground?

If so then soon we should start seeing some structural scaffolding going up inside the ring of this remote assembly area.

I also think they will built the fairing in two halves and will assemble them as soon as the bottom engine/tank section is complete. Until then they will stay separated in order to minimize the risk of high winds destroying them.

If I remember right, they built the last fairing in 2 pieces; the straight piece as one section and the curved bit as another, then assemble on a still day. Get each part right, use smaller cranes (safety?), easier wind protection and for the wind issue; it just makes sense.
They actually built it in three components. Then the top two were mated off the jig. The third was on the jig. Then the three were mated on the jig.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/04/2019 04:43 pm


If I remember right, they built the last fairing in 2 pieces; the straight piece as one section and the curved bit as another, then assemble on a still day. Get each part right, use smaller cranes (safety?), easier wind protection; it just makes sense.
From January 2.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ngkiwi on 03/04/2019 05:53 pm
Here we go again  :D - speculation is rife - thanks SpaceX for making it all so public and giving us the opportunity of seeing a rocket (hopper) being built
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CapitalistOppressor on 03/04/2019 06:58 pm
Those containers are stacked as a wind break around a pad the same way that they were for the original build in November / December, that's why I asked.

https://forum.nasaspaceflight.com/index.php?topic=47301.msg1915456#msg1915456 (https://forum.nasaspaceflight.com/index.php?topic=47301.msg1915456#msg1915456)

Long time lurker. But going through RGVAriealPhotography's twitter feed I noticed this interesting detail today.

That’s clearly another water tank. Nothing to see here, move along...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/04/2019 07:18 pm
There's plenty of room in the main area for a small side project.  Why is this thing being built so far out of the way?

Perhaps to leave room back in the main area for something else, or so that the big cranes have room to move about.

I know, but this is such a tiny pad, and they already have the tent there as a wind breaker.... 

Instead they went of to a place that's disconnected from the main work area, built a wind breaker out of containers... and if these two structures are related, they'll have to haul it back to the main area anyway...

But if it's a different thing - is it the next prototype?  Seems a bit... modest...

It's nothing more than two sections being built in parallel. It makes sense to build both section in parallel to save time.

Elon has reiterated that the orbital test vehicle is already being built. More so, this is probably not the process they will use to build the orbital prototype. That one will have to test entry loads and fluid dynamics that would break Star Hopper in half. So no. I do not think any of this is part of the next vehicle.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ejb749 on 03/04/2019 10:21 pm
I'm not sure how close my scaling is, but this is probably pretty close to what the hopper will look like on the pad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Arb on 03/04/2019 11:07 pm
What are these?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DistantTemple on 03/04/2019 11:10 pm
Space heaters, for comfortable working environment and possible for drying moisture from materials and work pieces.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 03/04/2019 11:19 pm
To me, they would appear to be gravity feed fuel or oil tanks that are often seen around construction areas with the safety catch pan underneath them.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/05/2019 01:12 am
I'm not sure how close my scaling is, but this is probably pretty close to what the hopper will look like on the pad.
I think the pad is about 100 feet wide by 90 feet deep in that photo, so the ship should be quite a bit bigger at 130 feet.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/05/2019 08:25 am
There's plenty of room in the main area for a small side project.  Why is this thing being built so far out of the way?

Perhaps to leave room back in the main area for something else, or so that the big cranes have room to move about.

I know, but this is such a tiny pad, and they already have the tent there as a wind breaker.... 

Instead they went of to a place that's disconnected from the main work area, built a wind breaker out of containers... and if these two structures are related, they'll have to haul it back to the main area anyway...

But if it's a different thing - is it the next prototype?  Seems a bit... modest...

It's nothing more than two sections being built in parallel. It makes sense to build both section in parallel to save time.

Elon has reiterated that the orbital test vehicle is already being built. More so, this is probably not the process they will use to build the orbital prototype. That one will have to test entry loads and fluid dynamics that would break Star Hopper in half. So no. I do not think any of this is part of the next vehicle.

I don’t know what else you are expecting to see? We know from recent job postings that Starship welders are expected to work at height in the open. We know that the structure will be thin walled stainless, and we know the automatic welding machine does very high quality field welds. Apart from maybe some more Sprung structures and some more tooling I think we are looking at SS/SH final assembly.

The new barrel section may be part of fairing 2, or a full scale test item, or indeed the start of the Starship orbital prototype. With the agressive schedule they are on my money is on fairing 2 being the test item and this being the start of Starship.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/05/2019 10:05 am
With the agressive schedule they are on my money is on fairing 2 being the test item and this being the start of Starship.

Honest question: could this really be the orbital prototype? Boeing built a giant indoor welding stand for the SLS core stage. How can SpaceX build something similar simply out of a tent in the boonies (sorry Nomadd and BCG)?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: tyrred on 03/05/2019 10:15 am
They're not as similar as you may think.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/05/2019 11:07 am
With the agressive schedule they are on my money is on fairing 2 being the test item and this being the start of Starship.

Honest question: could this really be the orbital prototype? Boeing built a giant indoor welding stand for the SLS core stage. How can SpaceX build something similar simply out of a tent in the boonies (sorry Nomadd and BCG)?

Boeing has access to massive government funding for SLS. The expectation of the customer is for bespoke tooling in a traditional aerospace factory environment. There is no incentive, indeed there is a huge disincentive, to depart from this model. SpaceX in contrast is developing this on a shoestring and in a hurry. There is every incentive to determine what production needs to have, rather than wants to have. Musk also has previous form in non traditional manufacturing facilities in using Sprung structures for the previous composite version in San Paulo and the additional Tesla Model 3 production line.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/05/2019 12:16 pm
In the "scrap yard" behind the wind break there are some large curved pieces that could be joined to form a cone.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: StuffOfInterest on 03/05/2019 12:17 pm
With the talk about some of the parts being built possibly being for an orbital prototype, keep in mind that the skin is going to be considerably different than the hopper's.  With transpirational cooling (how is that even a word?) there will need to be holes, channels, and a backing to the skin.  I don't believe they will weld up some sheet stainless and then drill holes in it.  The manufacturing technique will have to be quite a bit different than what is going on outside currently.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 03/05/2019 12:45 pm
As per Elon's last statement on the matter, the first orbital prototype for Starship is not being built at Boca Chica, but in the Port of LA tent (likely with components being made at Hawthorne and then roaded over to the tent for assembly). That would be using a closer to 'production' assembly process, as that prototype will need transpiration cooling and actuated fins. With all the highly visible action in Texas, I don't think any of the avid SpaceX watchers have been skulking around trying to peek through that particular tent flap recently.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThereIWas3 on 03/05/2019 12:55 pm
How about both, with construction of substructures being done in the Port of Los Angeles tent, to be later transported to Boca Chica for final assembly?  I think it all has to be put together very close to the launch location because it is too big to move very far.  I do not see them risking shipping this thing through the Panama Canal.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/05/2019 01:05 pm
With the talk about some of the parts being built possibly being for an orbital prototype, keep in mind that the skin is going to be considerably different than the hopper's.  With transpirational cooling (how is that even a word?) there will need to be holes, channels, and a backing to the skin.  I don't believe they will weld up some sheet stainless and then drill holes in it.

I'm assuming that the pieces that are welded together for the orbital prototype would come pre-drilled (assuming that the right model is pores, rather than under-skin heat absorption with periodic venting -- the exact technique hasn't been communicated afaik?), and then those panels could be assembled similar to how these are, unless there is some in-plane, inter-panel plumbing, in which case ...?  Perhaps you get the dual-ply panels with exposed inner edge-channels, weld the outer plates, lay the (separate) channeled piping, and then weld the inner edges?  Slightly different construction, but it would mean that the complex inner structure that has to be built to endure large temperature deltas / expansion wouldn't need to be done in the field.

Such a thing seems possible, and if you're going to do construction in BC, I think you want the least amount of equipment exposed to the hurricane season as you can get, so simple is better.  I still suspect that Brownsville construction is more likely for the final starship using rented space from an existing yard, but in the meantime, we can enjoy watching prototype development.

The question I have is how they're going to hop-test within the 12 flight limit?  Or do flight limits not apply for tests?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/05/2019 01:44 pm
With the agressive schedule they are on my money is on fairing 2 being the test item and this being the start of Starship.

Honest question: could this really be the orbital prototype? Boeing built a giant indoor welding stand for the SLS core stage. How can SpaceX build something similar simply out of a tent in the boonies (sorry Nomadd and BCG)?

The SLS giant indoor welding machine (Vertical Assembly Center, VAC) is needed to perform circumference friction stir welding (FSW) to join the tank barrel sections. If you don't use FSW to do circumference joins, there's no need for such a giant machine. It's not clear whether FSW is usable or desirable for stainless steel, but in any case, as discussed earlier in this thread, SpaceX can afford to trade significant amount of extra dry mass on orbital prototype for radically lower production cost using simple tooling.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/05/2019 02:14 pm
With the talk about some of the parts being built possibly being for an orbital prototype, keep in mind that the skin is going to be considerably different than the hopper's.  With transpirational cooling (how is that even a word?) there will need to be holes, channels, and a backing to the skin.  I don't believe they will weld up some sheet stainless and then drill holes in it.

I'm assuming that the pieces that are welded together for the orbital prototype would come pre-drilled (assuming that the right model is pores, rather than under-skin heat absorption with periodic venting -- the exact technique hasn't been communicated afaik?), and then those panels could be assembled similar to how these are, unless there is some in-plane, inter-panel plumbing, in which case ...?  Perhaps you get the dual-ply panels with exposed inner edge-channels, weld the outer plates, lay the (separate) channeled piping, and then weld the inner edges?  Slightly different construction, but it would mean that the complex inner structure that has to be built to endure large temperature deltas / expansion wouldn't need to be done in the field.

Such a thing seems possible, and if you're going to do construction in BC, I think you want the least amount of equipment exposed to the hurricane season as you can get, so simple is better.  I still suspect that Brownsville construction is more likely for the final starship using rented space from an existing yard, but in the meantime, we can enjoy watching prototype development.

The question I have is how they're going to hop-test within the 12 flight limit?  Or do flight limits not apply for tests?

Welding pre drilled plates into the outer barrel then installing the stringers and second skin internally has the advantages of keeping a smooth outer form and keeping the attachment welds inside the vehicle; both would seem desirable on hot sections. Elon has already commented that you will need to be very close to see the pores.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 03/05/2019 04:02 pm
As per Elon's last statement on the matter, the first orbital prototype for Starship is not being built at Boca Chica, but in the Port of LA tent (likely with components being made at Hawthorne and then roaded over to the tent for assembly). That would be using a closer to 'production' assembly process, as that prototype will need transpiration cooling and actuated fins. With all the highly visible action in Texas, I don't think any of the avid SpaceX watchers have been skulking around trying to peek through that particular tent flap recently.
Your information is out of date, SpaceX has pulled out of their lease in the port of LA and will no longer be building anything there. I do not know about their other facilities in the area. Presumably they will be able to do some of that work in Hawthorne or elsewhere.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ejb749 on 03/05/2019 04:16 pm
I think the pad is about 100 feet wide by 90 feet deep in that photo, so the ship should be quite a bit bigger at 130 feet.
If I use the front edge of the pad as 100 ft, the hopper gets huge!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/05/2019 04:32 pm
I think the pad is about 100 feet wide by 90 feet deep in that photo, so the ship should be quite a bit bigger at 130 feet.
If I use the front edge of the pad as 100 ft, the hopper gets huge!
Using the three "mount points" sunk in the concrete pad as reference, this scale looks reasonable (for anyone questioning this, please read back through the analysis of the diameter of the circle described by these mount points).

It IS huge...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ejb749 on 03/05/2019 04:38 pm
Here's a comparison with the section being built now, with a guy and some lifts around for scale.
Looks to me like they are going to need a lot more tanks to be able to fill this thing!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 03/05/2019 04:38 pm
SpaceX has their own fire truck.

A 9 year fresher engine 501 (https://www.flickr.com/photos/rickm15/4835658713/in/photostream/)

 ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 03/05/2019 05:08 pm
In the "scrap yard" behind the wind break there are some large curved pieces that could be joined to form a cone.

I have commented on the huge carbon steel pipe fittings in the same yard in the past.  I find it interesting that SpaceX has not removed them when they cleaned up the area.  I'm still wondering what they will be used for.  If you look closely the elbow is the size of a truck!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/05/2019 06:07 pm
I think the pad is about 100 feet wide by 90 feet deep in that photo, so the ship should be quite a bit bigger at 130 feet.
If I use the front edge of the pad as 100 ft, the hopper gets huge!

Yep. Those triangle concrete foundation line up better with the 9m diameter, they are probably attachment points for the launch mount that will support the 9m outer edge of the Hopper/Starship - NOT the legs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BunkerTheHusky on 03/05/2019 06:07 pm
Apologies if this was already discussed, but do we speculate that SpaceX will need to build a hopper version of the Super Heavy? Would there be anything new to learn from it after all the successful Falcon 9 landings?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: groundbound on 03/05/2019 07:18 pm
Apologies if this was already discussed, but do we speculate that SpaceX will need to build a hopper version of the Super Heavy? Would there be anything new to learn from it after all the successful Falcon 9 landings?

There has been a food fight about it on another thread.

I have stayed out of that one. The one thing not mentioned that might lead to some sort of limited SH is that in 2019 the supply of Raptors may be limited. I could envision a SH test program being developed that solved these two functions simultaneously:

*What do we most need to learn first?
*How many Raptors do we have?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/05/2019 09:47 pm
These were delivered at the new gate off hwy. 4.

Time to get moving! :D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 03/05/2019 10:07 pm
>
With transpirational cooling (how is that even a word?)
>

It's a biological term. You transpire when you sweat.

tran·spi·ra·tion  (trăn′spə-rā′shən)
n.
The act or process of transpiring, especially through the stomata of plant tissue or the pores of the skin.

tran′spi·ra′tion·al adj.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureMartian97 on 03/05/2019 10:25 pm
These were delivered at the new gate off hwy. 4.

Looks like a transporter to me  ;D

Thanks again for your continued coverage!

Edit: Found this video of one (or a similar one) in action: https://www.youtube.com/watch?v=9N8wJo1q7S0
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HeartofGold2030 on 03/05/2019 10:30 pm
These were delivered at the new gate off hwy. 4.

Looks like a transporter to me  ;D

Thanks again for your continued coverage!

Edit: Found this video of one (or a similar one) in action: https://www.youtube.com/watch?v=9N8wJo1q7S0

I found this interesting picture, seems like this is how the Roll-Lift™ might be used to transport the hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/05/2019 10:32 pm
>
With transpirational cooling (how is that even a word?)
>

It's a biological term. You transpire when you sweat.

tran·spi·ra·tion  (trăn′spə-rā′shən)
n.
The act or process of transpiring, especially through the stomata of plant tissue or the pores of the skin.

tran′spi·ra′tion·al adj.

While it's used in biology (can attest - am biologist), it's an older word coming from medieval latin (trans=through spirare= to breath). I think it's oldest attestation is from the 16th century, which is prior to the point western scientists ("natural philosophers", as they'd have been called at the time) first were able to use microscopes to describe and define pores and cells, etc. (Hook and van Leeuwenhoek did seminal microscopy research in the late 17th century, and it's from Hook that we get the word "cell").
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Jcc on 03/05/2019 10:38 pm
Apologies if this was already discussed, but do we speculate that SpaceX will need to build a hopper version of the Super Heavy? Would there be anything new to learn from it after all the successful Falcon 9 landings?

Some of us speculate that they need a Super Heavy hopper. Much better than cratering a complete Super Heavy. And they can build it out of a structural test item to save even more money.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/05/2019 11:32 pm
Apologies if this was already discussed, but do we speculate that SpaceX will need to build a hopper version of the Super Heavy? Would there be anything new to learn from it after all the successful Falcon 9 landings?

Some of us speculate that they need a Super Heavy hopper. Much better than cratering a complete Super Heavy. And they can build it out of a structural test item to save even more money.

If I'm not mistaken, EM has said there won't be a SH hopper. They understand booster tech (especially landing) well enough to go right into a production booster. Of course, that does not mean they will not first test the heck out of it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/05/2019 11:52 pm
I found this interesting picture, seems like this is how the Roll-Lift™ might be used to transport the hopper.

The road won't be wide enough for two on each side of the hopper. (nor the ramp to the pad) So they will likely just use one and balance it - like this picture.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/05/2019 11:54 pm
Some of us speculate that they need a Super Heavy hopper. Much better than cratering a complete Super Heavy. And they can build it out of a structural test item to save even more money.

If I'm not mistaken, EM has said there won't be a SH hopper. They understand booster tech (especially landing) well enough to go right into a production booster. Of course, that does not mean they will not first test the heck out of it.

Yep. They might test-hop a SH, but probably won't build a low-fi "hopper" version of SH.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: lonestriker on 03/05/2019 11:55 pm
Apologies if this was already discussed, but do we speculate that SpaceX will need to build a hopper version of the Super Heavy? Would there be anything new to learn from it after all the successful Falcon 9 landings?

Some of us speculate that they need a Super Heavy hopper. Much better than cratering a complete Super Heavy. And they can build it out of a structural test item to save even more money.

If I'm not mistaken, EM has said there won't be a SH hopper. They understand booster tech (especially landing) well enough to go right into a production booster. Of course, that does not mean they will not first test the heck out of it.

As far as I am aware, he has not said that definitively.  He said that they would start with the harder part of BFR, the upper stage first. (https://space.stackexchange.com/a/25971)  And Super Heavy hardware in the Spring:

https://twitter.com/elonmusk/status/1071610949432356864?lang=en
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureMartian97 on 03/06/2019 12:04 am
I found this interesting picture, seems like this is how the Roll-Lift™ might be used to transport the hopper.

The road won't be wide enough for two on each side of the hopper. (nor the ramp to the pad) So they will likely just use one and balance it - like this picture.

I'm wondering how they will lift it high enough off the ground. It looks like the transporter is too short to account for the fins. Unless the extra ring they are building will be used to lift it higher when transported?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cinder on 03/06/2019 12:13 am
Some of us speculate that they need a Super Heavy hopper. Much better than cratering a complete Super Heavy. And they can build it out of a structural test item to save even more money.

If I'm not mistaken, EM has said there won't be a SH hopper. They understand booster tech (especially landing) well enough to go right into a production booster. Of course, that does not mean they will not first test the heck out of it.

Yep. They might test-hop a SH, but probably won't build a low-fi "hopper" version of SH.
Is some kind of rolling apparatus under the Hopper feet dismissable?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MKremer on 03/06/2019 12:33 am
These were delivered at the new gate off hwy. 4.

Time to get moving! :D
But moving what?   There are several very long jacketed tanks still sitting around at the upper storage location.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/06/2019 12:52 am
I found this interesting picture, seems like this is how the Roll-Lift(http://emoji.tapatalk-cdn.com/emoji769.png) might be used to transport the hopper.

The road won't be wide enough for two on each side of the hopper. (nor the ramp to the pad) So they will likely just use one and balance it - like this picture.
When they move the BFH, and I stand by what I’ve said before, they’ll use two of this type of mover, side by side and slaved together. It will pick the hopper up at the hold down points (don’t expect the BFH to support it’s own weight on its own legs fully fueled, so logic dictates there will be support points, which would also serve as hold down points). These points will either be along the cylinder circumference or just outside it.

Legs free to extend past roadside and the two movers slaved next to each other have enough road.

Expect a jackup rig to be assembled on the deck above the joined movers in coming weeks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/06/2019 02:36 am
As per Elon's last statement on the matter, the first orbital prototype for Starship is not being built at Boca Chica, but in the Port of LA tent (likely with components being made at Hawthorne and then roaded over to the tent for assembly). That would be using a closer to 'production' assembly process, as that prototype will need transpiration cooling and actuated fins. With all the highly visible action in Texas, I don't think any of the avid SpaceX watchers have been skulking around trying to peek through that particular tent flap recently.
Your information is out of date, SpaceX has pulled out of their lease in the port of LA and will no longer be building anything there. I do not know about their other facilities in the area. Presumably they will be able to do some of that work in Hawthorne or elsewhere.

Did they pull out of both locations?

I understood they pulled out of the main factory site, but did they also shut down the existing circus tent in the small site?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 03/06/2019 04:27 am
SpaceX has their own fire truck.

A 9 year fresher engine 501 (https://www.flickr.com/photos/rickm15/4835658713/in/photostream/)

 ;D
If they need a fire truck (and they surely need at least one) why is it surprising they bought a used one? 9 years old is still quite a bit of life left in fire trucks but significantly cheaper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/06/2019 05:07 am
I found this interesting picture, seems like this is how the Roll-Lift™ might be used to transport the hopper.

The road won't be wide enough for two on each side of the hopper. (nor the ramp to the pad) So they will likely just use one and balance it - like this picture.
The road is 34 feet wide and weight bearing all the way to the edge, and the ramp is wider.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/06/2019 05:13 am
I found this interesting picture, seems like this is how the Roll-Lift™ might be used to transport the hopper.

The road won't be wide enough for two on each side of the hopper. (nor the ramp to the pad) So they will likely just use one and balance it - like this picture.
The road is 34 feet wide and weight bearing all the way to the edge, and the ramp is wider.

But the Hopper core diameter alone is almost 30ft, plus legs. So it still won't be wide enough for two of them to carry the hopper between them, if you look at the picture attached to the post I was quoting. (which had two "roll-lifts" carrying a tall cylinder on outside)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/06/2019 07:20 am
It looks like the hopper base is going into test, the pad is progressing nicely, and we now know how hopper is going to be moved. So what else? Obviously Raptors and a fairing. However, there are two things I’ve not seen any evidence of.

The first is electronics which I presume have been installed at the bottom for easy access.

The second is the RCS. We know that at least initially Starship will get cold gas thrusters. I’m presuming these will get installed in the lower fairing l; remember the four ‘ventilation’ holes in fairing? Could they fly without RCS? Have I missed anything else?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/06/2019 08:19 am
I found this interesting picture, seems like this is how the Roll-Lift™ might be used to transport the hopper.

The road won't be wide enough for two on each side of the hopper. (nor the ramp to the pad) So they will likely just use one and balance it - like this picture.
The road is 34 feet wide and weight bearing all the way to the edge, and the ramp is wider.

But the Hopper core diameter alone is almost 30ft, plus legs. So it still won't be wide enough for two of them to carry the hopper between them, if you look at the picture attached to the post I was quoting. (which had two "roll-lifts" carrying a tall cylinder on outside)
See my post a few back...


https://forum.nasaspaceflight.com/index.php?topic=47301.msg1918697#msg1918697 (https://forum.nasaspaceflight.com/index.php?topic=47301.msg1918697#msg1918697)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 03/06/2019 12:37 pm
As per Elon's last statement on the matter, the first orbital prototype for Starship is not being built at Boca Chica, but in the Port of LA tent (likely with components being made at Hawthorne and then roaded over to the tent for assembly). That would be using a closer to 'production' assembly process, as that prototype will need transpiration cooling and actuated fins. With all the highly visible action in Texas, I don't think any of the avid SpaceX watchers have been skulking around trying to peek through that particular tent flap recently.
Your information is out of date, SpaceX has pulled out of their lease in the port of LA and will no longer be building anything there. I do not know about their other facilities in the area. Presumably they will be able to do some of that work in Hawthorne or elsewhere.
SpaceX have two separate plots and leases. One was the intended 'final' construction site for BFR/BFS and required extensive demolition and construction work, that's PoLA Berth 240 with the lease left to lapse. There's also PoLB Pier T where the spring structure containing the CF mandrels and handling hardware are. As far as I am aware, that lease remains active and the structure is still there.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Spindog on 03/06/2019 01:10 pm
I dont know for sure but I definitely have the impression that the abandonment of the carbon fiber core and, I presume, release of many of those employees was all part of the cost and time savings of welding up the starship prototypes and orbital rockets at Boca. They may make sections at Hawthorn and truck transport them to Boca but it seems that making any large structures at the port and transporting them by water is out.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/06/2019 02:13 pm
SpaceX has their own fire truck.

A 9 year fresher engine 501 (https://www.flickr.com/photos/rickm15/4835658713/in/photostream/)

 ;D

That was a shocker to see.  A few years back there were three digits I could dial on my phone and two minutes later that same truck would have come to my door.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Robertleelittleiii on 03/06/2019 03:21 pm
FYI:  Here is some info for that Blue Roll-lift:

https://www.scheuerle.com/fileadmin/data_all/brochures/tii-group-spmt-en.pdf
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: joncz on 03/06/2019 03:52 pm
Jump to the 35 second mark.

https://www.youtube.com/watch?v=oHXN9qq-S6Y&t=35s

Edit: Thx, dnavas
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 03/06/2019 04:23 pm
SpaceX has their own fire truck.

A 9 year fresher engine 501 (https://www.flickr.com/photos/rickm15/4835658713/in/photostream/)
If they need a fire truck (and they surely need at least one) why is it surprising they bought a used one? 9 years old is still quite a bit of life left in fire trucks but significantly cheaper.
I'm not surprised at all. I figured somewhere there was a picture of the original fire truck. Turns out it took two minutes of searching, not the ten minutes I expected.

It's just interesting to connect dots and learn more about the engine (http://www.spartanmotors.com/emergency-response/cab-chassis/).

That was a shocker to see.  A few years back there were three digits I could dial on my phone and two minutes later that same truck would have come to my door.

Love the "nationalization" of SpaceX. Hey, you don't always need new stuff for 85% of situations...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 03/06/2019 04:32 pm
Nationalization?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 03/06/2019 04:48 pm
Nationalization?

Taking parts and people from around the country. Just as needed.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/06/2019 06:15 pm
Wonder why they abandoned the girth welder in favor of a hanging stage.

Well, actually, I had a theory when they first brought it in - especially as it was a double sided unit.

It, including two humans, was too heavy for the relatively thin metal of the hat (which it was suspected on) and was causing deformation along the top edge.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: geza on 03/06/2019 07:01 pm
https://www.youtube.com/watch?v=oHXN9qq-S6Y?t=36
I like this video very much. I learnt a lot from it about the state of art of moving extremely large structures, including offshore ones.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 03/06/2019 08:18 pm
Panels are up and the welding begins. The fire truck looks official now with the new sign on the door.

Thanks gal. ;D I really should have expected them to have stuff like the truck, but it completely skipped my mind.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThereIWas3 on 03/06/2019 08:30 pm
The shiny steel on this new cylinder looks considerably less wrinkly than on the hopper base behind it in the photo.  Thicker I assume.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/06/2019 08:55 pm
The shiny steel on this new cylinder looks considerably less wrinkly than on the hopper base behind it in the photo.  Thicker I assume.
What's cladding the base is basically a foil that's tack welded. The stuff being used on the new hat is actual sheet metal.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 03/06/2019 09:02 pm
The shiny steel on this new cylinder looks considerably less wrinkly than on the hopper base behind it in the photo.  Thicker I assume.

It really does look like they're "doing this one right the first time", which unsurprisingly takes longer... at least it feels like it's taking longer. Anyone care to guestimate how long the first "hat" took?

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/06/2019 10:18 pm
What are the scenarios in which the fire truck may be helpful?

- Naturally occurring grass fire approaching
- Stopping grass fires set by BFH
- Present during fuel transfer

Anything else?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Eer on 03/06/2019 10:45 pm
What are the scenarios in which the fire truck may be helpful?

- Naturally occurring grass fire approaching
- Stopping grass fires set by BFH
- Present during fuel transfer

Anything else?
Office fires, electrical fires related to distribution or solar generating systems.  Vehicle fires, equipment heat-caused fires.  People are welding things, here. It's an industrial work place.  Needs a rapid fire response team with resources commensurate to the size and scope of the industrial setting, I'd think.

I'm betting a manufacturing floor in Hawthorne has a fire response team - and without having fire suppression systems for all their far flung facilities on site, I'd expect a mobile pumper would make sense.

No?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: matthewkantar on 03/06/2019 10:45 pm
What are the scenarios in which the fire truck may be helpful?

- Naturally occurring grass fire approaching
- Stopping grass fires set by BFH
- Present during fuel transfer

Anything else?

They absolutely rule at parades.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: matthewkantar on 03/06/2019 10:48 pm
It appears they are using the Roll-Lifts as a work platform. They moved these onto the Roll-Lift and started to weld on them. The last pic they moved that piece over but then decided to put it back on the ground.

It appears that construction of a rig to move the hopper has started atop the multi-wheel moving equipment.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/06/2019 10:51 pm
It appears they are using the Roll-Lifts as a work platform. They moved these onto the Roll-Lift and started to weld on them. The last pic they moved that piece over but then decided to put it back on the ground.

Transport vehicles ready, transport vehicles spaced apart for road width and Hopper diameter, transport stand being welded together, Hopper hatches closed down, Scaffolding and work platform removed, Hopper pressure checks ongoing or done, pad looks quite done. Can only be days till the grand move. :D

My guess would be that the nosecone still goes on before move, but i am not quite sure. The nose seems to need a few more days and the transport looks almost ready. Maybe they booked the transports well in advance and the first nosecone being blown over blew the timeplan over too. Dunno what costs more, waiting a few days and mount the Nosecone and pay more rent for the multi-wheelers, or drive the Hopper base over and move the Nosecone later in a separate haul. Gut feeling says one transport is cheaper than two, even if a few days are still needed for Nosecone assembly and mounting on Hopper base.

Engines will probably be mounted on Hopper post-move. Even if they were ready yet, there would be no reason to have them in for the transport and risk any damage.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: theinternetftw on 03/07/2019 01:53 am
SpaceX have two separate plots and leases. One was the intended 'final' construction site for BFR/BFS and required extensive demolition and construction work, that's PoLA Berth 240 with the lease left to lapse. There's also PoLB Pier T where the spring structure containing the CF mandrels and handling hardware are. As far as I am aware, that lease remains active and the structure is still there.

This post prompted me to go look for some new imagery of that BFR tent. Couldn't find any, as there's no more tent. (https://forum.nasaspaceflight.com/index.php?topic=45633.msg1919064#msg1919064)

EDIT: Hold the phone, Planet has eyes on (https://forum.nasaspaceflight.com/index.php?topic=45633.msg1919107#msg1919107) as of February. Might be bad Google imagery.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/07/2019 04:39 am
SpaceX have two separate plots and leases. One was the intended 'final' construction site for BFR/BFS and required extensive demolition and construction work, that's PoLA Berth 240 with the lease left to lapse. There's also PoLB Pier T where the spring structure containing the CF mandrels and handling hardware are. As far as I am aware, that lease remains active and the structure is still there.

This post prompted me to go look for some new imagery of that BFR tent. Couldn't find any, as there's no more tent. (https://forum.nasaspaceflight.com/index.php?topic=45633.msg1919064#msg1919064)

Is it possible the tent in Boca Chica is the same tent that was at the port?

EDIT:
Lest anybody get excited with this idea, theinternetftw appears to have evidence that debunks the cross-country tent theory. It will always have a place in my heart, however, and as they say: we'll always have boca chica.

This post prompted me to go look for some new imagery of that BFR tent. Couldn't find any, as there's no more tent. (https://forum.nasaspaceflight.com/index.php?topic=45633.msg1919064#msg1919064)

Just want to put a new post in the thread for those who read that the BFR tent was gone: Looks like it could well still be there (so says Planet as of February) (https://forum.nasaspaceflight.com/index.php?topic=45633.msg1919107#msg1919107).  Google may for some reason have taken down their old tent shots in favor of using two year old imagery for that location.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: maximuvinal on 03/07/2019 04:43 am
all right 2,3 is a stand for two legs. they stand in one line. 1 - separately for the third leg
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cheapchips on 03/07/2019 05:18 am

I'm 50% of the way to convincing myself that they're not going to bother with a new nosecone.  The two straight sided sections of nosecone V2 are getting close to being longer than V1 with no sign of tapered sections.   This might be due to the different construction but the tapered sections did appear earlier on the last build.

Removing the flares at the top of the legs, slapping on some shiny sheets to the dome and getting ready to move are also sloppy evidence of them ditching the cone.

That would make nosecone two the orbital prototype.  Three months of build and fitting would have them pretty close to the June target. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jded on 03/07/2019 07:37 am

I'm 50% of the way to convincing myself that they're not going to bother with a new nosecone.  The two straight sided sections of nosecone V2 are getting close to being longer than V1 with no sign of tapered sections.   This might be due to the different construction but the tapered sections did appear earlier on the last build.

Removing the flares at the top of the legs, slapping on some shiny sheets to the dome and getting ready to move are also sloppy evidence of them ditching the cone.

That would make nosecone two the orbital prototype.  Three months of build and fitting would have them pretty close to the June target.

I was thinking that with all the commonality between the Starship and Super Heavy, and lack of commonality between Hopper and Starship, Hopper would be just as good/bad testbed for Super Heavy as it is for Starship, if it only had a long tube instead of a nosecone. Maybe they are building two variants of the top part, to simulate both w/r to aerodynamics.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: theinternetftw on 03/07/2019 07:57 am
This post prompted me to go look for some new imagery of that BFR tent. Couldn't find any, as there's no more tent. (https://forum.nasaspaceflight.com/index.php?topic=45633.msg1919064#msg1919064)

Just want to put a new post in the thread for those who read that the BFR tent was gone: Looks like it could well still be there (so says Planet as of February) (https://forum.nasaspaceflight.com/index.php?topic=45633.msg1919107#msg1919107).  Google may for some reason have taken down their old tent shots in favor of using two year old imagery for that location.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 03/07/2019 10:13 am
What are the scenarios in which the fire truck may be helpful?

- Naturally occurring grass fire approaching
- Stopping grass fires set by BFH
- Present during fuel transfer

Anything else?

They absolutely rule at parades.

Very off-topic. I was at the 2002 Bastille Day parade on the Champs Elysées. The crowd remained silent for all of the French Armed forces passing by. Only when a New York fire engine drove by (with US firefighters sitting on top) did the crowd loudly cheer and applaud.

(So much for thinking that the French are anti-American...)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 03/07/2019 10:23 am
What are the scenarios in which the fire truck may be helpful?

- Naturally occurring grass fire approaching
- Stopping grass fires set by BFH
- Present during fuel transfer

Anything else?

They absolutely rule at parades.

Very off-topic. I was at the 2002 Bastille Day parade on the Champs Elysées. The crowd remained silent for all of the French Armed forces passing by. Only when a New York fire engine drove by (with US firefighters sitting on top) did the crowd loudly cheer and applaud.

(So much for thinking that the French are anti-American...)

Who thinks the French are anti-American?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rakaydos on 03/07/2019 11:30 am
What are the scenarios in which the fire truck may be helpful?

- Naturally occurring grass fire approaching
- Stopping grass fires set by BFH
- Present during fuel transfer

Anything else?

They absolutely rule at parades.

Very off-topic. I was at the 2002 Bastille Day parade on the Champs Elysées. The crowd remained silent for all of the French Armed forces passing by. Only when a New York fire engine drove by (with US firefighters sitting on top) did the crowd loudly cheer and applaud.

(So much for thinking that the French are anti-American...)

Who thinks the French are anti-American?
*cough* "freedom fries" *cough*
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AJW on 03/07/2019 12:05 pm
I used to work at a ranch that was about 20 minutes from the nearest county fire station and as a result, insurance costs for the facility were, shall we say, astronomical.

The property owner very wisely built a fire department on the property, and all security personnel were trained as both Firefighters and EMTs.   The savings in insurance easily covered the cost of the equipment and having our own fire department built a great bond between our crew and local Fire and law enforcement.

A quick Google check finds that the SpaceX launch facility is 26 minutes from Brownsville Station #5.   A lot can happen in the time it takes for crews to arrive at a scene, better to have first responders and equipment where you might need it. And besides, the trucks do look great in a parade.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: joncz on 03/07/2019 12:27 pm
It appears they are using the Roll-Lifts as a work platform. They moved these onto the Roll-Lift and started to weld on them. The last pic they moved that piece over but then decided to put it back on the ground.

https://www.youtube.com/watch?v=oHXN9qq-S6Y?t=36

Reference that video (don't know why the link won't launch at the 36 second mark) - they're likely building cribbing / rigging to attach to the Hopper for the move.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 03/07/2019 01:31 pm
With the tank access ports sealed and purge gear already hooked up to the hopper, I would expect it to make at least one round of propellant load and unload before the nose is attached. No engine yet, so probably no test fire for that load/unload round, but if they were to weld the nose on they would almost certainly want to inspect the inside of the weld seam, which would mean entering the tank and then cleaning & purging again.
The nose is not needed for static fires, and for low-speed hover tests can be substituted by a mass simulator. Only once they start higher speed testing will the nose be necessary.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 03/07/2019 01:34 pm
Wonder why they abandoned the girth welder in favor of a hanging stage.

Well, actually, I had a theory when they first brought it in - especially as it was a double sided unit.

It, including two humans, was too heavy for the relatively thin metal of the hat (which it was suspected on) and was causing deformation along the top edge.
This morning they moved the girth welder over to the new section.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 03/07/2019 02:20 pm
Hey BocaChicaGal,

Once again, thank you very much for the excellent photos! Top notch job! :D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/07/2019 02:25 pm
It appears they are using the Roll-Lifts as a work platform. They moved these onto the Roll-Lift and started to weld on them. The last pic they moved that piece over but then decided to put it back on the ground.

Transport vehicles ready, transport vehicles spaced apart for road width and Hopper diameter, transport stand being welded together, Hopper hatches closed down, Scaffolding and work platform removed, Hopper pressure checks ongoing or done, pad looks quite done. Can only be days till the grand move. :D

My guess would be that the nosecone still goes on before move, but i am not quite sure. The nose seems to need a few more days and the transport looks almost ready. Maybe they booked the transports well in advance and the first nosecone being blown over blew the timeplan over too. Dunno what costs more, waiting a few days and mount the Nosecone and pay more rent for the multi-wheelers, or drive the Hopper base over and move the Nosecone later in a separate haul. Gut feeling says one transport is cheaper than two, even if a few days are still needed for Nosecone assembly and mounting on Hopper base.

Engines will probably be mounted on Hopper post-move. Even if they were ready yet, there would be no reason to have them in for the transport and risk any damage.
Don't forget it still needs feet
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 03/07/2019 02:45 pm
The Hopper's legs will be dangling in the air when its on its "crawler" for the move. That might be a great time to add the feet. Just a thought.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 03/07/2019 04:50 pm
What are the scenarios in which the fire truck may be helpful?

- Naturally occurring grass fire approaching
- Stopping grass fires set by BFH
- Present during fuel transfer

Anything else?

They absolutely rule at parades.
This one now has a SpaceX logo but still has the "call 911" badging... I wonder if SpaceX have coordinated with local 911 dispatch about this. I doubt it. I also doubt that anyone would actually be confused by that badging. Many sites I work at have both an internal security to call and a way to call 911 from inside the PBX
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 03/07/2019 05:11 pm
I wonder if SpaceX have coordinated with local 911 dispatch about this. I doubt it.
I would expect them to, as that is best practice for industrial sites with their own response teams. Coordination greatly improves outcomes for incident response, as the USCSB can attest (https://www.csb.gov/videos/?SID=3597). SpaceX's response team would have the most knowledge of the hazards on site, and are able to deploy and operate fixed assets (like the directable fire suppression hoses mounted over the berm) that the local units would not. Likewise, local dispatch can coordinate additional plant and local warnings and evacuations that SpaceX could not on their own..
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/07/2019 05:15 pm

I'm 50% of the way to convincing myself that they're not going to bother with a new nosecone.  The two straight sided sections of nosecone V2 are getting close to being longer than V1 with no sign of tapered sections.   This might be due to the different construction but the tapered sections did appear earlier on the last build.

Removing the flares at the top of the legs, slapping on some shiny sheets to the dome and getting ready to move are also sloppy evidence of them ditching the cone.

That would make nosecone two the orbital prototype.  Three months of build and fitting would have them pretty close to the June target.

Agreed with every word.

And I would like to add to your rational arguments a non-rational one: the new sections look too good to be the fairing of the "old" hopper. These sections deserve a much better base.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureMartian97 on 03/07/2019 05:22 pm

I'm 50% of the way to convincing myself that they're not going to bother with a new nosecone.  The two straight sided sections of nosecone V2 are getting close to being longer than V1 with no sign of tapered sections.   This might be due to the different construction but the tapered sections did appear earlier on the last build.

Removing the flares at the top of the legs, slapping on some shiny sheets to the dome and getting ready to move are also sloppy evidence of them ditching the cone.

That would make nosecone two the orbital prototype.  Three months of build and fitting would have them pretty close to the June target.

Agreed with every word.

And I would like to add to your rational arguments a non-rational one: the new sections look too good to be the fairing of the "old" hopper. These sections deserve a much better base.

They are currently building the tapered sections for the fairing. I still believe they will put that fairing on the hopper.

Nosecone panels being unloaded. Starting to put them together on the ground.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 03/07/2019 05:57 pm
https://forum.nasaspaceflight.com/assets/47120.0/1548174.jpg

Using BCG's last image, I was able to import that to CAD and using the 2X4 in the picture for scale, measure the thickness of the stainless steel sheet used for the cone. It works out to 4.7mm  or .188 inches..    7 gauge stainless steel.. very substantial material indeed. :D
 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/07/2019 06:00 pm
A few thoughts on the latest images

1. I continue to believe there will be 2 pads, one for launch and one for landing.
2. The  Faring will be a bit less tapered.
3. They'll transport the Lower half (engine / tanks) to the pad first and then come back for the Faring once that's fully assembled, bring to the  pad and attach with a crane.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/07/2019 06:08 pm
https://forum.nasaspaceflight.com/assets/47120.0/1548174.jpg

Using BCG's last image, I was able to import that to CAD and using the 2X4 in the picture for scale, measure the thickness of the stainless steel sheet used for the cone. It works out to 4.7mm  or .188 inches..    7 gauge stainless steel.. very substantial material indeed. :D

Same thickness as the Al-Li panels in the walls of the F9, from what I recall. About the same strength if that's annealed 301 SS, but stainless is much, much stiffer so it will resist buckling better. That might be able to reach a fairly large dynamic load in flight, even if they don't pressurize the fairing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lisa_R4 on 03/07/2019 06:11 pm
WRT the apparent preparations to move the Hopper vs. finishing the new fairing: perhaps they're going to move the lower section to a safe distance for pressure tests then move it back to finish the rest of construction? A RUD seems unlikely but you definitely wouldn't want it to happen in the middle of the yard if it does.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/07/2019 07:34 pm
There really are no signs whatsoever at this point that they will need or build a separate landing pad for the early Hopper testing. Everything essential for the first tests has made very visible progress, but they have not even cleared the downramp area that people suspect to be for a separate landing pad. And i doubt the value/necessity of it - if the first few meters up and down flight work and the Hopper doesnt crash, and you manage to land at launch pad, why would you not land on launch pad for the next bigger hops too?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/07/2019 07:52 pm
They moved what they were working on to under the Hopper.  ;D

In case somebody missed it: THEY in this case are the Roll-Lift workers, so this is part of the transporter...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/07/2019 08:18 pm
There really are no signs whatsoever at this point that they will need or build a separate landing pad for the early Hopper testing. Everything essential for the first tests has made very visible progress, but they have not even cleared the downramp area that people suspect to be for a separate landing pad. And i doubt the value/necessity of it - if the first few meters up and down flight work and the Hopper doesnt crash, and you manage to land at launch pad, why would you not land on launch pad for the next bigger hops too?
No sign? Seriously?  :) The entire pad barely existed 60 days ago. But I do understand your point and wouldn't be shocked if they didn't build a landing pad but I would be very surprised. For two reasons: We don't know what the Launch pad will accommodate. If it has hold-downs and the Hopper "sits" upon some sort of raised base, then it may preclude coming back to the Launch pad from a high hop. And if I am returning from a 5KM hop, I'd prefer to have some margin so as not to take out my only test launch pad with all my GSE. Especially since the Orbital test vehicle is right behind Hopper. But that's just me. We'll see.

Edit: Speaking of a launch mount: I wonder if something very similar to the 3 mount system they built to carry the hopper could also be attached to the 3 holes at the launch pad allowing a fully fueled Hopper to rest upon it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Ludus on 03/07/2019 08:31 pm
Will they later modify the hopper to be legless and takeoff/land on it’s launch mount to prove designs for doing that with SH?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JonathanD on 03/07/2019 08:33 pm
Will they later modify the hopper to be legless and takeoff/land on it’s launch mount to prove designs for doing that with SH?

Doubtful.  Also, Elon has since mentioned he expects first versions of SH will have legs.  Landing in the launch clamps is a future state (and imho, an unnecessary one).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/07/2019 08:41 pm
There might at first be a "clean" launch pad that allows landing for the early Hopper flights.

But eventually for the Starship orbital prototype, they will certainly need some kind of launch mount and therefore separate landing pad. A flame duct will be needed for 7(!) Raptors at lift off, and the legs are unlikely to be strong enough to support the entire vehicle fully tanked in Earth gravity.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BunkerTheHusky on 03/07/2019 09:09 pm
I have to say, I'm suddenly convinced that we're seeing a second hopper already being constructed! I'd still like to think that a fairing hat is being made for Hopper 1, but now that BCG has pictures of the new "fairing" on the concrete mount, I think it's only a matter of days before we see this one sprout legs, too! Boy it's fun watching this story unfold!

And as an after thought to the above, I thought the newly laid out tapered segments looked off. I think they're the start of a tank dome!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: doyouwonda on 03/07/2019 10:27 pm
Assembling a tapered nosecone section.

Photos like this have now put me firmly in the camp that this is either a 2nd version of Starhopper or the full on orbital prototype. This doesn't look at all like the shape of the Starship nose taper. This looks much more like a LOX or CH4 tank dome.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Eylrid on 03/07/2019 10:37 pm
I have to say, I'm suddenly convinced that we're seeing a second hopper already being constructed! I'd still like to think that a fairing hat is being made for Hopper 1, but now that BCG has pictures of the new "fairing" on the concrete mount, I think it's only a matter of days before we see this one sprout legs, too! Boy it's fun watching this story unfold!

And as an after thought to the above, I thought the newly laid out tapered segments looked off. I think they're the start of a tank dome!

They put the first fairing on the concrete mount, too.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/07/2019 10:40 pm
There might at first be a "clean" launch pad that allows landing for the early Hopper flights.

But eventually for the Starship orbital prototype, they will certainly need some kind of launch mount and therefore separate landing pad. A flame duct will be needed for 7(!) Raptors at lift off, and the legs are unlikely to be strong enough to support the entire vehicle fully tanked in Earth gravity.

If (a big IF) one of the first Starships to head to mars will be contain ISRU stuff and use its own tanks to store propellant as it's made, then we should suspect the landing legs to be capable of holding its weight in mars gravity - so that puts a theoretical lower limit on the mass they can support. Is it as simple as 38% fuel load can be supported?

Edits: i do bad words
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureMartian97 on 03/07/2019 11:00 pm
Something big is coming.

Hopper move tomorrow?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: geza on 03/08/2019 01:24 am
Assembling a tapered nosecone section.

Photos like this have now put me firmly in the camp that this is either a 2nd version of Starhopper or the full on orbital prototype. This doesn't look at all like the shape of the Starship nose taper. This looks much more like a LOX or CH4 tank dome.

Why should they build a second hopper? They plan to lose the first one? If this is the orbital prototype, then we should see them to build the double walled structure for transpirational cooling.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/08/2019 01:47 am
Something big is coming.

Hopper move tomorrow?
Good bet.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/08/2019 01:52 am
Assembling a tapered nosecone section.

Photos like this have now put me firmly in the camp that this is either a 2nd version of Starhopper or the full on orbital prototype. This doesn't look at all like the shape of the Starship nose taper. This looks much more like a LOX or CH4 tank dome.

Why should they build a second hopper? They plan to lose the first one? If this is the orbital prototype, then we should see them to build the double walled structure for transpirational cooling.

Yeah. I do not see EM launching a fairingless hopper - no way, no how. This is just a better constructed hopper fairing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jketch on 03/08/2019 02:22 am
Before today, I felt 99% confident that the extra steel constructions were hopper fairings. But it seems strange to move the hopper tomorrow before attaching the fairings.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 03/08/2019 02:25 am
Before today, I felt 99% confident that the extra steel constructions were hopper fairings. But it seems strange to move the hopper tomorrow before attaching the fairings.

Should be easier to move without the fairing... surely?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: masterxel on 03/08/2019 02:32 am
Before today, I felt 99% confident that the extra steel constructions were hopper fairings. But it seems strange to move the hopper tomorrow before attaching the fairings.

Pressure test seems more realistic
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 03/08/2019 02:35 am
Pressure test seems more realistic

I can't imagine them doing a pressure test /before/ moving to the launch site.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: masterxel on 03/08/2019 03:06 am
Pressure test seems more realistic

I can't imagine them doing a pressure test /before/ moving to the launch site.

To elaborate on my hopefully realistic expectations:

They're moving the hopper to the launch site or elsewhere to safely perform a pressure test away from the ongoing fairing construction. Afterward they'll move it back to join it with the finished fairing and install the Hopper Raptors. Finally one more move back to the launch site for more testing and eventually the test launch.

Sorry for not being clear since I totally agree with you.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/08/2019 03:15 am
Its not true as some say that SpaceX is just throwing this together in an open field with no fixturing or finesse as say, SLS is doing.  Here is one example; specially cut pine blocks being used to keep the rocket parts away from the open field.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/08/2019 03:18 am
Before today, I felt 99% confident that the extra steel constructions were hopper fairings. But it seems strange to move the hopper tomorrow before attaching the fairings.

I'm the opposite, before today I'm not sure what they're building is the new fairing, now with the tapered section it does look like it's the new fairing. Still possible they're building something else at the 2nd build site though.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/08/2019 03:24 am
We've seen the shape of the upper part of the nose fairing that was blown away and it was hmm, what, more or less that of a revolved parabola, with every panel having compound curvature.

We've seen the hopper dome, hemispherical being made from panels having compound curvature.

Now we're seeing panels being joined together which each have simple single dimension curvature (slip rolls) but with interesting perimeter cuts, trapezoids more or less.  That's different.

What's up with that ??
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/08/2019 03:34 am
Its not true as some say that SpaceX is just throwing this together in an open field with no fixturing or finesse as say, SLS is doing.  Here is one example; specially cut pine blocks being used to keep the rocket parts away from the open field.

Well, they used high tech pine blocks to support early F9 tank section too, so it's a proud tradition

Photo credit: Chris Miller/Spaceflight Now
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BunkerTheHusky on 03/08/2019 04:10 am
Why should they build a second hopper? They plan to lose the first one? If this is the orbital prototype, then we should see them to build the double walled structure for transpirational cooling.

My speculative answer to this question, and mind you that this is coming from a costume designer, wanna be engineer, is that during the build of this original Hopper, they learned a lot of lessons on how to build it better. The original is still to be used in pressure, and flight testing, but they will have to make a vehicle that is stronger and better built for higher speed and altitude testing. The original Hopper seems to be imminently leaving the build site, they have the build team on hand, and the experience gained from the first one. Time to build an orbital *possibly* vehicle that we know eventually will be needed and hinted at being ready by early summer. It has taken roughly 3 months to build Hopper one thus far, and Elon time deadline for the next one is in roughly 3 months.

With all that being said, I'm using something tasty and edible to make my next hat, because I'd be happy to eat it if proven wrong.

Edit - Quote re-added after going MIA
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/08/2019 07:52 am
The Hopper was rolled out to the launch pad today. If they intend to cap the hopper with a new fairing, they should perform fit checks before the drive. As we remember, the first fairing didn't fit initially, and they brought it back to the concrete jig to make some adjustment.

I read the theory here that they move hopper to perform pressure tests and then will return it to attach the fairing. But I don't buy this theory.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: vaporcobra on 03/08/2019 09:34 am
My only question: just... why? :(

(http://bit.ly/2ELfsKL)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: tyrred on 03/08/2019 09:49 am
My only question: just... why? :(

(http://bit.ly/2ELfsKL)

Meh, it'll buff out later... Or else somebody is eating their hat somewhere.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JBF on 03/08/2019 11:20 am
My only question: just... why? :(

(http://bit.ly/2ELfsKL)

Meh, it'll buff out later... Or else somebody is eating their hat somewhere.
The shiny on the hopper is just decorative anyways.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: born01930 on 03/08/2019 11:23 am
I believe the first hat was for photo op only...it was too flimsy to fly. First hops don't need a fairing, maybe when they start flying higher they can add it for aerodynamic loading.

The squished foil liner has been cut and snipped all over by now, what's another little wrinkle?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 03/08/2019 12:22 pm
Assembling a tapered nosecone section.

Photos like this have now put me firmly in the camp that this is either a 2nd version of Starhopper or the full on orbital prototype. This doesn't look at all like the shape of the Starship nose taper. This looks much more like a LOX or CH4 tank dome.

I agree, they look more like dome sections. Very odd.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 03/08/2019 12:31 pm
Pressure test seems more realistic

I can't imagine them doing a pressure test /before/ moving to the launch site.

There is a very large difference between leak testing and pressure testing. The difference in the test pressure is substantial.  I would imagine leak testing at the build area with gas and pressure testing at the launch site with water.  No question I have been wrong before but this is how I would do it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/08/2019 12:35 pm
Assembling a tapered nosecone section.

Photos like this have now put me firmly in the camp that this is either a 2nd version of Starhopper or the full on orbital prototype. This doesn't look at all like the shape of the Starship nose taper. This looks much more like a LOX or CH4 tank dome.

I agree, they look more like dome sections. Very odd.
Perhaps but they could also have decided to just top off the fairing with the equivalent of a tank dome. Just like how Grasshopper and F9R looked. Flying tanks basically.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MizaruSpaceXNut on 03/08/2019 12:59 pm
Maria says that the hopper is on the move!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lampyridae on 03/08/2019 01:38 pm
On the pad now. Wow, it looks like they really just gonna launch it off of some packed dirt just as soon as they're done sticking in the engines and welding a new nosecone from the plates lying around on the dirt. #spacex
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/08/2019 01:38 pm
On the pad now. Wow, it looks like they really just gonna launch it off of some packed dirt just as soon as they're done sticking in the engines and welding a new nosecone from the plates lying around on the dirt. #spacex
This view may look like that, but quite the opposite is true - they've done a lot of work prepping the pad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/08/2019 01:40 pm
Watch live here:
https://youtu.be/qIFpLblpC-E
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lampyridae on 03/08/2019 01:41 pm
On the pad now. Wow, it looks like they really just gonna launch it off of some packed dirt just as soon as they're done sticking in the engines and welding a new nosecone from the plates lying around on the dirt. #spacex
This view may look like that, but quite the opposite is true - they've done a lot of work prepping the pad.

Oh of course, geotechnical studies, packing the dirt etc etc but the point is they're not going with traditional concrete like you'd think. If you could call a VTVL launch/landing pad "traditional." I belatedly realised they must want some understanding of what the exhaust plume does to dirt, this being a Mars rocket and all.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/08/2019 01:41 pm
On the pad now. Wow, it looks like they really just gonna launch it off of some packed dirt just as soon as they're done sticking in the engines and welding a new nosecone from the plates lying around on the dirt. #spacex
This view may look like that, but quite the opposite is true - they've done a lot of work prepping the pad.

Oh of course, geotechnical studies etc etc but the point is they're not going with traditional concrete like you'd think. If you could call a VTVL launch/landing pad "traditional." I belatedly realised they must want some understanding of what the exhaust plume does to dirt, this being a Mars rocket and all.
The pad is rebar reinforced concrete
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lampyridae on 03/08/2019 01:44 pm
On the pad now. Wow, it looks like they really just gonna launch it off of some packed dirt just as soon as they're done sticking in the engines and welding a new nosecone from the plates lying around on the dirt. #spacex
This view may look like that, but quite the opposite is true - they've done a lot of work prepping the pad.

Oh of course, geotechnical studies etc etc but the point is they're not going with traditional concrete like you'd think. If you could call a VTVL launch/landing pad "traditional." I belatedly realised they must want some understanding of what the exhaust plume does to dirt, this being a Mars rocket and all.
The pad is rebar reinforced concrete

Really? Must have missed a few updates of the construction. I thought it was still just graded and packed earth.

EDIT: checked the pics, holy carp, that was some quick work!

It's pretty cool that we're watching the Dragon 2.0 capsule being fished onto Go Searcher and at the same time the Hopper being moved.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: sghill on 03/08/2019 01:59 pm
Assembling a tapered nosecone section.

Photos like this have now put me firmly in the camp that this is either a 2nd version of Starhopper or the full on orbital prototype. This doesn't look at all like the shape of the Starship nose taper. This looks much more like a LOX or CH4 tank dome.

Why should they build a second hopper? They plan to lose the first one? If this is the orbital prototype, then we should see them to build the double walled structure for transpirational cooling.

IMHO, they will have to make at least two higher fidelity articles to develop and practice in-orbit tanker to starship refueling- even if it's on the ground.

Two hoppers makes sense even if one of them doesn't fly.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/08/2019 02:02 pm
Horizontal divert test completed and successful.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/08/2019 02:04 pm
Assembling a tapered nosecone section.

Photos like this have now put me firmly in the camp that this is either a 2nd version of Starhopper or the full on orbital prototype. This doesn't look at all like the shape of the Starship nose taper. This looks much more like a LOX or CH4 tank dome.

I agree, they look more like dome sections. Very odd.

Not at all. They are building new Starship prototype, so they need new domes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 03/08/2019 02:07 pm
Any orbital prototype is going to need transpiration cooling. Until we start seeing perforated double-layer sheets being assembled, those are either fairing parts or a suborbital prototype.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/08/2019 02:10 pm
I wish people wouldn't state things as if they are fact, when instead they are actually supposition. I feel statements are much more compelling if they are backed up with a logical argument, stated reasons behind the statement, and sources cited when applicable.

Otherwise people should say something to the effect, "It's my belief that..."

It makes for a much more informative forum and helps to establish individual credibility.


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/08/2019 02:14 pm
I wish people wouldn't state things as if they are fact, when instead they are actually supposition. I feel statements are much more compelling if they are backed up with a logical argument, stated reasons behind the statement, and sources cited when applicable.

OK then how's this rephrasing;

The horizontal divert test appears to have been completed and appears to have been successful.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 03/08/2019 02:15 pm
Agree Johnny...this entire thread series starting from Nomadd's observation that the new water tower looked like it might actually be a hopper has been a continuous exercise in humility for long-time alt.space watchers and even some newer SpaceX fans.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/08/2019 02:17 pm
I wish people wouldn't state things as if they are fact, when instead they are actually supposition. I feel statements are much more compelling if they are backed up with a logical argument, stated reasons behind the statement, and sources cited when applicable.

OK then how's this rephrasing;

The horizontal divert test appears to have been completed and appears to have been successful.
LOL - it is my personal opinion that my comment wasn't intended for you.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: born01930 on 03/08/2019 02:26 pm
I wish people wouldn't state things as if they are fact, when instead they are actually supposition. I feel statements are much more compelling if they are backed up with a logical argument, stated reasons behind the statement, and sources cited when applicable.

OK then how's this rephrasing;

The horizontal divert test appears to have been completed and appears to have been successful.
LOL - it is my personal opinion that my comment wasn't intended for you.
Is that a fact or supposition?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 03/08/2019 02:29 pm
I wish people wouldn't state things as if they are fact, when instead they are actually supposition. I feel statements are much more compelling if they are backed up with a logical argument, stated reasons behind the statement, and sources cited when applicable.

OK then how's this rephrasing;

The horizontal divert test appears to have been completed and appears to have been successful.
LOL - it is my personal opinion that my comment wasn't intended for you.
Is that a fact or supposition?

 ???

 :-X
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/08/2019 02:45 pm
Hopper at the launch site.

In BCGal's last image you can see they've already attached large flexible hoses to the GSE attach panels.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/08/2019 02:49 pm
Its my belief that many NSF members have expressed the supposition that bouncy feet will be added to the hopper legs at this point, before it gets lowered.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: goretexguy on 03/08/2019 02:57 pm
Here is one example; specially cut pine blocks being used to keep the rocket parts away from the open field.
Perhaps SpaceX would prefer the term, 'recyclable cellulose spacers'.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/08/2019 03:10 pm
I wish people wouldn't state things as if they are fact, when instead they are actually supposition.

I suspect it was a reproach to me. The reproach is fair, but sometimes I am too lazy to write these necessary words - "I think", "I believe", "I suppose". I've put a phrase "In my humble opinion" in my signature. Could it work?  :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/08/2019 03:20 pm
Before today, I felt 99% confident that the extra steel constructions were hopper fairings. But it seems strange to move the hopper tomorrow before attaching the fairings.

It actually makes sense. A fairingless hopper would have a lower center of gravity which would make it a bit more stable to transport. Same with the fairing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/08/2019 03:23 pm
Pressure test seems more realistic

I can't imagine them doing a pressure test /before/ moving to the launch site.

To elaborate on my hopefully realistic expectations:

They're moving the hopper to the launch site or elsewhere to safely perform a pressure test away from the ongoing fairing construction. Afterward they'll move it back to join it with the finished fairing and install the Hopper Raptors. Finally one more move back to the launch site for more testing and eventually the test launch.

Sorry for not being clear since I totally agree with you.

That would be very counter productive. They'll do the joining of the fairing at the launch site.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RedLineTrain on 03/08/2019 03:26 pm
I've put a phrase "In my humble opinion" in my signature. Could it work?  :)

No, because there are those who have information.  It is important to know what is information and what is opinion.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/08/2019 03:40 pm
A few things of minor interest in BCG's recent images;
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: masterxel on 03/08/2019 03:54 pm
That would be very counter productive. They'll do the joining of the fairing at the launch site.

I think the final assembly could occur at the launch site as well, but also think that SpaceX is not shy about moving components back and forth multiple times. I believe each Merlin engine makes either 2 or 3 trips between Hawthorne and McGregor before the final trip to launch site for example.

They will hopefully do what is most efficient and I'm not sure if it's more efficient to move the hopper back or move the fairing plus all necessary construction equipment to the launch site. I am leaning towards hopper going on more trips based on the above.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/08/2019 04:16 pm
Question to BCG, Nomadd, and neighbors -

The road closure would have completely prevented you from leaving BCVille by car to get to the outside world right?  And would have prevented others from getting to the beach.  How / if was this communicated to you and others that would be affected?  Road signs?  Newspapers?  Flyers on your doors?  In your mailboxes?  Nothing?  With how much advance time and how long did they project the closure to take?  ISTM that their level of community engagement and good neighborlyness on this may give some insight to how you may be notified that someone in your neighborhood is going to set fire to a bunch of rocket fuel at some time down the road.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Arb on 03/08/2019 04:34 pm
Foot first(?) look - human for scale.

Cropped from one of BocaChicaGals photos.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: eriblo on 03/08/2019 04:49 pm
Question to BCG, Nomadd, and neighbors -

The road closure would have completely prevented you from leaving BCVille by car to get to the outside world right?  And would have prevented others from getting to the beach.  How / if was this communicated to you and others that would be affected?  Road signs?  Newspapers?  Flyers on your doors?  In your mailboxes?  Nothing?  With how much advance time and how long did they project the closure to take?  ISTM that their level of community engagement and good neighborlyness on this may give some insight to how you may be notified that someone in your neighborhood is going to set fire to a bunch of rocket fuel at some time down the road.
There is a relevant update thread with most of your answers in case you missed it...
https://forum.nasaspaceflight.com/index.php?topic=47001.msg1919452#msg1919452
https://forum.nasaspaceflight.com/index.php?topic=47001.msg1919487#msg1919487
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 03/08/2019 04:54 pm
To join the fairing to the hopper would mean either moving the hopper to the construction site, or moving the fairing to the launch site. The construction site has large cranes and a jig specifically for holding the flimsy-until-affixed fairing. There is also an existing jig for moving the hopper around. It makes more sense to bring the hopper to the fairing than vice versa.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 03/08/2019 04:56 pm
Question to BCG, Nomadd, and neighbors -

The road closure would have completely prevented you from leaving BCVille by car to get to the outside world right?  And would have prevented others from getting to the beach.  How / if was this communicated to you and others that would be affected?  Road signs?  Newspapers?  Flyers on your doors?  In your mailboxes?  Nothing?  With how much advance time and how long did they project the closure to take?  ISTM that their level of community engagement and good neighborlyness on this may give some insight to how you may be notified that someone in your neighborhood is going to set fire to a bunch of rocket fuel at some time down the road.
Yesterday I had heard there was a sign as you came out of Brownsville on Hwy. 4 that said on 3-8-19 expect delays up to 3 hours. We were not notified by SpaceX. Since the control center is close to the village it was only a short time that we would not have been able to leave if we had to go to Brownsville this morning. A longer wait if we wanted to go to the beach.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/08/2019 05:27 pm
To join the fairing to the hopper would mean either moving the hopper to the construction site, or moving the fairing to the launch site. The construction site has large cranes and a jig specifically for holding the flimsy-until-affixed fairing. There is also an existing jig for moving the hopper around. It makes more sense to bring the hopper to the fairing than vice versa.
except that for each move they have to close the road. the cranes can be moved without closure.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/08/2019 05:33 pm
A few things of minor interest in BCG's recent images;

They didn't use a crane, so maybe that's the max lift height of the transporter. lift it 30 cm, place supports under the legs, drop the transporter down and bolt in the spacer, repeat?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/08/2019 05:34 pm
To join the fairing to the hopper would mean either moving the hopper to the construction site, or moving the fairing to the launch site. The construction site has large cranes and a jig specifically for holding the flimsy-until-affixed fairing. There is also an existing jig for moving the hopper around. It makes more sense to bring the hopper to the fairing than vice versa.

Actually I think the easiest things to move are the cranes and construction equipment, not the hopper. So moving the fairing would save one potentially hazardous trip with a much taller hopper and a significantly reduced center of gravity on the transporter. Honestly, the fairing can be finished at the construction site to the point that minimal equipment (mostly cranes and scaffolding) would be needed at the launch site.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/08/2019 05:36 pm
Foot first(?) look - human for scale.

Cropped from one of BocaChicaGals photos.
That foot is only trivially larger in diameter than the pre-foot and being only an inch or so below offers very little in the way of shock absorption.  My guess is that between the two plates exist some pressure sensors or load cells.  And similarly, the BCG zoom image showing kapton tape that I posted a page or so back would seem to be the location of some strain gauges.  ...Or not either individually or combined.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/08/2019 05:41 pm
They'll do the joining of the fairing at the launch site.

The Hopper top looks smooth and finished from this side:

(https://forum.nasaspaceflight.com/assets/47120.0/1548541.jpg)

No place for the fairing connection here.

And once again, they didn't perform fit check. If they need to adjust the fairing, it would be harder to do at the launch site, without the concrete jig.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Prettz on 03/08/2019 05:55 pm
Why is half the dome shiny and half of it not?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/08/2019 06:12 pm
They'll do the joining of the fairing at the launch site.

The Hopper top looks smooth and finished from this side:

(https://forum.nasaspaceflight.com/assets/47120.0/1548541.jpg)

No place for the fairing connection here.

And once again, they didn't perform fit check. If they need to adjust the fairing, it would be harder to do at the launch site, without the concrete jig.
I expect them to build an interface ring to mate base to fairing, if a fairing is to be added, which I expect will be. This ring is relatively small and light so can be test fit on both ends.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Spindog on 03/08/2019 06:17 pm
Why is half the dome shiny and half of it not?
Well it's pretty obviously the same side as the finished shiny fins and fillets and not on the other side with the unfinished fin. It would seem to be cosmetic since the hopper should never experience atmospheric heating. Some folks offered ideas for the shiny dome a few pages back but, it really seems to me that they intend to fly the bottom of the hopper without the nosecone part. No other reason really seems to make sense, especially with the dome only clad one side.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BurnumBurnum on 03/08/2019 06:20 pm
Why is half the dome shiny and half of it not?
The shiny side is the good side for all the press images and videos. All the fixtures are on the non-shiny side, so the pictures will look nice and clean  ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/08/2019 06:42 pm
Question to BCG, Nomadd, and neighbors -

The road closure would have completely prevented you from leaving BCVille by car to get to the outside world right?  And would have prevented others from getting to the beach.  How / if was this communicated to you and others that would be affected?  Road signs?  Newspapers?  Flyers on your doors?  In your mailboxes?  Nothing?  With how much advance time and how long did they project the closure to take?  ISTM that their level of community engagement and good neighborlyness on this may give some insight to how you may be notified that someone in your neighborhood is going to set fire to a bunch of rocket fuel at some time down the road.
No notice but the signs on the road. We could have driven around the back side of the control center if needed.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 03/08/2019 07:21 pm
Zoom edited BCG's latest image of BFH Lift.

Seems to be a good bit of "scrunch" on that bottom near the GSE attachment.

I hope there isn't too much damage!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/08/2019 07:25 pm
Zoom edited BCG's latest image of BFH Lift.

Seems to be a good bit of "scrunch" on that bottom near the GSE attachment.

I hope there isn't too much damage!
That's just the metal foil spot welded over the actual steel plates that make up the base of the BFH. They've snipped that stuff off all over the thing when adding the through-hulls and such, and not with a lot of precision or care either.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: venir on 03/08/2019 07:48 pm
I managed to get a better pic of this gizmo on the unfinished fin/leg.

From the update thread, text behind it appears to say "Hydraulics Bulkhead".
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/08/2019 07:55 pm
Zoom edited BCG's latest image of BFH Lift.

Seems to be a good bit of "scrunch" on that bottom near the GSE attachment.

I hope there isn't too much damage!

The structural steel appears to be undamaged. The foil is bent, but the actual outer shell of the vehicle is being held with field fabricated clamps.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/08/2019 08:27 pm
I managed to get a better pic of this gizmo on the unfinished fin/leg.

From the update thread, text behind it appears to say "Hydraulics Bulkhead".

What are the parts that will require hydraulics on this thing? My guesses:

1. Gimbaling equipment
2. Landing struts, if they add them? Musk said they would have them, but I've seen no sign of them
3. ???
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Prettz on 03/08/2019 08:32 pm
Why is half the dome shiny and half of it not?
Well it's pretty obviously the same side as the finished shiny fins and fillets and not on the other side with the unfinished fin. It would seem to be cosmetic since the hopper should never experience atmospheric heating. Some folks offered ideas for the shiny dome a few pages back but, it really seems to me that they intend to fly the bottom of the hopper without the nosecone part. No other reason really seems to make sense, especially with the dome only clad one side.
I missed some updates. So it looks like they're really going to do the first hop, or at least engine light, without the nose.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: raketa on 03/08/2019 08:41 pm
I think nose will connect at launchpad when it is done.
I think it make place for Orbital Starship.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/08/2019 08:49 pm
From the brownsville herald article (https://www.brownsvilleherald.com/news/local/spacex-prototype-moved-to-launch-pad/article_89dc1d40-41c4-11e9-8076-87fdf3df4800.html):

Quote
the vehicle will be tethered during initial testing and hops will not be visible from offsite.

Nomadd, BCG, this sounds like a challenge? I think they haven't been reading the forums ;P
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: loekf on 03/08/2019 08:54 pm
From the brownsville herald article (https://www.brownsvilleherald.com/news/local/spacex-prototype-moved-to-launch-pad/article_89dc1d40-41c4-11e9-8076-87fdf3df4800.html):

Quote
the vehicle will be tethered during initial testing and hops will not be visible from offsite.

Nomadd, BCG, this sounds like a challenge? I think they haven't been reading the forums ;P

That Brownsville Herald is even blocking visitors from the EU, they must be living in a kind of cocoon over there, in Texas.

Are the really planning to light up Raptors so soon ?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/08/2019 08:54 pm
From the brownsville herald article (https://www.brownsvilleherald.com/news/local/spacex-prototype-moved-to-launch-pad/article_89dc1d40-41c4-11e9-8076-87fdf3df4800.html):

Quote
the vehicle will be tethered during initial testing and hops will not be visible from offsite.

Nomadd, BCG, this sounds like a challenge? I think they haven't been reading the forums ;P

How many millimetres are they planning for the first hop?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: joek on 03/08/2019 08:59 pm
Tethered also means they don't need FAA permit or license, as long as they avoid materials which would require such (e.g., hypergolics).  Once they go untethered we should see an indication on the FAA site (although not necessarily before the tests occur).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/08/2019 09:01 pm
I managed to get a better pic of this gizmo on the unfinished fin/leg.

From the update thread, text behind it appears to say "Hydraulics Bulkhead".

What are the parts that will require hydraulics on this thing? My guesses:

1. Gimbaling equipment
2. Landing struts, if they add them? Musk said they would have them, but I've seen no sign of them
3. ???

My guess - hydraulically operated ball valves...

As to nose cone or not... After seeing the one pic... NO nose cone on this hopper... IMHO
They tried... it broke... moving on...

As for the two separate Caldwell crews still working back up the road...
That will be an improved/replacement Hopper v.2 on the concrete ring now...
And that one on the side pad... I still think control/VIP viewing tower... Still (likely wrong on that)

All the above... My opinions and guesses...  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/08/2019 09:12 pm
I wish people wouldn't state things as if they are fact, when instead they are actually supposition.

I suspect it was a reproach to me. The reproach is fair, but sometimes I am too lazy to write these necessary words - "I think", "I believe", "I suppose". I've put a phrase "In my humble opinion" in my signature. Could it work?  :)

It's a fair counter-point and one I've pondered.  We should adopt an acronym which ITSM we rarely do around these parts.  I propose one of the following:

STATIQ:  Subject To All The Inumerable Qualifications
STATSD: Subject to All The Standard Disclaimers
DOTBRO:  Don't Overthink This Bro
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lar on 03/08/2019 10:44 pm
Don't anybody start a poll or so help me, I'm gonna turn this car around.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/08/2019 10:47 pm
Don't anybody start a poll or so help me, I'm gonna turn this car around.

Poll: How quickly will Lar turn this car around?

1. 1-10 more posts
2. 10-100 more posts
3. infinity, he hasn't got in in him
4. okay that's it, I'm turning this car around

;P
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FlattestEarth on 03/08/2019 11:47 pm
Hydraulics Bulkhead
Main Fuel Valve Hydraulic Open/Close
Oxidizer Preburner Fuel Valve Hydraulic Open/Close
Fuel Preburner Oxidizer Valve Hydraulic Open/Close


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Stefan.Christoff.19 on 03/09/2019 01:07 am
If it's tethered that probably would be easier to do without the nose cone. It's also easier to see attach points on the hopper. So hop tethered without the nose and then when they learn how to make it hover really low, add the nose cone and try for a higher altitude and maneuvering... In my humble opinion ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CraigLieb on 03/09/2019 01:39 am
This is Texas... so maybe the first hopper test will be equivalent to telling a youngster to get out of the wagon with a “Hop on down from there Partner!” To encourage the test vehicle to get down from the transport vehicles. ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 03/09/2019 01:45 am
This is Texas... so maybe the first hopper test will be equivalent to telling a youngster to get out of the wagon with a “Hop on down from there Partner!” To encourage the test vehicle to get down from the transport vehicles. ;D
Actually I've been wondering about that.  Did they use a crane to get the hopper on the roll-lift vehicles?  How will they get it down? I haven't seen a video or written description of this.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 03/09/2019 02:01 am
This is Texas... so maybe the first hopper test will be equivalent to telling a youngster to get out of the wagon with a “Hop on down from there Partner!” To encourage the test vehicle to get down from the transport vehicles. ;D
Actually I've been wondering about that.  Did they use a crane to get the hopper on the roll-lift vehicles?  How will they get it down? I haven't seen a video or written description of this.
It rolls up under it, the roll-lift vehicle are quite capable of lifting or dropping the hopper without any assistance, they have a significant jack height.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/09/2019 02:17 am
Hydraulics Bulkhead
Main Fuel Valve Hydraulic Open/Close
Oxidizer Preburner Fuel Valve Hydraulic Open/Close
Fuel Preburner Oxidizer Valve Hydraulic Open/Close

These are some good guesses. I suppose that would mean the valves are controlled hydraulically. What kinds of valves are normally present in comparable engines, and are they commonly hydraulic?
(I am completely ignorant of valve types, or... really anything about valves)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/09/2019 02:32 am
Before something gets started I want to stop it.
Elon said Raptor (singular)
Austin Barnard said Raptors (plural)
Austin had some booboo.
Let's not amplify it.
Raptor
Sure there's gonna be more coming, but best information is one next week.

So do the figgerers among us figger 1 makes it go up or just makes it loud and the ground hot and scares the critters?

p.s. Check out how the airspace is getting busy down there - Austin's drone passes by another drone.

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920080#msg1920080 (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920080#msg1920080)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/09/2019 02:39 am
p.s. Check out how the airspace is getting busy down there - Austin's drone passes by another drone.

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920080#msg1920080 (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920080#msg1920080)

Yep, it is drone mania down there.  :D

As a drone flier myself, I do wonder if now that SpaceX soon will do hops, that they will try to register the area as an active air field - preventing a lot of public drone traffic within the immediate vicinity.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/09/2019 02:48 am
Yea maybe legally they'll do that but there's very few soft spots on the thing that would be affected even if flying into a flock full grown drones at any speed they'll be doing at drone altitude and there's little risk of having a drone get sucked into an air intake or smashing the windshield or puncturing the tanks.  If I were running the show from the SpaceX side I'd invite all the drones to come and do battle with the big droneswatter and I'd give awards for the drones that did the most wake turbulations and survived and I'd give other awards for the drone with the highest recorded temperature that still survived.  Bring it on.  But, any drones or drone parts that fall on SpaceX property remain the property of SpaceX and / or its contractors.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/09/2019 03:01 am
Crosspostal from Snotis on the Raptor thread   https://forum.nasaspaceflight.com/index.php?topic=47506.msg1920078#msg1920078 (https://forum.nasaspaceflight.com/index.php?topic=47506.msg1920078#msg1920078)

Quote
SpaceX spokesman James Gleeson said in an email that the Starship prototype was moved to the launch pad in preparation for testing, though the public won’t be able to see the first tests.

“SpaceX will conduct checkouts of the newly installed ground systems and perform a short static fire test in the days ahead,” he said. “Although the prototype is designed to perform sub-orbital flights, or hops, powered by the SpaceX Raptor engine, the vehicle will be tethered during initial testing and hops will not be visible from offsite. SpaceX will establish a safety zone perimeter in coordination with local enforcement and signage will be in place to alert the community prior to the testing.”
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/09/2019 06:18 am
Probably they'll open wells at the launch pad under the hopper and tether legs to fasteners inside the wells.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/09/2019 07:21 am
Hydraulics Bulkhead
Main Fuel Valve Hydraulic Open/Close
Oxidizer Preburner Fuel Valve Hydraulic Open/Close
Fuel Preburner Oxidizer Valve Hydraulic Open/Close

Attached the Raptor schema for clarity. These valves are marked with numbers:
1 - Main Fuel Valve
2 - Oxidizer Preburner Fuel Valve
3 - Fuel Preburner Oxidizer Valve
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/09/2019 07:49 am
Before something gets started I want to stop it.
Elon said Raptor (singular)
Austin Barnard said Raptors (plural)
Austin had some booboo.
Let's not amplify it.
Raptor
Sure there's gonna be more coming, but best information is one next week.

So do the figgerers among us figger 1 makes it go up or just makes it loud and the ground hot and scares the critters?

p.s. Check out how the airspace is getting busy down there - Austin's drone passes by another drone.

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920080#msg1920080 (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920080#msg1920080)
There should be enough thrust for small hops (thrust circa 200 tons max, dry weight less than 80 tons probably). The big problem with flying with only one engine is the lack of any obvious means of roll control. Even with three engines I’d expect to see some form of RCS. I’t could go in the fairing, I just don’t think there is going to be one. I figger they could be hiding a set of cold gas thrusters in the skirt?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marokrile on 03/09/2019 09:07 am
Is there an option to fire a raptor on hopper as a test stand or a static fire. Should it have to be throttled down or the hopper had to be clamped?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DistantTemple on 03/09/2019 09:19 am
If it is as EM says "tethered" then it is not a "launch event" and can it therefore not be counted against the yearly quota?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: john57sharp on 03/09/2019 09:41 am
This is Texas... so maybe the first hopper test will be equivalent to telling a youngster to get out of the wagon with a “Hop on down from there Partner!” To encourage the test vehicle to get down from the transport vehicles. ;D
Actually I've been wondering about that.  Did they use a crane to get the hopper on the roll-lift vehicles?  How will they get it down? I haven't seen a video or written description of this.
It rolls up under it, the roll-lift vehicle are quite capable of lifting or dropping the hopper without any assistance, they have a significant jack height.

The transporters remind this child of the sixties of these
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: guckyfan on 03/09/2019 10:25 am
If it is as EM says "tethered" then it is not a "launch event" and can it therefore not be counted against the yearly quota?

If it requires beach closure it may. Beach closures is the rationale behind the limitation.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: geza on 03/09/2019 12:14 pm
Hydraulics Bulkhead
Main Fuel Valve Hydraulic Open/Close
Oxidizer Preburner Fuel Valve Hydraulic Open/Close
Fuel Preburner Oxidizer Valve Hydraulic Open/Close

Attached the Raptor schema for clarity. These valves are marked with numbers:
1 - Main Fuel Valve
2 - Oxidizer Preburner Fuel Valve
3 - Fuel Preburner Oxidizer Valve

Why don't we need valves between the tank and the main inlet of the turbopump for both fuel and oxigen? Sure, my uneducatedness.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/09/2019 12:34 pm
Hydraulics Bulkhead
Main Fuel Valve Hydraulic Open/Close
Oxidizer Preburner Fuel Valve Hydraulic Open/Close
Fuel Preburner Oxidizer Valve Hydraulic Open/Close

Attached the Raptor schema for clarity. These valves are marked with numbers:
1 - Main Fuel Valve
2 - Oxidizer Preburner Fuel Valve
3 - Fuel Preburner Oxidizer Valve

Why don't we need valves between the tank and the main inlet of the turbopump for both fuel and oxigen? Sure, my uneducatedness.
Good question but I think it best answered over on the Raptor thread.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 03/09/2019 12:35 pm
Hydraulics Bulkhead
Main Fuel Valve Hydraulic Open/Close
Oxidizer Preburner Fuel Valve Hydraulic Open/Close
Fuel Preburner Oxidizer Valve Hydraulic Open/Close

Attached the Raptor schema for clarity. These valves are marked with numbers:
1 - Main Fuel Valve
2 - Oxidizer Preburner Fuel Valve
3 - Fuel Preburner Oxidizer Valve

Why don't we need valves between the tank and the main inlet of the turbopump for both fuel and oxigen? Sure, my uneducatedness.

You do, and tank valves were shown on earlier CAD pictures. My problem is where to put the Raptor's LOX main valve. The only place it makes sense, assuming we have sketched the LOX preburner correctly, is upstream of the pump. Normally you want two valves in series to insure propellant shut down.

You shouldn't need the engines to pressure test the tanks. Tank valves are part of the vehicle, not the engine.

Just as a mind bender, the Super Heavy will have 3 x 31 tank valves. One extra valve for the CH4 header tank. The Star Ship will have 4 x 7.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SDSmith on 03/09/2019 12:42 pm
I'm assuming they need water for cooling when they start engine testing. I've not read of any water deliveries much less testing of the water system.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThereIWas3 on 03/09/2019 01:16 pm
People talk about the "ooo! 300 bar combustion chamber pressure!"  But then I see on the diagram that the pressure in the preburner is 512 bar!   Am I reading this wrong?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/09/2019 01:45 pm
Just as a mind bender, the Super Heavy will have 3 x 31 tank valves. One extra valve for the CH4 header tank. The Star Ship will have 4 x 7.

Looking at your picture, I see 4 tank valves for the single engine - two pairs, connected in parallel. Are they doubled for redundancy? Do your figures for the Super Heavy (3 x 31) imply that it will have a one valve for a tank, without redundancy?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/09/2019 01:47 pm
Just as a mind bender, the Super Heavy will have 3 x 31 tank valves. One extra valve for the CH4 header tank. The Star Ship will have 4 x 7.

Looking at your picture, I see 4 tank valves for the single engine - two pairs, connected in parallel. Are they doubled for redundancy? Do your figures for the Super Heavy (3 x 31) imply that it will have a one valve for a tank, without redundancy?
Guys - please take this to the proper thread - you've run this one off its rails.


https://forum.nasaspaceflight.com/index.php?topic=47506.msg1920200#msg1920200



Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/09/2019 02:17 pm
I'm assuming they need water for cooling when they start engine testing. I've not read of any water deliveries much less testing of the water system.
Water trucks have been running regularly to the pad for two weeks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Peter.Colin on 03/09/2019 02:26 pm
I'm assuming they need water for cooling when they start engine testing. I've not read of any water deliveries much less testing of the water system.
Water trucks have been running regularly to the pad for two weeks.

A Watertower I've seen transported to the pad  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Crispy on 03/09/2019 02:29 pm
People talk about the "ooo! 300 bar combustion chamber pressure!"  But then I see on the diagram that the pressure in the preburner is 512 bar!   Am I reading this wrong?

No. Turbopump pressure is always higher than combustion chamber pressure, otherwise you wouldn't be able to pump anything into the chamber!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 03/09/2019 02:42 pm
Just as a mind bender, the Super Heavy will have 3 x 31 tank valves. One extra valve for the CH4 header tank. The Star Ship will have 4 x 7.

Looking at your picture, I see 4 tank valves for the single engine - two pairs, connected in parallel. Are they doubled for redundancy? Do your figures for the Super Heavy (3 x 31) imply that it will have a one valve for a tank, without redundancy?
Guys - please take this to the proper thread - you've run this one off its rails.


https://forum.nasaspaceflight.com/index.php?topic=47506.msg1920200#msg1920200

My point was that these are vehicle tank valves not engine valves, but yes the discussion should go to the engineering threads for SS and SH, not Raptor.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Peter.Colin on 03/09/2019 02:44 pm
I'm assuming they need water for cooling when they start engine testing. I've not read of any water deliveries much less testing of the water system.

The water deluge system is mainly for absorbing acoustic energy, not so much cooling.
The previous Falcon 9 hopper didn't need it.
But the 3 raptor engines at full throttle on the starhopper might need it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/09/2019 03:24 pm
I'm assuming they need water for cooling when they start engine testing. I've not read of any water deliveries much less testing of the water system.
Water trucks have been running regularly to the pad for two weeks.
I should note that it looks like quality water (drinking water type trucks), not regular tankers. It could be distilled.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 03/09/2019 03:33 pm
I'm assuming they need water for cooling when they start engine testing. I've not read of any water deliveries much less testing of the water system.
Water trucks have been running regularly to the pad for two weeks.
I should note that it looks like quality water (drinking water type trucks), not regular tankers. It could be distilled.
Sounds like for cleaning and proof pressure testing, a good sign of progress.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/09/2019 05:13 pm
Still working on the tapered panels.

I'm disconvinced that the curvature of those tapered panels individually or togetherly matches or nearmatches what we saw in the tinfoil hat.  Actually I'm not convinced its going to be a tinfoil hat though it certainly may be.  I'm not convinced its another hopper though it may be.  I'm not convinced its some form of SuperHeavy though it may be.  Ain't no water tower that's for sure.

Q: Looking at the two cylinders it appears one is made from shiny stainless and one from not so shiny stainless.  Is that correct or am I misinterpreting the visual evidence?

Request to Boca Chicans: Look for parts that may be parts to make an under-Raptor deflector.  Heavy curved sections probably with water cooling channels, welded tubing etc.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 03/09/2019 07:06 pm
Eye-balling it, I think that the tinfoil Hopper tapered a good deal more than the CGI Starship models we've seen. Maybe this iteration of the Hopper, with a lesser taper, approximates the Starship outer mold line more closely? - So, we'll see a taller cylindrical section capped by a stouter snout. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 03/09/2019 07:14 pm
More parts of ? on the ground.  :) A couple pics of the Hopper at the launch site.

 IMG_5723 (2).JPG


- Bocachicagal's latest set of pics is of such good quality that you can quite easily see that the top dome is of slightly lesser diameter than the Hopper body itself. There is a definite "ledge" to weld/bolt a superstructure on top. May not happen before the first tethered tests but surely later.... I'd guess. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/09/2019 07:30 pm
After seeing the latest photos...there is no way this Starship Prototype Hopper is returning to that launch pad from any significantly high launch  profile. Don't @me :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cheapchips on 03/09/2019 07:56 pm
I'm not saying that the curved section looks like a tank dome section, but it does look awfully like a tank dome section. Must be a perspective trick.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47070.0;attach=1539847;image)

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47120.0;attach=1548688;image)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MTom on 03/09/2019 08:14 pm
I'm not saying that the curved section looks like a tank dome section, but it does look awfully like a tank dome section. Must be a perspective trick.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47070.0;attach=1539847;image)

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47120.0;attach=1548688;image)

I don't think this is a tank dome section. The plates are much thinner. See the earlier photos from BCG.

I would guess it will be the nose cone.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/09/2019 08:21 pm
What is that yellow cord? I thought touch papers were supposed to be blue? ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/09/2019 10:22 pm
BCG:
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 03/09/2019 10:57 pm
Maybe the bottom of the fuel tank similar to the original ITS?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Prettz on 03/09/2019 11:40 pm
Maybe the bottom of the fuel tank similar to the original ITS?
You don't think they've changed the geometry down there since switching off carbon fiber (even more so for the booster)?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/10/2019 01:40 am
Maybe the bottom of the fuel tank similar to the original ITS?
You don't think they've changed the geometry down there since switching off carbon fiber (even more so for the booster)?

Optimal tank shapes don't really change with the material, at least for simple shapes like this.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: 2megs on 03/10/2019 02:34 am
Optimal tank shapes don't really change with the material, at least for simple shapes like this.

That original shape looked to be optimal for placing a ring of taller vacuum nozzles around a central cluster of shorter sea level nozzles. When they changed the nozzle lengths, that could have driven a change in the tank shape. Maybe.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/10/2019 02:41 am
I noticed a hole in the fairing this morning. The second section has been anchored to the containers. It is a bit breezy here today.
I had noticed there’s another hole below as well, right where the cylinder sits on the concrete jig.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: EngrDavid on 03/10/2019 03:02 am
They would probably have to reroute the plumbing on the hopper if they are going to have a nose cone mounted on top of it.


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/10/2019 03:13 am
Maybe the bottom of the fuel tank similar to the original ITS?
You don't think they've changed the geometry down there since switching off carbon fiber (even more so for the booster)?

Optimal tank shapes don't really change with the material, at least for simple shapes like this.
They can when they're thrust structures.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureMartian97 on 03/10/2019 03:31 am
They would probably have to reroute the plumbing on the hopper if they are going to have a nose cone mounted on top of it.

Or cut a slot out of the fairing
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Prettz on 03/10/2019 04:00 am
Maybe the bottom of the fuel tank similar to the original ITS?
You don't think they've changed the geometry down there since switching off carbon fiber (even more so for the booster)?

Optimal tank shapes don't really change with the material, at least for simple shapes like this.
There wasn't anything simple about that shape, though. We had these discussions back when it was revealed. Check the squared-off bottom of the methane tank on the booster, especially. Can stainless steel do that?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/10/2019 05:11 am
Maybe the bottom of the fuel tank similar to the original ITS?

That's the 2016 version though, they switched to a normal dome (with a bulge) in 2017 version.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/10/2019 07:04 am
Maybe the bottom of the fuel tank similar to the original ITS?

That's the 2016 version though, they switched to a normal dome (with a bulge) in 2017 version.

This is SpaceX, they can switch again!

This really does look more like a dome than a fairing, and the elongated shape narrows the options to the aft dome. The central hole would nicely fit the aft dome of a header tank assembly too. From earlier renders the aft dome sits directly onto the ‘hexaweb’ thrust structure so it may not need to take massive loads.

We’all find out (hopefully very soon) if they stick it pointy side down into one of the barrel sections.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/10/2019 07:21 am
Might I suggest a more sharper taper atop an elongated constant diameter? Unheard of, know...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/10/2019 07:40 am
Maybe the bottom of the fuel tank similar to the original ITS?
You don't think they've changed the geometry down there since switching off carbon fiber (even more so for the booster)?

Optimal tank shapes don't really change with the material, at least for simple shapes like this.
There wasn't anything simple about that shape, though. We had these discussions back when it was revealed. Check the squared-off bottom of the methane tank on the booster, especially. Can stainless steel do that?

I guess I missed that discussion at the time. A flat tank bottom on a tank that size seems equally implausible for either composite or steel. I would have chalked it up to a detail that was bound to change. (And it appears to have) Or is there some miraculous aspect of composite tanks that makes it plausible?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/10/2019 07:41 am
Might I suggest a more sharper taper atop an elongated constant diameter? Unheard of, know...

Agreed, I think they are doing a stronger but simpler “fairing” shape in this 2nd attempt. That’s my current theory.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/10/2019 07:53 am
I noticed a hole in the fairing this morning. The second section has been anchored to the containers. It is a bit breezy here today.
I had noticed there’s another hole below as well, right where the cylinder sits on the concrete jig.

Don't tell me these are attachment points for the fins/legs  :)

Still I'd like to inspect the fairing from other sides.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/10/2019 08:38 am
Might I suggest a more sharper taper atop an elongated constant diameter? Unheard of, know...

The render shows a smooth compound curved transition from the barrel to the nose tip, but that is not the profile of the fairing/dome thing where we have a relatively sharp transition to a straight sided conical section. That sharp curve would equate to a hotspot on an actual vehicle. Not conclusive, this could be a compromise profile for ease of manufacturing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Roy_H on 03/10/2019 02:50 pm
I have been somewhat puzzled by the stainless steel skin mounted on the Hopper. It appeared to be simply cosmetic, but not all that attractive as it is dimpled and wrinkled. But I thought it was just Elon wanting it to look like the final article. Then they did the same to the dome on top, and I thought this very strange because it will get covered eventually by the top shell. Now I wonder if there isn't a functional reason, to reduce heating from the hot Texas sun of the fuels during testing. Thoughts anyone?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 03/10/2019 03:48 pm
BCG:

I'm really kid of surprised that there has been no discussion about the High Pressure Methane trailers at the Launch site.  To me at least that is a tell of what SpaceX plans in the very near future.  Some have speculated that the initial Raptor is just a fit check.  I would offer that this indicates that the Hopper may indeed fly with a single Raptor soon and fueling tests will also be underway this week.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/10/2019 05:07 pm
Undoubtedly the Raptor coming to BC will be used for the fist tethered firings in very near future, maybe next week.

I wonder how they'll liquefy the compressed methane. Is the refrigerator included inside the tank?

As for the oxygen, I still believe the two vertical tanks on the left on attached image *could* be oxygen tanks. I know, they are labeled as "Liquid Nitrogen", and the trucks around them - "Compressed Nitrogen". But I don't understand why they need nitrogen in such volumes, and I don't see another tanks for the oxygen storage.

Image credit: Austin Barnard
https://mobile.twitter.com/austinbarnard45/status/1104201247140315136
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 03/10/2019 05:55 pm
More parts of ? on the ground.  :) A couple pics of the Hopper at the launch site.
Using BCG's convenient side-on shot, here's an estimate of bulkhead position within the hopper. Lower bulkhead cannot be attached below the non-sealed cable run entry (highlighted by small green square) or the cable runs would penetrate the tank and the contents would flow out. The common bulkhead must be joined to the outer wall between the lowermost edge of the upper access hatch and the uppermost edge of the lower access hatch, in order for each hatch to access the two separate tanks. I've depicted it in its uppermost possible position.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: gideonlow on 03/10/2019 06:23 pm
These have been added since (I think) yesterday.  Could they be struts to integrate landing shock absorbers?



Edit: Images cropped from today's BCG photo updates. Thx BCG!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 03/10/2019 06:40 pm
More EXCELLENT shots BCG! Thank you again!  :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bogeyman on 03/10/2019 06:51 pm
But I don't understand why they need nitrogen in such volumes, and I don't see another tanks for the oxygen storage

Maybe they use the nitrogen for leak checks?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 03/10/2019 06:53 pm
It is likely the safest gas to use to check out cryogenic systems.. and the cheapest of any as well, I suppose.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Coastal Ron on 03/10/2019 06:56 pm
As for the oxygen, I still believe the two vertical tanks on the left on attached image *could* be oxygen tanks. I know, they are labeled as "Liquid Nitrogen", and the trucks around them - "Compressed Nitrogen". But I don't understand why they need nitrogen in such volumes, and I don't see another tanks for the oxygen storage.

I'm not an expert on liquified gas storage, but I would imagine that mis-labeling tanks is not only EXTREMELY dangerous (i.e. nitrogen is inert, but oxygen is reactive), but likely violates a number of laws.

Let's stick with Occam's razor (https://en.wikipedia.org/wiki/Occam%27s_razor) here...  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/10/2019 07:03 pm
What's the current thinking about shock absorbers? Do people think they won't bother at all? Or will they bolt them on at some point before the first hop when they put the hat on?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/10/2019 08:15 pm
These have been added since (I think) yesterday.  Could they be struts to integrate landing shock absorbers?

(https://forum.nasaspaceflight.com/assets/47301.0/1548902.jpg)

Edit: Images cropped from today's BCG photo updates. Thx BCG!

Could be for tethering, imho.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/10/2019 08:26 pm
But I don't understand why they need nitrogen in such volumes, and I don't see another tanks for the oxygen storage

Maybe they use the nitrogen for leak checks?

Maybe.

But assume the leak checks are completed. Will these tanks stay empty, waiting for the next vehicle assembling? Why not use trucks like one was arrived to the pad today, instead of stationary tanks?

I'd expect stationary oxygen tanks for the multiple use, instead of nitrogen tanks used once for each vehicle.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 03/10/2019 08:38 pm
Liquid nitrogen is colder than either LOX or LCH4.. I suspect that liquid nitrogen might be used for supercooling both the LOX and the CH4 during loading.

Just a guess $ 0.02
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 03/10/2019 08:43 pm
Liquid nitrogen is colder than either LOX or LCH4.. I suspect that liquid nitrogen might be used for supercooling both the LOX and the CH4 during loading.

Just a guess $ 0.02

You also want to purge with GN2.  It will take a bunch for those tanks.  Naturally the Raptor(s) will also have to be purged.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Zardar on 03/10/2019 10:00 pm
These have been added since (I think) yesterday.  Could they be struts to integrate landing shock absorbers?



Edit: Images cropped from today's BCG photo updates. Thx BCG!

I think they might be just to hold up the propellant fill/drain hoses. If they fire up the hopper with the hoses attached and lying on the ground as they are now, they might get incinerated.

There dosn't seem to be any service masts yet.

They would need to leave the drain hoses attached to quickly safe the hopper after a test-fire.


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/10/2019 11:43 pm
So we think we've got a Raptor coming and we've got Raptor food on site and there's word that there'll be some tethered down testing and we now see BFH tethered down to eye bolts going down to the three huge anchor blocks we saw and wondered about.  The tethers are quite substantial and appear to be made from nylon or polyester which would be incompatible with the exhalings of Raptor(s).  So one or more elements of what we think we know isn't correct.

Maybe this is just anchoring against the wind, and they'll be removed for testing?

[edit: and it looks like OxCartMark removed and rewrote his note, but, point remains....]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/10/2019 11:43 pm
Each leg has one of these Slingmax slings around it and it's anchored down.

Lots of thoughts here.

So we think we've got a Raptor coming and we've got Raptor food on site and there's word that there'll be some tethered down testing and we now see BFH tethered down to eye bolts going down to the three huge anchor blocks we saw and wondered about.  The tethers are quite substantial and appear to be made from nylon or polyester which would be incompatible with the exhalings of Raptor(s).  So one or more elements of what we think we know isn't correct.

Those saddles with holes that are wrapped over the legs that some suggested were tie down locations, they're tie down locations.  Though why they were necessary or why the holes remains a bit up for discussion.

What is all of the stuff around the legs and why is it necessary and why the caution tape to keep people out?  And what is the material on that roll?

Methane could be there to start filling the liquid methane tanks by using liquid N2 to liquefy the methane.  Perhaps they're just going at it slowly and we'll see a number of those pressure tankers daily or weekly to eventually fill the tanks.  Or perhaps they are to spin up the turbines.  Or perhaps to fill the methane tank on BFK with gas before the liquid is in (probably not, nitrogen seems more likely).

"Nitrogen Refrigerated Liquid" - I chuckle every time I see that on the road.  Its a massive understatement.  My broccoli is refrigerated, this is in another class altogether.  Its similar to saying "the Raptor works by the process of gently oxidizing methane"
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/11/2019 01:27 am
Each leg has one of these Slingmax slings around it and it's anchored down.

Lots of thoughts here.

So we think we've got a Raptor coming and we've got Raptor food on site and there's word that there'll be some tethered down testing and we now see BFH tethered down to eye bolts going down to the three huge anchor blocks we saw and wondered about.  The tethers are quite substantial and appear to be made from nylon or polyester which would be incompatible with the exhalings of Raptor(s).  So one or more elements of what we think we know isn't correct.

Those saddles with holes that are wrapped over the legs that some suggested were tie down locations, they're tie down locations.  Though why they were necessary or why the holes remains a bit up for discussion.

What is all of the stuff around the legs and why is it necessary and why the caution tape to keep people out?  And what is the material on that roll?

Methane could be there to start filling the liquid methane tanks by using liquid N2 to liquefy the methane.  Perhaps they're just going at it slowly and we'll see a number of those pressure tankers daily or weekly to eventually fill the tanks.  Or perhaps they are to spin up the turbines.  Or perhaps to fill the methane tank on BFK with gas before the liquid is in (probably not, nitrogen seems more likely).

"Nitrogen Refrigerated Liquid" - I chuckle every time I see that on the road.  Its a massive understatement.  My broccoli is refrigerated, this is in another class altogether.  Its similar to saying "the Raptor works by the process of gently oxidizing methane"
Caution tape because there’s three open holes. The slings are shackled to anchors in the holes. There’s some L2 info / imagery related to this.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magicsound on 03/11/2019 02:21 am
The LN could be for cryo-testing the tanks and plumbing. Thermal shrinkage can be significant at the tank mountings and  pipe joints. Proper design can deal with that but still needs to be tested.

LN might also do cryo-hardening of the SS, especially where welding has messed with it.

There's also opportunity for a rough test of autogenous pressurization, in the real thermal environment of the hopper. The vapor pressure and viscosity of LN will be different from LM and LO, but the pressure data costs nothing extra once the tanks are filled.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Inoeth on 03/11/2019 02:42 am
Well we just found Raptor Serial Number 2 will be the first engine installed on the hopper https://twitter.com/elonmusk/status/1104945142065070081

Clearly the first one is still damaged and probably will never fly if they've already made some improvements for the next generation engine... and clearly they're confident in the design if it's already going to the hopper sometime this upcoming week.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/11/2019 07:39 am
This looks like a strain gauge...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureSpaceTourist on 03/11/2019 08:27 am
A great few seconds of video showing care taken when moving the hopper:

https://twitter.com/rogerlewisholt/status/1105034197692047362

Quote
Plant saveing! 🌵🚀🌵

Credit🎥Maria Pointer
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Star One on 03/11/2019 08:53 am
Well we just found Raptor Serial Number 2 will be the first engine installed on the hopper https://twitter.com/elonmusk/status/1104945142065070081

Clearly the first one is still damaged and probably will never fly if they've already made some improvements for the next generation engine... and clearly they're confident in the design if it's already going to the hopper sometime this upcoming week.

For some reason that link goes to a thread and not a specific tweet though I can see it down the thread.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Roy_H on 03/11/2019 09:59 am
As for the oxygen, I still believe the two vertical tanks on the left on attached image *could* be oxygen tanks. I know, they are labeled as "Liquid Nitrogen", and the trucks around them - "Compressed Nitrogen". But I don't understand why they need nitrogen in such volumes, and I don't see another tanks for the oxygen storage.

No, I am sure the tanks will not be used for O2. But my theory is that liquid nitrogen used with heat exchangers is the easiest way to liquify and super cool oxygen and methane.

Edit: Oops, I missed SpaceWoof's post above. Anyhow I agree with him.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cheapchips on 03/11/2019 10:26 am
I thought I'd show a stacked version of the sections under construction.  Best my paint skills can manage, but I didn't think I'd seen one in the thread. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: enbandi on 03/11/2019 10:30 am

No, I am sure the tanks will not be used for O2. But my theory is that liquid nitrogen used with heat exchangers is the easiest way to liquify and super cool oxygen and methane.


If you make a quick google for "bulk liquefied gas storage" or "Air gas cryogenic storage" you will find that several different gas vendors/companies are treating Liquid O2, N2 and Ar as equal, offering similar services, machinery and the same storage tank types for this three material. So I think those big nitrogen tanks can be used for oxygen storage as well. Paperwork, recertification and so may applies.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 03/11/2019 12:17 pm
Worth noting I think, that AFAIK, the Raptor engine has never been tested vertically, which is obviously the way it will be used. This is important for testing startup etc because fuel pools in different places.

So I would expect (my own supposition) that they will anchor the hopper very solidly for quite a few preliminary engine tests - they effectly have a vertical test stand with the hopper. The main problem is damage to the concrete pad, with no flame deflector (yet) in place. 

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/11/2019 12:51 pm
Worth noting I think, that AFAIK, the Raptor engine has never been tested vertically, which is obviously the way it will be used. This is important for testing startup etc because fuel pools in different places.

So I would expect (my own supposition) that they will anchor the hopper very solidly for quite a few preliminary engine tests - they effectly have a vertical test stand with the hopper. The main problem is damage to the concrete pad, with no flame deflector (yet) in place.

Why build a launchpad, move the hopper there, get it ready for launch, then after all that undo all that work to try to build a flame deflector. Wouldn't that be counter productive? If there was ever going to be one, it would be there right now. I don't think there will be a flame deflector. Besides, they will start with a single raptor so the loads on the pad will be significantly less than with 3 raptors. Remember, this is the Starship we're talking about not Super Heavy.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/11/2019 01:12 pm
Worth noting I think, that AFAIK, the Raptor engine has never been tested vertically, which is obviously the way it will be used. This is important for testing startup etc because fuel pools in different places.

So I would expect (my own supposition) that they will anchor the hopper very solidly for quite a few preliminary engine tests - they effectly have a vertical test stand with the hopper. The main problem is damage to the concrete pad, with no flame deflector (yet) in place.

Why build a launchpad, move the hopper there, get it ready for launch, then after all that undo all that work to try to build a flame deflector. Wouldn't that be counter productive? If there was ever going to be one, it would be there right now. I don't think there will be a flame deflector. Besides, they will start with a single raptor so the loads on the pad will be significantly less than with 3 raptors. Remember, this is the Starship we're talking about not Super Heavy.

Starships will only take off from Mars.  On Earth, they launch on top of SH.

On Mars, they'll have to set up the taking-off part after the ship landed.  They must have a concept for that.  Why not test it here with one engine first?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/11/2019 01:51 pm
So I would expect (my own supposition) that they will anchor the hopper very solidly for quite a few preliminary engine tests - they effectly have a vertical test stand with the hopper. The main problem is damage to the concrete pad, with no flame deflector (yet) in place.

Shouldn't hurt it much if they only run it for a few seconds. They have done this many times with Merlin on Grasshopper, F9R-Dev1, and all the F9 booster RTLS landings.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/11/2019 01:55 pm
I'm not sure about light, but that Raptor certainly looks tight. You'd need a big shoehorn to fit any more wires or plumbing in there...

The LCH4 pump is definitely still vertical, too. Attached an crop from BCG's latest pic with my annotations.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Star One on 03/11/2019 02:17 pm
The first Raptor has arrived now.

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920974#msg1920974

You can get a bit of an idea of its size here.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ejb749 on 03/11/2019 02:37 pm
They instrumented the heck out of that thing!  I can't wait to see if all three of them are like that.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: matthewkantar on 03/11/2019 02:50 pm
This engine does not look like it has been test fired. Any clues from its appearance if it has been test fired?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Gotorah on 03/11/2019 03:03 pm
As for a Flame Deflector, a steel sheet on the concrete world be quick and cheap to install and also to remove when tests are over.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/11/2019 03:10 pm
Measuring the erosion of the concrete might tell them a lot about how a prepared or even unprepared Mars surface will fare. it's probably best to do those kinds of tests early before even more infrastructure is at the pad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZachF on 03/11/2019 03:34 pm
Worth noting I think, that AFAIK, the Raptor engine has never been tested vertically, which is obviously the way it will be used. This is important for testing startup etc because fuel pools in different places.

So I would expect (my own supposition) that they will anchor the hopper very solidly for quite a few preliminary engine tests - they effectly have a vertical test stand with the hopper. The main problem is damage to the concrete pad, with no flame deflector (yet) in place.

Why build a launchpad, move the hopper there, get it ready for launch, then after all that undo all that work to try to build a flame deflector. Wouldn't that be counter productive? If there was ever going to be one, it would be there right now. I don't think there will be a flame deflector. Besides, they will start with a single raptor so the loads on the pad will be significantly less than with 3 raptors. Remember, this is the Starship we're talking about not Super Heavy.

Starships will only take off from Mars.  On Earth, they launch on top of SH.


Or the moon
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZachF on 03/11/2019 03:36 pm
This engine does not look like it has been test fired. Any clues from its appearance if it has been test fired?

Your statement is at odds with your question.   :P
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 03/11/2019 03:37 pm
Worth noting I think, that AFAIK, the Raptor engine has never been tested vertically, which is obviously the way it will be used. This is important for testing startup etc because fuel pools in different places.

So I would expect (my own supposition) that they will anchor the hopper very solidly for quite a few preliminary engine tests - they effectly have a vertical test stand with the hopper. The main problem is damage to the concrete pad, with no flame deflector (yet) in place.

Why build a launchpad, move the hopper there, get it ready for launch, then after all that undo all that work to try to build a flame deflector. Wouldn't that be counter productive? If there was ever going to be one, it would be there right now. I don't think there will be a flame deflector. Besides, they will start with a single raptor so the loads on the pad will be significantly less than with 3 raptors. Remember, this is the Starship we're talking about not Super Heavy.

Just to clarify, I was not saying one way or the other whether they would build any sort of flame deflector or trench.  Just that there will be damage to the concrete pad when they run the engines, especially if they do a lot of testing prior to hopping. Which I suspect they will given the engine has never been tested vertically.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/11/2019 03:50 pm
Worth noting I think, that AFAIK, the Raptor engine has never been tested vertically, which is obviously the way it will be used. This is important for testing startup etc because fuel pools in different places.

So I would expect (my own supposition) that they will anchor the hopper very solidly for quite a few preliminary engine tests - they effectly have a vertical test stand with the hopper. The main problem is damage to the concrete pad, with no flame deflector (yet) in place.

Why build a launchpad, move the hopper there, get it ready for launch, then after all that undo all that work to try to build a flame deflector. Wouldn't that be counter productive? If there was ever going to be one, it would be there right now. I don't think there will be a flame deflector. Besides, they will start with a single raptor so the loads on the pad will be significantly less than with 3 raptors. Remember, this is the Starship we're talking about not Super Heavy.

Just to clarify, I was not saying one way or the other whether they would build any sort of flame deflector or trench.  Just that there will be damage to the concrete pad when they run the engines, especially if they do a lot of testing prior to hopping. Which I suspect they will given the engine has never been tested vertically.
There is a fairly large water deluge rainbird on the pad. This may mitigate issues...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: robert_d on 03/11/2019 04:09 pm
The first Raptor has arrived now.



MY goodness, the 'insanity'  ;) continues. They have it out (and may have transported it) unwrapped??
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/11/2019 04:15 pm
The first Raptor has arrived now.



MY goodness, the 'insanity'  ;) continues. They have it out (and may have transported it) unwrapped??

According to the the person actually called Maria, it was uncrated (https://www.facebook.com/groups/1541938906124567/permalink/2259188607732923/).

Quote
1st raptor is uncrated at rocket shipyard at BocaChica! @ 8:45 am monday, March 11, 2019!. Going into onion dome by forklift.

So it seems that it did not arrive "naked".
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: groundbound on 03/11/2019 04:20 pm
As for a Flame Deflector, a steel sheet on the concrete world be quick and cheap to install and also to remove when tests are over.

Better yet, use stainless steel sheets that are transpiration cooled by methane.  :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Eventually Rises on 03/11/2019 04:23 pm

Just to clarify, I was not saying one way or the other whether they would build any sort of flame deflector or trench.  Just that there will be damage to the concrete pad when they run the engines, especially if they do a lot of testing prior to hopping. Which I suspect they will given the engine has never been tested vertically.

The most recent tweet in the Elon tweet timeline is "yeah it might break" which is hard to read as anything but swagger, but maybe they literally aren't too worried about the integrity of the concrete pad.  The hopper is a much more…robust structure than we're used to thinking about.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/11/2019 04:26 pm
Measuring the erosion of the concrete might tell them a lot about how a prepared or even unprepared Mars surface will fare. it's probably best to do those kinds of tests early before even more infrastructure is at the pad.

Would they truck in some proxy for regolith and sensor the legs to see what taking off from an unprepared surface would do?  They'd have to do something serious to shield the tank farm but otherwise might be doable.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 03/11/2019 04:49 pm
This looks like a strain gauge...

May be correct but it the largest one in area I have ever seen.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZachF on 03/11/2019 04:52 pm
I'm not sure about light, but that Raptor certainly looks tight. You'd need a big shoehorn to fit any more wires or plumbing in there...

The LCH4 pump is definitely still vertical, too. Attached an crop from BCG's latest pic with my annotations.

@Envy887

I suspect that looking at the hardware hanging off of it, the "??" area is probably the spark ignition system.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/11/2019 04:57 pm
damage to the concrete

Here's one potential scenario that plays out in my head, put this in your FMEA and consider it - Raptor bores a hole through the concrete directly in the middle, turns the newly compacted earth underneath into a fluidized bed, the remaining 95% of the pad comes up hovercraft-ly, thus raising the feet up but the knees are still restrained by the three massive subterranean anchors, the legs break, it gets tilted sideways, crazy things happen, and you need a 2nd hopper (of which I've been and remain an advocate (advocate for a 2nd hopper, not an advocate for crazy things to happen)).


They have it out (and may have transported it) unwrapped??


OK so how's it that you could transport such a thing across 1663 miles of fruited plain past ~10,000 mericans who each on average have 2.7 internet connected high def cameras in their pockets and we don't see it until it shows up in BCV?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/11/2019 05:01 pm
This looks like a strain gauge...

May be correct but it the largest one in area I have ever seen.

Strain gauges was my assumption as well when I first saw that a few days ago.  But I don't think we're looking directly at the strain gauges but rather after placing strain gauges and little jumper wires to larger wires and potting then for extra protection they put some kapton tape over all of it ~ is my read.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/11/2019 05:06 pm
I'm not sure about light, but that Raptor certainly looks tight. You'd need a big shoehorn to fit any more wires or plumbing in there...

The LCH4 pump is definitely still vertical, too. Attached an crop from BCG's latest pic with my annotations.

@Envy887

I suspect that looking at the hardware hanging off of it, the "??" area is probably the spark ignition system.

Yes, I think it's the injector and igniter system for the fuel preburner
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HMXHMX on 03/11/2019 05:09 pm
damage to the concrete

Here's one potential scenario that plays out in my head, put this in your FMEA and consider it - Raptor bores a hole through the concrete directly in the middle, turns the newly compacted earth underneath into a fluidized bed, the remaining 95% of the pad comes up hovercraft-ly, thus raising the feet up but the knees are still restrained by the three massive subterranean anchors, the legs break, it gets tilted sideways, crazy things happen, and you need a 2nd hopper (of which I've been and remain an advocate (advocate for a 2nd hopper, not an advocate for crazy things to happen)).


...

Nearly 40 years ago I watched Bob Truax static fire his "Project Private Enterprise" rocket at a 45° angle.  The jet from the four 1000 lbf Atlas verniers was about four feet from the unprotected ground here in the Silicon Valley.  After the firing I went for a close look...and those tiny engines had neatly excavated a grave-sized hole about 6-8 foot deep.  Raptor will be 100x more thrust.

Having said that, I'll note that for takeoffs, direct impingement on the concrete is likely not a problem.  Thors and Jupiters were fired from minimally prepared sites with very shallow uncooled steel deflectors.  That was 150-170K lbf.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/11/2019 05:14 pm
Measuring the erosion of the concrete might tell them a lot about how a prepared or even unprepared Mars surface will fare. it's probably best to do those kinds of tests early before even more infrastructure is at the pad.

Would they truck in some proxy for regolith and sensor the legs to see what taking off from an unprepared surface would do?  They'd have to do something serious to shield the tank farm but otherwise might be doable.

Maybe at some point but not now. They will want to prove it works vertically, prove the flight software and run a host of other urgent tests that are far more pressing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rockets4life97 on 03/11/2019 05:22 pm
What a day. The hopper gets a raptor and SLS is delayed again.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/11/2019 05:39 pm
What a day. The hopper gets a raptor and SLS is delayed again.

Which leads me to re-post the progress chart I originally put up December 31st.  And in digging that one up I found another one of my art efforts from the past that applies equally well to where we are today...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 03/11/2019 07:05 pm
 :o :o :o So gang...not really comfortable having a smoking section that close to thousands of gallon of Methane and Oxygen....

Then again i used to see pictures on the oil rig walls i worked in the GOM where they DD is peering down the borehole with at lit cig in his mouth... WITH the MMS guy smoking too...

so smoking was forbidden on the drill floor by the time i was working out there in the early '90s.. so rule one... no smoking near ignition sources...  :D ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/11/2019 07:05 pm
A few pics from the launch site.
if there was any lingering doubt about the shiny foil having a function: They added some more, but only to the sides facing one direction (i think east). so that's where they're going to set up the cameras.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Boer on 03/11/2019 07:07 pm
These have been added since (I think) yesterday.  Could they be struts to integrate landing shock absorbers?

(https://forum.nasaspaceflight.com/assets/47301.0/1548902.jpg)

Edit: Images cropped from today's BCG photo updates. Thx BCG!

Could be for tethering, imho.

or just some support for the fuel lines as they are using it now...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lisa_R4 on 03/11/2019 07:50 pm
:o :o :o So gang...not really comfortable having a smoking section that close to thousands of gallon of Methane and Oxygen....

Long lenses compress distance, that sign is probably a long way from the pad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: joncz on 03/11/2019 07:54 pm
:o :o :o So gang...not really comfortable having a smoking section that close to thousands of gallon of Methane and Oxygen....

Then again i used to see pictures on the oil rig walls i worked in the GOM where they DD is peering down the borehole with at lit cig in his mouth... WITH the MMS guy smoking too...

so smoking was forbidden on the drill floor by the time i was working out there in the early '90s.. so rule one... no smoking near ignition sources...  :D ;)

https://www.youtube.com/watch?v=7HXW3gRpnFk
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/11/2019 07:59 pm
Flag holders?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: sghill on 03/11/2019 08:05 pm

Just to clarify, I was not saying one way or the other whether they would build any sort of flame deflector or trench.  Just that there will be damage to the concrete pad when they run the engines, especially if they do a lot of testing prior to hopping. Which I suspect they will given the engine has never been tested vertically.

The most recent tweet in the Elon tweet timeline is "yeah it might break" which is hard to read as anything but swagger, but maybe they literally aren't too worried about the integrity of the concrete pad.  The hopper is a much more…robust structure than we're used to thinking about.

I still believe they will unveil a portable flame diverter to take care of this problem

Something that can be carried in cargo to the surface of Mars or the moon.

They'll wheel it out, anchor it in place under the vehicle, and then fly off without the risk of debris blasts.

But we've got other threads for this specific topic.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/11/2019 08:06 pm
Flag holders?

With the newest Photos from BCG, it's the Hopper's Hoppy Beverage Holder (HHBH)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/11/2019 08:52 pm
Its huffing and puffing! Soon it will be roaring!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DistantTemple on 03/11/2019 10:11 pm
Well it better not blow the house down - or up!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Scylla on 03/11/2019 10:45 pm
Unloading a lot of metal with interesting shapes.
(Blown up from RGVArialPhotography tweet on update thread)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/11/2019 10:47 pm
Unloading a lot of metal with interesting shapes.
(Blown up from RGVArialPhotography tweet on update thread)

(also looking at same latest drone pics)

Whole lot of structural building kinda steel being piled on pad where the Hopper WAS (till moved)....   ???
The kind you make a STEEL framed building out of...
The short fats are side post/beams and the long skinny ones are trusses for the roof...
IMHO

Just saying...  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/11/2019 10:58 pm
Looking at the tanking test, it seems, perhaps, that the foil lining they put on the tank dome will help deflect the outgassing once the fairing is put on.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/11/2019 11:10 pm
Unloading a lot of metal with interesting shapes.
(Blown up from RGVArialPhotography tweet on update thread)

It looks like the frame for another sprung structure.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/11/2019 11:11 pm
If one Tent produces one Hopper, then two tents produce ... ?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: billh on 03/11/2019 11:31 pm
If one Tent produces one Hopper, then two tents produce ... ?
Baby tents.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: matthewkantar on 03/11/2019 11:34 pm
Two tents should be be written as one fifth. Proper fractions only.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AJW on 03/11/2019 11:54 pm
This could lead to discussion about both past and present tents?

<snip>
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 03/12/2019 12:21 am
If one Tent produces one Hopper, then two tents produce ... ?

Or, they lengthen the existing tent.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/12/2019 03:23 am
Hard to believe they did an overflight of the property and the hopper.  Tony

Not hard to believe if you know him.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpacePhileon on 03/12/2019 07:29 am
In the latter overflights of the tent region (video link at appropriate time) (https://www.youtube.com/watch?v=nVwRKI8Uep8?t=337), you can see the curved dome/nosecone sections.

Given their similarity to the dome sections, I thought I'd compare it to the previous dome (attached). There are similarities and there are differences:

Similarities:
1. Quarter sections without top dome
2. Vaguely similar shapes/curvature

Differences:
1. Different material (thinner gauge, by the looks of it, and shiny vs. matte)
2. Proportions of sections off (confirmed dome: longer upper parts, short outer parts, new piece: roughly even proportions)
3. Actual dome has "offsets" on the outer dome sections, new piece does not

I think I'm still in the "it's part of a new tinfoil hat nosecone" camp, but I'm less surely in that camp, and leaning closer to the "ItS a dOmE For tE nEW OrBItAl PrOtOTyPe StaRsHIp" camp. Where do you guys stand?

The better comparison would be these with the original hat's nosecone before assembly, but that sorta popped out of nowhere from inside the tent (so no pics), and was the first real confirmation that this was a hopper and not a water tank.
[/quote]

Well, Elon Musk mentioned that the orbital Starship would have a "smoothly curving nose section", in contrast to the earlier nose section of the Hopper. Perhaps they decided to build the new nose section for the Hopper more like the Starship's one....

https://twitter.com/elonmusk/status/1083568315656822784

Quote
This is for suborbital VTOL tests. Orbital version is taller, has thicker skins (won’t wrinkle) & a smoothly curving nose section.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/12/2019 08:19 am
Let me lead the charge for the ‘it’s obviously a dome dang it’ camp.

The construction method is identical to that for the previous domes but the geometry is different. They share the same initial curve but terminate in a conical rather than a dished end. This is as you would expect as this should be the aft dome which interfaces with the thrust structure and header tank assembly. The geometry is also wrong for a fairing, with a sharp rather than a gradual curve.

My other line of reasoning is that the hopper looks sort of finished and ready to fly. That partial foil finish to the top dome, wether it is for thermal control or aesthetics, looks to me like the outside of the vehicle rather than something about to be buried. It is also quite obvious that SpaceX aren’t spending a single dollar they don’t need to. They got their photo shoot with fairing 1; unless it is essential to simulate Starship dynamics (which seems unlikely in a low velocity vehicle) they would not put the resources into replacing it.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: KDH on 03/12/2019 08:57 am
Do you not have any legislation around flying drones over people / property in the US ?  In the UK you are not allowed to fly within 150ft of a building or person.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/12/2019 10:09 am
Flying over someone's property, and especially over someone's expensive equipment and over people without prior explicit permission by the property owner (SpaceX) is dangerous, reckless and irresponsible.

We have the great privilege to be able to witness drone footage from responsible pilots, such as
Austing Barnard, Spadre and RGV Aerial Photography.

The actions of an irresponsible pilot, which i shall not name for i hope the links will be deleted by moderation (in fact i will report those posts after writing this here up) are not only bad in themself, they also endanger the current freedom other drone users are enjoying thanks to SpaceX being highly tolerant in the issue.

If SpaceX is forced to ask authorities to create and enforce a no-drone zone, it will be because of such irresponsible piloting. We should not support such behaviour by linking to resulting material and giving it views.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris Bergin on 03/12/2019 10:20 am
Do you not have any legislation around flying drones over people / property in the US ?  In the UK you are not allowed to fly within 150ft of a building or person.

It'd be a no no, but rarely leads to action, in the UK. No idea what the rules are in Texas.

Worth adding, the video is not hosted by us (it's on youtube). It's not taken by a member of this site, and I'm sure if the authorities wish to take action, it been shown on several sites (here, Facebook, Reddit and Twitter) will provide a useful "outing" to the authorities to take action based on the local laws. So watch for the video to be taken down if they act, which means the youtube link will go dead as again, it's not hosted here, it's a youtube link.

My personal note is the guy is an idiot and I fully expect there's officials who will go after him for this.

So we can get back to discussing the vehicle and not whatever drone law there is in your the UK or Germany.......if as one would assume, this isn't allowed in Texas, they'll know who to go after per the youtube link.

I've deleted it from the update thread at least as I would expect that youtube link to go dead, but I'd also say you could downvote the video on youtube and post notice on the video's comment section he should probably think about removing it himself and see if he does.

--

EDIT: I've now removed the video link completely from the threads as the guy sounds like he's related to the "Webcam that shall not be named" guy!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OldPeopleBurning on 03/12/2019 10:47 am
Let me lead the charge for the ‘it’s obviously a dome dang it’ camp.

The construction method is identical to that for the previous domes but the geometry is different. They share the same initial curve but terminate in a conical rather than a dished end. This is as you would expect as this should be the aft dome which interfaces with the thrust structure and header tank assembly. The geometry is also wrong for a fairing, with a sharp rather than a gradual curve.

I agree. If this was the top of the fairing, it would be easier to build in rings. The only benefit I can see in building it in quarter sections is so it can be assembled within another structure. It's the classic "Why is a manhole cover round?" question. They did not build the last fairing or top tank bulkhead in quarters.

Also, there are a stack of rectangular steel sheets that are curved in only one axis laying next to the section within the shipping container windbreak. This tells me it's going higher without tapering.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/12/2019 12:17 pm
Let me lead the charge for the ‘it’s obviously a dome dang it’ camp.

The construction method is identical to that for the previous domes but the geometry is different. They share the same initial curve but terminate in a conical rather than a dished end. This is as you would expect as this should be the aft dome which interfaces with the thrust structure and header tank assembly. The geometry is also wrong for a fairing, with a sharp rather than a gradual curve.

My other line of reasoning is that the hopper looks sort of finished and ready to fly. That partial foil finish to the top dome, wether it is for thermal control or aesthetics, looks to me like the outside of the vehicle rather than something about to be buried. It is also quite obvious that SpaceX aren’t spending a single dollar they don’t need to. They got their photo shoot with fairing 1; unless it is essential to simulate Starship dynamics (which seems unlikely in a low velocity vehicle) they would not put the resources into replacing it.

I respectfully disagree.

You have to understand the vision to understand why flying a complete hopper is important - even for just a  hopper. EM has said in the past "We need the public". That includes the average Joe out there who perhaps is just now hearing about spaceX for the first time. Why Hopper is being build out in the open? You may think it's the effect of limited resources but I happen to think that it is a conscious decision to bring us all in and create excitement about the project. Drone footage, pictures, a steady stream of info from EM himself, a presentation on progress like clockwork every year... It's all part of the plan folks. EM understands that we view this as much his project as it is ours.

So yeah, if you want the public's eye, you fly the hopper fully assembled as it was presented to the world.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: xxPunchyxx on 03/12/2019 12:23 pm
I apologize if this has already been mentioned and discarded, but why does the new construction have to be either space ship hopper 2.0 or a nosecone?  No, it's not a new water tower, lol.  But does it have to be one of those 2 things?

The space ship hopper has the shiny reflective stuff on one side of the top (for the sake of a photo shoot?).  They already moved it and are pressure testing and prepping for engine installation.  The new construction doesn't look like its tapering right for a nosecone.  The hopper is ready to fly soon.  There are a ton of reasons why they would not need the nose cone, even if it did turn out to be tapering differently or something.

They learned a lot by building the space ship hopper, but they haven't flown it yet.  So why build version 2.0 without testing 1.0.   They learned some things already during the build, but the critical stuff is yet to be discovered.  The hops may reveal something critical that must be changed in version 2.0.  I don't think they'd build 2.0 without learning those critical lessons first.  That would not be consistent with their past development practices.

So, my vote is that the new construction is a SH booster hopper 1.0.  They want experience building a larger pressure vessel booster with dual tanks for meth and lox.  They want to test landing a tall cylinder, just like they did with Falcon.  Yes, they are very good at that already.  But they have only done it dependably after a lot of hard work testing and failing on the different block iterations of Falcon with merlin engines.  They realized testing can be done really cheaply and quickly so they are building a test booster.  That way, there are no surprises when they build the real thing.

Of course, it could be a water tower... lol.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/12/2019 12:46 pm
I apologize if this has already been mentioned and discarded, but why does the new construction have to be either space ship hopper 2.0 or a nosecone?  No, it's not a new water tower, lol.  But does it have to be one of those 2 things?

The space ship hopper has the shiny reflective stuff on one side of the top (for the sake of a photo shoot?).  They already moved it and are pressure testing and prepping for engine installation.  The new construction doesn't look like its tapering right for a nosecone.  The hopper is ready to fly soon.  There are a ton of reasons why they would not need the nose cone, even if it did turn out to be tapering differently or something.

They learned a lot by building the space ship hopper, but they haven't flown it yet.  So why build version 2.0 without testing 1.0.   They learned some things already during the build, but the critical stuff is yet to be discovered.  The hops may reveal something critical that must be changed in version 2.0.  I don't think they'd build 2.0 without learning those critical lessons first.  That would not be consistent with their past development practices.

So, my vote is that the new construction is a SH booster hopper 1.0.  They want experience building a larger pressure vessel booster with dual tanks for meth and lox.  They want to test landing a tall cylinder, just like they did with Falcon.  Yes, they are very good at that already.  But they have only done it dependably after a lot of hard work testing and failing on the different block iterations of Falcon with merlin engines.  They realized testing can be done really cheaply and quickly so they are building a test booster.  That way, there are no surprises when they build the real thing.

Of course, it could be a water tower... lol.


The construction of 2.0 probably doesn't have anything to do with hopper testing. The hopper is for testing engines, controls and software without risking an expensive orbital prototype.
 The nosecone could be important to make mass distribution and aerodynamics more like the real ship, which would be important in developing control and landing software and procedures. This new one is much closer in weight to the real thing than the original was, so it would be even better.
 You could be right and this new device will never fly, but that's not as much fun to talk about.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 03/12/2019 01:04 pm
Unloading a lot of metal with interesting shapes.
(Blown up from RGVArialPhotography tweet on update thread)

It looks like the frame for another sprung structure.

The material is for a Steel building as mentioned above.  You can also see the steel panels stacked in the photo.  The frame will go up shortly and we will see it is not a tent.

A couple of more thoughts:
1.  The earth moving equipment has been removed from the launch site.  That does not bode well for what was thought to be the lower circle for landing.
2.  Come on Elon, give the guys a bathroom at the build and launch sites.  Its time!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 03/12/2019 01:29 pm
I apologize if this has already been mentioned and discarded, but why does the new construction have to be either space ship hopper 2.0 or a nosecone?  No, it's not a new water tower, lol.  But does it have to be one of those 2 things?

The space ship hopper has the shiny reflective stuff on one side of the top (for the sake of a photo shoot?).  They already moved it and are pressure testing and prepping for engine installation.  The new construction doesn't look like its tapering right for a nosecone.  The hopper is ready to fly soon.  There are a ton of reasons why they would not need the nose cone, even if it did turn out to be tapering differently or something.

They learned a lot by building the space ship hopper, but they haven't flown it yet.  So why build version 2.0 without testing 1.0.   They learned some things already during the build, but the critical stuff is yet to be discovered.  The hops may reveal something critical that must be changed in version 2.0.  I don't think they'd build 2.0 without learning those critical lessons first.  That would not be consistent with their past development practices.

So, my vote is that the new construction is a SH booster hopper 1.0.  They want experience building a larger pressure vessel booster with dual tanks for meth and lox.  They want to test landing a tall cylinder, just like they did with Falcon.  Yes, they are very good at that already.  But they have only done it dependably after a lot of hard work testing and failing on the different block iterations of Falcon with merlin engines.  They realized testing can be done really cheaply and quickly so they are building a test booster.  That way, there are no surprises when they build the real thing.

Of course, it could be a water tower... lol.
Think they just could modify the hat on the hopper to simulate the superheavy first stage for landing.
Add some ballast if needed add fins on top part for control and so on.

Now it could be an second hopper more suited for this and an backup of the first or it could be part of the orbital version. Or simply an tank, for the full rocket they need a lot of methane and LOX.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/12/2019 01:39 pm
I've said this before (2/15/19), but I think I'll just go ahead and re-say it (and then be wrong, though I really doubt it).

"Finally - and this again is just my opinion - but I have to say it: There is a ZERO percent chance this thing will fly without the hat. Absolutely zero. To even suggest it shows a disconnect from what SpaceX is, and more specifically, who Elon is. From the beginning I had speculated they are building a mass / shape simulator for hop testing. And of course I still believe that. Not to mention adding some form of protection to the hardware on the dome. But all of that doesn't matter - it's so much more...

Elon is stating (and I am in 100% agreement) that what is happening in Boca Chica represents the very future of spaceflight - human exploration - Mars colonization - Moon returning - space tourism - and arguably the survival of humanity itself (go reread Tim Urban's most excellent blog post if you don't see that).  This is NOT "just another launch vehicle in its development cycle".

This is a statement. A globally-watched tentative first step on the path towards walking off this planet and onto another. This BFH is the very first manifestation of the Starship. Elon's Starship. And he ain't - no way no how - gonna fly it without a hat..."

https://forum.nasaspaceflight.com/index.php?topic=47301.msg1911741#msg1911741
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThereIWas3 on 03/12/2019 01:50 pm
2.  Come on Elon, give the guys a bathroom at the build and launch sites.  Its time!

You don't like the Porta-Loos?  :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/12/2019 02:18 pm
it would be strange if they built a second tent. What purpose did the tent serve, really, other than to disassemble the crumpled fairing?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: abaddon on 03/12/2019 02:23 pm
it would be strange if they built a second tent. What purpose did the tent serve, really, other than to disassemble the crumpled fairing?
Absence of evidence is not evidence of absence.  There are many things they might do in the tent, like prepping Raptor engines for integration with the hopper, that they would not want to conduct outside where all of the prying drones can see.

That said - I don't know why they'd build a second tent either.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/12/2019 02:44 pm
it would be strange if they built a second tent. What purpose did the tent serve, really, other than to disassemble the crumpled fairing?

The tent existed before the fairing crumpled, so I'm going to assume that's an amusing note about our lack of knowledge about what's going on under it much in the same way as "Drone Duel Detritus Defense" might be as a response.  :>

Is it possible that the tent is where they're constructing the SS/SH?  A tent seems to have been the choice for the previous carbon fiber test article (abandoned) absent a more permanent structure.  The weather in LA seems more conducive to that sort of arrangement, but....

Even so, I don't see what a second tent brings you.  HQ for hopper tests?  Seems like a small, permanent building might work better for that?

I dunno, just guessing -- I'm still waiting for some kind of lightning control at the pad, so what do I know?!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/12/2019 03:00 pm
Unloading a lot of metal with interesting shapes.
(Blown up from RGVArialPhotography tweet on update thread)

Baffles and stringers for the orbital prototype???
I'm still sitting on the fence, btw.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: testguy on 03/12/2019 03:18 pm
Unloading a lot of metal with interesting shapes.
(Blown up from RGVArialPhotography tweet on update thread)

Baffles and stringers for the orbital prototype???
I'm still sitting on the fence, btw.

Unless my eyes are deceiving me, the steel delivered and the manor it how it was delivered looks exacting like the all the steel buildings I have had delivered and erected in the past.  If it looks like a steel building, gets erected like a steel building and there is no tent like material covering a light weight aluminum frame then it is just a simple steel building.  This is not rocket science folks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/12/2019 03:22 pm
The tent existed before the fairing crumpled, so I'm going to assume that's an amusing note about our lack of knowledge about what's going on under it much in the same way as "Drone Duel Detritus Defense" might be as a response.  :>
The tent didn't have sidewalls before the fairing was dragged in so at most it provided limited weather protection. Some of the smaller sub assemblies like the current dome/fairing being built could be built in the tent, but they aren't doing so. the tent also precludes using the cranes, so moving around heavy sub assemblies is a bit harder. it's also too short unless they build horizontal, which they could do (like at hawthorn) but so far have only done vertical assembly.

I bet it was used to process plumbing/sensors/electronics coming in from hawthorn, but it's a very big building for that. they likely have enough space that they don't need a second big empty tent.

it could be a tall structure with a gantry crane like the VAB or a welding jig (but not FSW) like for SLS, but i doubt the concrete pad they poured is a suitable foundation for either.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/12/2019 03:40 pm
I dunno, just guessing -- I'm still waiting for some kind of lightning control at the pad, so what do I know?!

I think that's what's laying in sections down at the notional landing pad...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/12/2019 03:58 pm
I dunno, just guessing -- I'm still waiting for some kind of lightning control at the pad, so what do I know?!

I think that's what's laying in sections down at the notional landing pad...

I have been wondering about this for a while. The sections clearly were meant for either a lightning tower or a crane, but did not get assembled for either when there was plenty of time to do it.

My best current guess: Some plans changed. Maybe with the change to stainless steel, the Hopper became its own lightning tower.

[edit]

This morning the upper bulkhead access hatch has been opened.

Is it normal to inspect the inside of a tank after a pressure test? Assuming that is why it was opened?

[/edit]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/12/2019 04:10 pm
I dunno, just guessing -- I'm still waiting for some kind of lightning control at the pad, so what do I know?!

I think that's what's laying in sections down at the notional landing pad...

Yeah, that's what I thought too.

My best current guess: Some plans changed. Maybe with the change to stainless steel, the Hopper became its own lightning tower.

...and that's what I've been wondering -- is it a good idea to use steel that wraps liquified O2 and CH4 as a lightning rod?  Steel isn't a *bad* conductor, but it isn't copper either....  I would have expected metallic tie-downs, though, if that were the case....

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ejb749 on 03/12/2019 04:39 pm
If that's a new steel building going up, there should be building permits. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Peter.Colin on 03/12/2019 04:42 pm
Unloading a lot of metal with interesting shapes.
(Blown up from RGVArialPhotography tweet on update thread)

Baffles and stringers for the orbital prototype???
I'm still sitting on the fence, btw.

Unless my eyes are deceiving me, the steel delivered and the manor it how it was delivered looks exacting like the all the steel buildings I have had delivered and erected in the past.  If it looks like a steel building, gets erected like a steel building and there is no tent like material covering a light weight aluminum frame then it is just a simple steel building.  This is not rocket science folks.

Maybe its for a vertical manufacturing building for the SuperHeavy and orbital StarShip
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MKremer on 03/12/2019 05:43 pm
I dunno, just guessing -- I'm still waiting for some kind of lightning control at the pad, so what do I know?!

I think that's what's laying in sections down at the notional landing pad...

I have been wondering about this for a while. The sections clearly were meant for either a lightning tower or a crane, but did not get assembled for either when there was plenty of time to do it.

My best current guess: Some plans changed. Maybe with the change to stainless steel, the Hopper became its own lightning tower.
That's possible, there's probably still many welding ground connections still hooked up.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/12/2019 07:01 pm
Unloading a lot of metal with interesting shapes.
(Blown up from RGVArialPhotography tweet on update thread)

Baffles and stringers for the orbital prototype???
I'm still sitting on the fence, btw.

Unless my eyes are deceiving me, the steel delivered and the manor it how it was delivered looks exacting like the all the steel buildings I have had delivered and erected in the past.  If it looks like a steel building, gets erected like a steel building and there is no tent like material covering a light weight aluminum frame then it is just a simple steel building.  This is not rocket science folks.

Maybe its for a vertical manufacturing building for the SuperHeavy and orbital StarShip

Yep, I have previously argued that they are going to replace the tent with a more permanent assembly building.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/12/2019 07:14 pm
Yep, I have previously argued that they are going to replace the tent with a more permanent assembly building.

Concur.  Less sure about vertical construction though.  You'd need some pretty serious work to build an assembly building tall enough.  ejb749's point about building permits is probably worth a sleuthing or two.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: prelator on 03/12/2019 07:29 pm
Flying over someone's property, and especially over someone's expensive equipment and over people without prior explicit permission by the property owner (SpaceX) is illegal, dangerous, reckless and irresponsible.

We have the great privilege to be able to witness drone footage from responsible pilots, such as
Austing Barnard, Spadre and RGV Aerial Photography.

The actions of an irresponsible pilot, which i shall not name for i hope the links will be deleted by moderation (in fact i will report those posts after writing this here up) are not only bad in themself, they also endanger the current freedom other drone users are enjoying thanks to SpaceX being highly tolerant in the issue.

If SpaceX is forced to ask authorities to create and enforce a no-drone zone, it will be because of such irresponsible piloting. We should not support such behaviour by linking to resulting material and giving it views.
Long time lurker here, been following this thread for a while. Just wanted to chime in to reply to this. I'm both a lawyer and a drone enthusiast who has followed drone law for years, and I hate seeing this dangerous misconception out there.

In the US, it is NOT illegal to fly drones over private property in any way, shape, or form. Drones are considered aircraft and are regulated by the FAA. They operate in the National Airspace System, which includes anything from the ground up. Landowners do not own the airspace of their property, and do not have any right to restrict aircraft (including drones) from flying over their property.

There are some oddities of Texas law that purport to restrict overflight of and drone photography of private property, but everyone in the drone legal community agrees that law is federally preempted and illegal. To my knowledge it has never been enforced, and if it were, it would likely be struck down if challenged in court.

While it is never a bad idea to show courtesy to landowners and not fly directly over their property, there is nothing illegal about doing so, and drone operators are completely within their legal rights to overfly private land. In the case of SpaceX, I agree it would be best not to fly directly over their equipment, but it is hardly illegal.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 03/12/2019 07:38 pm
While it is never a bad idea to show courtesy to landowners and not fly directly over their property, there is nothing illegal about doing so, and drone operators are completely within their legal rights to overfly private land. In the case of SpaceX, I agree it would be best not to fly directly over their equipment, but it is hardly illegal.
The only Supreme Court case on the issue was US v Causby from 1946 in which a NC man was ruled to have legally shot down a "drone" craft at 83 feet altitude.  So apparently we own our airspace up to 83 feet.  A more recent case from Kentucky gave the same result but with unclear precedent.  https://arstechnica.com/tech-policy/2017/03/judge-rules-in-favor-of-drone-slayer-dismisses-lawsuit-filed-by-pilot/

Dear moderator:  This post and the one immediately preceding it may be in the wrong thread.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: flyright on 03/12/2019 07:54 pm
While it is never a bad idea to show courtesy to landowners and not fly directly over their property, there is nothing illegal about doing so, and drone operators are completely within their legal rights to overfly private land. In the case of SpaceX, I agree it would be best not to fly directly over their equipment, but it is hardly illegal.
The only Supreme Court case on the issue was US v Causby from 1946 in which a NC man was ruled to have legally shot down a "drone" craft at 83 feet altitude.  So apparently we own our airspace up to 83 feet.  A more recent case from Kentucky gave the same result but with unclear precedent.  https://arstechnica.com/tech-policy/2017/03/judge-rules-in-favor-of-drone-slayer-dismisses-lawsuit-filed-by-pilot/

Dear moderator:  This post and the one immediately preceding it may be in the wrong thread.

Under the FARs, aircraft must maintain at least 500 feet from any person or structure. I didn't think that drone video looked like it was taken from more than 500 feet above the hopper.

edit: clarified.   Agree that this post and preceeding should be in another thread, or deleted.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/12/2019 07:54 pm
Fair enough, i removed the word illegal from my post because i can not with certainty state what is US/Texan law in this case. But my other points still stand. With that said, can we get back on topic?

Both bulkhead access hatches have been opened.

Looks like the tanks get ventilated, possible to allow workers to get in and do inspection.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: brainbit on 03/12/2019 07:59 pm
Quote from: Scylla on 03/11/2019 10:45 pm
Unloading a lot of metal with interesting shapes.
(Blown up from RGVArialPhotography tweet on update thread)

I think this may be an exhaust deflector. It is missing for an Raptor tests.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: prelator on 03/12/2019 08:20 pm
While it is never a bad idea to show courtesy to landowners and not fly directly over their property, there is nothing illegal about doing so, and drone operators are completely within their legal rights to overfly private land. In the case of SpaceX, I agree it would be best not to fly directly over their equipment, but it is hardly illegal.
The only Supreme Court case on the issue was US v Causby from 1946 in which a NC man was ruled to have legally shot down a "drone" craft at 83 feet altitude.  So apparently we own our airspace up to 83 feet.  A more recent case from Kentucky gave the same result but with unclear precedent.  https://arstechnica.com/tech-policy/2017/03/judge-rules-in-favor-of-drone-slayer-dismisses-lawsuit-filed-by-pilot/

Dear moderator:  This post and the one immediately preceding it may be in the wrong thread.
Drones didn't exist in 1946. That case was about extremely low overlights by military aircraft on approach to a nearby airbase disturbing a farmer's chickens, apparently sending them into a frenzy and causing them to peck each other to death. The court ruled against the government because of the actual harm the overflights caused to the farmer's property and livelihood, not because of a specific altitude. It basically established the rule that aircraft overflights have to cause some tangible harm on the ground in order to be considered trespassing.

Also, most drones (hobbyists excluded) are required to fly UNDER 500 feet, which is the minimum for other types of aircraft, in order to ensure separation between them.

Sorry to sidetrack this thread and I don't mind if this is deleted. Just wanted to clarify this, as there are huge misconceptions about drone laws out there.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/12/2019 08:23 pm
Do you not have any legislation around flying drones over people / property in the US ?  In the UK you are not allowed to fly within 150ft of a building or person.

It'd be a no no, but rarely leads to action, in the UK. No idea what the rules are in Texas.

Worth adding, the video is not hosted by us (it's on youtube). It's not taken by a member of this site, and I'm sure if the authorities wish to take action, it been shown on several sites (here, Facebook, Reddit and Twitter) will provide a useful "outing" to the authorities to take action based on the local laws. So watch for the video to be taken down if they act, which means the youtube link will go dead as again, it's not hosted here, it's a youtube link.

My personal note is the guy is an idiot and I fully expect there's officials who will go after him for this.

So we can get back to discussing the vehicle and not whatever drone law there is in your the UK or Germany.......if as one would assume, this isn't allowed in Texas, they'll know who to go after per the youtube link.

I've deleted it from the update thread at least as I would expect that youtube link to go dead, but I'd also say you could downvote the video on youtube and post notice on the video's comment section he should probably think about removing it himself and see if he does.

--

EDIT: I've now removed the video link completely from the threads as the guy sounds like he's related to the "Webcam that shall not be named" guy!

Hey Chris, it looks like the link is still active in a post quoting my own post (the one which was deleted with the offending link). Maybe it could do with a strikethrough or something? Sorry about causing a ruckus, I didn't even think about the fact that the video could be problematic. Thanks for pointing it out!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/12/2019 08:39 pm
After 6 days in Elon's genetic brew kettle the giant worms had grown to Texas size and were ready to be released...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/12/2019 09:23 pm
After 6 days in Elon's genetic brew kettle the giant worms had grown to Texas size and were ready to be released...

This sounds like a job for me... I'm gonna need a DNA sample and a PCR cycler, pronto.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/12/2019 09:56 pm
Pics from the launch site.

"GCH4 Igniter" sounds... dangerous. What is this thing for? What would they be testing by igniting gaseous methane (which is what I'm assuming "GCH4" is)?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cppetrie on 03/12/2019 09:59 pm
Pics from the launch site.

"GCH4 Igniter" sounds... dangerous. What is this thing for? What would they be testing by igniting gaseous methane (which is what I'm assuming "GCH4" is)?
Flaring off gas from the tankage would be my guess. Need an ignition source to ignite when venting is occurring.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/12/2019 10:03 pm
Pics from the launch site.
Thanks BCGal! I’ve been asking for images of the two panels by the berm. You got a great shot of one of them.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/12/2019 10:21 pm
If that's a new steel building going up, there should be building permits.

Not necessarily. Stargate went up without building permits because they are not required for State properties in Texas.

https://www.brownsvilleherald.com/news/local/official-stargate-doesn-t-need-building-permits/article_b187199e-ecf3-11e6-8ffb-bf728240b3a0.html
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: targon on 03/13/2019 01:19 am
This sounds like a job for me... I'm gonna need a DNA sample and a PCR cycler, pronto.
Where did you get primers? Maybe sequence it first?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/13/2019 02:23 am
This sounds like a job for me... I'm gonna need a DNA sample and a PCR cycler, pronto.
Where did you get primers? Maybe sequence it first?

Go for degenerate rDNA sequences first, puts you in the ballpark phylogenetically. Given the segmentation, I'd go with annelida. Metazoan rDNA doesn't vary too much anyways. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3458000/)

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/13/2019 02:26 am
Pics from the launch site.
Thanks BCGal! I’ve been asking for images of the two panels by the berm. You got a great shot of one of them.

Those hydraulic lines are new since her last shot of those panels two days ago.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 03/13/2019 07:09 am
Pics from the launch site.

I really hope they put some grass or groundcover on that dirt at some point...otherwise it's going to melt when it rains.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/13/2019 07:27 am
Pics from the launch site.

I really hope they put some grass or groundcover on that dirt at some point...otherwise it's going to melt when it rains.

I imagine it must be temporary, no? Once hopper hops, they've likely got to change the pad anyways. Is there a less long-term, cheap, easy solution for erosion of a temporary earthen structure? Sprayed concrete? Chainlink/some kind of mesh?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 03/13/2019 12:35 pm
Pics from the launch site.

"GCH4 Igniter" sounds... dangerous. What is this thing for? What would they be testing by igniting gaseous methane (which is what I'm assuming "GCH4" is)?
Presumably for the igniters used in Raptor, previously referred to as using "Gaseous CH4/O2 & heavy duty spark plugs (https://twitter.com/elonmusk/status/1092282107639021569?lang=en)".

::EDIT:: And pretty much confirmed with BCG's photo of a GOX IGNITER panel.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: sghill on 03/13/2019 03:11 pm

Maybe its for a vertical manufacturing building for the SuperHeavy and orbital StarShip

Yep, I have previously argued that they are going to replace the tent with a more permanent assembly building.

And I still think they will do manufacturing somewhere else like the Galveston/Houston area.

Brownsville doesn't have the required workforce and quality of life to attract them (sorry Brownsville fans, I know that sounds harsh- it's not a slight in any way to you).

I also opine they will place their off-shore launch operations somewhere near Galveston/ Houston for similar reasons.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 03/13/2019 03:27 pm

Maybe its for a vertical manufacturing building for the SuperHeavy and orbital StarShip

Yep, I have previously argued that they are going to replace the tent with a more permanent assembly building.

And I still think they will do manufacturing somewhere else like the Galveston/Houston area.

Brownsville doesn't have the required workforce and quality of life to attract them (sorry Brownsville fans, I know that sounds harsh- it's not a slight in any way to you).

I also opine they will place their off-shore launch operations somewhere near Galveston/ Houston for similar reasons.

Not offshore there.  Way, way too many offshore oil rigs there.  Massive interference with drilling ops. 
In contrast, for tens of miles offshore East from Boca Chica...nothing.  No rigs.

Map of rigs here...
https://saltwater-recon.com/oil-gas-platforms-map/

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/13/2019 03:30 pm

Maybe its for a vertical manufacturing building for the SuperHeavy and orbital StarShip

Yep, I have previously argued that they are going to replace the tent with a more permanent assembly building.

And I still think they will do manufacturing somewhere else like the Galveston/Houston area.

Brownsville doesn't have the required workforce and quality of life to attract them (sorry Brownsville fans, I know that sounds harsh- it's not a slight in any way to you).

People go where the jobs are. And even more so if the jobs are exciting. And I think you seriously overestimate how much SpaceX workforce cares about "quality of life" or high culture or whatever you think is missing from Brownsville. Low cost living has a quality of its own.

But this is definitely going off topic.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/13/2019 04:44 pm

Maybe its for a vertical manufacturing building for the SuperHeavy and orbital StarShip

Yep, I have previously argued that they are going to replace the tent with a more permanent assembly building.

And I still think they will do manufacturing somewhere else like the Galveston/Houston area.

Brownsville doesn't have the required workforce and quality of life to attract them (sorry Brownsville fans, I know that sounds harsh- it's not a slight in any way to you).

People go where the jobs are. And even more so if the jobs are exciting. And I think you seriously overestimate how much SpaceX workforce cares about "quality of life" or high culture or whatever you think is missing from Brownsville. Low cost living has a quality of its own.

But this is definitely going off topic.
No people in aggregate generally don't move much anymore. When the do, they generally stay in the same county (yes, that's county, not country).

https://www.move.org/moving-stats-facts/ has some readable data culled from https://www.census.gov/data/tables/time-series/demo/geographic-mobility/historic.html?kbid=93121&gclid=

Whether that applies to SpaceX, who knows. Brownsville might soon be one of the closest places on Earth to Mars, so that's a plus.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Cheapchips on 03/13/2019 06:32 pm
This piece is really bugging me. It's probably left over from the top of the third leg and they just haven't bothered to fit it now they've lopped the other legs' tops off.  It does look smoother down the sides than the fitted parts did, but it's hard to be sure on the shots we have.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 03/13/2019 08:20 pm
Regarding the overall Hopper design, something has been bothering me since I first saw the legs and it is making me even more uneasy now that we are approaching the first hops.

If the Hopper happens to come down hard on one of those legs... Won't the leg act like a spear pointed right at the upper tank? One long cylinder all the way from foot pad to the upper tank.

It just seems to me that the is a crumple zone missing somewhere...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/13/2019 08:25 pm
Regarding the overall Hopper design, something has been bothering me since I first saw the legs and it is making me even more uneasy now that we are approaching the first hops.

If the Hopper happens to come down hard on one of those legs... Won't the leg act like a spear pointed right at the upper tank? One long cylinder all the way from foot pad to the upper tank.

It just seems to me that the is a crumple zone missing somewhere...
I was expecting shock absorbing feet but maybe they would be problematic for the tethered tests so they're waiting till after to install them?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/13/2019 08:33 pm
There are three struts inside the tank connecting the tops of the legs in a large triangle. They aren't just welded to the thin tank wall.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lord of Night on 03/13/2019 08:40 pm
Regarding the overall Hopper design, something has been bothering me since I first saw the legs and it is making me even more uneasy now that we are approaching the first hops.

If the Hopper happens to come down hard on one of those legs... Won't the leg act like a spear pointed right at the upper tank? One long cylinder all the way from foot pad to the upper tank.

It just seems to me that the is a crumple zone missing somewhere...

Do you really think that Spacex engineers didn't think about that?

Mistakes are human, but I dare to think that they know their business.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: holmstar on 03/14/2019 12:52 am
In my opinion:
It seems to me that hopper 1 is intended only for very low (a few feet probably) tethered testing.  I doubt it will get a nose-cone.  It is likely essentially complete in it's current state (less the engines, of course).  They wouldn't have bothered to put a reflective coating on the dome if it wasn't going to remain exposed.  If it were going any higher than that it would need some sort of landing gear to soften the impact.  It very well could be that they will add landing gear and take it higher, but in it's current form I highly doubt it. 

I believe what is being constructed a mile away right now is hopper 2, which will be used for un-tethered testing up to a few miles high, maybe several miles, but definitely not an orbital prototype since there's no sign of anything that would suggest transpiration cooling.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 01:03 am
In my opinion:
It seems to me that hopper 1 is intended only for very low (a few feet probably) tethered testing.  I doubt it will get a nose-cone.  It is likely essentially complete in it's current state (less the engines, of course).  They wouldn't have bothered to put a reflective coating on the dome if it wasn't going to remain exposed.  If it were going any higher than that it would need some sort of landing gear to soften the impact.  It very well could be that they will add landing gear and take it higher, but in it's current form I highly doubt it. 

I believe what is being constructed a mile away right now is hopper 2, which will be used for un-tethered testing up to a few miles high, maybe several miles, but definitely not an orbital prototype since there's no sign of anything that would suggest transpiration cooling.

Hopper is Suborbital VTOL.  Orbital Prototype target for June.
Let's take EM at his word:  https://forum.nasaspaceflight.com/index.php?topic=47352.msg1907676#msg1907676

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/14/2019 01:09 am
Regarding the overall Hopper design, something has been bothering me since I first saw the legs and it is making me even more uneasy now that we are approaching the first hops.

If the Hopper happens to come down hard on one of those legs... Won't the leg act like a spear pointed right at the upper tank? One long cylinder all the way from foot pad to the upper tank.

It just seems to me that the is a crumple zone missing somewhere...

Before the tank domes were added, you could see three tubes inside, of equal diameter to the leg struts (~3'), forming a triangle and bracing the leg tips against exactly that deformation.  Without that reinforcement, exactly as you point out, the tank walls would buckle inwards really easily.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: wannamoonbase on 03/14/2019 01:09 am
In my opinion:
It seems to me that hopper 1 is intended only for very low (a few feet probably) tethered testing.  I doubt it will get a nose-cone.  It is likely essentially complete in it's current state (less the engines, of course).  They wouldn't have bothered to put a reflective coating on the dome if it wasn't going to remain exposed.  If it were going any higher than that it would need some sort of landing gear to soften the impact.  It very well could be that they will add landing gear and take it higher, but in it's current form I highly doubt it. 

I believe what is being constructed a mile away right now is hopper 2, which will be used for un-tethered testing up to a few miles high, maybe several miles, but definitely not an orbital prototype since there's no sign of anything that would suggest transpiration cooling.

Hopper is Suborbital VTOL.  Orbital Prototype target for June.
Let's take EM at his word:  https://forum.nasaspaceflight.com/index.php?topic=47352.msg1907676#msg1907676



Other than another place to test raptor, and amazing video and pictures for marketing and hype I don't see much value in the hopper.

An actual model of the starship makes much more sense.  But I don't see how that could be coming in 3 months.  Don't see the point of spending a dime on Hopper if there is a follow on vehicle 3 months behind it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: holmstar on 03/14/2019 01:10 am
Hopper is Suborbital VTOL.  Orbital Prototype target for June.
Let's take EM at his word:  https://forum.nasaspaceflight.com/index.php?topic=47352.msg1907676#msg1907676

Where did he say that this hopper is any more than a semi stationary test stand?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 01:22 am
Hopper is Suborbital VTOL.  Orbital Prototype target for June.
Let's take EM at his word:  https://forum.nasaspaceflight.com/index.php?topic=47352.msg1907676#msg1907676

Where did he say that this hopper is any more than a semi stationary test stand?

Sorry.  I gave you the direct link to the post that contained the sequence but the large number of Tweets screws up the loading of the page and doesn't index to the right spot.

https://twitter.com/elonmusk/status/1083568315656822784
Tweet Content  This is for suborbital VTOL tests. Orbital version is taller, has thicker skins (won’t wrinkle) & a smoothly curving nose section.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 01:24 am
Other than another place to test raptor, and amazing video and pictures for marketing and hype I don't see much value in the hopper.

An actual model of the starship makes much more sense.  But I don't see how that could be coming in 3 months.  Don't see the point of spending a dime on Hopper if there is a follow on vehicle 3 months behind it.

You don't have to. SpaceX does.  They have told us that.   3mos is ENORMOUS.  It's >12% (perhaps much greater) of the remaining calendar time to orbital launch.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/14/2019 01:34 am
Raptor has arrived at Boca Chica.

Where's it now?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: holmstar on 03/14/2019 01:50 am
Sorry.  I gave you the direct link to the post that contained the sequence but the large number of Tweets screws up the loading of the page and doesn't index to the right spot.

https://twitter.com/elonmusk/status/1083568315656822784
Tweet Content  This is for suborbital VTOL tests. Orbital version is taller, has thicker skins (won’t wrinkle) & a smoothly curving nose section.

Things change.  It may yet be that they'll take it for higher flights, but seems pretty doubtful without anything to cushion the landings.  Also all the connections to ground equipment seem to be set up for tethered testing.  Does it mean that they can't test it untethered?  Who knows, but the fact that there's hydraulic lines running to ground equipment would suggest that some control hardware is probably external.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: holmstar on 03/14/2019 02:01 am
Things change.  It may yet be that they'll take it for higher flights, but seems pretty doubtful without anything to cushion the landings.  Also all the connections to ground equipment seem to be set up for tethered testing.  Does it mean that they can't test it untethered?  Who knows, but the fact that there's hydraulic lines running to ground equipment would suggest that some control hardware is probably external.

Baseless

Most of the speculation in this thread is baseless.  What I stated isn't baseless.  For example, why add a hanger on the leg to hold the fuel lines if the fuel lines aren't going to be there during the test?  They only need to be held out of the way if they would otherwise be exposed to the engine blast.  But the above is just my opinion, as clearly stated.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 02:05 am
Most of the speculation in this thread is baseless.  What I stated isn't baseless but it's also just my opinion, as clearly stated.

Yeah it's all baseless.  Most of the speculation in this thread is a reconciliation of what is seen with what Elon has told us.  Elon has told us there are Shock Absorbing Feet to be installed.

You really need to review the record and stop making silly assumptions like the foil dome suggests they won't mate the fairing.  There's a physics reason for the foil.  Connections to the ground now during completion and WDR suggest little about the limitations of the hopping regime.

Go here:  https://forum.nasaspaceflight.com/index.php?topic=47352.0  There's a handy index that summarize everything EM has tweeted about the Starship system.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OTV Booster on 03/14/2019 02:27 am
My expert eye, trained by many Saturday mornings watching Rocky Jones Space Ranger and Captain Midnight, leads me to several conclusions.  Captain Video, IIRC, was Tuesday evenings. From the stills that Dave G posted from YouTube in the Texas launch site and discussion forum we see two separate shiny cylinders being fabricated.

They're also building some conical or dome sections that are laying around at the foot of the near cylinder. Some say all this will become the new tin hat but others point out that the curvy pieces don't match the first hat. Others say that li'l ol hopper don't need no stinking hat. It's ok the way it is.

Some say that the curvy pieces will be a bulkhead but others say the curve isn't right for that either. Somebody in this forum or another said that the curvy pieces looks juuuusssst right to be a bottom methane bulkhead and shaped to fit into the thrust structure. I wish I could find that post and give an attaboy. They're onto something.

I think the foreground cylinder is going to be a methane tank. The background cylinder is going to be a LOX tank. This puppy is going to be a new test article. Doesn't matter if you call it a high altitude hopper, a sub orbital or orbital prototype, or a big shiny cylinder, it's gonna be another test article.

Ignore everything you've heard about the (somewhat ambiguous) sequence of test articles and look at the evidence in front of you. They're not done and yet. They might strap 300 old leaking MG radiators (the only type of radiators MG's ever had) on the hot side and run methane through them. Or they might not. Gotta wait and see.

Oh, thank you Elon. You've brought fun and excitement back to space flight.

Phil
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: holmstar on 03/14/2019 02:42 am
Most of the speculation in this thread is baseless.  What I stated isn't baseless but it's also just my opinion, as clearly stated.

Yeah it's all baseless.  Most of the speculation in this thread is a reconciliation of what is seen with what Elon has told us.  Elon has told us there are Shock Absorbing Feet to be installed.

You really need to review the record and stop making silly assumptions like the foil dome suggests they won't mate the fairing.  There's a physics reason for the foil.  Connections to the ground now during completion and WDR suggest little about the limitations of the hopping regime.

Go here:  https://forum.nasaspaceflight.com/index.php?topic=47352.0  There's a handy index that summarize everything EM has tweeted about the Starship system.

I've read the entire thread, or threads actually.  The physics reason for the foil is to reflect light/heat.  Its not needed if there will be a nose-cone before testing unless just for aesthetics.  What assumptions of mine are silly?  He did say that.  He also said the SS would be carbon fiber...  until it wasn't.   Don't act like everything Elon has ever said is set in stone.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 02:52 am
I've read the entire thread, or threads actually.  The physics reason for the foil is to reflect light/heat.  Its not needed if there will be a nose-cone before testing unless just for aesthetics.  What assumptions of mine are silly?  He did say that.  He also said the SS would be carbon fiber...  until it wasn't.   Don't act like everything Elon has ever said is set in stone.

Of course it's not set in stone but it trumps the illogical leaps you are making.

Foil, ground connections and hydraulics lines don't in any way support the speculation that what Elon has said is no longer operative and this Hopper will mainly be tethered to a few feet.  But you're dug in on that so enjoy it.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: holmstar on 03/14/2019 03:04 am
I've read the entire thread, or threads actually.  The physics reason for the foil is to reflect light/heat.  Its not needed if there will be a nose-cone before testing unless just for aesthetics.  What assumptions of mine are silly?  He did say that.  He also said the SS would be carbon fiber...  until it wasn't.   Don't act like everything Elon has ever said is set in stone.

Of course it's not set in stone but it trumps the illogical leaps you are making.

Foil, ground connections and hydraulics lines don't in any way support the speculation that what Elon has said is no longer operative and this Hopper will mainly be tethered to a few feet.  But you're dug in on that so enjoy it.

That was my opinion, and I stated it as such, but assuming that it won't be tethered when there's evidence to the contrary is illogical. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/14/2019 06:35 am
My expert eye, trained by many Saturday mornings watching Rocky Jones Space Ranger and Captain Midnight, leads me to several conclusions.  Captain Video, IIRC, was Tuesday evenings. From the stills that Dave G posted from YouTube in the Texas launch site and discussion forum we see two separate shiny cylinders being fabricated.

They're also building some conical or dome sections that are laying around at the foot of the near cylinder. Some say all this will become the new tin hat but others point out that the curvy pieces don't match the first hat. Others say that li'l ol hopper don't need no stinking hat. It's ok the way it is.

Some say that the curvy pieces will be a bulkhead but others say the curve isn't right for that either. Somebody in this forum or another said that the curvy pieces looks juuuusssst right to be a bottom methane bulkhead and shaped to fit into the thrust structure. I wish I could find that post and give an attaboy. They're onto something.

I think the foreground cylinder is going to be a methane tank. The background cylinder is going to be a LOX tank. This puppy is going to be a new test article. Doesn't matter if you call it a high altitude hopper, a sub orbital or orbital prototype, or a big shiny cylinder, it's gonna be another test article.

Ignore everything you've heard about the (somewhat ambiguous) sequence of test articles and look at the evidence in front of you. They're not done and yet. They might strap 300 old leaking MG radiators (the only type of radiators MG's ever had) on the hot side and run methane through them. Or they might not. Gotta wait and see.

Oh, thank you Elon. You've brought fun and excitement back to space flight.

Phil

That would be me around p55 of this thread.  After a surprisingly hostile reaction (people do love their hats around here) I decided to lie low and only emerge in triumph if the curved sections are installed ‘pointy side down’.

There has really been nothing in the imagery since then to advance the discussion. However, with low confidence my personal view is that  (if they break neatly into sections) the first barrel section is likely to be the aft skirt and the new barrel would then be the lower (LOX) tank of the orbital prototype.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FlattestEarth on 03/14/2019 08:48 am
That was my opinion, and I stated it as such, but assuming that it won't be tethered when there's evidence to the contrary is illogical.

Luckily no one has assumed it won't be tethered.  Just stop.  You are all over the place and none of it makes any sense.  You can have any opinion you want but it's illogical, baseless, and doesn't comport with what EM has stated. 

For example, why add a hanger on the leg to hold the fuel lines if the fuel lines aren't going to be there during the test?  They only need to be held out of the way if they would otherwise be exposed to the engine blast.

Uh?  For Strain Relief  Look at the pictures.  If you think they are going to fire up Raptors with the Propellant Lines "held out of the way" well ......    The leaps you are making are just off the charts.

There are no quick disconnects and no one is going to approach the fueled hopper so for now they are staying connected.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Oersted on 03/14/2019 09:49 am
Regarding the overall Hopper design, something has been bothering me since I first saw the legs and it is making me even more uneasy now that we are approaching the first hops.

If the Hopper happens to come down hard on one of those legs... Won't the leg act like a spear pointed right at the upper tank? One long cylinder all the way from foot pad to the upper tank.

It just seems to me that the is a crumple zone missing somewhere...

Do you really think that Spacex engineers didn't think about that?

Mistakes are human, but I dare to think that they know their business.

They evidently know their business but they also designed the collapsing tinfoil hat.

I well recall internal the triangular structure connecting the top of the legs. However, that triangle is basically perpendicular to the legs so I don't see how it can resist much upwards force through the legs (It always helps, of course).

The original Grasshopper had legs much more independent of the tank structure.

Anyway, we'll either get beautiful, perfect flights or spectacular kabooms, it is all good. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 03/14/2019 10:28 am
Assumptions:
- Hopper will be test-fired with at least one Raptor, at least once, attached to the ground (like every SpaceX vehicle other than Grashopper)
- Hopper will be used for subsonic and supersonic flight testing, but not orbital flight testing (as per Elon's previous tweets stating this is what it will do)
- The fairing is not necessary for static firing
- The fairing is necessary for flight testing
- The fairing is not necessary but highly desirable for low-speed hop testing
- SpaceX are happy to weld bits onto an cut bits off of the hopper as required
- The orbital Starship prototype will not carry any paying customers or payload

Assumed testing regime:
- Static fire Hopper as it is currently configured: no fairing, non-detachable links to GSE, insulated top of tank dome. Qualifies plumbing and Raptor operation off of test stand.
- Once static fired, install quick-disconnects for GSE, landing leg buffers, and cold-gas thrusters (confirmed by Elon tweet to have replaced gaseous Methalox thrusters) for hop tests
- Also build a landing pad
- Install the fairing at this time if it is ready
- Perform short hop tests. Not tethered, because what the hell would you tether it to?! Qualifies Starship landing sequence
- Install fairing if not already installed
- Install upper control surfaces
- Perform high speed tests. Qualifies Starship subsonic and supersonic aerodynamic design and control surfaces & control laws.
- Start testing of first Starship orbital prototype, safe in the knowledge that you won't lose the much more expensive (and non-revenue-generating, unlike F9 landing tests) model to a problem during operational regimes that could have been discovered with a cheaper model.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 03/14/2019 10:34 am
In my opinion:
It seems to me that hopper 1 is intended only for very low (a few feet probably) tethered testing.  I doubt it will get a nose-cone.  It is likely essentially complete in it's current state (less the engines, of course).  They wouldn't have bothered to put a reflective coating on the dome if it wasn't going to remain exposed.  If it were going any higher than that it would need some sort of landing gear to soften the impact.  It very well could be that they will add landing gear and take it higher, but in it's current form I highly doubt it. 

I believe what is being constructed a mile away right now is hopper 2, which will be used for un-tethered testing up to a few miles high, maybe several miles, but definitely not an orbital prototype since there's no sign of anything that would suggest transpiration cooling.

Hopper is Suborbital VTOL.  Orbital Prototype target for June.
Let's take EM at his word:  https://forum.nasaspaceflight.com/index.php?topic=47352.msg1907676#msg1907676



Other than another place to test raptor, and amazing video and pictures for marketing and hype I don't see much value in the hopper.

An actual model of the starship makes much more sense.  But I don't see how that could be coming in 3 months.  Don't see the point of spending a dime on Hopper if there is a follow on vehicle 3 months behind it.
they save time, but they also don't have to risk the orbital prototype doing landing tests.
Guess they will also use the hopper for engine out tests and similar high risk stuff.

An idea of mine is to rebuild it to test landing of first stage too.

The orbital version need an significantly more complex hull because of the cooling, it also need rcs and equipment need to be rated for space so you don't want to loose the orbital version, you are also hesitant to build an second before you know how well the first works out.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris Bergin on 03/14/2019 11:12 am
We'll be needing another new thread soon, probably when Raptor is installed as a good cut off point for Thread 3, but a reminder that you all should be civil.

A drive-by one word post of "baseless" results in that post being removed. Flapping one's arms around shouting "OMG, you have a different opinion than mine!" isn't any better. If you disagree with someone, calmly explain your own counter opinion.

A lot of you may be thinking "Huh? But the thread looks fine to me!" - that's because we do trim the weeds out when required, but this warning is to stop the weeds from growing back.

(Way too many words to say "Please behave yourselves - no food fights" ;D)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kmatk620 on 03/14/2019 12:01 pm
Hello all. Long time lurker, first time poster. These Starship threads are really exciting to a casual observer like myself. Love all the wonderful insights from you experienced folk.

I'm hoping someone more knowledgable can clear something up for me. The top of the legs are connected with a triangular truss that appears to be contained within the LOx tank. When fueled these tubes will be submerged in cryogenic oxygen. Will this not cause the air within  the tubes to condense, resulting in a drastic pressure differential between the ~3bar LOx and low pressure interior of the tube? I don't doubt the steel could withstand this, but it could compromise strength during landing, no? Perhaps they put some holes to allow the LOx to flow in and out of the truss?

I'm just a lowly pizza man so I apologize if this has been addressed or is a matter of little concern.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/14/2019 12:07 pm
Regarding the overall Hopper design, something has been bothering me since I first saw the legs and it is making me even more uneasy now that we are approaching the first hops.

If the Hopper happens to come down hard on one of those legs... Won't the leg act like a spear pointed right at the upper tank? One long cylinder all the way from foot pad to the upper tank.

It just seems to me that the is a crumple zone missing somewhere...

Do you really think that Spacex engineers didn't think about that?

Mistakes are human, but I dare to think that they know their business.

They evidently know their business but they also designed the collapsing tinfoil hat.

I well recall internal the triangular structure connecting the top of the legs. However, that triangle is basically perpendicular to the legs so I don't see how it can resist much upwards force through the legs (It always helps, of course).

The original Grasshopper had legs much more independent of the tank structure.

Anyway, we'll either get beautiful, perfect flights or spectacular kabooms, it is all good.
You need more experience with struts then.  That triangle is exactly right for that.

The fairing was lost for failure of a concrete block....  That's irrelevant here.

I suggest moving on...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 03/14/2019 12:21 pm
Hello all. Long time lurker, first time poster. These Starship threads are really exciting to a casual observer like myself. Love all the wonderful insights from you experienced folk.

I'm hoping someone more knowledgable can clear something up for me. The top of the legs are connected with a triangular truss that appears to be contained within the LOx tank. When fueled these tubes will be submerged in cryogenic oxygen. Will this not cause the air within  the tubes to condense, resulting in a drastic pressure differential between the ~3bar LOx and low pressure interior of the tube? I don't doubt the steel could withstand this, but it could compromise strength during landing, no? Perhaps they put some holes to allow the LOx to flow in and out of the truss?

I'm just a lowly pizza man so I apologize if this has been addressed or is a matter of little concern.
Good question. I assume they are open to the LOX.
You could have them open to outside but that would increase cooling and be an leak point
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Doesitfloat on 03/14/2019 12:35 pm
Just for fun I'm going to say the opposite.
They are sealed. The effect of the small amount of air inside them is negligible. They are at the top of the tank so they displace very little liquid  oxygen.  The primary loads for these struts is in landing and off center landing. Once sized for those forces the secondary buoyancy loads were negligible. So the best way to avoid contamination is to seal them.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/14/2019 01:14 pm
According to bocachicagal's lates photo, they are putting another level of panels on the faring:

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1922181#msg1922181

I'm not sure how tall this is tracking now, especially since it looks like they are going to go with a less tapered nose cone but perhaps they decided to also go full height for an even higher fidelity prototype?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: programmerdan on 03/14/2019 01:17 pm
Yeah, looking firmer and firmer that this isn't just a new nosecone -- they've moved on. This is full ship prototype 2.

(IMHO)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/14/2019 01:18 pm
According to bocachicagal's lates photo, they are putting another level of panels on the faring:

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1922181#msg1922181

I'm not sure how tall this is tracking now, especially since it looks like they are going to go with a less tapered nose cone but perhaps they decided to also go full height for an even higher fidelity prototype?

I'm still thinking this is a fairing, but I'm less certain by the day. Could we really look at the tanks of the orbital prototype?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/14/2019 01:36 pm
To be clear, I still think this is the Fairing / Nosecone. I'm just curious if they decided to make it full height as opposed to the first iteration which was shorter than what the SS will eventually be.

*However, they may also have decided to build this fairing version in such a way that it can also be used/modified for the Orbital version when those sub assemblies start to arrive.
 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FlokiViking on 03/14/2019 01:37 pm
I'm still thinking this is a fairing, but I'm less certain by the day. Could we really look at the tanks of the orbital prototype?
I am moving to the camp that this is a flyer, whereas what is on the pad now is a ground test fixture only.
But I also think this might be the suborbital prototype to be used for high altitude and reentry profile testing.  I think I remember reading somewhere that was the planned progression (reentry test flights prior to orbital flights).
We'll get additional data points when we see what provisions they make for the fins (if we are correct about this being the next flyer).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OTV Booster on 03/14/2019 01:46 pm
I think the foreground cylinder is going to be a methane tank. The background cylinder is going to be a LOX tank. This puppy is going to be a new test article. Doesn't matter if you call it a high altitude hopper, a sub orbital or orbital prototype, or a big shiny cylinder, it's gonna be another test article.

Ignore everything you've heard about the (somewhat ambiguous) sequence of test articles and look at the evidence in front of you. They're not done and yet. They might strap 300 old leaking MG radiators (the only type of radiators MG's ever had) on the hot side and run methane through them. Or they might not. Gotta wait and see.

Phil

That would be me around p55 of this thread.  After a surprisingly hostile reaction (people do love their hats around here) I decided to lie low and only emerge in triumph if the curved sections are installed ‘pointy side down’.

There has really been nothing in the imagery since then to advance the discussion. However, with low confidence my personal view is that  (if they break neatly into sections) the first barrel section is likely to be the aft skirt and the new barrel would then be the lower (LOX) tank of the orbital prototype.

Thanks for the pointer. I went back and gave you an attaboy. The reaction to your post was less about what the visible curvy pieces are for and more about flying with no hat. Little actual comment on the curvy metal. Personally, I'd rather fly with a helmet.

There seems to be a lot of argument that the hopper has operational needs for the hat but I can't see the first one having the strength to buck much wind or the mass to simulate the orbital vehicle without a lot of modification. That might have been in the plans but I think not. If they actually intended it to fly they would have built it probably used heavier stainless to start with, but in the end the hat/no hat is way low on the list of interesting things going on down there.

Can't wait for BCG or Nomadd to get a pic of a flatbed with a load of MG radiators. ;D

Phil
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Dave G on 03/14/2019 01:49 pm
My expert eye, trained by many Saturday mornings watching Rocky Jones Space Ranger and Captain Midnight, leads me to several conclusions.  Captain Video, IIRC, was Tuesday evenings. From the stills that Dave G posted from YouTube in the Texas launch site and discussion forum we see two separate shiny cylinders being fabricated.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Hypergolic96 on 03/14/2019 02:01 pm
If this is a new prototype, are the metal panels thick enough?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/14/2019 02:06 pm
I'm hoping someone more knowledgable can clear something up for me. The top of the legs are connected with a triangular truss that appears to be contained within the LOx tank. When fueled these tubes will be submerged in cryogenic oxygen. Will this not cause the air within  the tubes to condense, resulting in a drastic pressure differential between the ~3bar LOx and low pressure interior of the tube? I don't doubt the steel could withstand this, but it could compromise strength during landing, no? Perhaps they put some holes to allow the LOx to flow in and out of the truss?

The presumed internal vacuum only raises the pressure differential by ~1 bar so the pressure differential is 4 bar.  My presumed dimensions for the tubing in the triangular strut is 32" OD, 5/8" wall.  That results in stresses of 47 psi in the stainless steel tubing, approximately .15% of the yield strength of 304 stainless steel, insignificant.  Tupperware could handle that stress though I wouldn't recommend its use in LOX.  Much higher will be the stresses acting longitudinally in the triangular strut from landing leg inputs and from pressure acting on the walls of the tank.  Also somewhat significant and certainly higher in magnitude will be bending stresses due to the weight of the horizontal struts and buoyancy forces when its in the LOX.  Oh and the stresses due to temperature changes particularly when it first comes into contact with the LOX will be significant.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/14/2019 02:25 pm
With all the sections being added to the two fairing sections being built, I am now inclined to believe that one of them may not be a fairing at all but it will be used to fully enclose the base now on the launchpad. It would make sense since the height of the hopper would be substantially taller with the two new sections. can anyone tell the diameter of the new sections?.

Just a thought.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/14/2019 02:30 pm
With all the sections being added to the two fairing sections being built, I am now inclined to believe that one of them may not be a fairing at all but it will be used to fully enclose the base now on the launchpad. It would make sense since the height of the hopper would be substantially taller with the two new sections. can anyone tell the diameter of the new sections?.

Just a thought.

On second thought, that would make the access ports inaccessible. :P
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 03/14/2019 02:42 pm
Hello all. Long time lurker, first time poster. These Starship threads are really exciting to a casual observer like myself. Love all the wonderful insights from you experienced folk.

I'm hoping someone more knowledgable can clear something up for me. The top of the legs are connected with a triangular truss that appears to be contained within the LOx tank. When fueled these tubes will be submerged in cryogenic oxygen. Will this not cause the air within  the tubes to condense, resulting in a drastic pressure differential between the ~3bar LOx and low pressure interior of the tube? I don't doubt the steel could withstand this, but it could compromise strength during landing, no? Perhaps they put some holes to allow the LOx to flow in and out of the truss?

I'm just a lowly pizza man so I apologize if this has been addressed or is a matter of little concern.

I think you answered your own question as well.

Quote
Perhaps they put some holes to allow the LOx to flow in and out of the truss?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dglow on 03/14/2019 03:06 pm
To be clear, I still think this is the Fairing / Nosecone. I'm just curious if they decided to make it full height as opposed to the first iteration which was shorter than what the SS will eventually be.
I can imagine: when EM learned the first iteration blew over he demanded the replacement be built to full scale.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: raketa on 03/14/2019 03:42 pm
1/I think Elon find out, that they don't need nose for hopper and they start to build Orbital version.
2/After Hopper will finish testing, they will switch raptor engine to orbital prototype.
3/I think they have 2 time constraints, build raptors(1-2/month) and completion of rocket assembly(5-6 month)
4/I think there is no time constraints on most of the  components, since they could use almost everything from Falcon 9 rocket, and produce sheet of metal for skin is easy
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Dave G on 03/14/2019 04:02 pm
Pardon my ignorance, but does anyone know what these notches are?

I see them at the bottom of both of the barrel sections.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/14/2019 04:15 pm
According to bocachicagal's lates photo, they are putting another level of panels on the faring:

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1922181#msg1922181

I'm not sure how tall this is tracking now, especially since it looks like they are going to go with a less tapered nose cone but perhaps they decided to also go full height for an even higher fidelity prototype?

My estimate on the heights, based on the assumption that diameter is 9m:
1. The water tower section (currently on the pad): 11m (not including the top dome)
2. The two new cylinders being built: Each section is 2.55m high, one has 3 sections, the other 4, so 7.65m and 10.2m respectively
3. The ship height in dearMoon presentation is 55m, 40m of it is straight cylinder. Right now all 3 hopper parts put together is 28.85m high, so still some way to go if they do decide to build it to full height. Also the dearMoon ship's nose section is 15m high, it has a much gradual curve than the curved section we're seeing. If they changed the nose to use the sharper curve section we're seeing, the straight cylinder part would be even higher.

For comparison, the old fairing is about 24m height with a 11m straight section.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Elmar Moelzer on 03/14/2019 04:33 pm
I am in the camp that this is the tanks for a second prototype (orbital or otherwise). If it does taper, then that is not recognizable at this point. So I do not believe that this is the nose cone. Of course I would not be surprised if my prediction was wrong and they just changed the design to a more straight nose cone...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 04:38 pm
Pardon my ignorance, but does anyone know what these notches are?  I see them at the bottom of both of the barrel sections.

I have a weak hypothesis they are an access port for joining/unjoining the barrel segments to each other and to the Hopper Base but I'm not at all confident that truly makes sense.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 03/14/2019 04:42 pm
Pardon my ignorance, but does anyone know what these notches are?  I see them at the bottom of both of the barrel sections.

I have a weak hypothesis they are an access port for joining/unjoining the barrel segments to each other and to the Hopper Base but I'm not at all confident that truly makes sense.

Looks like just protrusions from the base for aligning/stiffening the bottom ring during construction & when the hold downs are not bolted down.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: prelator on 03/14/2019 04:56 pm
I think this news article can shed some light on the purpose of the hopper and its upcoming test regimen: https://www.brownsvilleherald.com/news/local/county-approves-authority-for-road-closures-for-rocket-testing/article_ef6a2fd4-466b-11e9-aa6e-1b3a1be10f5a.html#.XIqQtxSSuE8.twitter

Quote
“SpaceX will conduct checkouts of the newly installed ground systems and perform a short static fire test in the days ahead,” Gleeson said. “Although the prototype is designed to perform sub-orbital flights, or hops, powered by the SpaceX Raptor engine, the vehicle will be tethered during initial testing and hops will not be visible from offsite. SpaceX will establish a safety zone perimeter in coordination with local enforcement and signage will be in place to alert the community prior to the testing.”
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: r1279 on 03/14/2019 04:58 pm
Pardon my ignorance, but does anyone know what these notches are?

I see them at the bottom of both of the barrel sections.

Considering their position, I wonder if they are related to the welding machine [that the notches made it easier to start/stop the weld that close to the ground]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 05:00 pm
I think this news article can shed some light on the purpose of the hopper and its upcoming test regimen: https://www.brownsvilleherald.com/news/local/county-approves-authority-for-road-closures-for-rocket-testing/article_ef6a2fd4-466b-11e9-aa6e-1b3a1be10f5a.html#.XIqQtxSSuE8.twitter

Quote
“SpaceX will conduct checkouts of the newly installed ground systems and perform a short static fire test in the days ahead,” Gleeson said. “Although the prototype is designed to perform sub-orbital flights, or hops, powered by the SpaceX Raptor engine, the vehicle will be tethered during initial testing and hops will not be visible from offsite. SpaceX will establish a safety zone perimeter in coordination with local enforcement and signage will be in place to alert the community prior to the testing.”

Treviño and the county aren't the only ones!!!   ;D

Quote
As tests draw closer, Treviño said the county is on a learning curve as potential launches draw closer to becoming a reality.

“It’s exciting and we know that we keep moving closer and closer to that first test or whatever they’re going to be doing and we’re wishing them all the best of luck and we’re excited,” Treviño said.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 05:26 pm
Pardon my ignorance, but does anyone know what these notches are?

I see them at the bottom of both of the barrel sections.

Considering their position, I wonder if they are related to the welding machine [that the notches made it easier to start/stop the weld that close to the ground]

Welcome to the Forum.  IMO, you win today as I think you are exactly right:

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920689#msg1920689
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: oldAtlas_Eguy on 03/14/2019 05:30 pm
The rapid rate that the first engineering flight test unit was constructed and the progress on what looks to be the #2 EFTU it will be ready to take over testing in mid summer even if or not EFTU #1 crashes or not. It looks that #2 will be a closer match to a SS orbital than that of #1.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/14/2019 06:39 pm
Pardon my ignorance, but does anyone know what these notches are?

I see them at the bottom of both of the barrel sections.

Considering their position, I wonder if they are related to the welding machine [that the notches made it easier to start/stop the weld that close to the ground]

Welcome to the Forum.  IMO, you win today as I think you are exactly right:

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920689#msg1920689 (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920689#msg1920689)
Point to make - the girth welder only makes horizontal welds (hence the name). It uses a conveyor to hold flux to the arc (submerging the arc in flux), and the entire rig rolls along on bogies suspended to the top edge of the work piece (the cylinder). There are automated vertical welders, but this isn't one of them.

Beyond that, I am pretty positive these notches were made after the bottom cylinder section was welded together.

Finally, I believe that there is a rectangular hole cut in the cylinder on the concrete jig, maybe about 16' up.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/14/2019 06:47 pm
Pardon my ignorance, but does anyone know what these notches are?

My bad guess:  Metallurgical samples sent to a lab.  If this is like hopper 1 there is a heavy box section ring going around the bottom and cutting out samples here wouldn't hurt much.  I yield the rest of my time and I yield the floor to anyone with a more reasonable guess.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 06:52 pm
There are automated vertical welders, but this isn't one of them.

Haven't been following welding pics super-closely but they haven't used a vertical rig on-site?  I just recall looking at the vertical welds and they struck me as perhaps machine-made.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/14/2019 07:41 pm
There are automated vertical welders, but this isn't one of them.

Haven't been following welding pics super-closely but they haven't used a vertical rig on-site?  I just recall looking at the vertical welds and they struck me as perhaps machine-made.
Well, you're kinda half right...

The cylinder is comprised of curved sections. However these sections themselves are made out of four panels. Those sections are pre-assembled out of sight - possibly in the tent. Those four panels sections are two panels wide and two tall. The welds that join these four panels are very clean and look like they were done by some form of automation. Exceptionally clean. Keep in mind therefore that you will see both very clean vertical AND horizontal welds, alongside less clean horizontal and vertical welds.

These four panel sections are then built into a cylinder segment. When they are placed they are held to their neighbor by six or so vertically stacked horizontal bars on the inside of the cylinder - picture this: Left hand four panel segment (SegA) is craned next to another four panel segment (SebB). Along the vertical seam where these two segments meet they weld little horizontal tabs with a hole in it, so SegA and SegB have these tabs on either side of the vertical seam. Then horizontal bars with slots in them are fit so the the tab protrudes through the slot and a metal wedge is dropped through the hole in the tab, thereby locking the horizontal bar into place and voila, SegA and SegB are held together by these bars. They can then do a vertical weld, removing the tabs and bars as they go.

The same technique applies when they go up, but the horizontal bars become vertical bars, and they remove a set at a time as the girth welder works around the cylinder, joining the bottom segment to the top segment (and each segment is two panels high)

You can easily see this in the pics. The bars are yellow.

So - in conclusion - you will see clean vertical and horizontal welds - they are the welds making up the four panel sections. And you will see less clean vertical and horizontal welds they are made by a human (vertical - joining sections together to make one complete segment) and girth welder (horizontal - joining vertical segments together to make the cylinder taller)...

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: abaddon on 03/14/2019 08:38 pm
Hopper will be test-fired with at least one Raptor, at least once, attached to the ground (like every SpaceX vehicle other than Grashopper)
Nitpick: and F9R Dev 1 and Crew Dragon pad abort test article and Crew Dragon hover test article (I think those last two were different, but they could be one and the same).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/14/2019 09:05 pm
I caught some testing being done on the Hopper.

Another tank pressure test, or do the clouds coming from the ground equipment tell a different story?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/14/2019 09:12 pm
cropped this pic to point out the condensation on the cooling tower and what looks like a cryo liquid dump on the slope. (not methane, of course.)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NGC 4258 on 03/14/2019 09:16 pm
Some watching Starship Cam believe a static fire or something fiery was just spotted. There was obviously a flash where the engine is supposed to go.

I think it might have been an ignitor test or something of the sort.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/14/2019 09:27 pm
Id be careful to put too much weight in spotted flashes on that distance when the Hopper is so reflective. But if our local observers can confirm some sort of ignition, that would be wonderful. :D Cant be a full burn cause they would have had to close the road before that.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kansan52 on 03/14/2019 09:28 pm
Reflection off cloud/fog caused by liquid nitrogen?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jimothytones on 03/14/2019 09:28 pm
Some watching Starship Cam believe a static fire or something fiery was just spotted. There was obviously a flash where the engine is supposed to go.

I think it might have been an ignitor test or something of the sort.

Could it be the flare stack?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/14/2019 09:30 pm
Now we need not only cameras and camera drones but also microphones and maybe seismometers.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/14/2019 09:40 pm
Some watching Starship Cam believe a static fire or something fiery was just spotted. There was obviously a flash where the engine is supposed to go.

I think it might have been an ignitor test or something of the sort.

I betcha next time they do a fueling test they'll tell the welders to stop first, you can't mix the two.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DistantTemple on 03/14/2019 09:51 pm
Just testing effectiveness of the smoking station shown in a photo of the pad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NGC 4258 on 03/14/2019 09:54 pm
Just testing effectiveness of the smoking station shown in a photo of the pad.
Is it Elon again?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Keldor on 03/14/2019 09:55 pm
Just testing effectiveness of the smoking station shown in a photo of the pad.

Some of those chain smokers must take smoking very seriously.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureMartian97 on 03/14/2019 09:55 pm
Some watching Starship Cam believe a static fire or something fiery was just spotted. There was obviously a flash where the engine is supposed to go.

I think it might have been an ignitor test or something of the sort.

Raptor hasn't been installed on the hopper yet so not a static fire
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/14/2019 09:57 pm
Hopefully it doesn't mean an imminent need for paramedics   :o

Maybe they put something in to eat up anything the liquid oxygen might have reacted with?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/14/2019 10:05 pm
For all we know... a workers truck with real good headlights on the front end... left the pad down the ramp, turned the corner at the entrance... and the internet just had a heart attack with the sudden flash of light from same...  ::)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/14/2019 10:15 pm
 There was nobody on site during that test. The road was blocked for parts of it. I stood on the wrong side of the closure for 30 minutes talking to an employee who was very good at not saying anything before I could walk home. You had to get shots between the fog banks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/14/2019 10:21 pm
Raptor hasn't been installed on the hopper yet so not a static fire

Do we know that?  No madd?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Hitech on 03/14/2019 10:23 pm
My take on "Hopper 1" is that it will never "hop". It is a path finder for hookup and vertical engine start testing. The foil on the outside is somewhat cosmetic and perhaps a test to characterize the fuel heating and external icing. Even at that, they are going to need protection for those tie downs or in short order the tie downs will be no more.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: r1279 on 03/14/2019 10:34 pm
My take on "Hopper 1" is that it will never "hop". It is a path finder for hookup and vertical engine start testing. The foil on the outside is somewhat cosmetic and perhaps a test to characterize the fuel heating and external icing. Even at that, they are going to need protection for those tie downs or in short order the tie downs will be no more.

I wouldn't know one way or the other, but doesn't this seem like far too much work in order to achieve that end.  SpaceX is about minimally viable product.  Elon has said it's for vertical test hops.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 10:37 pm
My take on "Hopper 1" is that it will never "hop". It is a path finder for hookup and vertical engine start testing. The foil on the outside is somewhat cosmetic and perhaps a test to characterize the fuel heating and external icing. Even at that, they are going to need protection for those tie downs or in short order the tie downs will be no more.

I think the argument for "no hop" is quite weak.  Here's why ... all STATSD (Subject to All the Standard Disclaimers).

A notional Hopper v2 is 3 months away based on the Hopper v1 Build Timeline.  They aren't even as far along as they were on December 19th.  https://forum.nasaspaceflight.com/index.php?topic=47070.0   Not hopping Hopper v1 is a massive shift right in testing schedule.  I can't conceptualize what advantage anyone feels obtains from the "WDR/Vertical Stand" Hopper theory.

Foil should always be necessary to reject heating.

Straps are temporary anchoring that wouldn't be used during test.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/14/2019 10:41 pm
Suggest think about this...
What will the exhaust gas temps be once the gas is expanded thru a nozzle... expand in free air across the 3+meters to the concrete... then expand outward at least 5 meters in all directions before it hits anything of note...  ???

My guess is the gas temp will be low enough to not even singe the tie downs...  ;)

Gases cool on expansion.... just saying...  :P
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: mme on 03/14/2019 10:42 pm
My take on "Hopper 1" is that it will never "hop". It is a path finder for hookup and vertical engine start testing. The foil on the outside is somewhat cosmetic and perhaps a test to characterize the fuel heating and external icing. Even at that, they are going to need protection for those tie downs or in short order the tie downs will be no more.
This is a strange take. Elon said it would hop. He's confirmed it will start small, just like the grasshopper program. He's confirmed that it will start with tethered hops. Why this flood of people suddenly convinced that a perfectly good hopper won't hop? Hopping is what hoppers do.

Have you doubters seen the early grasshopper hops?

https://www.youtube.com/watch?v=pzXlUw2WhcE
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lars-J on 03/14/2019 10:46 pm
My take on "Hopper 1" is that it will never "hop". It is a path finder for hookup and vertical engine start testing. The foil on the outside is somewhat cosmetic and perhaps a test to characterize the fuel heating and external icing. Even at that, they are going to need protection for those tie downs or in short order the tie downs will be no more.
This is a strange take. Elon said it would hop. He's confirmed it will start small, just like the grasshopper program. He's confirmed that it will start with tethered hops. Why this flood of people suddenly convinced that a perfectly good hopper won't hop? Hopping is what hoppers do.

Have you doubters seen the early grasshopper hops?

Indeed. It would benefit the signal to noise ratio if the large number of new posters familiarized themselves with SpaceX and its development history. That would reduce the # of "hot take: SpaceX is not going to do what SpaceX said it was going to do" posts and the inevitable counter-arguments.

Will the Hopper hop/fly as-is? No... But no one has claimed it is finished as-is either.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/14/2019 10:56 pm
Right now i am waiting for some noise signalling huge progress. :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: eriblo on 03/14/2019 11:13 pm
Suggest think about this...
What will the exhaust gas temps be once the gas is expanded thru a nozzle... expand in free air across the 3+meters to the concrete... then expand outward at least 5 meters in all directions before it hits anything of note...  ???

My guess is the gas temp will be low enough to not even singe the tie downs...  ;)

Gases cool on expansion.... just saying...  :P

You might want to rethink that  ;) Even if the flow expands perfectly and has a relatively low internal temperature the whole point of the exercise is to convert the internal energy to kinetic energy relative to the surroundings. After those 3 meters your nice cool flow impacts the ground at Mach 10 which might heat things up a bit...

One can also put the raptor into a black box and argue from first principles: You are pumping about 7 GW of fuel into this box, what do you expect to get out?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/14/2019 11:19 pm
Suggest think about this...
What will the exhaust gas temps be once the gas is expanded thru a nozzle... expand in free air across the 3+meters to the concrete... then expand outward at least 5 meters in all directions before it hits anything of note...  ???

My guess is the gas temp will be low enough to not even singe the tie downs...  ;)

Gases cool on expansion.... just saying...  :P

You might want to rethink that  ;) Even if the flow expands perfectly and has a relatively low internal temperature the whole point of the exercise is to convert the internal energy to kinetic energy relative to the surroundings. After those 3 meters your nice cool flow impacts the ground at Mach 10 which might heat things up a bit...

One can also put the raptor into a black box and argue from first principles: You are pumping about 7 GW of fuel into this box, what do you expect to get out?

Does it?... Mach 10?... I don't think so... IMHO...
Please show the math...  ;)

On edit...
My point is because of the very high expansion ratio from chamber throat to 10 meters radius... the cooling is more then you may think...

I welcome a resident rocket science major to post numbers showing I'm wrong on this... :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/14/2019 11:22 pm
Suggest think about this...
What will the exhaust gas temps be once the gas is expanded thru a nozzle... expand in free air across the 3+meters to the concrete... then expand outward at least 5 meters in all directions before it hits anything of note...  ???

My guess is the gas temp will be low enough to not even singe the tie downs...  ;)

Gases cool on expansion.... just saying...  :P

You might want to rethink that  ;) Even if the flow expands perfectly and has a relatively low internal temperature the whole point of the exercise is to convert the internal energy to kinetic energy relative to the surroundings. After those 3 meters your nice cool flow impacts the ground at Mach 10 which might heat things up a bit...

One can also put the raptor into a black box and argue from first principles: You are pumping about 7 GW of fuel into this box, what do you expect to get out?

You guys need to sort this out.  My mouse is hovering over BUY for my front row static fire seats on StubHub.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 03/14/2019 11:52 pm
I wonder what the law is like in Texas when it comes to parabolic microphones  ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: gaballard on 03/15/2019 12:10 am
(Apologies if this has been mentioned already!)

The tapered section in these photos:

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1922304#msg1922304 (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1922304#msg1922304)

Looks like one of the tank bulkheads (shown in the most recent cutaways of SS (https://static2.businessinsider.com/image/5acbc21b146e711f008b49e1-1867/11-elon-musk-iac-2017-mars-colonization-bfr-big-rocket-talk-slides-spacex.jpg))... that and the fact that it's a duller steel makes me think it might be for the orbital prototype.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SPadre on 03/15/2019 12:13 am
Rewind to 4:50 on Starship Cam to see the flames, a short blast. Locking Starship Cam on to Boca Chica launch pad full time now, no more beach views. When visibility improves I will zoom it in.

https://www.youtube.com/watch?v=L7zia2HqOOc
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/15/2019 12:41 am
I wonder what the law is like in Texas when it comes to parabolic microphones  ;D

To hear the sound which is of current interest you could use a 1978 Mr. Microphone from a garage sale, just throw it in the weeds somewhere.  Parabolic, diabolic, convergent, divergent, buried, wouldn't matter.


Suggest think about this...
What will the exhaust gas temps be once the gas is expanded thru a nozzle... expand in free air across the 3+meters to the concrete... then expand outward at least 5 meters in all directions before it hits anything of note...  ???

My guess is the gas temp will be low enough to not even singe the tie downs...  ;)

Gases cool on expansion.... just saying...  :P

You might want to rethink that  ;) Even if the flow expands perfectly and has a relatively low internal temperature the whole point of the exercise is to convert the internal energy to kinetic energy relative to the surroundings. After those 3 meters your nice cool flow impacts the ground at Mach 10 which might heat things up a bit...

One can also put the raptor into a black box and argue from first principles: You are pumping about 7 GW of fuel into this box, what do you expect to get out?

Possibly cool when it comes out then warmed by ricocheting off the concrete and turbulance and then ricocheting off the straps.  But the only reason I can think of to use nylon straps rather than steel would be to make video for high school physics teachers to show over the next few decades.  At great risk.  A great segue for me to dig up this ice video:

Go to 86 seconds, I can't get the time to work automatically.
https://www.youtube.com/watch?v=rowVdcnwJr8?t=86 (https://www.youtube.com/watch?v=rowVdcnwJr8?t=86)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: masterxel on 03/15/2019 12:45 am
Subject to All the Standard Disclaimers:

I don't see any reason that the remaining pieces under construction couldn't be assembled into a single final Starhopper, except larger than expected at the full 55m size. See this mockup for example:
https://ourplnt.com/wp-content/uploads/2019/01/Starhopper-Starship-Super-Heavy.jpg

Eyeballing it from the aerial shots: water tower with legs + fairing 2.0 bottom half + fairing 2.0 top half + nose cone could match the middle "Starship 55m" mockup in terms of length / height.

I'm firmly in the "not hopper 2.0 and not SuperHeavyHopper" camp although I share the expectation that SpaceX will continue to surprise and break expectations in seemingly obvious ways.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/15/2019 12:52 am
My take on "Hopper 1" is that it will never "hop". It is a path finder for hookup and vertical engine start testing. The foil on the outside is somewhat cosmetic and perhaps a test to characterize the fuel heating and external icing. Even at that, they are going to need protection for those tie downs or in short order the tie downs will be no more.

You're from the flat hopper society eh?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Pete on 03/15/2019 12:56 am

Does it?... Mach 10?... I don't think so... IMHO...
Please show the math...  ;)

Raptor sealevel ISP is about 330
This requires an exhaust velocity of about 3234 m/s. Which is mach 9.43
So yes, not mach 10.

The Raptor engine is very slightly overexpanded at sealevel, thus the pressure of the exhaust is just below atmospheric, thus the exhaust plume does not expand wider than the nozzle until it slows down significantly.
(see the very tight "beam" of exhaust plume during the Raptor tests)

The Raptor burns up to 800Kg of methane and Oxygen per second, releasing energy of 13 000 Mj per second. That is a 13 Gigawatt blowtorch.
That energy has to go *somewhere*
So yes, there is your math.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/15/2019 01:07 am
Q:  A uniform laminar flow stream of CO2 and water vapor at 20C and 9.43 mach encounters a flat surface perpendicular to the flow.  What is the stagnation temperature?  What is the stagnation pressure?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 03/15/2019 01:20 am
To hear the sound which is of current interest you could use a 1978 Mr. Microphone from a garage sale, just throw it in the weeds somewhere.  Parabolic, diabolic, convergent, divergent, buried, wouldn't matter.

I was just thinking that all this video surveillance is great, but can we hear what they're saying?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/15/2019 01:52 am
The Raptor burns up to 800Kg of methane and Oxygen per second, releasing energy of 13 000 Mj per second. That is a 13 Gigawatt blowtorch.
That energy has to go *somewhere*
So yes, there is your math.

So check my figgerin here.  It seems that one Raptor produces (or at least consumes) power equivalent to 55% of the entire electric generating system (all sources) in the state of California  :o  And there's going to be a multitude of them stuck onto the bottom of SS and SH?   :o :o :o

https://www.energy.ca.gov/almanac/electricity_data/electric_generation_capacity.html (https://www.energy.ca.gov/almanac/electricity_data/electric_generation_capacity.html)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: edzieba on 03/15/2019 04:37 am
Hopper will be test-fired with at least one Raptor, at least once, attached to the ground (like every SpaceX vehicle other than Grashopper)
Nitpick: and F9R Dev 1 and Crew Dragon pad abort test article and Crew Dragon hover test article (I think those last two were different, but they could be one and the same).
F9R was static fired on the holddowns it subsequently launched from: https://www.youtube.com/watch?v=KlR4FErqRf8
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/15/2019 11:20 am
Rewind to 4:50 on Starship Cam to see the flames, a short blast. Locking Starship Cam on to Boca Chica launch pad full time now, no more beach views. When visibility improves I will zoom it in.

Can you provide a link to the time you reference? There is no 4:50 in this video.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: sghill on 03/15/2019 11:36 am
I wonder what the law is like in Texas when it comes to parabolic microphones  ;D

As long as it's shaped like a rifle, you're good to go.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/15/2019 12:08 pm
Rewind to 4:50 on Starship Cam to see the flames, a short blast. Locking Starship Cam on to Boca Chica launch pad full time now, no more beach views. When visibility improves I will zoom it in.

Can you provide a link to the time you reference? There is no 4:50 in this video.
I believe that’s meant to mean go backwards 4 minutes 50 seconds from the end...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lampyridae on 03/15/2019 12:13 pm
Well, a Raptor's now there to be plugged in.

https://twitter.com/SpacePadreIsle/status/1106533231804010497
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/15/2019 12:27 pm
Well...

It seems the color of that light and the color of the flash in the video are similar and a bit distinctive.  One could draw the conclusion that they are the same if one were so inclined.


There is no 4:50 in this video.

There is.  At the bottom left of the screen is a time of day.  But I saw nothing at 4:50 when I looked.  Admittedly I only gave it a once over looksee.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/15/2019 12:28 pm
Rewind to 4:50 on Starship Cam to see the flames, a short blast. Locking Starship Cam on to Boca Chica launch pad full time now, no more beach views. When visibility improves I will zoom it in.

Can you provide a link to the time you reference? There is no 4:50 in this video.
I believe that’s meant to mean go backwards 4 minutes 50 seconds from the end...

No.  It was 4:50pm Local.  When I looked it was a Live Stream that could be back up several hours.  The window to back up to 4:50pm would be passed now.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/15/2019 12:31 pm
There is.  At the bottom left of the screen is a time of day.  But I saw nothing at 4:50 when I looked.  Admittedly I only gave it a once over looksee.

I watched it several times.  It was hard not to conclude it was very evocative of a flaring of gasses from underneath the center of the hopper on the pad that started and ended within about 1.5 seconds.  Definitely not looking like any of the obvious alternatives.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: r1279 on 03/15/2019 12:44 pm
There is.  At the bottom left of the screen is a time of day.  But I saw nothing at 4:50 when I looked.  Admittedly I only gave it a once over looksee.

I watched it several times.  It was hard not to conclude it was very evocative of a flaring of gasses from underneath the center of the hopper on the pad that started and ended within about 1.5 seconds.  Definitely not looking like any of the obvious alternatives.

Or watch the feed today.  Pretty much every light looks like fire with environmental distortion, vibration, out of focus [including the car light that obviously drove to the beach, turned around, turned its lights off].

They could have turned this bright site light on.  A vehicle could have turned around/turned it's lights on.  Or perhaps it was the flare, but I just don't think it's visible form this camera angle, it seems more like you can only see the top of the tower through the legs when you are close and low.

Regardless, it wasn't a static fire.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 03/15/2019 01:06 pm

Does it?... Mach 10?... I don't think so... IMHO...
Please show the math...  ;)

Raptor sealevel ISP is about 330
This requires an exhaust velocity of about 3234 m/s. Which is mach 9.43
So yes, not mach 10.

The Raptor engine is very slightly overexpanded at sealevel, thus the pressure of the exhaust is just below atmospheric, thus the exhaust plume does not expand wider than the nozzle until it slows down significantly.
(see the very tight "beam" of exhaust plume during the Raptor tests)

The Raptor burns up to 800Kg of methane and Oxygen per second, releasing energy of 13 000 Mj per second. That is a 13 Gigawatt blowtorch.
That energy has to go *somewhere*
So yes, there is your math.

Nit pick: Forgot about higher sonic exit velocity due to exit temperature. According to CEA the theoretical exit conditions are as follows:
O/F         Temp         Velocity         Sonic Velocity           Mach
3.7         2166 K      3422 m/s          914 m/s                 3.744

Exit velocity is a few percent lower due to losses do to incomplete mixing, friction, etc...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/15/2019 01:07 pm
Raptor at the launch site.

From the SPadre.com livestream chat (times are UTC):

Quote
13:04 Spadre.com South Padre Island Information
At launch pad now, raptor just pulled up on flatbed, cranes moving to install
[...]
13:21 Spadre.com South Padre Island Information
Heavy rain windy, lightning, crews just left launch pad

It appears that Mr. Raptor is mounted on a lift table having four hand cranked jack screws to allow it to be tilted raised / lowered a bit.  If I was to guess that table will be lifted off the trailer by a crane and put onto a suitably heavy scissor lift platform.  And I'd guess that the table has some x,y and rotate capability.

Those four jack screws look like they might be from the trailer parts catalog.  Definitely not expensive enough that they would have been considered by ULA for such a task.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/15/2019 01:31 pm
Raptor at the launch site.

From the SPadre.com livestream chat (times are UTC):

Quote
13:04 Spadre.com South Padre Island Information
At launch pad now, raptor just pulled up on flatbed, cranes moving to install
[...]
13:21 Spadre.com South Padre Island Information
Heavy rain windy, lightning, crews just left launch pad

It appears that Mr. Raptor is mounted on a lift table having four hand cranked jack screws to allow it to be tilted raised / lowered a bit.  If I was to guess that table will be lifted off the trailer by a crane and put onto a suitably heavy scissor lift platform.  And I'd guess that the table has some x,y and rotate capability.

Those four jack screws look like they might be from the trailer parts catalog.  Definitely not expensive enough that they would have been considered by ULA for such a task.
Dunno - remember the rolling steel work platform they made? I was expecting the engine to be placed on that and rolled under the BFH. It has a much larger dance floor than a scissor lift.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/15/2019 01:38 pm
I'm just worried right now about lightning.

That thing is just sticking out there, and even if it can be its own lightning rod, is that risky?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: LaunchedIn68 on 03/15/2019 02:12 pm
What is the size of the Raptor engine comparible to?  SSME?  What about thrust wise?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThereIWas3 on 03/15/2019 02:24 pm
I wonder what the Class-C motorhome with the SpaceX logo on it is for.  Carrying toools and test equipment?  A dry paperwork area that can be close to the work?  A visual screen to block ITAR-sensitive Raptor details from prying eyes during assumbly once the blanket comes off?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cuddihy on 03/15/2019 02:55 pm
I wonder what the Class-C motorhome with the SpaceX logo on it is for.  Carrying toools and test equipment?  A dry paperwork area that can be close to the work?

This, plus smaller electronics is my guess. Meaning, electronics related to Raptor control and Hopper GNC. If you had to take anything that gave you a funny reading back to the other area, that’s 20 min of wasted time each way. 4 trips a day and you’re losing 1.5 hrs of daylight.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: r1279 on 03/15/2019 02:58 pm
I wonder what the Class-C motorhome with the SpaceX logo on it is for.  Carrying toools and test equipment?  A dry paperwork area that can be close to the work?

This, plus smaller electronics is my guess.

Or a comfortable warm/dry place to eat lunch/drink coffee.  Especially with early starts/late days.

[But definitely agree with the need to have a technical office right there, to analyze engine data]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 03/15/2019 03:46 pm
What is the size of the Raptor engine comparible to?  SSME?  What about thrust wise?

SSME physically larger & heavier
SSME Thrust = 1,860 KN  sea level 
Raptor Thrust = 1,765 KN  sea level  (various thrust levels estimated here.  Real #s TBD; may be higher)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Prettz on 03/15/2019 04:10 pm
What is the size of the Raptor engine comparible to?  SSME?  What about thrust wise?
A very nice diagram comparing it to other engines was posted here:
https://forum.nasaspaceflight.com/index.php?topic=41363.msg1913583#msg1913583
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/15/2019 04:17 pm
Another pic of the liquid oxygen delivery. I am sure the tall tank on the right had previously been marked liquid nitrogen.

That explains a lot. They used one and the same tank for initial pressure testing with nitrogen, and now that that is done they do not need that much nitrogen storage capacity and use it for oxygen. It is one of those things that look obvious after the fact, but i would never have guessed cause i was stuck with the thought that a tank for x is a tank for x.  But no, it is a tank. Clean, refill, relabel. I feel honestly stupid for not seeing that. :D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 03/15/2019 04:19 pm
Another pic of the liquid oxygen delivery. I am sure the tall tank on the right had previously been marked liquid nitrogen.

That explains a lot. They used one and the same tank for initial pressure testing with nitrogen, and now that that is done they do not need that much nitrogen storage capacity and use it for oxygen. It is one of those things that look obvious after the fact, but i would never have guessed cause i was stuck with the thought that a tank for x is a tank for x.  But no, it is a tank. Clean, refill, relabel. I feel honestly stupid for not seeing that. :D

Actually that brings up a good point. If you purge a tank with LNG before using with LOX, what happens when you use a LOX for LNG storage first?

:thinking
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/15/2019 04:23 pm
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.

Are we absolutely sure that they have already installed 3 pressure bulk heads inside the existing hopper? Or have they just installed 2 for the lox tank + some support structures for the Raptor below it? If so could the dome segments we can now see be the missing 3rd bulkhead - the top of the methane tank? This tank might extend up into the lower portion of the "hat" cylinder.

If this is correct then we should see the dome installed into the hat cylinder pointing up in the lower half of the hat cylinder then attached to the top of the hopper base (or may be attach the hat cylinder and then install the third bulkhead. Finally attach a proper hat nose cone to form a full scale Starship hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/15/2019 04:54 pm
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.

Are we absolutely sure that they have already installed 3 pressure bulk heads inside the existing hopper? Or have they just installed 2 for the lox tank + some support structures for the Raptor below it? If so could the dome segments we can now see be the missing 3rd bulkhead - the top of the methane tank? This tank might extend up into the lower portion of the "hat" cylinder.

If this is correct then we should see the dome installed into the hat cylinder pointing up in the lower half of the hat cylinder then attached to the top of the hopper base (or may be attach the hat cylinder and then install the third bulkhead. Finally attach a proper hat nose cone to form a full scale Starship hopper.
You might want to think that one through a bit more. Then look at the existing dome, perhaps the vent. You might get your answer. :-)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/15/2019 05:10 pm
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.

Are we absolutely sure that they have already installed 3 pressure bulk heads inside the existing hopper? Or have they just installed 2 for the lox tank + some support structures for the Raptor below it? If so could the dome segments we can now see be the missing 3rd bulkhead - the top of the methane tank? This tank might extend up into the lower portion of the "hat" cylinder.

If this is correct then we should see the dome installed into the hat cylinder pointing up in the lower half of the hat cylinder then attached to the top of the hopper base (or may be attach the hat cylinder and then install the third bulkhead. Finally attach a proper hat nose cone to form a full scale Starship hopper.
You might want to think that one through a bit more. Then look at the existing dome, perhaps the vent. You might get your answer. :-)

Yes! Vents presumably one for LOX and one for Methane both with U tube tops. Unless they add additional pipework and the second one is something else. But you are probably right.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/15/2019 05:15 pm
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.

Are we absolutely sure that they have already installed 3 pressure bulk heads inside the existing hopper? Or have they just installed 2 for the lox tank + some support structures for the Raptor below it? If so could the dome segments we can now see be the missing 3rd bulkhead - the top of the methane tank? This tank might extend up into the lower portion of the "hat" cylinder.

If this is correct then we should see the dome installed into the hat cylinder pointing up in the lower half of the hat cylinder then attached to the top of the hopper base (or may be attach the hat cylinder and then install the third bulkhead. Finally attach a proper hat nose cone to form a full scale Starship hopper.
You might want to think that one through a bit more. Then look at the existing dome, perhaps the vent. You might get your answer. :-)

Yes! Vents presumably one for LOX and one for Methane both with U tube tops. Unless they add additional pipework and the second one is something else. But you are probably right.
Besides they have two hatched and two sets of GSE plumbing.

But I am a bit at a loss re the cylinder(s). I’ve decided to clam up re them though and just see what happens.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/15/2019 06:19 pm
The Raptor burns up to 800Kg of methane and Oxygen per second, releasing energy of 13 000 Mj per second. That is a 13 Gigawatt blowtorch.
That energy has to go *somewhere*
So yes, there is your math.

So check my figgerin here.  It seems that one Raptor produces (or at least consumes) power equivalent to 55% of the entire electric generating system (all sources) in the state of California  :o  And there's going to be a multitude of them stuck onto the bottom of SS and SH?   :o :o :o

https://www.energy.ca.gov/almanac/electricity_data/electric_generation_capacity.html (https://www.energy.ca.gov/almanac/electricity_data/electric_generation_capacity.html)
That's an impressive comparison, but do note that electric power is only 30-50%  of the thermal power of the generator-turbine stack...

So one Raptor is maybe 25% of the average power production for CA...  Still mond boggling when x31...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/15/2019 06:59 pm
The Raptor burns up to 800Kg of methane and Oxygen per second, releasing energy of 13 000 Mj per second. That is a 13 Gigawatt blowtorch.
That energy has to go *somewhere*
So yes, there is your math.

So check my figgerin here.  It seems that one Raptor produces (or at least consumes) power equivalent to 55% of the entire electric generating system (all sources) in the state of California  :o  And there's going to be a multitude of them stuck onto the bottom of SS and SH?   :o :o :o

https://www.energy.ca.gov/almanac/electricity_data/electric_generation_capacity.html (https://www.energy.ca.gov/almanac/electricity_data/electric_generation_capacity.html)
That's an impressive comparison, but do note that electric power is only 30-50%  of the thermal power of the generator-turbine stack...

So one Raptor is maybe 25% of the average power production for CA...  Still mond boggling when x31...
Makes the output of the Hover dam look a bit mediocre at only 2000 MJ/S
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/15/2019 07:06 pm
Makes the output of the Hover dam look a bit mediocre at only 2000 MJ/S

That's about what you'd need to jump the engines / run the fuel pumps....
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WindyCity on 03/15/2019 10:00 pm
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.
Wouldn't a full-scale "orbital test vehicle" have to have a fuselage engineered for transpiration cooling? Is there any indication that the structure under construction at BC (not referring to the hopper) shows that feature?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/15/2019 10:13 pm
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.
Wouldn't a full-scale "orbital test vehicle" have to have a fuselage engineered for transpiration cooling? Is there any indication that the structure under construction at BC (not referring to the hopper) shows that feature?
Nope, and that's part of the conundrum...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/15/2019 11:19 pm
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.
Wouldn't a full-scale "orbital test vehicle" have to have a fuselage engineered for transpiration cooling? Is there any indication that the structure under construction at BC (not referring to the hopper) shows that feature?
The real thing will have payload and have to survive coming in from BEO. The test model will have less than half the total heat load. Not sure about peak load.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/15/2019 11:19 pm
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.
Wouldn't a full-scale "orbital test vehicle" have to have a fuselage engineered for transpiration cooling? Is there any indication that the structure under construction at BC (not referring to the hopper) shows that feature?
Nope, and that's part of the conundrum...

Is it? IF(!!) these are parts of the orbital prototype, then these would be the tank walls. My understanding is, that the heat shield gets then attached to the tank walls as an additional layer.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: meekGee on 03/15/2019 11:25 pm
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.
Wouldn't a full-scale "orbital test vehicle" have to have a fuselage engineered for transpiration cooling? Is there any indication that the structure under construction at BC (not referring to the hopper) shows that feature?
Nope, and that's part of the conundrum...

Is it? IF(!!) these are parts of the orbital prototype, then these would be the tank walls. My understanding is, that the heat shield gets then attached to the tank walls as an additional layer.
That's what we're all dying to see...  How exactly do you pull that off in a manner that supports external aero loads, accommodates CTE deformations, and still functions...

And how do you add actuated fins to it...

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/15/2019 11:34 pm
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.
Wouldn't a full-scale "orbital test vehicle" have to have a fuselage engineered for transpiration cooling? Is there any indication that the structure under construction at BC (not referring to the hopper) shows that feature?
Nope, and that's part of the conundrum...

Is it? IF(!!) these are parts of the orbital prototype, then these would be the tank walls. My understanding is, that the heat shield gets then attached to the tank walls as an additional layer.
That's what we're all dying to see...  How exactly do you pull that off in a manner that supports external aero loads, accommodates CTE deformations, and still functions...

And how do you add actuated fins to it...

Well, there are those recently arrived "tent poles". Until these are actually used to erect a building, the possibility remains, that these are actually stringers, baffles and struts to strengthen the tanks and create the thrust structure and hardpoints to attach (among other things) the fins.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/15/2019 11:47 pm
Nope, and that's part of the conundrum...
And how do you add actuated fins to it...

It seems to me that you are answering your own question.  ;)    But what about this?

I've had one thing nagging at me as a possible reconciliation of the higher fidelity work at the Fab site with the Hopper v1-and-Only thesis is that they build an Orbital Prototype Fairing that can serve both as the Optics, Mass, and OML Fairing for Hopper v1 and can be repurposed for the Orbital Mk1 SS.

For example, could there be a dome bulkhead pre-installed in the fairing to serve the (not sure here but presumably larger) tanks for an Orbital Mk1 SS.  That fairing needing only the actuating canard fins added later along with whatever additional reinforcement is needed.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/15/2019 11:48 pm
Well, there are those recently arrived "tent poles". Until these are actually used to erect a building, the possibility remains, that these are actually stringers, baffles and struts to strengthen the tanks and create the thrust structure and hardpoints to attach (among other things) the fins.

They look a bit heavy for that. But on the other hand they call it "Super Heavy" so there is that...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/16/2019 12:31 am
This may be an optical illusion, but one photo, IMG_6080 (2).JPG (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1922304#msg1922304) convinced me the curved sections are not tank dome parts, but nose cone sections. They look like dome sections from other angles, but this particular angle shows very convincingly they're section of a cone with a ~60 degree slope. So right now I'm firmly in the "this is a new hopper fairing" camp.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: strawwalker on 03/16/2019 01:38 am

It appears that Mr. Raptor is mounted on a lift table having four hand cranked jack screws to allow it to be tilted raised / lowered a bit.  If I was to guess that table will be lifted off the trailer by a crane and put onto a suitably heavy scissor lift platform.  And I'd guess that the table has some x,y and rotate capability.

Those four jack screws look like they might be from the trailer parts catalog.  Definitely not expensive enough that they would have been considered by ULA for such a task.
Dunno - remember the rolling steel work platform they made? I was expecting the engine to be placed on that and rolled under the BFH. It has a much larger dance floor than a scissor lift.

Is that platform on wheels? I can't seem to find pictures that include the feet, although it would certainly be convenient. It looks like the trailer parts catalog jacks have been modified with some not so cheap dollies. No need for wheels on the work platform, or a turn table for alignment. You can see the casters better in the second image in this bocachicagal post:

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923148#msg1923148

2.5 ton Techimpex caster dolley: http://www.jackxchange.com/products/RT-2.5.cfm
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/16/2019 01:57 am
This may be an optical illusion, but one photo, IMG_6080 (2).JPG (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1922304#msg1922304) convinced me the curved sections are not tank dome parts, but nose cone sections. They look like dome sections from other angles, but this particular angle shows very convincingly they're section of a cone with a ~60 degree slope. So right now I'm firmly in the "this is a new hopper fairing" camp.
One bit of observation to add further confusion - I had thought the onion sections were covered in the protective film we’ve seen, but BCGals photos seem to show that’s not the case - so they don’t appear to be the highly polished stainless the the cylinders are made from.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/16/2019 01:58 am
To hear the sound which is of current interest you could use a 1978 Mr. Microphone from a garage sale, just throw it in the weeds somewhere.  Parabolic, diabolic, convergent, divergent, buried, wouldn't matter.

I was just thinking that all this video surveillance is great, but can we hear what they're saying?

Dude, all you're gonna hear is "give me that hammer", "Weld That", "bolt this", Bolt that"...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: niwax on 03/16/2019 02:04 am
To hear the sound which is of current interest you could use a 1978 Mr. Microphone from a garage sale, just throw it in the weeds somewhere.  Parabolic, diabolic, convergent, divergent, buried, wouldn't matter.

I was just thinking that all this video surveillance is great, but can we hear what they're saying?

Dude, all you're gonna hear is "give me that hammer", "Weld That", "bolt this", Bolt that"...
"Damn cameras"
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/16/2019 02:29 am
 Except for one Alpha Hotel from South Padre, people have been pretty careful not to get too invasive.
 Personally, I believe in showing respect for any next door neighbor who has the equivalent of a small nuke in explosive substances stashed on his property.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WindyCity on 03/16/2019 02:57 am
The real thing will have payload and have to survive coming in from BEO. The test model will have less than half the total heat load. Not sure about peak load.

So are you suggesting than an orbital test vehicle could survive reentry from LEO without having transpiration cooling? What would shield it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: targon on 03/16/2019 03:15 am
The real thing will have payload and have to survive coming in from BEO. The test model will have less than half the total heat load. Not sure about peak load.

So are you suggesting than an orbital test vehicle could survive reentry from LEO without having transpiration cooling? What would shield it?

Less aggressive reentry would allow it. It would consume more fuel though. Cooling needed to save fuel while utilizing atmosphere to slow down the spacecraft.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 03/16/2019 03:34 am
>
And how do you add actuated fins to it...

Unless they've switched to extendable slats and fins in the "Y" configuration  for drag control. ISTM they'd use way less power.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/16/2019 04:10 am
The real thing will have payload and have to survive coming in from BEO. The test model will have less than half the total heat load. Not sure about peak load.

So are you suggesting than an orbital test vehicle could survive reentry from LEO without having transpiration cooling? What would shield it?
Nope. Just saying it would be easier than the real thing will have to handle.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/16/2019 06:03 am
This may be an optical illusion, but one photo, IMG_6080 (2).JPG (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1922304#msg1922304) convinced me the curved sections are not tank dome parts, but nose cone sections. They look like dome sections from other angles, but this particular angle shows very convincingly they're section of a cone with a ~60 degree slope. So right now I'm firmly in the "this is a new hopper fairing" camp.

Pity. You was probably the first (https://forum.nasaspaceflight.com/index.php?topic=47301.msg1913882#msg1913882) who suggested that the new sections belong to the new ship. And now you're giving up your glory  :(

No, the curved sections are not the fairing nose, but the bulkhead, the lower conical head of the methane tank. It will be installed inside the cylindric section, which is now on the concrete jig, with a conical end down.

Even the leader of the New Hopper Fairing camp Johnnyhinbos noticed that the curved sections are not polished, that is, will not be exposed...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ShSch on 03/16/2019 06:55 am
This is what Elon had to say back in January about temperatures encountered by SS during a reentry from LEO. So they might not need any active cooling on a suborbital flight. Or they might have to cool only 20% of the surface, those that we didn't see yet (leading edges?). Perhaps someone with better knowledge of physics than me can estimate the highest entry velocity that would keep things below 1450K.
January 23, 2019 (https://twitter.com/elonmusk/status/1088091464909766656?ref_src=twsrc%5Etfw)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/16/2019 07:18 am
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.
Wouldn't a full-scale "orbital test vehicle" have to have a fuselage engineered for transpiration cooling? Is there any indication that the structure under construction at BC (not referring to the hopper) shows that feature?
Nope, and that's part of the conundrum...

Elon has already said that you will need to be close to see the holes. Some of the steel sheets may have been pre-perforated. The distribution system may be internal and therefore not have been fitted yet.

It would be boring if it was too easy!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: guckyfan on 03/16/2019 08:43 am
Elon has already said that you will need to be close to see the holes. Some of the steel sheets may have been pre-perforated. The distribution system may be internal and therefore not have been fitted yet.

It would be boring if it was too easy!

There will be a sandwich structure to circulate the methane. I would expect sandwich plates made in a factory setting and then installed as part of the rocket body on site. No indication of that visible yet.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/16/2019 08:46 am
Seems to have been a lot of speculation that they might be building a second hopper or orbital test vehicle due to the appearance of what look like dome bulkhead like steel segments.

Are we absolutely sure that they have already installed 3 pressure bulk heads inside the existing hopper? Or have they just installed 2 for the lox tank + some support structures for the Raptor below it? If so could the dome segments we can now see be the missing 3rd bulkhead - the top of the methane tank? This tank might extend up into the lower portion of the "hat" cylinder.

If this is correct then we should see the dome installed into the hat cylinder pointing up in the lower half of the hat cylinder then attached to the top of the hopper base (or may be attach the hat cylinder and then install the third bulkhead. Finally attach a proper hat nose cone to form a full scale Starship hopper.
You might want to think that one through a bit more. Then look at the existing dome, perhaps the vent. You might get your answer. :-)

Another possibility - they need to pressurise the new taller hat to give it stability and strength in flight? So they put a dome at the top of the cylinder right under the pointy bit and pressurize the whole thing to several bar?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/16/2019 10:39 am
This is what Elon had to say back in January about temperatures encountered by SS during a reentry from LEO. So they might not need any active cooling on a suborbital flight. Or they might have to cool only 20% of the surface, those that we didn't see yet (leading edges?). Perhaps someone with better knowledge of physics than me can estimate the highest entry velocity that would keep things below 1450K.
January 23, 2019 (https://twitter.com/elonmusk/status/1088091464909766656?ref_src=twsrc%5Etfw)
Welcome to the forum. You're right to say they might not need any cooling on a suborbital flight. One of the problems they face is the difficulty in accurately modelling the hypersonic environment high in the atmosphere. So I would expect an incremental approach which slowly ramped up the temperature and stress by flying higher and faster each time. By the time they're at the limit of what they can do without cooling they can add some modest cooling units and push things a little further. Eventually their models will be improved and they will have a better understanding of how to build the final heat shield
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lord of Night on 03/16/2019 10:45 am

Even the leader of the New Hopper Fairing camp Johnnyhinbos noticed that the curved sections are not polished, that is, will not be exposed...

I was skeptical until now, but that's the best argument in favor of a "not a new fairing nos4"
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/16/2019 11:40 am
This is what Elon had to say back in January about temperatures encountered by SS during a reentry from LEO. So they might not need any active cooling on a suborbital flight. Or they might have to cool only 20% of the surface, those that we didn't see yet (leading edges?). Perhaps someone with better knowledge of physics than me can estimate the highest entry velocity that would keep things below 1450K.
January 23, 2019 (https://twitter.com/elonmusk/status/1088091464909766656?ref_src=twsrc%5Etfw)
Welcome to the forum. You're right to say they might not need any cooling on a suborbital flight. One of the problems they face is the difficulty in accurately modelling the hypersonic environment high in the atmosphere. So I would expect an incremental approach which slowly ramped up the temperature and stress by flying higher and faster each time. By the time they're at the limit of what they can do without cooling they can add some modest cooling units and push things a little further. Eventually their models will be improved and they will have a better understanding of how to build the final heat shield
It would also be just a thin walled tank with cryo fluid behind it. The steel will be cooled by evaporating fuel and oxygen. As long as they can dump the gas overboard it might do surprisingly well. so it will take a certain heat flux to heat it past the critical temp. Is it possible it could do LEO without transpiration cooling? Just a plain old "hot structure"?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rsdavis9 on 03/16/2019 11:46 am

It would also be just a thin walled tank with cryo fluid behind it. The steel will be cooled by evaporating fuel and oxygen. As long as they can dump the gas overboard it might do surprisingly well. so it will take a certain heat flux to heat it past the critical temp. Is it possible it could do LEO without transpiration cooling? Just a plain old "hot structure"?

Yes!

That was one of my first suggestions of how to cool for reentry.
Maybe some way to spray liquid methane(or liquid oxygen) internally to cool the inside.
Could go a long way to surviving reentry temps. And if nothing else will provide lots of data of how to proceed to the next level.
Extremely KISS.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/16/2019 11:55 am

Even the leader of the New Hopper Fairing camp Johnnyhinbos noticed that the curved sections are not polished, that is, will not be exposed...

I was skeptical until now, but that's the best argument in favor of a "not a new fairing nos4"

That and the fact that it has about four times the curvature than the graceful fairing, and would frankly look silly!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/16/2019 01:01 pm
I guess they're installing one of the side engines, first?  :o

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/16/2019 01:04 pm
I guess they're installing one of the side engines, first?  :o

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406 (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406)
I wonder if they'll use this engine for test fitting all three locations then finalize it in the center spot.

Also - BCGal - any new developments at the build site with the cylinders and the relocated onion sections?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: TorenAltair on 03/16/2019 01:26 pm
I guess they're installing one of the side engines, first?  :o

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406

Should be no problem, when they tie the hopper to the ground so they can test the system as a whole. Just add the next Raptor in ~2 Weeks in the center.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: targon on 03/16/2019 01:29 pm

It would also be just a thin walled tank with cryo fluid behind it. The steel will be cooled by evaporating fuel and oxygen. As long as they can dump the gas overboard it might do surprisingly well. so it will take a certain heat flux to heat it past the critical temp. Is it possible it could do LEO without transpiration cooling? Just a plain old "hot structure"?

Yes!

That was one of my first suggestions of how to cool for reentry.
Maybe some way to spray liquid methane(or liquid oxygen) internally to cool the inside.
Could go a long way to surviving reentry temps. And if nothing else will provide lots of data of how to proceed to the next level.
Extremely KISS.

I believe, transpirationally supplied methane burns in the atmosphere and creates a layer of plasma shielding ss from high temperatures. Similar effect is utilized in landing capsules without methane.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Restless on 03/16/2019 02:04 pm
So now thanks to one of BCGal's pics, we see a converted liquid N2 tank has been filled with LOX, and also one of Austin Barnard's pics shows a Gen X LNG truck at the site. Test firing should begin soon!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Rondaz on 03/16/2019 02:46 pm
SpaceX Confirms Test Launch of Rocket Prototype Days Away

March 15, 2019 2:19 PM in News

By: Daisy Martinez

https://www.krgv.com/news/spacex-confirms-test-launch-of-rocket-prototype-days-away/
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/16/2019 02:57 pm
I guess they're installing one of the side engines, first?  :o

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406

That's certainly a surprise, but hardly my first.  I had figured that 3 & 4 would get more extensive tests and tuning at McGregor, but it sure looks like they'll be going in sooner rather than later.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/16/2019 03:03 pm
Seems the local news still need to learn the difference between a static fire and a launch, but i like how they seem to try to be impartial and informative, neither hyping it up nor being alarmist.

And if the first ignition really comes today, that would be awesome. :D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Stan-1967 on 03/16/2019 03:30 pm
Following the assembly of the Hopper make me think this thread could be merged into the "Steampunk Mars" thread that died out a few months back. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/16/2019 04:00 pm
I guess they're installing one of the side engines, first?  :o

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406

Two mysteries; the first Raptor is mounted in a side position, and there is no obvious means of roll control for the vehicle. Possible answer; the engines may be the only means of roll control and therefore the hopper cannot fly unless at least the two outer engines are fitted. Simples?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureMartian97 on 03/16/2019 04:10 pm
I guess they're installing one of the side engines, first?  :o

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406

Two mysteries; the first Raptor is mounted in a side position, and there is no obvious means of roll control for the vehicle. Possible answer; the engines may be the only means of roll control and therefore the hopper cannot fly unless at least the two outer engines are fitted. Simples?

It's centered now.

Raptor has been moved into position.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/16/2019 04:24 pm
So now thanks to one of BCGal's pics, we see a converted liquid N2 tank has been filled with LOX, and also one of Austin Barnard's pics shows a Gen X LNG truck at the site. Test firing should begin soon!
LNG trucks can hold any of the cryo fluids. You have to look for the actual Methane of N2 or LOX label to tell which. The vertial LOX and LN2 tanks are both mainly marketed as LNG tanks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/16/2019 04:27 pm

Even the leader of the New Hopper Fairing camp Johnnyhinbos noticed that the curved sections are not polished, that is, will not be exposed...

I was skeptical until now, but that's the best argument in favor of a "not a new fairing nos4"

That and the fact that it has about four times the curvature than the graceful fairing, and would frankly look silly!

The polished thing is not a deal breaker, the current top dome of the hopper was not polished either, but they found ways to attach shiny sheets on it to make it look like polished.

As for the curvature, I think there is a high probability that they redesigned it this way. If I'm not mistaken, gradually curved nose is easier to do in composite, but hard to do in metal, so it's possible they redesigned the nose to be shorter after switching to steel just so that it's easier to manufacture. A shorter nose also means more useful payload volume, probably makes payload bay door easier to design/build too. The only drawback is higher heat flux during reentry, but with active cooling they can route more coolant to this area to compensate.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Coastal Ron on 03/16/2019 05:08 pm
I guess they're installing one of the side engines, first?  :o

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406

Two mysteries; the first Raptor is mounted in a side position...

They may be doing fit checks for all of the positions using this first engine. Best to find out any mounting problems now, when you only have one engine you have to move around.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 03/16/2019 05:58 pm
Another pic of the liquid oxygen delivery. I am sure the tall tank on the right had previously been marked liquid nitrogen.
i assumed they produced LOX and nitrogen on site by cooling air.
Yes this might not been installed yet, I assume they want an plant large enough for operational use then they install it. They need larger tanks to, tanks the size of an full rocket or more.
it might be some other thing they are welding. inner tank, insulation and outer shell.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 03/16/2019 06:13 pm
I guess they're installing one of the side engines, first?  :o

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406 (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406)
I wonder if they'll use this engine for test fitting all three locations then finalize it in the center spot.

Also - BCGal - any new developments at the build site with the cylinders and the relocated onion sections?

I have not been paying much attention to what has been going on with the cylinders. Too busy with Raptor. With the windy and wet weather we have been having the last few days there has been no more panels added. Posted a couple pics of the tapered sections.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/16/2019 06:21 pm
I guess they're installing one of the side engines, first?  :o

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406 (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923406#msg1923406)
I wonder if they'll use this engine for test fitting all three locations then finalize it in the center spot.

Also - BCGal - any new developments at the build site with the cylinders and the relocated onion sections?

I have not been paying much attention to what has been going on with the cylinders. Too busy with Raptor. With the windy and wet weather we have been having the last few days there has been no more panels added. Posted a couple pics of the tapered sections.

Copy that - forgot you guys are experiencing an arctic vortex...

BTW, I figured out what those tapered sections are...

https://forum.nasaspaceflight.com/index.php?topic=42585.msg1923501#msg1923501

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/16/2019 06:26 pm
Forgive me.  Catching up.  Lots of structural steel beams, claddding (?), and metal roofing panels visible in BCG's latest pictures.    A few glimpses in earlier pictures but didn't see anything mentioned here in that timeframe.

Discussed yet?
https://forum.nasaspaceflight.com/index.php?topic=47120.msg1923489#msg1923489
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/16/2019 06:34 pm
Jup. At least 3 running theories, from new tent to permanent metal building to Super Heavy structural reenforcement parts. With permanent metal building the leading theory right now.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/16/2019 07:01 pm
Jup. At least 3 running theories, from new tent to permanent metal building to Super Heavy structural reenforcement parts. With permanent metal building the leading theory right now.

Recently?  I only found some discussion from around the 11th with a grainy aerial photo.  BCG's last (cropped here) seem to settle the issue as Permanent Bldg IMO.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OldPeopleBurning on 03/16/2019 07:31 pm

Even the leader of the New Hopper Fairing camp Johnnyhinbos noticed that the curved sections are not polished, that is, will not be exposed...

I was skeptical until now, but that's the best argument in favor of a "not a new fairing nos4"

That and the fact that it has about four times the curvature than the graceful fairing, and would frankly look silly!

Also, the lift points seem permanent and are on the inside of the curves. I'm guessing the pieces are intended to be moved pointy side down otherwise the chains will rub on the edges.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/16/2019 07:48 pm

Even the leader of the New Hopper Fairing camp Johnnyhinbos noticed that the curved sections are not polished, that is, will not be exposed...

I was skeptical until now, but that's the best argument in favor of a "not a new fairing nos4"

That and the fact that it has about four times the curvature than the graceful fairing, and would frankly look silly!

Also, the lift points seem permanent and are on the inside of the curves. I'm guessing the pieces are intended to be moved pointy side down otherwise the chains will rub on the edges.

The parts look like they combine into the protrusion for the header tanks seen on the lower bulkhead of Starship in the cutaway drawings.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 03/16/2019 08:00 pm

Even the leader of the New Hopper Fairing camp Johnnyhinbos noticed that the curved sections are not polished, that is, will not be exposed...

I was skeptical until now, but that's the best argument in favor of a "not a new fairing nos4"

That and the fact that it has about four times the curvature than the graceful fairing, and would frankly look silly!

Also, the lift points seem permanent and are on the inside of the curves. I'm guessing the pieces are intended to be moved pointy side down otherwise the chains will rub on the edges.

The parts look like they combine into the protrusion for the header tanks seen on the lower bulkhead of Starship in the cutaway drawings.

If so, then it seems to make the case this is the "Starship Mk 1 orbital design" propulsion module. With the San Pedro Sprung structure folding those parts had to go somewhere.

https://twitter.com/elonmusk/status/1076611280700530688
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/16/2019 09:34 pm
We've missed the early opportunity but its not too late its something we need to get to.  How's about some of the engineers here work together to make some toys for our field team?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/16/2019 09:43 pm
I always wondered how those remote cams trigger. Light from rocket flame? Sound? Timer? Radio?

But the fact that the Hopper has the shiny glued on stuff mostly on one side of the dome makes me think that SpaceX is going to do at least one static fire photoshoot while it is still hatless. So may not need remote cameras. Hm. I wonder if professional rocket photographers have already called up SpaceX and asked for remote camera setup opportunities for Boca Chica first static fires/hops.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/16/2019 09:50 pm
The way I'm hoping it is is that you don't need no stinkin permission.  This ain't no air force base.  There's a public beach, ocean, non-SpaceX land surrounding it.  Not trying to be an *** about it but when you decide to do the coolest thing around right next to a public road you aren't really trying for privacy.  Exhibitionism needs accomplices.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/16/2019 10:02 pm
I always wondered how those remote cams trigger. Light from rocket flame? Sound? Timer? Radio?

But the fact that the Hopper has the shiny glued on stuff mostly on one side of the dome makes me think that SpaceX is going to do at least one static fire photoshoot while it is still hatless. So may not need remote cameras. Hm. I wonder if professional rocket photographers have already called up SpaceX and asked for remote camera setup opportunities for Boca Chica first static fires/hops.
Sound activated. Ask Vaporcobra...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/16/2019 10:11 pm
I'm figuring with only the one single engine mounted... it will always be tied down and just be restrained static fires...
They got no roll control to go flying with...  :P

BUT... once they hang two more Raptor's on this "water tower"... things WILL get more interesting...
Full control in roll, pitch, yaw... check
Excess power to climb away with gusto... check

That will be the day that remote cameras will be needed..
 8)

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/16/2019 10:12 pm
I'm figuring with only the one single engine mounted... it will always be tied down and just be restrained static fires...
They got no roll control to go flying with...  :P

BUT... once they hang two more Raptor's on this "water tower"... things WILL get more interesting...
Full control in roll, pitch, yaw... check
Excess power to climb away with gusto... check

 8)

Grasshopper flew with one engine.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: mwood on 03/16/2019 10:21 pm
I'm figuring with only the one single engine mounted... it will always be tied down and just be restrained static fires...
They got no roll control to go flying with...  :P

BUT... once they hang two more Raptor's on this "water tower"... things WILL get more interesting...
Full control in roll, pitch, yaw... check
Excess power to climb away with gusto... check

 8)

Grasshopper flew with one engine.

One gimbaled engine will give full control except roll. Thrusters could solve that but I don't think there has been any evidence of thrusters, yet.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Robotbeat on 03/16/2019 10:43 pm
SpaceX Confirms Test Launch of Rocket Prototype Days Away

March 15, 2019 2:19 PM in News

By: Daisy Martinez

https://www.krgv.com/news/spacex-confirms-test-launch-of-rocket-prototype-days-away/
1) That old couple is super cute.
2) "and hops will not be visible from offsite" LOL, SpaceX, you underestimate the power of our space stanning.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/16/2019 11:10 pm
The way I'm hoping it is is that you don't need no stinkin permission.  This ain't no air force base.  There's a public beach, ocean, non-SpaceX land surrounding it.  Not trying to be an *** about it but when you decide to do the coolest thing around right next to a public road you aren't really trying for privacy.  Exhibitionism needs accomplices.
Good point. You shouldnt really need permission. However cant hurt to have some help from SpaceX, like knowing when to set up remote cameras so you do not have to leave em standing around for long periods in areas that anyone can access. And for really close up shots, you would have to put em on SpaceX's dirt mound.

But if SpaceX has to announce each static fire time window, then i guess nothing is stopping remote camera placement at good times and good place. :D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/16/2019 11:55 pm
I'm figuring with only the one single engine mounted... it will always be tied down and just be restrained static fires...
They got no roll control to go flying with...  :P

Not true. That problem was solved back in the 90s by the Rotary Rocket Corporation and their solution could be cut and pasted onto the current hopper. It would look like the picture below. Grabbing a tail rotor from an aircraft scrapyard and welding it to the hopper would take less time than waiting to get the next Raptor(s) especially given the number of welders that are there already.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/16/2019 11:57 pm
Grabbing a tail rotor from an aircraft scrapyard and welding it to the hopper would take less time than waiting to get the next Raptor(s) especially given the number of welders that are there already.

This is wrong on so many levels.   :D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Gliderflyer on 03/17/2019 12:12 am
Not true. That problem was solved back in the 90s by the Rotary Rocket Corporation and their solution could be cut and pasted onto the current hopper. It would look like the picture below.
The Roton ATV didn't have a tail rotor and used thrusters mounted to the side for axial roll control (which I guess would be yaw from the pilots perspective?). I assume they were peroxide monoprop, but I don't know for sure.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/17/2019 12:14 am
Oh.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/17/2019 12:24 am
SpaceX Confirms Test Launch of Rocket Prototype Days Away

March 15, 2019 2:19 PM in News

By: Daisy Martinez

https://www.krgv.com/news/spacex-confirms-test-launch-of-rocket-prototype-days-away/
1) That old couple is super cute.
2) "and hops will not be visible from offsite" LOL, SpaceX, you underestimate the power of our space stanning.
Bonnie isn't that short. Terry could have played Chewbacca.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WindyCity on 03/17/2019 12:28 am
This is what Elon had to say back in January about temperatures encountered by SS during a reentry from LEO. So they might not need any active cooling on a suborbital flight. Or they might have to cool only 20% of the surface, those that we didn't see yet (leading edges?). Perhaps someone with better knowledge of physics than me can estimate the highest entry velocity that would keep things below 1450K.
January 23, 2019 (https://twitter.com/elonmusk/status/1088091464909766656?ref_src=twsrc%5Etfw)

Elon's tweet appears to answer my question. Thanks. It seems amazing to me that no active shielding would be necessary for reentry from LEO. The grade of stainless steel they're using is hardy stuff. I wonder how much margin the spacecraft would have for off-nominal reentry angles or orientation.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JonathanD on 03/17/2019 12:46 am
Elon's tweet appears to answer my question. Thanks. It seems amazing to me that no active shielding would be necessary for reentry from LEO. The grade of stainless steel they're using is hardy stuff. I wonder how much margin the spacecraft would have for off-nominal reentry angles or orientation.

They will have active shielding, but that doesn't mean a heat shield.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HMXHMX on 03/17/2019 12:54 am
Not true. That problem was solved back in the 90s by the Rotary Rocket Corporation and their solution could be cut and pasted onto the current hopper. It would look like the picture below.
The Roton ATV didn't have a tail rotor and used thrusters mounted to the side for axial roll control (which I guess would be yaw from the pilots perspective?). I assume they were peroxide monoprop, but I don't know for sure.

They were. Three of the rotor tip thrusters were used, mounted on a movable plate connected to the rudder pedals by cables.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: groundbound on 03/17/2019 01:43 am
Not true. That problem was solved back in the 90s by the Rotary Rocket Corporation and their solution could be cut and pasted onto the current hopper. It would look like the picture below.
The Roton ATV didn't have a tail rotor and used thrusters mounted to the side for axial roll control (which I guess would be yaw from the pilots perspective?). I assume they were peroxide monoprop, but I don't know for sure.

They were. Three of the rotor tip thrusters were used, mounted on a movable plate connected to the rudder pedals by cables.

I'm waiting for someone to claim that you don't have a good source for this information.  ;D ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/17/2019 02:46 am
This classes as an update (via L2).

Boca Chica locals told there will be a safety perimeter - via roadblocks - around the SpaceX site NET next week per upcoming "testing".

This suggests Static Fire testing on Starship Hopper may be upcoming, now Raptor is installed.

What are we going to do about those green nylon hold down straps?  Still present in the latest pictures.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 03/17/2019 03:44 am
Elon's tweet appears to answer my question. Thanks. It seems amazing to me that no active shielding would be necessary for reentry from LEO. The grade of stainless steel they're using is hardy stuff. I wonder how much margin the spacecraft would have for off-nominal reentry angles or orientation.

They will have active shielding, but that doesn't mean a heat shield.

If it's not a heat shield, what's the "active shielding" shielding? :^)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rakaydos on 03/17/2019 04:09 am
Not true. That problem was solved back in the 90s by the Rotary Rocket Corporation and their solution could be cut and pasted onto the current hopper. It would look like the picture below.
The Roton ATV didn't have a tail rotor and used thrusters mounted to the side for axial roll control (which I guess would be yaw from the pilots perspective?). I assume they were peroxide monoprop, but I don't know for sure.

They were. Three of the rotor tip thrusters were used, mounted on a movable plate connected to the rudder pedals by cables.

I'm waiting for someone to claim that you don't have a good source for this information.  ;D ;D
I take it from context that HMXHMX worked on Roton? I've occasionally seen the design referenced, but it doesnt have the popular culture presence that rocket-rockets have.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/17/2019 04:46 am
I'm figuring with only the one single engine mounted... it will always be tied down and just be restrained static fires...
They got no roll control to go flying with...  :P

BUT... once they hang two more Raptor's on this "water tower"... things WILL get more interesting...
Full control in roll, pitch, yaw... check
Excess power to climb away with gusto... check

 8)

Grasshopper flew with one engine.

Grasshopper has cold gas thrusters for roll control: https://twitter.com/elonmusk/status/264832219040845824

I think the hopper will have them too, it's what the two red COPVs are for. And I bet the fairing and thrusters will be installed before the other two Raptors, and they'll just hop it using one Raptor at first. Raptors are easily the most expensive part on this thing, no need to risk 3 at the same time when you can fly with one.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/17/2019 05:24 am
My latest guesses, and why..

1)The red COPV's... one is high pressure gaseous oxygen and one high pressure gaseous methane...
   Act as startup sources for the Raptor's preburners and as high pressure reservoirs keeping same fed.
    Tapped thru major pressure drop regulators to provide the low tank head pressures.
     Kept at full pressure by Raptor(s) when they are running.

2)We have had eyes on hopper all thru build and there is no hint of thruster plumbing or placement that I have seen.
   Hence my guess, that they will NOT install any thrusters on Hopper 1 and not free flight it till 3 Raptors are installed.
    Thrusters are really not needed in the flight envelope as defined for this machine
     Demo of three engine, full 4 axis flight control DOES seem to be a Hopper 1 demo goal IMHO.
      Force issue by no freeflight till 3 Raptors in place and No back up thrusters for roll control installed
       Single engine hops of inches or up to the stretch of the tie-downs for now, is all we may see or hear.
        The pits the tie-downs are in MAY allows several feet of travel if I understood a construction pic seen a while back

3) Hopper 1 will never get a fairing now IMHO...
     No time to waste now, after the "show" one was lost in the wind storm
      What it has now (zip ties and all that) should work fine to fly at up to at least 200 knots IMHO.
       For what it is... It's purpose... It's reason to exist... It does not need any more.

Time will tell... If I'm right or wrong...  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ShSch on 03/17/2019 06:16 am
Welcome to the forum. You're right to say they might not need any cooling on a suborbital flight. One of the problems they face is the difficulty in accurately modelling the hypersonic environment high in the atmosphere. So I would expect an incremental approach which slowly ramped up the temperature and stress by flying higher and faster each time. By the time they're at the limit of what they can do without cooling they can add some modest cooling units and push things a little further. Eventually their models will be improved and they will have a better understanding of how to build the final heat shield
Thank you. This was more or less my point. Without knowing the exact relation between the entry velocity and the surface temperature, I would haphazard a guess that they can reach up to 80-90% of the orbital velocity without needing an active cooling. By the time they reach such speeds in their testing, they are going to have a new higher fidelity prototype available.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureSpaceTourist on 03/17/2019 07:15 am
https://twitter.com/rogerlewisholt/status/1107191861108764673

Quote
Here is a composite image I just put together. It shows the 2 new sections of Hopper nose cone next to the old nose cone. This combined straight section is clearly taller than on the original nose cone. @John_Gardi @Avron_p @maximiliklinger
📷source photos by @austinbarnard45

Of course it may be that the two sections under construction don’t go together, but interesting to see how tall they now are.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/17/2019 09:31 am
Added full-size starship for comparison.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kclay on 03/17/2019 01:11 pm
1st time posting to this forum, but been following with great interest.  Regarding the mystery dome under construction, I put together a best guess for how the shape might extrapolate to a finished form, and how that would fit if the 2 cylindrical sections were stacked on the hopper.  Not seeing how it would work as a bottom tank dome if my scaling is anything close to correct.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/17/2019 01:30 pm
1st time posting to this forum, but been following with great interest.  Regarding the mystery dome under construction, I put together a best guess for how the shape might extrapolate to a finished form, and how that would fit if the 2 cylindrical sections were stacked on the hopper.  Not seeing how it would work as a bottom tank dome if my scaling is anything close to correct.
First post - and first like! 

Great first post - you contributed with something of value, a nice visualization.

I wonder if the foil that was attached to a section of the dome was a test to see how it looked, because they may have had to change materials for the tapering section of the fairing for whatever reason (this is pure speculation and I don’t attribute it with much confidence), and therefore had to use non-polished stainless...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 03/17/2019 02:07 pm
My latest guesses, and why..

1)The red COPV's... one is high pressure gaseous oxygen and one high pressure gaseous methane...
   Act as startup sources for the Raptor's preburners and as high pressure reservoirs keeping same fed.
    Tapped thru major pressure drop regulators to provide the low tank head pressures.
     Kept at full pressure by Raptor(s) when they are running.

2)We have had eyes on hopper all thru build and there is no hint of thruster plumbing or placement that I have seen.
   Hence my guess, that they will NOT install any thrusters on Hopper 1 and not free flight it till 3 Raptors are installed.
    Thrusters are really not needed in the flight envelope as defined for this machine
     Demo of three engine, full 4 axis flight control DOES seem to be a Hopper 1 demo goal IMHO.
      Force issue by no freeflight till 3 Raptors in place and No back up thrusters for roll control installed
       Single engine hops of inches or up to the stretch of the tie-downs for now, is all we may see or hear.
        The pits the tie-downs are in MAY allows several feet of travel if I understood a construction pic seen a while back

3) Hopper 1 will never get a fairing now IMHO...
     No time to waste now, after the "show" one was lost in the wind storm
      What it has now (zip ties and all that) should work fine to fly at up to at least 200 knots IMHO.
       For what it is... It's purpose... It's reason to exist... It does not need any more.

Time will tell... If I'm right or wrong...  ;)
Agree on the two first but not the last, the fairing is not needed for short hover tests but important for high attitude ones as it it provide stability especially on decent. without the fairing air resistance will probably go down if it tilt to the side, with the fairing air resistance will go up as failing will generate drag.

Yes you can compensate with the engines but this will require trust all the time. pretty sure the will fly with engine off part of the flights.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OTV Booster on 03/17/2019 02:08 pm
1st time posting to this forum, but been following with great interest.  Regarding the mystery dome under construction, I put together a best guess for how the shape might extrapolate to a finished form, and how that would fit if the 2 cylindrical sections were stacked on the hopper.  Not seeing how it would work as a bottom tank dome if my scaling is anything close to correct.


Welcome to the forum.

I’m a bulkheader, not a noseconer and have to agree the lines don’t quite match up for a bulkhead but there are a couple visual effects that make that thingie look more cone shaped than it really is.

1. The edge is not quite square on to the camera making it look a tad more verticle than it really is. If you picture it rotated further so it is at a right angle to the view line it would look straight up and down. Rotate it so it’s edge on and not quite so steep.
2. When they butt two of these together I think we’ll see curved edges well mated up but the tapered sections will show gaps and need to be pulled in to mate. This will bring it in to a more rounded shape. The truncation is where the prop tanks for landing will protrude. Probably not perfictly spherical but - just a guess- with the small tank protruding an elipsoid will distribute tensional stress best. Expert input most welcome here.


But then on the gripping hand I might just be seeing what I expect to see.


Phil
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HMXHMX on 03/17/2019 02:14 pm
Not true. That problem was solved back in the 90s by the Rotary Rocket Corporation and their solution could be cut and pasted onto the current hopper. It would look like the picture below.
The Roton ATV didn't have a tail rotor and used thrusters mounted to the side for axial roll control (which I guess would be yaw from the pilots perspective?). I assume they were peroxide monoprop, but I don't know for sure.

They were. Three of the rotor tip thrusters were used, mounted on a movable plate connected to the rudder pedals by cables.

I'm waiting for someone to claim that you don't have a good source for this information.  ;D ;D
I take it from context that HMXHMX worked on Roton? I've occasionally seen the design referenced, but it doesnt have the popular culture presence that rocket-rockets have.

Yes, I was CEO of the company.  But let's not take this discussion further afield; there is always PM for followup.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OTV Booster on 03/17/2019 02:46 pm
My latest guesses, and why..

     Demo of three engine, full 4 axis flight control DOES seem to be a Hopper 1 demo goal IMHO.
      Force issue by no freeflight till 3 Raptors in place

Time will tell... If I'm right or wrong...  ;)

Minor quibble. Raptors are a bottleneck. After tethered hops and the next engine shows up they could move the current engine to the side, install the 2nd opposite and boogie. Third engine extends the test envelope further when it shows up.

Keep moving. Pure SpaceX.

Phil
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/17/2019 04:10 pm
1st time posting to this forum, but been following with great interest.  Regarding the mystery dome under construction, I put together a best guess for how the shape might extrapolate to a finished form, and how that would fit if the 2 cylindrical sections were stacked on the hopper.  Not seeing how it would work as a bottom tank dome if my scaling is anything close to correct.

Scaling from the ‘Dear Moon’ cross section the aft skirt is around 10m long. The aft dome and barrel join will be at the top of the lower section rather than halfway up as you have drawn. From my rough scaling this gives around 3m clear at the bottom, conveniently close to the length of a Raptor.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: FutureSpaceTourist on 03/17/2019 05:11 pm
Another visualisation showing relative size with expected hopper & full size starship

https://twitter.com/rogerlewisholt/status/1107311137572487168

Quote
Here is another look at the sizes. @John_Gardi @Avron_p

Image constructed useing photos taken by @austinbarnard45
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/17/2019 06:20 pm
Another visualisation showing relative size with expected hopper & full size starship

https://twitter.com/rogerlewisholt/status/1107311137572487168

Quote
Here is another look at the sizes. @John_Gardi @Avron_p

Image constructed useing photos taken by @austinbarnard45
That would be a little better if it didn't have the concrete base in it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OTV Booster on 03/17/2019 07:10 pm
1st time posting to this forum, but been following with great interest.  Regarding the mystery dome under construction, I put together a best guess for how the shape eemight extrapolate to a finished form, and how that would fit if the 2 cylindrical sections were stacked on the hopper.  Not seeing how it would work as a bottom tank dome if my scaling is anything close to correct.

Scaling from the ‘Dear Moon’ cross section the aft skirt is around 10m long. The aft dome and barrel join will be at the top of the lower section rather than halfway up as you have drawn. From my rough scaling this gives around 3m clear at the bottom, conveniently close to the length eof a Raptor.

I’ve been trying to visualize the construction sequence of an orbital article and your post is a great help.

ISTM a full up SS Will be too tall to move like the hopper so it needs to move in sections. With the BC launch limitations I don’t know where it will go, but go it must. Here’s a first hack on build sequence.

Skirt with thrust structure, aft bulkhead and landing tanks. Next up the meth tank maybe w/common bulkhead. Then the lox tank w/upper bulkhead. The fins may span between sections and make moving more difficult so the pillow blocks (hinges) might go on and fins added later. What comes next depends on the variant.

Somebody suggested the tanker makes sense for the first orbital ship. It’s needed to test prop transfer and should be the easiest to build. Makes sense to me. There is no operational need to carry both props for mars refueling but it might make sense for lesser missions, so the final buildout could be done in two tank sections or one tank in two sections.

Total of five sections to be assembled elsewhere. Now if we just knew where elsewhere is...

Phil

PS. Sure would be convenient if they could move it to the pad and launch for the cape with a high loft, overshoot then retropulsion for an F9 RTLS profile. That and a FAA license and comment period. NOMADD you could make a killing selling/renting noise cancelling headphones and pet sized acustic isolation chambers.
Edit: typo
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/17/2019 07:13 pm
Elon confirms that the structures under construction in Boca Chica are the orbital Starship test article.

Quote
We decided to skip building a new nosecone for Hopper. Don’t need it. What you see being built is the orbital Starship vehicle.

https://twitter.com/elonmusk/status/1107373237208416256

https://twitter.com/elonmusk/status/1107374051410886656
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marokrile on 03/17/2019 07:14 pm
Elon twitt storm coming...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/17/2019 07:16 pm
Any evidence from the Cape that something is being built there?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/17/2019 07:20 pm
1st time posting to this forum, but been following with great interest.  Regarding the mystery dome under construction, I put together a best guess for how the shape eemight extrapolate to a finished form, and how that would fit if the 2 cylindrical sections were stacked on the hopper.  Not seeing how it would work as a bottom tank dome if my scaling is anything close to correct.

Scaling from the ‘Dear Moon’ cross section the aft skirt is around 10m long. The aft dome and barrel join will be at the top of the lower section rather than halfway up as you have drawn. From my rough scaling this gives around 3m clear at the bottom, conveniently close to the length eof a Raptor.

I’ve been trying to visualize the construction sequence of an orbital article and your post is a great help.

ISTM a full up SS Will be too tall to move like the hopper so it needs to move in sections. With the BC launch limitations I don’t know where it will go, but go it must. Here’s a first hack on build sequence.

Skirt with thrust structure, aft bulkhead and landing tanks. Next up the meth tank maybe w/common bulkhead. Then the lox tank w/upper bulkhead. The fins may span between sections and make moving more difficult so the pillow blocks (hinges) might go on and fins added later. What comes next depends on the variant.

Somebody suggested the tanker makes sense for the first orbital ship. It’s needed to test prop transfer and should be the easiest to build. Makes sense to me. There is no operational need to carry both props for mars refueling but it might make sense for lesser missions, so the final buildout could be done in two tank sections or one tank in two sections.

Total of five sections to be assembled elsewhere. Now if we just knew where elsewhere is...

Phil

PS. Sure would be convenient if they could move it to the pad and launch for the cape with a high loft, overshoot then retropulsion for an F9 RTLS profile. That and a FAA license and comment period. NOMADD you could make a killing selling/renting noise cancelling headphones and pet sized acustic isolation chambers.
Edit: typo
Looks like they will be building another orbital prototype in Florida in addition to the one currently under construction at Boca Chica.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/17/2019 07:23 pm
Alrighty then - the “cylinders are for the next prototype” camp folks are right!

Cheers to you - never a dull moment, and I couldn’t be happier to be wrong...!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/17/2019 07:26 pm
Finally - and this again is just my opinion - but I have to say it: There is a ZERO percent chance this thing will fly without the hat. Absolutely zero. To even suggest it shows a disconnect from what SpaceX is, and more specifically, who Elon is. From the beginning I had speculated they are building a mass / shape simulator for hop testing. And of course I still believe that. Not to mention adding some form of protection to the hardware on the dome. But all of that doesn't matter - it's so much more...

Elon is stating (and I am in 100% agreement) that what is happening in Boca Chica represents the very future of spaceflight - human exploration - Mars colonization - Moon returning - space tourism - and arguably the survival of humanity itself (go reread Tim Urban's most excellent blog post if you don't see that).  This is NOT "just another launch vehicle in its development cycle".

This is a statement. A globally-watched tentative first step on the path towards walking off this planet and onto another. This BFH is the very first manifestation of the Starship. Elon's Starship. And he ain't - no way no how - gonna fly it without a hat...


I've said this before (2/15/19), but I think I'll just go ahead and re-say it (and then be wrong, though I really doubt it).

"Finally - and this again is just my opinion - but I have to say it: There is a ZERO percent chance this thing will fly without the hat. Absolutely zero. To even suggest it shows a disconnect from what SpaceX is, and more specifically, who Elon is. From the beginning I had speculated they are building a mass / shape simulator for hop testing. And of course I still believe that. Not to mention adding some form of protection to the hardware on the dome. But all of that doesn't matter - it's so much more...

Elon is stating (and I am in 100% agreement) that what is happening in Boca Chica represents the very future of spaceflight - human exploration - Mars colonization - Moon returning - space tourism - and arguably the survival of humanity itself (go reread Tim Urban's most excellent blog post if you don't see that).  This is NOT "just another launch vehicle in its development cycle".

This is a statement. A globally-watched tentative first step on the path towards walking off this planet and onto another. This BFH is the very first manifestation of the Starship. Elon's Starship. And he ain't - no way no how - gonna fly it without a hat..."

https://forum.nasaspaceflight.com/index.php?topic=47301.msg1911741#msg1911741

(That's my diabolical highlighting)   ;D

https://twitter.com/elonmusk/status/1107373237208416256 (https://twitter.com/elonmusk/status/1107373237208416256)

edit: This was written at the same time as Johnnyhinbos' throwing in the towel above.  Its intended to be poking  fun at his position but not piling on afterward if that makes sense.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/17/2019 07:27 pm
Finally - and this again is just my opinion - but I have to say it: There is a ZERO percent chance this thing will fly without the hat. Absolutely zero. To even suggest it shows a disconnect from what SpaceX is, and more specifically, who Elon is. From the beginning I had speculated they are building a mass / shape simulator for hop testing. And of course I still believe that. Not to mention adding some form of protection to the hardware on the dome. But all of that doesn't matter - it's so much more...

Elon is stating (and I am in 100% agreement) that what is happening in Boca Chica represents the very future of spaceflight - human exploration - Mars colonization - Moon returning - space tourism - and arguably the survival of humanity itself (go reread Tim Urban's most excellent blog post if you don't see that).  This is NOT "just another launch vehicle in its development cycle".

This is a statement. A globally-watched tentative first step on the path towards walking off this planet and onto another. This BFH is the very first manifestation of the Starship. Elon's Starship. And he ain't - no way no how - gonna fly it without a hat...


I've said this before (2/15/19), but I think I'll just go ahead and re-say it (and then be wrong, though I really doubt it).

"Finally - and this again is just my opinion - but I have to say it: There is a ZERO percent chance this thing will fly without the hat. Absolutely zero. To even suggest it shows a disconnect from what SpaceX is, and more specifically, who Elon is. From the beginning I had speculated they are building a mass / shape simulator for hop testing. And of course I still believe that. Not to mention adding some form of protection to the hardware on the dome. But all of that doesn't matter - it's so much more...

Elon is stating (and I am in 100% agreement) that what is happening in Boca Chica represents the very future of spaceflight - human exploration - Mars colonization - Moon returning - space tourism - and arguably the survival of humanity itself (go reread Tim Urban's most excellent blog post if you don't see that).  This is NOT "just another launch vehicle in its development cycle".

This is a statement. A globally-watched tentative first step on the path towards walking off this planet and onto another. This BFH is the very first manifestation of the Starship. Elon's Starship. And he ain't - no way no how - gonna fly it without a hat..."

https://forum.nasaspaceflight.com/index.php?topic=47301.msg1911741#msg1911741

(That's my diabolical highlighting)   ;D

https://twitter.com/elonmusk/status/1107373237208416256 (https://twitter.com/elonmusk/status/1107373237208416256)
Yeah - nothing to see here, move along...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: joek on 03/17/2019 07:31 pm
Looks like they will be building another orbital prototype in Florida in addition to the one currently under construction at Boca Chica.

Related question: per Musk's tweet, where at "...Cape Kennedy, Florida"?  NB: Cape Kennedy, not CCAFS; assuming not a slip of the tongue.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/17/2019 07:32 pm
Yeah - nothing to see here, move along...

I've had styrofoam board moments myself.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/17/2019 07:34 pm
Yeah - nothing to see here, move along...

I've had styrofoam board moments myself.
No styrofoam, but there will be hexagonal "tiles" :o
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kclay on 03/17/2019 07:36 pm
Wow!  That clears up a lot of speculation.  So from the parts on hand, assuming the second cylinder gets another section, they build a third cylinder, and the old nosecone shape is rebuilt, it goes together something like this.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/17/2019 07:40 pm
Wow!  That clears up a lot of speculation.  So from the parts on hand, assuming the second cylinder gets another section, they build a third cylinder, and the old nosecone shape is rebuilt, it goes together something like this.
Yes - be interesting to see how that pans out, although aparently no nose cone is needed for the hopper!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/17/2019 07:55 pm
No styrofoam, but there will be hexagonal "tiles" :o

My styrofoam reference has to do with a contention of mine on L2 that turned out to be a whole bunch of wrong, nothing to do with heat resisting tiles.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/17/2019 07:58 pm
Raptor's coming.  Let's get ready to rumble!!!  First thing we need to do is to prepare BCV like there's gonna be an earthquake.  Because there's gonna be an earthquake.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 03/17/2019 07:59 pm
Alrighty then - the “cylinders are for the next prototype” camp folks are right!

Cheers to you - never a dull moment, and I couldn’t be happier to be wrong...!
Ok I was wrong :) still sees issues but I assume they have done simulations and wind tunnel test and not only played KSP like me :)

Still a bit weird. Should not the parts have two layers? or is the outer sweating layer added later.

I assumed they would start with the complex bottom part with "hexaweb" plumbing to the engines and other flight systems and trusters. skirt and probably some thermal protection as in extra layers of thin plates is probably enough to protect engines and other systems.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/17/2019 08:11 pm
Still a bit weird. Should not the parts have two layers? or is the outer sweating layer added later.

One of Elon's tweets this afternoon said transpiration cooling would only be needed in critical parts, not everywhere.  That seems reasonable to me for return from earth orbit but I'm surprised it also applies to returns from higher energies.

I've not been following the transpiration thread but my guesses on transpiration fall into two camps;
   a) that very thin panels will be tack welded over the main structure and that these thin panels won't be that much different from the shiny stainless that was put over the structure of hopper 1.  It won't be necessary to keep the thin outer layer below annealing temperature because no strength is required of it.  Perhaps those panels will be laser perfed or perhaps there'll be just one methane feed under each panel and bleed will happen at the edges of each sheet.
   b) Perhaps some wicking material (ceramic felt or similar) will be between the outer layer and the inner layer and the holes in the outer will be much larger than we had been lead to believe.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/17/2019 08:15 pm
Now that we know that the cylinders being built up are "real" and we seem to know that they're 1/4" or 6mm thick I think we need to reconsider the emphasis that we took from Elon's earlier tween that there would be a lot of structural reinforcement of the walls to allow it to stand without pressure.  To me it now looks as if there will be some but nowhere near as much as I think most of us envisioned.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HeartofGold2030 on 03/17/2019 08:30 pm
Now that we know that the cylinders being built up are "real" and we seem to know that they're 1/4" or 6mm thick I think we need to reconsider the emphasis that we took from Elon's earlier tween that there would be a lot of structural reinforcement of the walls to allow it to stand without pressure.  To me it now looks as if there will be some but nowhere near as much as I think most of us envisioned.

I wouldn't count your chickens too soon if I were you, they still haven't put anything into the cylinders yet, so I'd wait until the tanks are installed before making assumptions about the vehicle's structure.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jketch on 03/17/2019 08:33 pm
If the steel plates are truly 6mm thick, I don't know how they're going to acheive a good dry mass with SS. If they're still planning on making Starship 55m high and 9m in diameter, the mass of a 6mm thick cylinder is going to be 70 metric tons. That's without legs, engines, tanks, and whatever TPS they're going to need. It's really hard for me to see how it could possibly get to orbit on it's own with such a high dry mass. I guess it's possible they'll taper the steel higher up the structure.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: niwax on 03/17/2019 08:34 pm
Now that we know that the cylinders being built up are "real" and we seem to know that they're 1/4" or 6mm thick I think we need to reconsider the emphasis that we took from Elon's earlier tween that there would be a lot of structural reinforcement of the walls to allow it to stand without pressure.  To me it now looks as if there will be some but nowhere near as much as I think most of us envisioned.

I wouldn't count your chickens too soon if I were you, they still haven't put anything into the cylinders yet, so I'd wait until the tanks are installed before making assumptions about the vehicle's structure.

There's still the open question of header tanks for internal structure, too
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/17/2019 08:37 pm
IMHO... as of today and for now...
I am in the - Hopper 2 is just a much better Hopper (full size OML, more features, lessons learned to date) and NOT a production intent orbital capable item...
Still suborbital... Still a 5km (16,400 foot) flight level limited flying machine to start with...
They will likely last flight land Hopper 1 on the lower flat area there... Salvage it for Raptors, and other usable items... and scrap it in place... (assuming it never has a RUD moment during testing)

Now if/when Hopper 1 has a RUD/Wreck... then good thing Hopper 2 was already in work...  ;D

Now the flying machine mentioned as to be built in Florida by EM... THAT one will be the one that will be of most interest, and likely will see flight above the Karman Line first at some point...

;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/17/2019 08:41 pm
If the steel plates are truly 6mm thick, I don't know how they're going to acheive a good dry mass with SS. If they're still planning on making Starship 55m high and 9m in diameter, the mass of a 6mm thick cylinder is going to be 70 metric tons. That's without legs, engines, tanks, and whatever TPS they're going to need. It's really hard for me to see how it could possibly get to orbit on it's own with such a high dry mass. I guess it's possible they'll taper the steel higher up the structure.

It seems reasonable to envision it tapering, as Atlas did.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JH on 03/17/2019 08:48 pm
Still suborbital... Still a 5km (16,000 foot) flight level limited flying machine...

Musk disagrees...

https://twitter.com/elonmusk/status/1107373237208416256
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/17/2019 08:51 pm
Still suborbital... Still a 5km (16,000 foot) flight level limited flying machine...

Musk disagrees...

https://twitter.com/elonmusk/status/1107373237208416256

I took that tweet to mean full size OML with hard shell Hopper 2... LIKE the later Orbital class machine... IMHO
His main point of the tweet is the first two sentences... NOT a new nosecone for Hopper 1...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: GregTheGrumpy on 03/17/2019 08:55 pm
If the steel plates are truly 6mm thick, I don't know how they're going to acheive a good dry mass with SS. If they're still planning on making Starship 55m high and 9m in diameter, the mass of a 6mm thick cylinder is going to be 70 metric tons. That's without legs, engines, tanks, and whatever TPS they're going to need. It's really hard for me to see how it could possibly get to orbit on it's own with such a high dry mass. I guess it's possible they'll taper the steel higher up the structure.

I seem to recall that the SS weight trade off was that less internal structuring was needed than with CF.  It may not be all of it, but I understood it to be most of it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lord of Night on 03/17/2019 09:14 pm
Still suborbital... Still a 5km (16,000 foot) flight level limited flying machine...

Musk disagrees...

https://twitter.com/elonmusk/status/1107373237208416256

I took that tweet to mean full size OML with hard shell Hopper 2... LIKE the later Orbital class machine... IMHO
His main point of the tweet is the first two sentences... NOT a new nosecone for Hopper 1...

His main point is "What you see being built IS the orbital starship"
Not a hopper 2, the orbital ship.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OTV Booster on 03/17/2019 09:17 pm
1st time posting to this forum, but been following with great interest.  Regarding the mystery dome under construction, I put together a best guess for how the shape eemight extrapolate to a finished form, and how that would fit if the 2 cylindrical sections were stacked on the hopper.  Not seeing how it would work as a bottom tank dome if my scaling is anything close to correct.

Scaling from the ‘Dear Moon’ cross section the aft skirt is around 10m long. The aft dome and barrel join will be at the top of the lower section rather than halfway up as you have drawn. From my rough scaling this gives around 3m clear at the bottom, conveniently close to the length eof a Raptor.

I’ve been trying to visualize the construction sequence of an orbital article and your post is a great help.

ISTM a full up SS Will be too tall to move like the hopper so it needs to move in sections. With the BC launch limitations I don’t know where it will go, but go it must. Here’s a first hack on build sequence.

Skirt with thrust structure, aft bulkhead and landing tanks. Next up the meth tank maybe w/common bulkhead. Then the lox tank w/upper bulkhead. The fins may span between sections and make moving more difficult so the pillow blocks (hinges) might go on and fins added later. What comes next depends on the variant.

Somebody suggested the tanker makes sense for the first orbital ship. It’s needed to test prop transfer and should be the easiest to build. Makes sense to me. There is no operational need to carry both props for mars refueling but it might make sense for lesser missions, so the final buildout could be done in two tank sections or one tank in two sections.

Total of five sections to be assembled elsewhere. Now if we just knew where elsewhere is...

Phil

PS. Sure would be convenient if they could move it to the pad and launch for the cape with a high loft, overshoot then retropulsion for an F9 RTLS profile. That and a FAA license and comment period. NOMADD you could make a killing selling/renting noise cancelling headphones and pet sized acustic isolation chambers.
Edit: typo
Looks like they will be building another orbital prototype in Florida in addition to the one currently under construction at Boca Chica.


Um, uh...  I was suggesting (musing would be more accurate) launching from BC to the Cape for testing, not saying they’re building at the Cape. Or has something come up that I’m not aware of?

Being confused is in my job description. I’m told I do a good job. 😳
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BrianPeterson on 03/17/2019 09:19 pm
Now the flying machine mentioned as to be built in Florida by EM...

It could be the first stage booster. Build the starship orbital test model in Boca. At some point test fly it to the Cape and mate it up. My guess keep an eye on the landing pad area to suddenly start sprouting a water tower. But I'm probably completely wrong.  :P
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/17/2019 09:21 pm
For those peering back upon these threads for the historical record, I, without artifice, admit to being....mistaken. No hat for this hopper.  But...I was correct that they're looking at KSC to launch an operational SH/SS. I don't think they'll get regulatory approval to  do so at BC. But hey, getting used to being wrong on Elon Tweet-Storm Sundays.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: QuantumG on 03/17/2019 09:22 pm
Starship really seems to be a race against time...

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/17/2019 09:24 pm
Now the flying machine mentioned as to be built in Florida by EM...

It could be the first stage booster. Build the starship orbital test model in Boca. At some point test fly it to the Cape and mate it up. My guess keep an eye on the landing pad area to suddenly start sprouting a water tower. But I'm probably completely wrong.  :P
https://twitter.com/elonmusk/status/1107370515570671616
Tweet Content:  Where will the first orbital flights of Starship occur from?  Working on regulatory approval for both Boca Chica, Texas, and Cape Kennedy, Florida. Will also be building Starship & Super Heavy simultaneously in both locations.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 03/17/2019 09:25 pm
Now the flying machine mentioned as to be built in Florida by EM...

It could be the first stage booster. Build the starship orbital test model in Boca. At some point test fly it to the Cape and mate it up. My guess keep an eye on the landing pad area to suddenly start sprouting a water tower. But I'm probably completely wrong.  :P

No way they're flying the orbital model to the Cape hopping over FL, assuming that is what was meant.
Easy to ship things from Texas to the Cape but Elon indicates that BOTH sites are build sites & launch sites.
Of course that could change.
I'm old enough to remember when Elon said the build site was Long Beach, CA.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OTV Booster on 03/17/2019 09:25 pm
Looks like they will be building another orbital prototype in Florida in addition to the one currently under construction at Boca Chica.

Related question: per Musk's tweet, where at "...Cape Kennedy, Florida"?  NB: Cape Kennedy, not CCAFS; assuming not a slip of the tongue.


I’m not seeing a link to this. Could somebody post it.
Thanks
Phil


Edit. Opps. Nevermind. found the link.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Semmel on 03/17/2019 09:27 pm
I dont get it with the tiles. I thought transpirational cooling was envisioned to NOT have tiles. Double duty for mechanical stiffness and shiny surface for reflection. Now there are tiles, just (additional?) transpirational cooling for hot spots. Its like.. the other way around from what I was expecting. Did everything change or was that a misinterpretation of some earlier information?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 03/17/2019 09:27 pm
Looks like they will be building another orbital prototype in Florida in addition to the one currently under construction at Boca Chica.

Related question: per Musk's tweet, where at "...Cape Kennedy, Florida"?  NB: Cape Kennedy, not CCAFS; assuming not a slip of the tongue.




I’m not seeing a link to this. Could somebody post it.
Thanks
Phil

Look back 4 posts.  It's there.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OTV Booster on 03/17/2019 09:30 pm
Looks like they will be building another orbital prototype in Florida in addition to the one currently under construction at Boca Chica.

Related question: per Musk's tweet, where at "...Cape Kennedy, Florida"?  NB: Cape Kennedy, not CCAFS; assuming not a slip of the tongue.




I’m not seeing a link to this. Could somebody post it.
Thanks
Phil

Look back 4 posts.  It's there.


Found it. Thanks
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BrianPeterson on 03/17/2019 09:31 pm
Starship really seems to be a race against time...

Well he has paying customers ready for the moon. And when it comes to Mars, there are specific launch windows that can't be changed. If he wants to get them before 10 years is out you got to get going.

This is an exciting time to be alive, maybe more exciting than those who lived through Kennedy's speech to the moon landing. For the first time in 50 years since Apollo 11 space exploration and development has a vision, and someone with the drive and the huzzapah to attain his goals. What we are experiencing is what is possible when there is a vision and a drive to make that vision reality. We haven't seen that since the Apollo 11 launch. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/17/2019 09:32 pm
So I'm guessing they're building Starship in BC and Super Heavy at the Cape. Where at the cape will they build this?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Eylrid on 03/17/2019 09:33 pm
Still suborbital... Still a 5km (16,000 foot) flight level limited flying machine...

Musk disagrees...

https://twitter.com/elonmusk/status/1107373237208416256

I took that tweet to mean full size OML with hard shell Hopper 2... LIKE the later Orbital class machine... IMHO
His main point of the tweet is the first two sentences... NOT a new nosecone for Hopper 1...

His main point is "What you see being built IS the orbital starship"
Not a hopper 2, the orbital ship.

When are people going to realize that SpaceX is actually going to use their prototypes to do the real testing they say they are? People saying the hopper won't actually hop or the orbital prototype won't actually do orbital testing baffle me. SpaceX doesn't do timid.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JH on 03/17/2019 09:35 pm
I'm old enough to remember when Elon said the build site was Long Beach, CA.

Once he decided that they could just weld things up in a field, he went a bit free-form, didn't he?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/17/2019 09:37 pm
So I'm guessing they're building Starship in BC and Super Heavy at the Cape. Where at the cape will they build this?
They will find an unused shed or just drain some swamp.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rakaydos on 03/17/2019 09:38 pm
I dont get it with the tiles. I thought transpirational cooling was envisioned to NOT have tiles. Double duty for mechanical stiffness and shiny surface for reflection. Now there are tiles, just (additional?) transpirational cooling for hot spots. Its like.. the other way around from what I was expecting. Did everything change or was that a misinterpretation of some earlier information?

It sounds like the prototype will have tiles, and any part of the prototype that the (ablative) tile actually ablates on, will be plumbed for transpirational cooling (hereafter refered to as "sweating")

The idea being that the machinery to make the starship sweat is extra mass, and it's difficult to adjust the sweat by section, with any section with too much sweat is wasting methane. So they send up the prototype with ablative so they can tune the sweat systems appropriately.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/17/2019 10:04 pm
Starship really seems to be a race against time...
Personally, regardless of how politically impossible most would say this is, (and it probably is in the short term), but I think this is a full court press to either outright displace SLS or make so much progress that NASA finds those funding "instruments" they mentioned previously for the Gateway program.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CardBoardBoxProcessor on 03/17/2019 10:05 pm
Oh, I called it. They aren't rebuilding the nose cone
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: guckyfan on 03/17/2019 10:12 pm
Ablative or not. These tiles will need to be resistant to humidity and rain. PicaX seems not to be, they coat it so it won't be damaged by water before launch.

Elon said once one of the most difficult parts for F9 block 5 was creating a hydrophob heat shield material.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/17/2019 10:15 pm
Ablative or not. These tiles will need to be resistant to humidity and rain. PicaX seems not to be, they coat it so it won't be damaged by water before launch.

Elon said once one of the most difficult parts for F9 block 5 was creating a hydrophob heat shield material.
So they decided on Stainless steel for Starship with lots of small holes through which they will pass methane gas.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JH on 03/17/2019 10:19 pm
Ablative or not. These tiles will need to be resistant to humidity and rain. PicaX seems not to be, they coat it so it won't be damaged by water before launch.

I imagine that they are TUFROC or a derivative of it, as SpaceX signed a SAA with NASA Ames last summer related to it. TUFROC (Toughened Uni-piece Fibrous Reinforced Oxidation-Resistant Composite) is designed to be non-ablative and survive up to ~2000 K. It's used on the leading edges of the X-37B.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BrianPeterson on 03/17/2019 10:21 pm
Ablative or not. These tiles will need to be resistant to humidity and rain. PicaX seems not to be, they coat it so it won't be damaged by water before launch.

Not ablative: <blockquote class="twitter-tweet" data-lang="en"><p lang="en" dir="ltr">Transpiration cooling will be added wherever we see erosion of the shield. Starship needs to be ready to fly again immediately after landing.  Zero refurbishment.</p>&mdash; Elon Musk (@elonmusk) March 17, 2019 (https://twitter.com/elonmusk/status/1107380559834046465?ref_src=twsrc%5Etfw)
<script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>

Is there such a thing as stainless steel based ceramic? As several pointed out in the Transpiration cooling posts these things are shinny.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/17/2019 10:23 pm
Wow this latest tweetstorm is such a goldmine.  :o

Elon really was not kidding when he said that the switch to Stainless Steel would accelerate the entire development program.

While trying to get the paperwork for both the Cape and Boca Chica could just be a case of not putting all eggs in one basket, i read it more as part of a relentless production & launch buildup.

And the hatless Hopper flying will look like a giant R2D2 of doom. :D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/17/2019 10:25 pm
I dont get it with the tiles. I thought transpirational cooling was envisioned to NOT have tiles. Double duty for mechanical stiffness and shiny surface for reflection. Now there are tiles, just (additional?) transpirational cooling for hot spots. Its like.. the other way around from what I was expecting. Did everything change or was that a misinterpretation of some earlier information?

It sounds like the prototype will have tiles, and any part of the prototype that the (ablative) tile actually ablates on, will be plumbed for transpirational cooling (hereafter refered to as "sweating")

The idea being that the machinery to make the starship sweat is extra mass, and it's difficult to adjust the sweat by section, with any section with too much sweat is wasting methane. So they send up the prototype with ablative so they can tune the sweat systems appropriately.

Ablative or not. These tiles will need to be resistant to humidity and rain. PicaX seems not to be, they coat it so it won't be damaged by water before launch.

Elon said once one of the most difficult parts for F9 block 5 was creating a hydrophob heat shield material.

I don't get it with the tiles.  And since the time that Semmel asked about tiles two more people have jumped in and talked about tiles.  Is there any information to suggest tiles?  As I said before I've not been on the transpiration cooling thread so maybe its coming from there an if so is there any info there to suggest it or have people there just talked themselves into it?  Seems Elon is the best source of info even if he changes his mind as the situation develops and he's not suggested it that I know of.  I think a lot of you guys still haven't gotten over that shuttle thing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BrianPeterson on 03/17/2019 10:27 pm
  As I said before I've not been on the transpiration cooling thread so maybe its coming from there an if so is there any info there to suggest it or have people there just talked themselves into it?  Seems Elon is the best source of info even if he changes his mind as the situation develops and he's not suggested it that I know of.  I think a lot of you guys still haven't gotten over that shuttle thing.

Click over to the Transpiration cooling thread, it's exploded today with posts. But yes the tiles come from Elon along with a video.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/17/2019 10:30 pm
Got it now I've seen the video of hex tiles being torch tested.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WindyCity on 03/17/2019 11:40 pm
Starship really seems to be a race against time...

Well he has paying customers ready for the moon. And when it comes to Mars, there are specific launch windows that can't be changed. If he wants to get them before 10 years is out you got to get going.

This is an exciting time to be alive, maybe more exciting than those who lived through Kennedy's speech to the moon landing. For the first time in 50 years since Apollo 11 space exploration and development has a vision, and someone with the drive and the huzzapah to attain his goals. What we are experiencing is what is possible when there is a vision and a drive to make that vision reality. We haven't seen that since the Apollo 11 launch.
Precisely. The key is having a mission objective. What NASA has been doing (aside from amazing scientific robotic missions) is building stuff around the country and then trying to find a purpose for it. That, coupled with cost-plus contracting, gives you 50+ years of chasing a white elephant's tail around in LEO. I respect and admire the folks at NASA. It's not their fault. The fault lies under the rotunda at the end of the Washington mall.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OTV Booster on 03/18/2019 12:01 am
Starship really seems to be a race against time...
Personally, regardless of how politically impossible most would say this is, (and it probably is in the short term), but I think this is a full court press to either outright displace SLS or make so much progress that NASA finds those funding "instruments" they mentioned previously for the Gateway program.

Naw, Elon’s too busy to worry about a not very comptitive competitor. He’s in a hurry so he can get starlink up & generate revenue. NASA money has strings and Elon is on a mission. He’ll do Gateway if it doesnt get in the way, he need the cash or it leads to R&D needed for mars on guvmnt bucks.

Phil
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/18/2019 12:19 am
My takeaways:

1)  Hopper will hop to 5km
2)  Starship Mk1 will test orbital heating though perhaps not orbital
3)  As stated by another, Regulatory Approach is a Full Court Press
4)  Boca and Cape means that both SH and SS Production Versions will be built both places.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Keldor on 03/18/2019 12:30 am
Regarding those funny semi-conical panels that everyone is speculating are tank ends or something, I wonder if they're going to be a shroud for Hopper.  I know Musk said that they're not rebuilding the big fairing, but it makes a lot of sense to have something up there to cover those exposed red tanks.  Then the cone is just a simple shroud.

It's not the right shape for a tank end or bulkhead - It looks taller  and more cone shaped than spherical, which not only creates a lot of empty space that's wasteful, but also is weaker and has more surface area and mass.  Generally you want some sort of compromise between spherical and flattish, trading extra area and wasted space against geometrical strength. The original BFR had a tank design like that so those big vacuum nozzles could fit around it.  But those are no longer part of the design.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: r1279 on 03/18/2019 12:43 am
but it makes a lot of sense to have something up there to cover those exposed red tank

If they hit anything with those tanks, they likely have bigger issues.  This doesn't have to be lifetime robust, or perfectly aerodynamic, just get through a few months of vertical hops. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/18/2019 12:44 am
LOL, if only I stuck to my original prediction.... I blame the weird shaped tank dome (really I still don't see them as tank dome, hey the orbital prototype will need a nose too...) and the parts for the steel prefab (why do they need a semi-permanent steel building if they're already building the ship outside...)

Consolation prize is I get to laugh at people who said there's zero chance SpaceX would hand weld orbital prototype in an open field ;)

If the steel plates are truly 6mm thick, I don't know how they're going to acheive a good dry mass with SS. If they're still planning on making Starship 55m high and 9m in diameter, the mass of a 6mm thick cylinder is going to be 70 metric tons. That's without legs, engines, tanks, and whatever TPS they're going to need. It's really hard for me to see how it could possibly get to orbit on it's own with such a high dry mass. I guess it's possible they'll taper the steel higher up the structure.

It can't get to orbit on its own, it's not an SSTO (I mean if Elon can build a reusable SSTO outdoors with hand welded tank, people will start jumping out of window at NASA/Boeing/LM....). Even though it's called an orbital prototype, it will just fly high mach suborbital flights on its own, it will need SuperHeavy for orbital flight.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Keldor on 03/18/2019 01:15 am
It can't get to orbit on its own, it's not an SSTO (I mean if Elon can build a reusable SSTO outdoors with hand welded tank, people will start jumping out of window at NASA/Boeing/LM....). Even though it's called an orbital prototype, it will just fly high mach suborbital flights on its own, it will need SuperHeavy for orbital flight.

Can anyone do the math on this?  The Falcon 9 first stage is actually capable of reaching orbit by itself, barely, and with no payload or return capability.  Starship has methalox engines with a higher ISP.  A SSTO flight and return without any payload might just be on the edge of possibility.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: groknull on 03/18/2019 01:19 am
Regarding those funny semi-conical panels that everyone is speculating are tank ends or something, I wonder if they're going to be a shroud for Hopper.  I know Musk said that they're not rebuilding the big fairing, but it makes a lot of sense to have something up there to cover those exposed red tanks.  Then the cone is just a simple shroud.

It's not the right shape for a tank end or bulkhead - It looks taller  and more cone shaped than spherical, which not only creates a lot of empty space that's wasteful, but also is weaker and has more surface area and mass.  Generally you want some sort of compromise between spherical and flattish, trading extra area and wasted space against geometrical strength. The original BFR had a tank design like that so those big vacuum nozzles could fit around it.  But those are no longer part of the design.

My emphasis.

Vacuum Raptors are no longer part of the first implementation of the design.  IIRC Musk indicated, at the #dearMoon event, that the cargo pods (surrounding the SL engines) could eventually be replaced by vacuum engines, one Vacuum Raptor for every two cargo pods.

A semi-conical lower tank end may still be part of the design.  A conic structure is also pretty good for transferring thrust forces from a central engine cluster to the main structure (barrel).  Alternate thrust structures, such as cruciform beams (e.g. Saturn S-1) can be pretty massive.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DiskOperatingSystem on 03/18/2019 01:23 am
Sorry if this has already been asked, but does anyone know what sort of protection the Raptors on BFH and later BFS with have from FOD. I know they will be inset a bit in the body, but for landing on pads in texas and eventually mars,  the plumbing and bell seem very close together in all the photos we have. In the BFH, I havent seen any protection for the body of the engine yet. Is this a concern or is BFH too bare bones in its construction for this to be a real worry?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RobLynn on 03/18/2019 01:26 am
It can't get to orbit on its own, it's not an SSTO (I mean if Elon can build a reusable SSTO outdoors with hand welded tank, people will start jumping out of window at NASA/Boeing/LM....). Even though it's called an orbital prototype, it will just fly high mach suborbital flights on its own, it will need SuperHeavy for orbital flight.

Can anyone do the math on this?  The Falcon 9 first stage is actually capable of reaching orbit by itself, barely, and with no payload or return capability.  Starship has methalox engines with a higher ISP.  A SSTO flight and return without any payload might just be on the edge of possibility.

No math to do until (if) we have better data on masses etc.  Some time and many design revisions back Elon did mention that might be possible to just barely achieve zero-payload SSTO with BFS (Starship).  Given >60tonne? Starship dry mass and large payload bay with similar volume to fuel tanks it would likely be possible to fill most of that payload volume with more fuel tanks, double the number of engines and achieve SSTO with substantial (compact) payload mass.  But SpaceX don't seem to be interested in doing that (though it would possibly be a way of getting useful payload to orbit out of less or limited numbers of Raptors).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jketch on 03/18/2019 01:27 am
Raptor as designed is supposed to have a sea level Isp of 330 and a vacuum Isp of around 360 (would be 380 with an extended nozzle). I'm not sure what the average Isp would be, but let's assume the midpoint at 345 for a quick and dirty calculation. That coorresponds to an exhaust velocity of 3.38 km/s.

The average delta-v to get to LEO, after accounting for losses due to gravity and drag is 9.4 km/s. So the SS would need a wet to dry mass ratio of e^(9.4/3.38)=16.11 to get to orbit. The Raptor is supposed to have a thrust of around 200 tons, so let's say the vehicle masses 1,100 ton total at liftoff. If you want to get that to orbit in one go, that equates to 65 tons of dry mass, which has to include whatever propellant you need to land, so the Starship itself can't mass more than about 60 tons.

This calculation is very sensitive to the average Isp. If you take a value closer to 360, you only need a wet to dry mass ratio of 13.5 to get to orbit, but that still means you only get 81 tons for the vehicle plus prop. So, I guess there isn't really a feasible way for SS to do SSTO and back.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Keldor on 03/18/2019 01:30 am
Sorry if this has already been asked, but does anyone know what sort of protection the Raptors on BFH and later BFS with have from FOD. I know they will be inset a bit in the body, but for landing on pads in texas and eventually mars,  the plumbing and bell seem very close together in all the photos we have. In the BFH, I havent seen any protection for the body of the engine yet. Is this a concern or is BFH too bare bones in its construction for this to be a real worry?

I doubt they'd want to add that sort of thing on hopper.  On top of being rather overkill for what Starhopper is going to be doing, they're going to want to be getting in and out of there to inspect the engines between flights.  Remember, the engines in Starhopper are prototypes too.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Keldor on 03/18/2019 01:40 am
Raptor as designed is supposed to have a sea level Isp of 330 and a vacuum Isp of around 360 (would be 380 with an extended nozzle). I'm not sure what the average Isp would be, but let's assume the midpoint at 345 for a quick and dirty calculation. That coorresponds to an exhaust velocity of 3.38 km/s.

The average delta-v to get to LEO, after accounting for losses due to gravity and drag is 9.4 km/s. So the SS would need a wet to dry mass ratio of e^(9.4/3.38)=16.11 to get to orbit. The Raptor is supposed to have a thrust of around 200 tons, so let's say the vehicle masses 1,100 ton total at liftoff. If you want to get that to orbit in one go, that equates to 65 tons of dry mass, which has to include whatever propellant you need to land, so the Starship itself can't mass more than about 60 tons.

This calculation is very sensitive to the average Isp. If you take a value closer to 360, you only need a wet to dry mass ratio of 13.5 to get to orbit, but that still means you only get 81 tons for the vehicle plus prop. So, I guess there isn't really a feasible way for SS to do SSTO and back.

They don't need to go as high as a normal LEO.  They just need to achieve a high enough altitude for the spacecraft to complete a single orbit to get back to the launch site.  I don't know how much delta-v this saves, though.

The problem with any sort of suborbital RTLS flight is that having to turn around and go back severely limits the amount of velocity the rocket will be able to reach.  Is reentry from half of orbital velocity very interesting in terms of testing?  Alternately, Starship itself should be light and small enough to consider a drone ship landing, even if this is right out for Super Heavy.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: matthewkantar on 03/18/2019 01:57 am
Is anyone else surprised the Raptor shipped to Boca Chica does not have its kevlar jacket on it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/18/2019 02:14 am
It's really hard for me to see how it could possibly get to orbit on it's own with such a high dry mass. I guess it's possible they'll taper the steel higher up the structure.
Maybe the plan isn't for the 2nd StarShip prototype to get to orbit on its own.  Maybe it does as StarShips are supposed to and rides the prototype SH to orbit.  It wouldn't take much of a shove from SH.


but it makes a lot of sense to have something up there to cover those exposed red tank

If they hit anything with those tanks, they likely have bigger issues.  This doesn't have to be lifetime robust, or perfectly aerodynamic, just get through a few months of vertical hops.

The red tanks do have a protective cover.  Its red.  The tank is black.  Really.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/18/2019 02:29 am
Sorry if this has already been asked, but does anyone know what sort of protection the Raptors on BFH and later BFS with have from FOD. I know they will be inset a bit in the body, but for landing on pads in texas and eventually mars,  the plumbing and bell seem very close together in all the photos we have. In the BFH, I havent seen any protection for the body of the engine yet. Is this a concern or is BFH too bare bones in its construction for this to be a real worry?

Yes, I would be worried about FOD hitting the engine body, either they'll add some protection later, or they know it's not a concern based on their experience with Grasshopper and F9R-Dev1 (for single engine the flow should push debris sideways?).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/18/2019 02:47 am
Article in the Brownsville Herald on the behind the scenes machinations to close roads for SpaceX;

https://www.brownsvilleherald.com/news/local/county-oks-spacex-policy-local-leaders-can-close-road-for/article_042f6afc-46ac-11e9-91ed-c3a6f674a14a.html (https://www.brownsvilleherald.com/news/local/county-oks-spacex-policy-local-leaders-can-close-road-for/article_042f6afc-46ac-11e9-91ed-c3a6f674a14a.html)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/18/2019 03:46 am
So no nose cone it is. On the bright side, we'll have a full stack by summer's end!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/18/2019 06:16 am
Wow!  That clears up a lot of speculation.  So from the parts on hand, assuming the second cylinder gets another section, they build a third cylinder, and the old nosecone shape is rebuilt, it goes together something like this.

The dome (yay!!!) is now in the right place, but the Raptor should be fully enclosed in the skirt to protect it from entry effects - there is plenty of room.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/18/2019 06:30 am
Starship really seems to be a race against time...
Personally, regardless of how politically impossible most would say this is, (and it probably is in the short term), but I think this is a full court press to either outright displace SLS or make so much progress that NASA finds those funding "instruments" they mentioned previously for the Gateway program.
I think EM is marching to the beat of a different drum he wants to get to Mars ASAP. The SpaceX mentality shares a lot with the likes of the army Special Forces and Musk is driving them at full throttle breakneck pace regardless of what NASA says or does.

That said I’m sure that as a secondary consideration EM is well aware that there might be a lot of advantageous fall out when SLS is swept away by his technological maelstrom. Nobody knows at what point the SLS program will rupture, but it seems highly likely that Musk, SpaceX and Starship will be instrumental in causing it and will be ideally placed to take advantage of it when it does happen.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Star One on 03/18/2019 06:44 am
Wow this latest tweetstorm is such a goldmine.  :o

Elon really was not kidding when he said that the switch to Stainless Steel would accelerate the entire development program.

While trying to get the paperwork for both the Cape and Boca Chica could just be a case of not putting all eggs in one basket, i read it more as part of a relentless production &amp; launch buildup.

And the hatless Hopper flying will look like a giant R2D2 of doom. :D

Can I just congratulate you on the R2D2 comment made me chuckle on my dreary commute.

Also I really should apologise and hold my hands up and say I was wrong when I said the Hopper would never fly without a hat because of EM’s sense of aesthetics, shows you I don’t know his aesthetic as well as I thought I did.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/18/2019 07:38 am
1)  Hopper will hop to 5km

There is this tweet: https://twitter.com/elonmusk/status/1107365369168056320

Quote

First (really short) hops with one engine. Suborbital flights with three.

5km is obviously "suborbital", so this would be technically correct. However, he makes a distinction between "hops" and "suborbital flights". Here is Wikipedia's definition (https://en.wikipedia.org/wiki/Sub-orbital_spaceflight) of a suborbital flight:

Quote
A sub-orbital spaceflight is a spaceflight in which the spacecraft reaches outer space, but its trajectory intersects the atmosphere or surface of the gravitating body from which it was launched, so that it will not complete one orbital revolution.

I really wonder, whether Elon's tweet means, that the flights with all thee engines will be similar to New Shepard's test flights.

What is possible with 3 Raptors and the fuel in the hopper? How high can they actually go?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: hkultala on 03/18/2019 07:43 am
1)  Hopper will hop to 5km

There is this tweet: https://twitter.com/elonmusk/status/1107365369168056320

Quote

First (really short) hops with one engine. Suborbital flights with three.

5km is obviously "suborbital", so this would be technically correct. However, he makes a distinction between "hops" and "suborbital flights". Here is Wikipedia's definition (https://en.wikipedia.org/wiki/Sub-orbital_spaceflight) of a suborbital flight:

Quote
A sub-orbital spaceflight is a spaceflight in which the spacecraft reaches outer space, but its trajectory intersects the atmosphere or surface of the gravitating body from which it was launched, so that it will not complete one orbital revolution.

I really wonder, whether Elon's tweet means, that they will try New Shepard like "hops".

You are confusing sub-orbital flight and sub-orbital spaceflight

Anything that takes off and does not reach orbit is sub-orbital flight.

It only becomes sub-orbital spaceflight if it reaches about 100km.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/18/2019 07:48 am
1)  Hopper will hop to 5km

There is this tweet: https://twitter.com/elonmusk/status/1107365369168056320

Quote

First (really short) hops with one engine. Suborbital flights with three.

5km is obviously "suborbital", so this would be technically correct. However, he makes a distinction between "hops" and "suborbital flights". Here is Wikipedia's definition (https://en.wikipedia.org/wiki/Sub-orbital_spaceflight) of a suborbital flight:

Quote
A sub-orbital spaceflight is a spaceflight in which the spacecraft reaches outer space, but its trajectory intersects the atmosphere or surface of the gravitating body from which it was launched, so that it will not complete one orbital revolution.

I really wonder, whether Elon's tweet means, that they will try New Shepard like "hops".

You are confusing sub-orbital flight and sub-orbital spaceflight

Anything that takes off and does not reach orbit is sub-orbital flight.

It only becomes sub-orbital spaceflight if it reaches about 100km.

I'm very much aware of this. But Elon's distinction between "hops" and "flights" makes me wonder, how high these latter flights will actually go. The 5km comes from the current FAA application. There is no reason that they can't apply for flights up to 50km or even 100km at a later date.

Once again: What's the technical limit of the hopper? How high can it actually go and safely land again?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 03/18/2019 08:41 am
Ablative or not. These tiles will need to be resistant to humidity and rain. PicaX seems not to be, they coat it so it won't be damaged by water before launch.

Not ablative: <blockquote class="twitter-tweet" data-lang="en"><p lang="en" dir="ltr">Transpiration cooling will be added wherever we see erosion of the shield. Starship needs to be ready to fly again immediately after landing.  Zero refurbishment.</p>&mdash; Elon Musk (@elonmusk) March 17, 2019 (https://twitter.com/elonmusk/status/1107380559834046465?ref_src=twsrc%5Etfw)

<script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>

Is there such a thing as stainless steel based ceramic? As several pointed out in the Transpiration cooling posts these things are shinny.
Sounds to me that they use an heat shield and then cool it places there its danger for it to erode.
This has the benefit that if cooling fails you just loose the heat shield and they can experiment more during test launches.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OccasionalTraveller on 03/18/2019 08:48 am
Starship really seems to be a race against time...
Personally, regardless of how politically impossible most would say this is, (and it probably is in the short term), but I think this is a full court press to either outright displace SLS or make so much progress that NASA finds those funding "instruments" they mentioned previously for the Gateway program.
I think there's also another factor: the US Air Force National Security Space Launch program (formerly EELV2). If they want to secure funding or contracts for the next phase, it would be good to show progress, particularly if that's greater progress than one of the three systems that won funding in the first phase (ULA Vulcan, Blue Origin New Glenn, Northrop Grumman OmegA).

If Starship/Super Heavy aren't far enough along, SpaceX might have to bid Falcon 9/Heavy to secure funding - but if they won, then they would be committed to keeping the Falcon family around for probably another ten years. They'd like to retire it earlier than that!

I'm not sure when the next down-select is supposed to happen, but the first launches are supposed to be October 2021. Launcher selection will have to happen pretty soon.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: alang on 03/18/2019 08:51 am
Article in the Brownsville Herald on the behind the scenes machinations to close roads for SpaceX;

https://www.brownsvilleherald.com/news/local/county-oks-spacex-policy-local-leaders-can-close-road-for/article_042f6afc-46ac-11e9-91ed-c3a6f674a14a.html (https://www.brownsvilleherald.com/news/local/county-oks-spacex-policy-local-leaders-can-close-road-for/article_042f6afc-46ac-11e9-91ed-c3a6f674a14a.html)

Hmm. Annoyingly it claims it won't allow access to EEA addresses due to GDPR
I suspect that some internet legislation is going to have perverse consequences.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/18/2019 08:59 am
Article in the Brownsville Herald on the behind the scenes machinations to close roads for SpaceX;

https://www.brownsvilleherald.com/news/local/county-oks-spacex-policy-local-leaders-can-close-road-for/article_042f6afc-46ac-11e9-91ed-c3a6f674a14a.html (https://www.brownsvilleherald.com/news/local/county-oks-spacex-policy-local-leaders-can-close-road-for/article_042f6afc-46ac-11e9-91ed-c3a6f674a14a.html)

Hmm. Annoyingly it claims it won't allow access to EEA addresses due to GDPR
I suspect that some internet legislation is going to have perverse consequences.
You should get a VPN. I'm based in the UK and got the same problem so I just dialed into a US server and now it's not an issue.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/18/2019 11:57 am
Once again: What's the technical limit of the hopper? How high can it actually go and safely land again?

OneSpeed did some sims indicating it could reach 50 km without going supersonic or shutting down any of the engines. Even higher if it could go supersonic or shut down/restart some engines.

https://forum.nasaspaceflight.com/index.php?topic=47179.msg1914751#msg1914751
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/18/2019 01:36 pm
A few random thoughts stirring through my mind -

1) LNG Safety
In the event of a crash or other catastrophic release...  Natural gas is lighter than air so it goes up, at least when the gas is at the same temperature as air.  The problem is that liquid natural gas and very cold natural gas are heavier than air and creep along the ground.  This is a problem that's not really a problem with RP-1 or hydrogen.  And, unlike hydrogen the mixture ratios of air and natural gas that will burn are relatively narrow so natural gas is a bit less likely to ignite and thus more likely to spread and travel before finding an ignition source.  Here by the power vested in me by me are my safety guidelines:
   a) Only fly when winds are predominantly heading offshore
   b) Set up a grid of highway flares or other ignition sources anywhere it may crash and in particular a line of ignition sources between the test site and the inhabited area.  Cold gas travels horizontally, fire goes up

2) Where to fly
The map below seems like a reasonable flying area to me.  Just my guess.  There should be more definition in Notams and notices to mariners.  I just checked the marine side and there's nothing showing - https://www.navcen.uscg.gov/pdf/lnms/lnm0811g2019.pdf (https://www.navcen.uscg.gov/pdf/lnms/lnm0811g2019.pdf)  Keep looking, aviation notices and marine notices are likely to be good sources of information as we go forward.

3) Stargate
I'm missing some knowledge because I didn't pay much attention to the Boca Chica launch site thread until Caldwell showed up.  Does Stargate have a role in launches?  Is that where they are going to control it from?  Or do we know where?  Perhaps from the building at the build site?  Perhaps from the motorhome?  It seems like there was some mention of fiber optic cable being run ~6 months back.  Was this from the pad area to the control area?

4) Coffee table book
It seems like BCGal and Nomadd are going to be in a position to publish a really awesome and authoritative coffee table book on the first steps to Mars some day not to far down the road.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: uncas on 03/18/2019 01:50 pm
<snip>
4) Coffee table book
It seems like BCGal and Nomadd are going to be in a position to publish a really awesome and authoritative coffee table book on the first steps to Mars some day not to far down the road.

That's a great idea! The Road to Mars: the Early Boca Chica Days by Nomadd and BocaChicaGal

Some century plant photos and other scene setting shots from the days when it seemed SpaceX had forgotten they'd bought land in south Texas. Then the rush of activity in December 2018 and 2019 to whenever the first full orbital flight actually happens.


I keep checking to see if the road closure has been scheduled. I hope we get a little advance warning when they do the actual static fire and that someone gets video!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/18/2019 03:10 pm
This was delivered within the control center area this morning.

This looks like a diesel powered fire pump.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 03/18/2019 03:24 pm
This was delivered within the control center area this morning.

This looks like a diesel powered fire pump.

Knowing SpaceX it's probably a LOX pump/something directly for launch... But it's probably just general site safety infrastructure.

Hey, a minor rainbird pump for three engine hops?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/18/2019 03:48 pm
Photo / observation request:  Monitor green hold down straps (changing to something more unmeltable?), Monitor whether the concrete launch slab has been cleared of all loose objects, Monitor construction vehicles being moved back a protective distance.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 03/18/2019 05:08 pm
A few random thoughts stirring through my mind -

1) LNG Safety
In the event of a crash or other catastrophic release...  Natural gas is lighter than air so it goes up, at least when the gas is at the same temperature as air.  The problem is that liquid natural gas and very cold natural gas are heavier than air and creep along the ground.  This is a problem that's not really a problem with RP-1 or hydrogen.  And, unlike hydrogen the mixture ratios of air and natural gas that will burn are relatively narrow so natural gas is a bit less likely to ignite and thus more likely to spread and travel before finding an ignition source.  Here by the power vested in me by me are my safety guidelines:
   a) Only fly when winds are predominantly heading offshore
   b) Set up a grid of highway flares or other ignition sources anywhere it may crash and in particular a line of ignition sources between the test site and the inhabited area.  Cold gas travels horizontally, fire goes up

2) Where to fly
The map below seems like a reasonable flying area to me.  Just my guess.  There should be more definition in Notams and notices to mariners.  I just checked the marine side and there's nothing showing - https://www.navcen.uscg.gov/pdf/lnms/lnm0811g2019.pdf (https://www.navcen.uscg.gov/pdf/lnms/lnm0811g2019.pdf)  Keep looking, aviation notices and marine notices are likely to be good sources of information as we go forward.

3) Stargate
I'm missing some knowledge because I didn't pay much attention to the Boca Chica launch site thread until Caldwell showed up.  Does Stargate have a role in launches?  Is that where they are going to control it from?  Or do we know where?  Perhaps from the building at the build site?  Perhaps from the motorhome?  It seems like there was some mention of fiber optic cable being run ~6 months back.  Was this from the pad area to the control area?

4) Coffee table book
It seems like BCGal and Nomadd are going to be in a position to publish a really awesome and authoritative coffee table book on the first steps to Mars some day not to far down the road.
This looks very reasonable, note that the upcoming test is static fire / tethered as in lifting an meter.
Later tests who goes up kilometers will probably burn east and then do an burn back to pad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/18/2019 05:57 pm
Once again: What's the technical limit of the hopper? How high can it actually go and safely land again?

OneSpeed did some sims indicating it could reach 50 km without going supersonic or shutting down any of the engines. Even higher if it could go supersonic or shut down/restart some engines.

https://forum.nasaspaceflight.com/index.php?topic=47179.msg1914751#msg1914751
Looking at that floppy cladding, I don't think supersonic is much of an option. Mach .1 maybe.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 03/18/2019 06:13 pm
Once again: What's the technical limit of the hopper? How high can it actually go and safely land again?

OneSpeed did some sims indicating it could reach 50 km without going supersonic or shutting down any of the engines. Even higher if it could go supersonic or shut down/restart some engines.

https://forum.nasaspaceflight.com/index.php?topic=47179.msg1914751#msg1914751
Looking at that floppy cladding, I don't think supersonic is much of an option. Mach .1 maybe.

Wash: "Oh God, Oh God, were all going to die!"
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/18/2019 06:14 pm
Once again: What's the technical limit of the hopper? How high can it actually go and safely land again?

OneSpeed did some sims indicating it could reach 50 km without going supersonic or shutting down any of the engines. Even higher if it could go supersonic or shut down/restart some engines.

https://forum.nasaspaceflight.com/index.php?topic=47179.msg1914751#msg1914751
Looking at that floppy cladding, I don't think supersonic is much of an option. Mach .1 maybe.

Yeah, without the fairing, the aerodynamics leave a bit to be desired.

On the other had, once you get high enough, aerodynamics don't really matter at all. It could fly slow through the soup and accelerate once high enough.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Tulse on 03/18/2019 06:35 pm
Once again: What's the technical limit of the hopper? How high can it actually go and safely land again?

OneSpeed did some sims indicating it could reach 50 km without going supersonic or shutting down any of the engines. Even higher if it could go supersonic or shut down/restart some engines.

https://forum.nasaspaceflight.com/index.php?topic=47179.msg1914751#msg1914751
Looking at that floppy cladding, I don't think supersonic is much of an option. Mach .1 maybe.

Wash: "Oh God, Oh God, were all going to die!"
Whereas if the cladding were properly attached, it would be like a leaf on the wind.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bogeyman on 03/18/2019 06:41 pm
This is all just so "Whow!" This is going to be a very exciting spring :)
If I were Boca Chica Gal, I'd get some money from the bank, set up a hotel with a viewing platform on the roof and earn myself a fortune ... (my 2 cents)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NH22077 on 03/18/2019 06:42 pm
Photo / observation request:  Monitor green hold down straps (changing to something more unmeltable?), Monitor whether the concrete launch slab has been cleared of all loose objects, Monitor construction vehicles being moved back a protective distance.

Mark,
The spansets around the BFH legs maybe gac flex. Which use 1/16" wirerope bands  instead of nylon bands as the core. The wirerope is fire rated. So you can use it without an extra fire safty to hang trusses, speakers, etc in theaters. Comes in verious sizes & strength ratings.
  I wouldn't use gac flex for static fires ether. The outer nylon jacket will met, catch fire & make a mess. But the Hopper won't go anywhere.
Ned
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/18/2019 07:26 pm
Photo / observation request:  Monitor green hold down straps (changing to something more unmeltable?), Monitor whether the concrete launch slab has been cleared of all loose objects, Monitor construction vehicles being moved back a protective distance.

Mark,
The spansets around the BFH legs maybe gac flex. Which use 1/16" wirerope bands  instead of nylon bands as the core. The wirerope is fire rated. So you can use it without an extra fire safty to hang trusses, speakers, etc in theaters. Comes in verious sizes & strength ratings.
  I wouldn't use gac flex for static fires ether. The outer nylon jacket will met, catch fire & make a mess. But the Hopper won't go anywhere.
Ned
They are Slingmax (https://slingmax.com/). The branding is visible in these BCG photos (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1920774#msg1920774).

core is K-spec yarn which is proprietary, it looks like, but they do have a spec sheet. 'critical temperature' is listed as 82 degrees c.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: martiantime on 03/18/2019 07:53 pm
The 4-th photo in the new NSF article (https://www.nasaspaceflight.com/2019/03/starhopper-first-flight-starship-superheavy-updates/) shows an aerial view of the construction site. The title is: Two sections of the Orbital Starship being constructed at Boca Chica from NSF Member Nomadd for L2.

Does it mean that Nomadd has his own drone?
Or is he constructing two sections of the Orbital Starship (for L2)? :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: loekf on 03/18/2019 08:18 pm
Next article update

ARTICLE: Starhopper first flight as early as this week; Starship/Superheavy updates -

https://www.nasaspaceflight.com/2019/03/starhopper-first-flight-starship-superheavy-updates/

- By Chris Gebhardt

With thanks to Mary (BocaChicaGal) for all her great photos and some photos from the L2 section.

https://twitter.com/NASASpaceflight/status/1107712492204109826

Little hopper looks almost like a certain robot from a scifi family saga. Just paint it blue and white ;-)

Stupid question..is there absolutely no chance it will tip over during a hop ?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Joffan on 03/18/2019 08:43 pm
Stupid question..is there absolutely no chance it will tip over during a hop ?

One thing that makes testing so interesting - effectively you are exploring and finding out what can possibly go wrong (and how to make things go right, of course). Given the way this test vehicle has been built and adapted, I would say there are no guarantees. Bring plenty of popcorn. Having said which, I would not expect a simple tip over unless a leg broke.

Assuming that the Hopper gets above say 50m, I could see that one protocol might be to put the impact point out to sea early in each flight. Then drift it back in on descent.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JohnLloydJones on 03/18/2019 08:45 pm
Next article update

ARTICLE: Starhopper first flight as early as this week; Starship/Superheavy updates -

https://www.nasaspaceflight.com/2019/03/starhopper-first-flight-starship-superheavy-updates/

- By Chris Gebhardt

With thanks to Mary (BocaChicaGal) for all her great photos and some photos from the L2 section.

https://twitter.com/NASASpaceflight/status/1107712492204109826

Little hopper looks almost like a certain robot from a scifi family saga. Just paint it blue and white ;-)

Stupid question..is there absolutely no chance it will tip over during a hop ?
Tip over? Well isn't that part of the reason the first "hops" will be tethered? At least until they are confident that everything is working as intended.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RDMM2081 on 03/18/2019 08:54 pm
Stupid question..is there absolutely no chance it will tip over during a hop ?

My stupid response is only to state for the record that I believe SpaceX will intentionally attempt to do a flip with this hopper v0.01 if it survives the first 3 actual hop tests.  I'll see myself to the party thread now.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/18/2019 09:41 pm
Stupid question..is there absolutely no chance it will tip over during a hop ?

My stupid response is only to state for the record that I believe SpaceX will intentionally attempt to do a flip with this hopper v0.01 if it survives the first 3 actual hop tests.  I'll see myself to the party thread now.
Absolutely no chance of it tipping over for reasons a, b and c, until it actualy does tip over. Then suddenly it will be obvious that it was going to tip over for reasons x, y and z
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RobLynn on 03/18/2019 10:32 pm
The finish of the (super heavy?) 'water towers' currently under construction at Boca Chica is surprising.  I expected to see very fine welds, no evidence of corrosion, no effort to make surface 'shiny' and possibly some exterior visible marks to show where internal stiffening structures were placed (spot welds or roll-seam welds.  But none of that seems in evidence.  It all seems very rough and 'agricultural'.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Joseph Peterson on 03/18/2019 10:43 pm
The finish of the (super heavy?) 'water towers' currently under construction at Boca Chica is surprising.  I expected to see very fine welds, no evidence of corrosion, no effort to make surface 'shiny' and possibly some exterior visible marks to show where internal stiffening structures were placed (spot welds or roll-seam welds.  But none of that seems in evidence.  It all seems very rough and 'agricultural'.

Well developing Martian agriculture does need to be an early goal.  Perhaps it is time for a new saying, farm as you fly.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: lonestriker on 03/18/2019 11:36 pm
Pics taken this afternoon of the launch site.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47120.0;attach=1550913;image)

I don't think I've seen mention of the use of the perforated bands of metal that were applied to the legs.  From BocaChicaGal's pictures, looks like they are reinforcements for the tie-downs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MKremer on 03/18/2019 11:45 pm
I don't think I've seen mention of the use of the perforated bands of metal that were applied to the legs.  From BocaChicaGal's pictures, looks like they are reinforcements for the tie-downs.
Yup, it's probably 20-25 pages ago or more by now, but when the first appeared on one leg, lots of speculations appeared. Many, like me, agreed they were doublers or extra reinforcing for something, like tiedowns.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 03/19/2019 12:00 am
The finish of the (super heavy?) 'water towers' currently under construction at Boca Chica is surprising.  I expected to see very fine welds, no evidence of corrosion, no effort to make surface 'shiny' and possibly some exterior visible marks to show where internal stiffening structures were placed (spot welds or roll-seam welds.  But none of that seems in evidence.  It all seems very rough and 'agricultural'.

Driveway metalworkers level and polish stainless steel welds every day, our sons and I among them. I'm sure SpaceX's crew knows how.

We made it a point to do the grinding, sanding & polishing last.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: lonestriker on 03/19/2019 12:06 am
I don't think I've seen mention of the use of the perforated bands of metal that were applied to the legs.  From BocaChicaGal's pictures, looks like they are reinforcements for the tie-downs.
Yup, it's probably 20-25 pages ago or more by now, but when the first appeared on one leg, lots of speculations appeared. Many, like me, agreed they were doublers or extra reinforcing for something, like tiedowns.

Thanks, I should have been more explicit.  I meant if there was confirmation/agreement about their actual purpose since we now have visual evidence of the intended use.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/19/2019 12:17 am
The finish of the (super heavy?) 'water towers' currently under construction at Boca Chica is surprising.  I expected to see very fine welds, no evidence of corrosion, no effort to make surface 'shiny' and possibly some exterior visible marks to show where internal stiffening structures were placed (spot welds or roll-seam welds.  But none of that seems in evidence.  It all seems very rough and 'agricultural'.
I don’t think you’re seeing any corrosion. Those rusty looking patches are actually burn through marks from things welded to the inside, such as padeyes, the temporary bars that hold sections together prior to welding, stiffener rings, etc. Not that that’s any better...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 12:37 am
I believe that both Elon and the Tesla spokesman that has been quoted in Texas media have referred to the tethered firing as being a flight.  And that "flight" seems to be coming in the next few days.  If so, maybe not after the first flight but very soon we've got some candy coming.  Reminder:
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 12:43 am
I don't think I've seen mention of the use of the perforated bands of metal that were applied to the legs.  From BocaChicaGal's pictures, looks like they are reinforcements for the tie-downs.
Yup, it's probably 20-25 pages ago or more by now, but when the first appeared on one leg, lots of speculations appeared. Many, like me, agreed they were doublers or extra reinforcing for something, like tiedowns.

Thanks, I should have been more explicit.  I meant if there was confirmation/agreement about their actual purpose since we now have visual evidence of the intended use.

Each leg has one of these Slingmax slings around it and it's anchored down.

...Those saddles with holes that are wrapped over the legs that some suggested were tie down locations, they're tie down locations.  Though why they were necessary or why the holes remains a bit up for discussion...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/19/2019 12:48 am
Pics taken this afternoon of the launch site.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47120.0;attach=1550913;image)

So what will happen to the mess of wires/tubes/propellant lines when they do the hop test? Do they:
a. Get someone to disconnect them after hopper is fully fueled
b. Hop with the lines attached
?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/19/2019 12:57 am
Pics taken this afternoon of the launch site.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47120.0;attach=1550913;image)

So what will happen to the mess of wires/tubes/propellant lines when they do the hop test? Do they:
a. Get someone to disconnect them after hopper is fully fueled
b. Hop with the lines attached
?
Probably disconnect by hand. I assume that's how they did it for grasshopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 01:09 am
If this program ends up the way that Elon is intending do you suppose that concrete ring ends up in the Smithsonian? As the machine that built the machine?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MichaelBlackbourn on 03/19/2019 01:14 am
If this program ends up the way that Elon is intending do you suppose that concrete ring ends up in the Smithsonian? As the machine that built the machine?

A stonelike circle that enabled travel to other planets....

A literal Stargate.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 01:22 am
If this program ends up the way that Elon is intending do you suppose that concrete ring ends up in the Smithsonian? As the machine that built the machine?

Elon has said a number of times that building a car manufacturing system is 100 times as difficult as building the car and building a rocket manufacturing system is 10 times as difficult as building the rocket.  But that comparison is based on Falcon 1, Falcon 9, Falcon Heavy.  Now with Starship the machine that builds the machine is a small microfraction of 1% as difficult as building the rocket.  A number of orders of magnitude improvement.  That is the revolution.

Its not an alien dreadnaught that got us to Mars it was a concrete ring.  Take some time to wrap your head around that.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 01:33 am
These have been added since (I think) yesterday.  Could they be struts to integrate landing shock absorbers?

(https://forum.nasaspaceflight.com/assets/47301.0/1548902.jpg)

Edit: Images cropped from today's BCG photo updates. Thx BCG!

Could be for tethering, imho.

or just some support for the fuel lines as they are using it now...

Yes.  Confirmed.

Pics taken this afternoon of the launch site.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/19/2019 01:36 am
If this program ends up the way that Elon is intending do you suppose that concrete ring ends up in the Smithsonian? As the machine that built the machine?

Elon has said a number of times that building a car manufacturing system is 100 times as difficult as building the car and building a rocket manufacturing system is 10 times as difficult as building the rocket.  But that comparison is based on Falcon 1, Falcon 9, Falcon Heavy.  Now with Starship the machine that builds the machine is a small microfraction of 1% as difficult as building the rocket.  A number of orders of magnitude improvement.  That is the revolution.

Its not an alien dreadnaught that got us to Mars it was a concrete ring.  Take some time to wrap your head around that.

When Elon talked about 10/100 times difficult, he was talking about mass production, not prototyping. The concrete ring is prototyping, he even called the first Starship build "orbital prototype", so totally different things. I don't think Starships for P2P or Mars mission would be built on concrete rings...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 01:43 am
If this program ends up the way that Elon is intending do you suppose that concrete ring ends up in the Smithsonian? As the machine that built the machine?

Elon has said a number of times that building a car manufacturing system is 100 times as difficult as building the car and building a rocket manufacturing system is 10 times as difficult as building the rocket.  But that comparison is based on Falcon 1, Falcon 9, Falcon Heavy.  Now with Starship the machine that builds the machine is a small microfraction of 1% as difficult as building the rocket.  A number of orders of magnitude improvement.  That is the revolution.

Its not an alien dreadnaught that got us to Mars it was a concrete ring.  Take some time to wrap your head around that.

When Elon talked about 10/100 times difficult, he was talking about mass production, not prototyping. The concrete ring is prototyping, he even called the first Starship build "orbital prototype", so totally different things. I don't think Starships for P2P or Mars mission would be built on concrete rings...

I think that is the manufacturing method. It looks like it may take some more of Elon's twitter shock treatments to align your thinking with the new reality   ;)

edit: unless you are talking about the added complexity of having interior accommodations which I've been guessing SpaceX will farm out to Winnebago
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/19/2019 02:16 am
If this program ends up the way that Elon is intending do you suppose that concrete ring ends up in the Smithsonian? As the machine that built the machine?

Elon has said a number of times that building a car manufacturing system is 100 times as difficult as building the car and building a rocket manufacturing system is 10 times as difficult as building the rocket.  But that comparison is based on Falcon 1, Falcon 9, Falcon Heavy.  Now with Starship the machine that builds the machine is a small microfraction of 1% as difficult as building the rocket.  A number of orders of magnitude improvement.  That is the revolution.

Its not an alien dreadnaught that got us to Mars it was a concrete ring.  Take some time to wrap your head around that.

When Elon talked about 10/100 times difficult, he was talking about mass production, not prototyping. The concrete ring is prototyping, he even called the first Starship build "orbital prototype", so totally different things. I don't think Starships for P2P or Mars mission would be built on concrete rings...

I think that is the manufacturing method. It looks like it may take some more of Elon's twitter shock treatments to align your thinking with the new reality   ;)

edit: unless you are talking about the added complexity of having interior accommodations which I've been guessing SpaceX will farm out to Winnebago

At the risk of going off topic: No, I meant the welding of the tanks, etc, it will go inside a proper factory after the prototyping phase. You can read this between the lines in their job description, something like "building early Starship and SuperHeavy faster than anyone imagined possible", keyword is "early".

If we use a Tesla analogy, what we're seeing is them putting together the Roadster 2 or Semi prototype they're showing off last year, the prototype does work, you can drive them around, but it's still sometime before they can mass produce them, and the latter will use different manufacturing method and is the hard part Elon was talking about.

The revolution may be this: With reusable rocket, prototype can actually earn significant amount of money. The car prototype can get some reservation fees, but you won't get real money until mass production starts. For a reusable rocket prototype, as long as the reuse works, it can launch real payload and earn real money right from the start.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThatOldJanxSpirit on 03/19/2019 06:10 am
If this program ends up the way that Elon is intending do you suppose that concrete ring ends up in the Smithsonian? As the machine that built the machine?

Elon has said a number of times that building a car manufacturing system is 100 times as difficult as building the car and building a rocket manufacturing system is 10 times as difficult as building the rocket.  But that comparison is based on Falcon 1, Falcon 9, Falcon Heavy.  Now with Starship the machine that builds the machine is a small microfraction of 1% as difficult as building the rocket.  A number of orders of magnitude improvement.  That is the revolution.

Its not an alien dreadnaught that got us to Mars it was a concrete ring.  Take some time to wrap your head around that.

When Elon talked about 10/100 times difficult, he was talking about mass production, not prototyping. The concrete ring is prototyping, he even called the first Starship build "orbital prototype", so totally different things. I don't think Starships for P2P or Mars mission would be built on concrete rings...

I think that is the manufacturing method. It looks like it may take some more of Elon's twitter shock treatments to align your thinking with the new reality   ;)

edit: unless you are talking about the added complexity of having interior accommodations which I've been guessing SpaceX will farm out to Winnebago

At the risk of going off topic: No, I meant the welding of the tanks, etc, it will go inside a proper factory after the prototyping phase. You can read this between the lines in their job description, something like "building early Starship and SuperHeavy faster than anyone imagined possible", keyword is "early".

If we use a Tesla analogy, what we're seeing is them putting together the Roadster 2 or Semi prototype they're showing off last year, the prototype does work, you can drive them around, but it's still sometime before they can mass produce them, and the latter will use different manufacturing method and is the hard part Elon was talking about.

The revolution may be this: With reusable rocket, prototype can actually earn significant amount of money. The car prototype can get some reservation fees, but you won't get real money until mass production starts. For a reusable rocket prototype, as long as the reuse works, it can launch real payload and earn real money right from the start.

Large ships (the seagoing type) are typically built in the open. You weld together the outer shell, then do the complex fitting out inside. The ship essentially becomes its own weathertight assembly facility. I really can’t see any reason to SpaceX not to do this.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: hrissan on 03/19/2019 07:40 am
Where is the source of info that first flights would be “tethered”? Grasshopper hopped without tether.

Is there a crane around which can withstand 50 tons SH suddenly falling from even 1-2 meters, especially with non-vertical speed component?

As I understand cranes are good at slooowly lifting objects, not withstanding objects wildly swinging...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jpo234 on 03/19/2019 08:09 am
Where is the source of info that first flights would be “tethered”? Grasshopper hopped without tether.

Is there a crane around which can withstand 50 tons SH suddenly falling from even 1-2 meters, especially with non-vertical speed component?

As I understand cranes are good at slooowly lifting objects, not withstanding objects wildly swinging...

https://www.brownsvilleherald.com/news/local/tethered-test-flights-to-begin-in-days-ahead-at-boca/article_d60f3c46-429c-11e9-9b18-23e8496132b2.html

They quote James Gleeson (https://twitter.com/gleesonjm):
Quote
“Although the prototype is designed to perform sub-orbital flights, or hops, powered by the SpaceX Raptor engine, the vehicle will be tethered during initial testing and hops will not be visible from offsite. SpaceX will establish a safety zone perimeter in coordination with local enforcement and signage will be in place to alert the community prior to the testing.”
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Crispy on 03/19/2019 08:25 am
Tethered to the ground, maybe. Enough slack to let it rise a metre or two, but not enough to tip over.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/19/2019 08:35 am
Large ships (the seagoing type) are typically built in the open. You weld together the outer shell, then do the complex fitting out inside. The ship essentially becomes its own weathertight assembly facility. I really can’t see any reason to SpaceX not to do this.

I think there are a goodly number of reasons to fabricate inside a building.

See my argument here:  https://forum.nasaspaceflight.com/index.php?topic=47688.msg1924433#msg1924433
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jerwah on 03/19/2019 08:41 am



edit: unless you are talking about the added complexity of having interior accommodations which I've been guessing SpaceX will farm out to Winnebago

Airstream is the only logical choice for an all stainless vehicle
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rpapo on 03/19/2019 09:09 am
Airstream is the only logical choice for an all stainless vehicle
Airstream trailers are or were built with an aluminum skin, not stainless steel.

https://en.wikipedia.org/wiki/Airstream
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Brigo on 03/19/2019 09:23 am
Hi, i am new here, this is my first post.
I just want to share with you my concern about the raptor production time, i readed somewhere that raptors can be build 2 every month (1 every 2 weeks)  and we need 3 for the hooper, 7 for the orbital prototype and 31 for the Superheavy that is 41, 82 week 20 month.
A lot of time, don't you think?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 03/19/2019 09:46 am
I readed somewhere that raptors can be build 2 every month (1 every 2 weeks)  and we need 3 for the hooper, 7 for the orbital prototype and 31 for the Superheavy that is 41, 82 week 20 month.
A lot of time, don't you think?
Was that build rate, or build time? When you have a team doing serial production you can start a new one before you finish the previous.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Joseph Peterson on 03/19/2019 10:01 am
Hi, i am new here, this is my first post.
I just want to share with you my concern about the raptor production time, i readed somewhere that raptors can be build 2 every month (1 every 2 weeks)  and we need 3 for the hooper, 7 for the orbital prototype and 31 for the Superheavy that is 41, 82 week 20 month.
A lot of time, don't you think?

Welcome to the forum.

I'd really need to see a source on the two per month figure because that seems laughably low once Raptor moves from development into production.

What I can address is engine counts.  Engines used on hopper can be reused on later rockets.  We can safely ignore these three.  Starship might not need all seven engines to begin orbital testing.  I could see only five being used if there is indeed an engine shortage.  The real savings come on Super Heavy.  Super Heavy is massive overkill for early testing.  The consensus here is that 19 engines is sufficient, although I believe early testing could begin with as few as 13.  This means that SpaceX doesn't need 41.  They need 20-24, or basically less than a year's worth at the quoted rate.

Add in any improvement in production rates and engine concerns go away.  I don't see an issue here.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Brigo on 03/19/2019 10:50 am
Hi, i am new here, this is my first post.
I just want to share with you my concern about the raptor production time, i readed somewhere that raptors can be build 2 every month (1 every 2 weeks)  and we need 3 for the hooper, 7 for the orbital prototype and 31 for the Superheavy that is 41, 82 week 20 month.
A lot of time, don't you think?

Welcome to the forum.

I'd really need to see a source on the two per month figure because that seems laughably low once Raptor moves from development into production.

What I can address is engine counts.  Engines used on hopper can be reused on later rockets.  We can safely ignore these three.  Starship might not need all seven engines to begin orbital testing.  I could see only five being used if there is indeed an engine shortage.  The real savings come on Super Heavy.  Super Heavy is massive overkill for early testing.  The consensus here is that 19 engines is sufficient, although I believe early testing could begin with as few as 13.  This means that SpaceX doesn't need 41.  They need 20-24, or basically less than a year's worth at the quoted rate.

Add in any improvement in production rates and engine concerns go away.  I don't see an issue here.

I can't find the quote about raptor production time, sorry, maybe i am wrong.
Anyway, if SpaceX can produce a raptor/week, we can get a full SS+SH stack in a year, i think this is completly reasonable.
Provided Spacex seems very confident about the SH, i expect no SH hopper, just a functional one that will be tested, as you said, with few raptors first.

Thanks for your answers
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/19/2019 10:52 am
Where is the source of info that first flights would be “tethered”? Grasshopper hopped without tether.

Is there a crane around which can withstand 50 tons SH suddenly falling from even 1-2 meters, especially with non-vertical speed component?

As I understand cranes are good at slooowly lifting objects, not withstanding objects wildly swinging...

Tether does not necessarily have to be done from the top. And no, they will probably not do "HOP/DROPS". They will all be "HOVER/SOFT LANDS" more than likely.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/19/2019 10:55 am
Large ships (the seagoing type) are typically built in the open. You weld together the outer shell, then do the complex fitting out inside. The ship essentially becomes its own weathertight assembly facility. I really can’t see any reason to SpaceX not to do this.

I think there are a goodly number of reasons to fabricate inside a building.

See my argument here:  https://forum.nasaspaceflight.com/index.php?topic=47688.msg1924433#msg1924433

You forgot about the cost of making a building to fabricate in. Reason enough not to.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/19/2019 11:03 am
I readed somewhere that raptors can be build 2 every month (1 every 2 weeks)  and we need 3 for the hooper, 7 for the orbital prototype and 31 for the Superheavy that is 41, 82 week 20 month.
A lot of time, don't you think?
Was that build rate, or build time? When you have a team doing serial production you can start a new one before you finish the previous.

Not to mention that if you  pour all of your resources into it (and all of spaceX F9 resources are indeed significant),
 you can build raptor engines in parallel, then you can manufacture many in a significantly reduced amount of time.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ramomlopes on 03/19/2019 11:05 am
Hello,

How does Mr. Musk intend to put StarHopper on an orbital flight without a launch vehicle? Is there a parallel assembly of a launch vehicle in other facilities?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/19/2019 11:13 am
I think there are a goodly number of reasons to fabricate inside a building.

See my argument here:  https://forum.nasaspaceflight.com/index.php?topic=47688.msg1924433#msg1924433

You forgot about the cost of making a building to fabricate in. Reason enough not to.

I didn't forget about anything.  A building is a cost, not a significant one that would rise to the level of "reason enough not to".   Structural steel is already on-site
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rpapo on 03/19/2019 11:16 am
Hello,

How does Mr. Musk intend to put StarHopper on an orbital flight without a launch vehicle? Is there a parallel assembly of a launch vehicle in other facilities?
Read the earlier posts.  The StarHopper is not expected to exceed five kilometers altitude, nor achieve any significant velocity.  The Hopper is a testbed for a variety of things, but orbit and especially orbital reentry are not on the list for this early prototype.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/19/2019 11:17 am
Large ships (the seagoing type) are typically built in the open. You weld together the outer shell, then do the complex fitting out inside. The ship essentially becomes its own weathertight assembly facility. I really can’t see any reason to SpaceX not to do this.

I think there are a goodly number of reasons to fabricate inside a building.

See my argument here:  https://forum.nasaspaceflight.com/index.php?topic=47688.msg1924433#msg1924433

You forgot about the cost of making a building to fabricate in. Reason enough not to.

A steel prefab building is dirt cheap, https://www.buildingsguide.com/blog/planning-steel-warehouse-building/ gives a cost of $6.73 per sq ft, SpaceX's original plan for the L.A. port factory calls for 80,000 sq ft in phase 1 and 200,000 sq ft in phase 2, that's just $500K to $1.3M.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rakaydos on 03/19/2019 11:21 am
Hello,

How does Mr. Musk intend to put StarHopper on an orbital flight without a launch vehicle? Is there a parallel assembly of a launch vehicle in other facilities?
Read the earlier posts.  The StarHopper is not expected to exceed five kilometers altitude, nor achieve any significant velocity.  The Hopper is a testbed for a variety of things, but orbit and especially orbital reentry are not on the list for this early prototype.
Adding to this, there is an "Orbital prototype" also being assembled in texas, which will do suborbital heat shield tests, before either a 0 payload SSTO and return, or being mounted to a SH prototype and orbital return.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/19/2019 11:29 am
A steel prefab building is dirt cheap, https://www.buildingsguide.com/blog/planning-steel-warehouse-building/ gives a cost of $6.73 per sq ft, SpaceX's original plan for the L.A. port factory calls for 80,000 sq ft in phase 1 and 200,000 sq ft in phase 2, that's just $500K to $1.3M.

Exactly!!!  This site suggest $20 upper-end for turnkey with material, foundation, and labor.  https://www.buildingsguide.com/faq/what-average-commercial-building-cost-square-foot/

And with the pivot to Stainless, it's likely nothing as ambitious as the LA Port 80K sqft would be needed, particularly with the cramped quarters at Boca.  Something on the order of 100'x300' which by the table below would be $230K base price roughly doubled with labor, etc... and you're at $500K.  Readily doable and well (IMO) worth it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: kessdawg on 03/19/2019 12:21 pm
Now subtract from the cost of the building the cost of downtime due to inclement weather, etc.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Dave G on 03/19/2019 12:22 pm
I suspect most of the manufacturing for Starship and Super Heavy will occur in Hawthorne. This includes the Raptor engines, avionics, etc. - basically any sub-assembly small enough to be road transported.

So we're only talking about building the large tank structures and doing the final assembly at Boca Chica.

Also note that the SpaceX owned property (shown in yellow below) is oddly shaped and disjointed.

With all this in mind, using tents and open-air construction may be the best option, at least for now.

By the way, doesn't Tesla build some of their Model 3 cars in a tent?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/19/2019 12:36 pm
A steel prefab building is dirt cheap, https://www.buildingsguide.com/blog/planning-steel-warehouse-building/ gives a cost of $6.73 per sq ft, SpaceX's original plan for the L.A. port factory calls for 80,000 sq ft in phase 1 and 200,000 sq ft in phase 2, that's just $500K to $1.3M.

Exactly!!!  This site suggest $20 upper-end for turnkey with material, foundation, and labor.  https://www.buildingsguide.com/faq/what-average-commercial-building-cost-square-foot/

And with the pivot to Stainless, it's likely nothing as ambitious as the LA Port 80K sqft would be needed, particularly with the cramped quarters at Boca.  Something on the order of 100'x300' which by the table below would be $230K base price roughly doubled with labor, etc... and you're at $500K.  Readily doable and well (IMO) worth it.

For the production ships it will most likely be done in a facility. I don't see the need for the prototypes. Best to cut time and money wherever you can to meet the 2022 target. If time wasn't an issue, then yeah, cost is not a big issue.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Star One on 03/19/2019 01:02 pm
I readed somewhere that raptors can be build 2 every month (1 every 2 weeks)  and we need 3 for the hooper, 7 for the orbital prototype and 31 for the Superheavy that is 41, 82 week 20 month.
A lot of time, don't you think?
Was that build rate, or build time? When you have a team doing serial production you can start a new one before you finish the previous.

Not to mention that if you  pour all of your resources into it (and all of spaceX F9 resources are indeed significant),
 you can build raptor engines in parallel, then you can manufacture many in a significantly reduced amount of time.

That’s not likely to happen with Crew Dragon reaching a critical point as a program.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: su27k on 03/19/2019 01:10 pm
I suspect most of the manufacturing for Starship and Super Heavy will occur in Hawthorne. This includes the Raptor engines, avionics, etc. - basically any sub-assembly small enough to be road transported.

So we're only talking about building the large tank structures and doing the final assembly at Boca Chica.

Also note that the SpaceX owned property (shown in yellow below) is oddly shaped and disjointed.

If I'm not mistaken, the hopper tent property (biggest yellow block, property id 399760) is 12.76 acres, that's 555,825.6 sq ft, more than enough to contain SpaceX's proposed L.A. port factory (80,000 to 200,000 sq ft).

Quote
With all this in mind, using tents and open-air construction may be the best option, at least for now.

By the way, doesn't Tesla build some of their Model 3 cars in a tent?

Tesla does use a big tent for general assembly line 4, but we're already seeing SpaceX has parts for a steel prefab building on their property as pointed out by AC in NC here (https://forum.nasaspaceflight.com/index.php?topic=47301.msg1923509#msg1923509), so it looks like they do want to build something that is not a tent.

What confuses me is that the amount of material seems to be too small for a big assembly building.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/19/2019 01:36 pm
I suspect most of the manufacturing for Starship and Super Heavy will occur in Hawthorne. This includes the Raptor engines, avionics, etc. - basically any sub-assembly small enough to be road transported.

So we're only talking about building the large tank structures and doing the final assembly at Boca Chica.

Also note that the SpaceX owned property (shown in yellow below) is oddly shaped and disjointed.

If I'm not mistaken, the hopper tent property (biggest yellow block, property id 399760) is 12.76 acres, that's 555,825.6 sq ft, more than enough to contain SpaceX's proposed L.A. port factory (80,000 to 200,000 sq ft).

Quote
With all this in mind, using tents and open-air construction may be the best option, at least for now.

By the way, doesn't Tesla build some of their Model 3 cars in a tent?

Tesla does use a big tent for general assembly line 4, but we're already seeing SpaceX has parts for a steel prefab building on their property as pointed out by AC in NC here (https://forum.nasaspaceflight.com/index.php?topic=47301.msg1923509#msg1923509), so it looks like they do want to build something that is not a tent.

What confuses me is that the amount of material seems to be too small for a big assembly building.
It would probably really help to have an indoor facility to build cylinder sections and work on the bottom one with the thrust structure and most of the plumbing even if they still assemble whole thing outdoors. A 200 foot tall building (Or bigger if they do the booster) is a whole different deal than a plain 50 foot tall warehouse.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 03/19/2019 01:40 pm
>
By the way, doesn't Tesla build some of their Model 3 cars in a tent

They build Model 3 in a ~13,000 sq/m (305x46x16m) Sprung Structure. Went up in 3 weeks.

While it's easy to think of them as a "just a tent" tension fabric buildings like Sprung and others make can be permanent and very strong, meeting hurricane code, and have been used everywhere from deserts to the poles.

I could see a Sprung assembly line for SS/SH barrel segments which get stacked and welded together in a VAB-like assembly structure.

I wouldn't be surprised if the SS propulsion and payload sections remain separate modules, allowing either to be swapped out for repair or mission type.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RedLineTrain on 03/19/2019 01:46 pm
I don't think Sprung has structures that are suitable for vertical construction.  As Nomadd says, 200-foot tall structures are a different thing entirely (not cheap).  Doesn't mean they can't introduce such a product line with the help of SpaceX, of course.  But they probably wouldn't be cheap.

Gwynne Shotwell has spoken about the unfavorable cost of vertical manufacturing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/19/2019 01:50 pm
By the way, doesn't Tesla build some of their Model 3 cars in a tent?
Yep, just down the road from me.  But Fremont isn't in danger from hurricanes, storms, or even just lightning.  Coastal waters are too cold, and it's sheltered behind a first line of defense set of mountains to the west along the coast AND it's situated at the bottom of the bay.  What we call rain around here is what most of you refer to as drizzle.  San Jose has gotten a total of 13.5 inches of rain since July 1st 2018, and our rain is nearly done.  It's not St. George UT, but Brownsville averages twice what we've gotten in a year.  It gets colder here -- I think we've had a couple of days of frost.  Probably not fun to assemble cars in ~40F weather.  Other than that, though....

I think it's a mistake not to take sheltering concerns seriously.  At an elevation of ~1m, I assume you've got other issues to think about as well, but I'm not familiar with the storm dynamics of the area.  If they wanted to build under tents, they should have stayed in LA where there's really no weather.  But even there they were planning physical buildings.  They were using tents while the building(s) were being architected and built.  Tents were used at Fremont because inside-building construction was taking too long.  I assume the same will happen here.  It's cool that we can watch progress on the prototypes, but I don't expect that access to continue.

Remains to be seen what will and what won't be done in the open.  Should be an interesting mix.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/19/2019 02:04 pm
Speaking of expectations:
Another pic of the liquid oxygen delivery. I am sure the tall tank on the right had previously been marked liquid nitrogen.

That tank is marked at 60,000 liters.  That's utterly insufficient for Starship.  Afaik we need more than ten times this amount of O2 for starship.

Just how big are the tanks in the hopper?

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CraigLieb on 03/19/2019 02:22 pm
If this program ends up the way that Elon is intending do you suppose that concrete ring ends up in the Smithsonian? As the machine that built the machine?

A stonelike circle that enabled travel to other planets....

A literal Stargate.
A hopper-off point?
One ring to launch them all?
The journey of a trillion miles begins with a single concrete step, or maybe a Mariachi band?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JamesH65 on 03/19/2019 02:53 pm
With regard to building a facility to build the SS in vs building outside, firstly it would need to be huge, which starts to bump the price, but also it will take some time to build, and there is litle evidence of foundations being built anywhere on site. And SpaceX appear to be in a hurry.

I'd be more inclined to think they would construct smaller buildings for subcomponent assembly, but build the main shell in the open from subcomponents. Bad weather much less likely to cause delays if done like this - because you can do indoors work when the weather is bad, and the outdoors work when it isn't. More akin to ship building that the current practice for rocket building.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/19/2019 03:26 pm
Speaking of expectations:
Another pic of the liquid oxygen delivery. I am sure the tall tank on the right had previously been marked liquid nitrogen.

That tank is marked at 60,000 liters.  That's utterly insufficient for Starship.  Afaik we need more than ten times this amount of O2 for starship.

Just how big are the tanks in the hopper?


There's a 95,000 gallon LOX tank and 80,000 gallon LCH4 tank nearby. Still not enough to fill a Starship, but enough for a full Hopper load. The small tanks are enough for the test fires and short hops.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 04:26 pm
I'm leaning toward thinking the concrete ring is the long term manufacturing facility. But I may be wrong. One way that manufacturing could be sped up by automation and quality control could be increased substantially would be if they were to skip the early step of forming the cylinder from pre-made and shipped panels.  They could use spiral welded stainless steel pipe pre-made to the necessary length and diameter elsewhere along the Gulf and barged in.  Then SH / SH could be flushed out on a concrete ring or in a factory as some are suggesting.

https://www.youtube.com/watch?v=x4l2IQQhw-U (https://www.youtube.com/watch?v=x4l2IQQhw-U)

There are no facilities making spiral welded pipe anywhere this large in diameter as far as I know so this would require a new facility ($$$) and that facility would probably need to be at the end of a steel mini-mill to get the continuous strip.  Then there may or may not be the ability to continuously vary the thickness as you go up.  Or not.  And the tapered nose on SS would still need to be another thing.  But for speed and consistency this couldn't be beat, a SH sized tube could be completed in a day I'd guess.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/19/2019 04:31 pm
I'm leaning toward thinking the concrete ring is the long term manufacturing facility. But I may be wrong. One way that manufacturing could be sped up by automation and quality control could be increased substantially would be if they were to skip the early step of forming the cylinder from pre-made and shipped panels.  They could use spiral welded stainless steel pipe pre-made to the necessary length and diameter elsewhere along the Gulf and barged in.  Then SH / SH could be flushed out on a concrete ring or in a factory as some are suggesting.

https://www.youtube.com/watch?v=x4l2IQQhw-U (https://www.youtube.com/watch?v=x4l2IQQhw-U)

There are no facilities making spiral welded pipe anywhere this large in diameter as far as I know so this would require a new facility ($$$) and that facility would probably need to be at the end of a steel mini-mill to get the continuous strip.  Then there may or may not be the ability to continuously vary the thickness as you go up.  Or not.  And the tapered nose on SS would still need to be another thing.  But for speed and consistency this couldn't be beat, a SH sized tube could be completed in a day I'd guess.

I think this tweet from early January puts the kibosh on that idea:

https://twitter.com/elonmusk/status/1081676911066017793?lang=en

It also, now that I'm bringing it up, shows that the skin will vary in thickness.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/19/2019 04:44 pm
I think this tweet from early January puts the kibosh on that idea:  It also, now that I'm bringing it up, shows that the skin will vary in thickness.

Nothing to world's largest lathe couldn't handle.   :D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Mark K on 03/19/2019 05:04 pm
I think this tweet from early January puts the kibosh on that idea:  It also, now that I'm bringing it up, shows that the skin will vary in thickness.

Nothing to world's largest lathe couldn't handle.   :D

Call up Abom79!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/19/2019 05:14 pm
There are probably a number of reasons for not using a building for the prototype but one significant one may be that they don't know where they will be building Starship and Superheavy with certainty yet and they don't won't to construct an expensive building only to find they can't use it or it’s inconvenient.(and they need to build the prototypes now)

When the authorities respond to the SpaceX request for launch permission for SH/SS from the Florida and Texas launch sites they will have a better idea. Could be both sites, either site or neither site all with different options for where to construct the building.

Other options for the building itself would be to construct both SS and SH horizontaly or construct SH horizontally and SS vertically. This would reduce the height of the required building.


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: StuffOfInterest on 03/19/2019 05:23 pm
Why is everyone stuck on the idea that the Starship or Super Heavy has to be assembled vertically?  Falcon 9 bodies are assembled horizontally.  SS/SH is bigger but could still be done horizontally with the proper support to avoid deformation.  Most likely, slices of the barrel would be built in a vertical orientation and then flipped horizontal for joining.  You would need a long structure, but it wouldn't need to be overly tall.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/19/2019 05:42 pm
The way the series production for Starship / Super heavy is going to work is sure a very exciting question, however this thread should stick to the Hopper a bit more i think.

Maybe discuss series production here?
https://forum.nasaspaceflight.com/index.php?topic=46996.0

Or open a new thread if you wanna go deeper?

On the Hopper side, flaring and a 6 hour window for first Raptor fire! Woo!  8)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OldPeopleBurning on 03/19/2019 05:51 pm
Why is everyone stuck on the idea that the Starship or Super Heavy has to be assembled vertically?  Falcon 9 bodies are assembled horizontally.  SS/SH is bigger but could still be done horizontally with the proper support to avoid deformation.  Most likely, slices of the barrel would be built in a vertical orientation and then flipped horizontal for joining.  You would need a long structure, but it wouldn't need to be overly tall.

I like this idea. They might not even need a long structure, just one with open ends and a track running through the middle. Something to keep out the elements while each section was made weather tight.

What I really want to see is the monster they will have to build to get it vertical when done. Maybe contract with a drawbridge company.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DistantTemple on 03/19/2019 06:03 pm
It will be long, and wide and relatively delicate, but not heavy by crane standards. So whatever lifts it could be similar, or it could be (like a) conventional crane. Not really a monster.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: raketa on 03/19/2019 06:04 pm
If this program ends up the way that Elon is intending do you suppose that concrete ring ends up in the Smithsonian? As the machine that built the machine?

Elon has said a number of times that building a car manufacturing system is 100 times as difficult as building the car and building a rocket manufacturing system is 10 times as difficult as building the rocket.  But that comparison is based on Falcon 1, Falcon 9, Falcon Heavy.  Now with Starship the machine that builds the machine is a small microfraction of 1% as difficult as building the rocket.  A number of orders of magnitude improvement.  That is the revolution.

Its not an alien dreadnaught that got us to Mars it was a concrete ring.  Take some time to wrap your head around that.

When Elon talked about 10/100 times difficult, he was talking about mass production, not prototyping. The concrete ring is prototyping, he even called the first Starship build "orbital prototype", so totally different things. I don't think Starships for P2P or Mars mission would be built on concrete rings...
1/are you sure? the way building is one of most break through i think
2/Components that need precision are build in factory but deliver as black box to rocket
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: raketa on 03/19/2019 06:12 pm
Hi, i am new here, this is my first post.
I just want to share with you my concern about the raptor production time, i readed somewhere that raptors can be build 2 every month (1 every 2 weeks)  and we need 3 for the hooper, 7 for the orbital prototype and 31 for the Superheavy that is 41, 82 week 20 month.
A lot of time, don't you think?

Welcome to the forum.

I'd really need to see a source on the two per month figure because that seems laughably low once Raptor moves from development into production.

What I can address is engine counts.  Engines used on hopper can be reused on later rockets.  We can safely ignore these three.  Starship might not need all seven engines to begin orbital testing.  I could see only five being used if there is indeed an engine shortage.  The real savings come on Super Heavy.  Super Heavy is massive overkill for early testing.  The consensus here is that 19 engines is sufficient, although I believe early testing could begin with as few as 13.  This means that SpaceX doesn't need 41.  They need 20-24, or basically less than a year's worth at the quoted rate.

Add in any improvement in production rates and engine concerns go away.  I don't see an issue here.

I can't find the quote about raptor production time, sorry, maybe i am wrong.
Anyway, if SpaceX can produce a raptor/week, we can get a full SS+SH stack in a year, i think this is completly reasonable.
Provided Spacex seems very confident about the SH, i expect no SH hopper, just a functional one that will be tested, as you said, with few raptors first.

Thanks for your answers
It  was estimate base on arrival first raptor 1 to Mc Gregor February 3 and availability Raptor 2 several days ago. It sound more like 1 raptor in month.  But raptor 2 has to be modified to fix issue with Raptor 21
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DistantTemple on 03/19/2019 06:20 pm
Building 1000 cars a week, with almost no defects that need any extra skilled intervention, is what is hard about cars. each with 1000's of parts and processes....
Building even 1 Starship a month will only have some automated processes, with a high level of skilled oversight. Having to return to re-do a task will not be likely to "bring the line to a halt" or produce a parking lot of vehicles that need rework!  Initially the market does not call for dozens of Starships, and when It begins to the build process will be adequately understood.  A new "line" to increase production of SS  will mean opening up another working bay at any time critical processes, not so much putting up an additional factory under a tent - complete with conveyors and all the robots!!!. I admit the engine production would be riper for more of a production line, but even 2 per day would not require the sort of infrastructure that cars at "one-a-minute" do.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Papagolash on 03/19/2019 07:44 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/19/2019 08:08 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Congrats on your first post - best to jump in with both feet. Thanks for the letter posting, - and it should definitely be posted in this thread. I believe it's been shared on the Boca Chica facility thread, but not here, so it's good to have this on record.

Edit: Correction - the letter was posted to the Photos and Updates thread:

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1924636#msg1924636
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/19/2019 08:18 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Not sure what locals got it, but I never saw one.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/19/2019 08:22 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Not sure what locals got it, but I never saw one.
Perhaps Nomadd they thought you were loco, not local...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/19/2019 09:04 pm
One of the legs has a different tether.

Looks like a massive Load Rachet wrapped in some Fire Resistant Foil Tape
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/19/2019 09:15 pm
One of the legs has a different tether.

Looks like a massive Load Rachet wrapped in some Fire Resistant Foil Tape

in that photo you can also see that the holes are welded inside. so the holes are just extra weld area instead of just being welded at the edges.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 09:38 pm
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Retired Downrange on 03/19/2019 09:55 pm
Why is everyone stuck on the idea that the Starship or Super Heavy has to be assembled vertically?  Falcon 9 bodies are assembled horizontally.  SS/SH is bigger but could still be done horizontally with the proper support to avoid deformation.  Most likely, slices of the barrel would be built in a vertical orientation and then flipped horizontal for joining.  You would need a long structure, but it wouldn't need to be overly tall.
The Saturn Rocket was 33 feet in diameter and was constructed and shipped horizontally.
(I used a screenshot of this collectspace.com photo as I don’t know how to link it)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 09:57 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Not sure what locals got it, but I never saw one.
Perhaps Nomadd they thought you were loco, not local...

Those who put their cats and dogs in the basement between 10 and 4 were thought to be quite insane by those who didn't get the letter.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: bocachicagal on 03/19/2019 10:14 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Not sure what locals got it, but I never saw one.
Perhaps Nomadd they thought you were loco, not local...
This local bocachicagal did not receive the letter.  :(
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/19/2019 10:18 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Not sure what locals got it, but I never saw one.
Perhaps Nomadd they thought you were loco, not local...
This local bocachicagal did not receive the letter.  :(

Maybe they just figured you two would be excited about the surprise.  ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: dnavas on 03/19/2019 10:18 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Not sure what locals got it, but I never saw one.
Perhaps Nomadd they thought you were loco, not local...
This local bocachicagal did not receive the letter.  :(

The original post in the Updates thread indicates that it was pulled from facebook, not received via snailmail.

Source: SpaceX Boca Chica Facebook group
Road Closures expected March 20
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/19/2019 10:26 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Not sure what locals got it, but I never saw one.
Perhaps Nomadd they thought you were loco, not local...
This local bocachicagal did not receive the letter.  :(
In all seriousness, I find it really remarkable that you guys didn’t receive this notification. How difficult is it to deliver this stuff to the villagers?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: eriblo on 03/19/2019 10:34 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Not sure what locals got it, but I never saw one.
Perhaps Nomadd they thought you were loco, not local...
This local bocachicagal did not receive the letter.  :(
In all seriousness, I find it really remarkable that you guys didn’t receive this notification. How difficult is it to deliver this stuff to the villagers?
Not sure anybody "got it", looks like that it's a public notice posted on the Cameron County Beach Patrol facebook page (https://www.facebook.com/cameroncountybeachpatrol/?tn-str=k*F) and possibly other places. You know, you have to check your local planning office and all that...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 10:39 pm
Official notices from the court regarding a safety issue go out through a beach patrol facebook page?   :o
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: jerwah on 03/19/2019 10:49 pm
Official notices from the court regarding a safety issue go out through a beach patrol facebook page?   :o
I started to doubt the veracity of the posting, but I was able to find it on the Cameron County official site.

http://www.co.cameron.tx.us/public_services/hwy_4_and_boca_chica_beach_closures.php

The big question is if the message boards on the road have been updated. My recollection was the original court order specified that was the local notice.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 10:52 pm
Official notices from the court regarding a safety issue go out through a beach patrol facebook page?   :o
I started to doubt the veracity of the posting, but I was able to find it on the Cameron County official site.

http://www.co.cameron.tx.us/public_services/hwy_4_and_boca_chica_beach_closures.php

The big question is if the message boards on the road have been updated. My recollection was the original court order specified that was the local notice.

I was just on the Cameron County website after I posted that also. I didn't find what you found but I did see that the home page for the county has at its top in very large lettering the word "SpaceX" with no other explanation.  And the agenda item from the March 14th meeting that lead to that road closure order.
http://www.co.cameron.tx.us/ (http://www.co.cameron.tx.us/)
http://www.co.cameron.tx.us/Agenda/2019.03.14%20-%20Special%20Meeting.pdf (http://www.co.cameron.tx.us/Agenda/2019.03.14%20-%20Special%20Meeting.pdf)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/19/2019 11:17 pm
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/19/2019 11:43 pm
I wonder... does Boca Chica have civil defense sirens?...  ???
You know... like the ones that blanket the Midwest and are mainly used as tornado/severe storm warnings...

 https://youtu.be/DpDGPC3wpd0 (https://youtu.be/DpDGPC3wpd0)

Seems like something could be worked out here with the local civil defense dept and SpaceX...  8)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/20/2019 12:15 am
Official notices from the court regarding a safety issue go out through a beach patrol facebook page?   :o
I started to doubt the veracity of the posting, but I was able to find it on the Cameron County official site.

http://www.co.cameron.tx.us/public_services/hwy_4_and_boca_chica_beach_closures.php

The big question is if the message boards on the road have been updated. My recollection was the original court order specified that was the local notice.

I was just on the Cameron County website after I posted that also. I didn't find what you found but I did see that the home page for the county has at its top in very large lettering the word "SpaceX" with no other explanation.  And the agenda item from the March 14th meeting that lead to that road closure order.
http://www.co.cameron.tx.us/ (http://www.co.cameron.tx.us/)
http://www.co.cameron.tx.us/Agenda/2019.03.14%20-%20Special%20Meeting.pdf (http://www.co.cameron.tx.us/Agenda/2019.03.14%20-%20Special%20Meeting.pdf)

The large SpaceX logo is clickable (at least, part of it is - this is not a good website), and brings you here:http://www.co.cameron.tx.us/public_services/hwy_4_and_boca_chica_beach_closures.php

The following are the relevant passages and figures included for your viewing pleasure:
Quote
Hwy 4 & Boca Chica Beach Closures

 

Cameron County Judge Eddie Treviño, Jr., on behalf of Cameron County and the Cameron County Commissioners Court as authorized by Court Order 2019O3002 hereby ORDERS AND HEREBY GIVES PUBLIC NOTICE of this Order to Temporarily Close State Highway 4 and Boca Chica Beach for the purpose of protecting Public Health and Safety during SpaceX testing activities on March 20th, 2019, in the time period between 10:00 a.m. Central Standard Time and 4:00 p.m. of the same day and in the alternative on either March 21,  or 22nd, 2019 2019, in the time period between 10:00 a.m. Central Standard Time and 4:00 p.m. of the same day in the event the March 20th temporary closure is not utilized.

 

In coordination with the county, SpaceX will establish a safety zone perimeter in that will include two temporary checkpoints on Highway 4, as shown on the 1st map below. Individuals who provide proof of residence between the two checkpoints will be allowed to proceed through the soft checkpoint and access their homes during testing. Access beyond the hard checkpoint to the beach will not be permitted during temporary closures. The beach will be closed as indicated on the 2nd map below. Those wishing to visit a beach during the closures may do so on South Padre Island at Beach Access 3, 4, 4 West and 5 West, free of charge.

It looks like the hard checkpoint is past the village, so Nomadd and BCG just have to get past the soft checkpoint. I suppose that means you'll not get any closeups from the beach or nearby during the tests, no?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Joseph Peterson on 03/20/2019 03:52 am
Hello,

How does Mr. Musk intend to put StarHopper on an orbital flight without a launch vehicle? Is there a parallel assembly of a launch vehicle in other facilities?

We're three pages in and no one has addressed your first ever NSF comment.  It seem it falls on me to rectify this.

First, and most importantly, welcome to the forum.

It is important to understand that reusable rockets have a significant advantage over expendable rockets, not having to reach orbit on the first attempt.  Instead SpaceX, and hopefully soon Blue Origin, can start by simply lifting off the pad a few feet, then touching back down.  This allows companies with reusable rockets to test things like lift off without having to design the entire system before they start testing in earnest.

What SpaceX has done is to build a hopper to learn how to launch and land their system without having to bother with the myriad difficulties going all the way to orbit entails.  Only once hopper has proved launch and landing will orbital attempts be made.  Orbital attempts will be made with a new vehicle built, in part, using lessons learned from hop tests.  That parallel build is already underway, with the first pieces of the orbital model showing up at Boca Chica more than a month ago.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Machdiamond on 03/20/2019 12:10 pm
Further update: the location described above seems slightly off for SpaceX? Aren't they ENE of Brownsville? Google maps coords for SpaceX site are 26.0621887 97.8002943. Please follow-up in discussion thread (https://forum.nasaspaceflight.com/index.php?topic=47301.0).

The FAA NOTAM the 255915.99N0971112.33 coordinates should read like 25°59'15.99"N 97°11'12.33"W

In the NOTAM it looks like decimals but it is actually in degrees. If you copy paste as I wrote above into google maps, the FAA NOTAM is centered on the site where the hopper was assembled rather than the launch pad (close enough).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: frederickm17 on 03/20/2019 01:17 pm
Not sure if this has been discussed yet, but I've been wondering whether the build process we are seeing for these prototypes is going to carry over to the final, mass production versions. Specifically with consideration of the process of cryoforming that Elon has previously mentioned.

It seems like cryoforming SS would be a complicated process that SX would need time to learn and perfect (being something they have not done in the past, and the recent switch to SS).

With that in mind, is the orbital starship prototype being built out of cryoformed SS sheets (cryoformed off site, shipped to BC and welded together), or is SX going to implement cryoforming at a later time?

I'm not a rocket scientist or an expert in cryoforming SS but it seems to me like having larger sheets with less welding would be better for an orbital ship.

So, are there going to be major changes to the production process between these prototypes and the mass production version? (specifically talking about the outer shell)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: tenkendojo on 03/20/2019 01:34 pm
Just a quick update, hopper test postponed to 10AM-4PM tomorrow (3/21):
Quote
March 20, 2019 (https://twitter.com/SpacePadreIsle/status/1108344652254638081?ref_src=twsrc%5Etfw)

<script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: livingjw on 03/20/2019 01:54 pm
Not sure if this has been discussed yet, but I've been wondering whether the build process we are seeing for these prototypes is going to carry over to the final, mass production versions. Specifically with consideration of the process of cryoforming that Elon has previously mentioned.

It seems like cryoforming SS would be a complicated process that SX would need time to learn and perfect (being something they have not done in the past, and the recent switch to SS).

With that in mind, is the orbital starship prototype being built out of cryoformed SS sheets (cryoformed off site, shipped to BC and welded together), or is SX going to implement cryoforming at a later time?

I'm not a rocket scientist or an expert in cryoforming SS but it seems to me like having larger sheets with less welding would be better for an orbital ship.

So, are there going to be major changes to the production process between these prototypes and the mass production version? (specifically talking about the outer shell)

- The prototypes they are currently building are, according to my calculations, overweight, so their stresses will be low enough that cryo-forming will not be needed.

- I do not believe we are seeing the final production technique.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/20/2019 01:56 pm
A couple pics from the launch site this morning. I also confirmed that testing for today has been scrubbed. :(

Gotta move those plastic outhouses or Raptor is going to do it for you.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Ultrafamicom on 03/20/2019 02:04 pm
Not sure if this has been discussed yet, but I've been wondering whether the build process we are seeing for these prototypes is going to carry over to the final, mass production versions. Specifically with consideration of the process of cryoforming that Elon has previously mentioned.

It seems like cryoforming SS would be a complicated process that SX would need time to learn and perfect (being something they have not done in the past, and the recent switch to SS).

With that in mind, is the orbital starship prototype being built out of cryoformed SS sheets (cryoformed off site, shipped to BC and welded together), or is SX going to implement cryoforming at a later time?

I'm not a rocket scientist or an expert in cryoforming SS but it seems to me like having larger sheets with less welding would be better for an orbital ship.

So, are there going to be major changes to the production process between these prototypes and the mass production version? (specifically talking about the outer shell)
I think it would be more pratical to do cryogenic treatment on plates rather than the whole ship?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JohnLloydJones on 03/20/2019 02:06 pm
Not sure if this has been discussed yet, but I've been wondering whether the build process we are seeing for these prototypes is going to carry over to the final, mass production versions. Specifically with consideration of the process of cryoforming that Elon has previously mentioned.

It seems like cryoforming SS would be a complicated process that SX would need time to learn and perfect (being something they have not done in the past, and the recent switch to SS).

With that in mind, is the orbital starship prototype being built out of cryoformed SS sheets (cryoformed off site, shipped to BC and welded together), or is SX going to implement cryoforming at a later time?

I'm not a rocket scientist or an expert in cryoforming SS but it seems to me like having larger sheets with less welding would be better for an orbital ship.

So, are there going to be major changes to the production process between these prototypes and the mass production version? (specifically talking about the outer shell)
I've been wondering about cryoforming, myself. Could it be that the the liquid nitrogen they filled the tanks with was a test of cryoforming? What sort of pressure would be needed to be effective?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 03/20/2019 02:10 pm
Do we need a poll on how many tack welded SS sheets pop off due to vibration from Raptor startup? And will it exceed the number of Port-o-lets blown over? #Snarkasm implied  ;D :o
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JohnLloydJones on 03/20/2019 02:10 pm
Not sure if this has been discussed yet, but I've been wondering whether the build process we are seeing for these prototypes is going to carry over to the final, mass production versions. Specifically with consideration of the process of cryoforming that Elon has previously mentioned.

It seems like cryoforming SS would be a complicated process that SX would need time to learn and perfect (being something they have not done in the past, and the recent switch to SS).

With that in mind, is the orbital starship prototype being built out of cryoformed SS sheets (cryoformed off site, shipped to BC and welded together), or is SX going to implement cryoforming at a later time?

I'm not a rocket scientist or an expert in cryoforming SS but it seems to me like having larger sheets with less welding would be better for an orbital ship.

So, are there going to be major changes to the production process between these prototypes and the mass production version? (specifically talking about the outer shell)

- The prototypes they are currently building are, according to my calculations, overweight, so their stresses will be low enough that cryo-forming will not be needed.

- I do not believe we are seeing the final production technique.
I'm sure you're right about not being needed, but maybe they used the Liquid Nitrogen fill as a test of the procedure.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/20/2019 02:21 pm
 Passed a LOX tanker and one and a half LN2 tankers walking back today.
 I found a couple in a Volkswagen about 500 feet from the hopper waiting for the launch.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CraigLieb on 03/20/2019 02:24 pm
Just a quick update, hopper test postponed to 10AM-4PM tomorrow (3/21):
Quote
March 20, 2019 (https://twitter.com/SpacePadreIsle/status/1108344652254638081?ref_src=twsrc%5Etfw)

<script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>

Weather looks better tomorrow. Are they not testing because of possible lightning today or just rain?
Makes sense to not fill a metal container with Methane and LOX with a storm coming.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: programmerdan on 03/20/2019 02:24 pm
Passed a LOX tanker and one and a half LN2 tankers walking back today.
 I found a couple in a Volkswagen about 500 feet from the hopper waiting for the launch.

I admire their bravery!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/20/2019 02:35 pm
Not sure if this has been discussed yet, but I've been wondering whether the build process we are seeing for these prototypes is going to carry over to the final, mass production versions. Specifically with consideration of the process of cryoforming that Elon has previously mentioned.

It seems like cryoforming SS would be a complicated process that SX would need time to learn and perfect (being something they have not done in the past, and the recent switch to SS).

With that in mind, is the orbital starship prototype being built out of cryoformed SS sheets (cryoformed off site, shipped to BC and welded together), or is SX going to implement cryoforming at a later time?

I'm not a rocket scientist or an expert in cryoforming SS but it seems to me like having larger sheets with less welding would be better for an orbital ship.

So, are there going to be major changes to the production process between these prototypes and the mass production version? (specifically talking about the outer shell)

- The prototypes they are currently building are, according to my calculations, overweight, so their stresses will be low enough that cryo-forming will not be needed.

- I do not believe we are seeing the final production technique.

Yes, it's hard to tell the thickness of the plates, but they appear to be ~6 mm which is thick enough to not need cold working. At 3 bar the hoop stress will be ~225 MPa, vs. the annealed 301 SS tensile strength of ~520 MPa at LOX temps.

A 50 m cylinder of 6 mm wall would be 68 t, which is overweight but not grossly so.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/20/2019 02:36 pm
Passed a LOX tanker and one and a half LN2 tankers walking back today.
 I found a couple in a Volkswagen about 500 feet from the hopper waiting for the launch.

How do you get half a tanker?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/20/2019 02:42 pm
Didnt you hear? If you dont drive your tank off SpaceX property fast enough, it ends up converted into a rocket. That truck only made it half way out i guess.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/20/2019 02:47 pm
Passed a LOX tanker and one and a half LN2 tankers walking back today.
I found a couple in a Volkswagen about 500 feet from the hopper waiting for the launch.

How do you get half a tanker?

More importantly, how to you get a couple in a Volkswagen.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CraigLieb on 03/20/2019 02:53 pm
Passed a LOX tanker and one and a half LN2 tankers walking back today.
 I found a couple in a Volkswagen about 500 feet from the hopper waiting for the launch.

I admire their bravery!
“Welcome hopper... make yourself at home. “
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/20/2019 03:03 pm
Passed a LOX tanker and one and a half LN2 tankers walking back today.
 I found a couple in a Volkswagen about 500 feet from the hopper waiting for the launch.

How do you get half a tanker?
Half length.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/20/2019 03:23 pm
Hi everyone, 1st time posting, been lurking for a few months. Surprised I haven't seen this posted yet but it looks like tomorrow is the 1st attempt at a hop, with back up dates being Thursday and Friday. Timeframe is 10am-4pm for all 3 days and it is referring to road closures for SpaceX testing. This is all according to a letter that the locals received earlier today, if I figure out how to post it I will.......think I figured it out.
Not sure what locals got it, but I never saw one.
Perhaps Nomadd they thought you were loco, not local...
This local bocachicagal did not receive the letter.  :(
In all seriousness, I find it really remarkable that you guys didn’t receive this notification. How difficult is it to deliver this stuff to the villagers?
Not sure anybody "got it", looks like that it's a public notice posted on the Cameron County Beach Patrol facebook page (https://www.facebook.com/cameroncountybeachpatrol/?tn-str=k*F) and possibly other places. You know, you have to check your local planning office and all that...
They said:
 “There’s no point in acting surprised about it. All the planning charts and demolition orders have been on display at your local planning department in Alpha Centauri for 50 of your Earth years, so you’ve had plenty of time to lodge any formal complaint and it’s far too late to start making a fuss about it now. … What do you mean you’ve never been to Alpha Centauri? Oh, for heaven’s sake, mankind, it’s only four light years away, you know. I’m sorry, but if you can’t be bothered to take an interest in local affairs, that’s your own lookout. Energize the demolition beams.”
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/20/2019 03:36 pm
Yes, it's hard to tell the thickness of the plates, but they appear to be ~6 mm which is thick enough to not need cold working. At 3 bar the hoop stress will be ~225 MPa, vs. the annealed 301 SS tensile strength of ~520 MPa at LOX temps.

I did the same calculation 2 days ago with the same inputs, 3 bar, 6mm plate thickness but came to a different conclusion.  I concluded it was right at the yield strength of annealed 304 when looking only at hoop stress.  Where I find the difference between your calculation is your 505 MPa at LOX temp. which is nearly double the room temperature yield strength.  I'm not finding that in a quick Google search, only a much smaller increase with temperature drop.  Here's the most definitive info I could find in an admittedly limited 2 minute search.  How confident are you in 520 MPa at cryo temp?  https://www.penflex.com/austenitic-steels-mechanical-properties-at-cryogenic-temperatures/scg.gov/pdf/lnms/lnm0811g2019.pdf (https://www.penflex.com/austenitic-steels-mechanical-properties-at-cryogenic-temperatures/scg.gov/pdf/lnms/lnm0811g2019.pdf)

Assuming your 520 is correct and that its ~2x the room temp yield strength then that brings up an interesting scenario in my mind.  When you're filling the tank you may get up to 3 bar before the top of the tank has cooled substantially in which case you may be over yield strength (hoop + longitudinal + structural).  Or maybe my perceived problem happens during reentry, its hard to envision all of the tank remaining at -320F.
   edit: oh, but I think we know the plan is for tank pressure to be reduced on return.

And... In looking up 304 cryo yield strength I came across this material which claims to have 2x the tensile properties of 304 while being otherwise similar.  And, it does show a 2x increase in t.s. at cryo temps.  Interesting.  Is this something that we armchairists have considered using in our design?  http://www.electralloy.com/images/pdf/Product_Sheets/Go_Carlson/Nitronic33.pdf (http://www.electralloy.com/images/pdf/Product_Sheets/Go_Carlson/Nitronic33.pdf)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/20/2019 04:13 pm
 I also did a detailed analysis and calculation by glancing at the plates next to a 2x4 and came up with a skosh less than 1/4".
 Except, this is the wrong thread since we're talking about the orbital prototype.
 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Slarty1080 on 03/20/2019 04:27 pm
Sounds interesting. Who knows what might be possible especiay since Musk has a foundry and has been researching super alloys for the Raptor oxygen turbo pump amoung other things so they might have an even better alloy.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magicsound on 03/20/2019 04:32 pm
OxCartMark wrote "I concluded it was right at the yield strength of annealed 304 when looking only at hoop stress. "

From EM comments a while back, SX is using a 310-based alloy, modified for maximum high temperature performance. Cryo yield strength of this alloy is almost 2X that of 304: 510 MPa vs. 269 at -196°C
https://www.nickelinstitute.org/media/1667/designguidelinesfortheselectionanduseofstainlesssteels_9014_.pdf

SH1 may be built from a more common alloy steel, because it won't see the high temp stress of re-entry. The orbital prototype will surely use the special steel mentioned by EM (unless they found something better in the past few months).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: envy887 on 03/20/2019 05:20 pm
Yes, it's hard to tell the thickness of the plates, but they appear to be ~6 mm which is thick enough to not need cold working. At 3 bar the hoop stress will be ~225 MPa, vs. the annealed 301 SS tensile strength of ~520 MPa at LOX temps.

I did the same calculation 2 days ago with the same inputs, 3 bar, 6mm plate thickness but came to a different conclusion.  I concluded it was right at the yield strength of annealed 304 when looking only at hoop stress.  Where I find the difference between your calculation is your 505 MPa at LOX temp. which is nearly double the room temperature yield strength.  I'm not finding that in a quick Google search, only a much smaller increase with temperature drop.  Here's the most definitive info I could find in an admittedly limited 2 minute search.  How confident are you in 520 MPa at cryo temp?  https://www.penflex.com/austenitic-steels-mechanical-properties-at-cryogenic-temperatures/scg.gov/pdf/lnms/lnm0811g2019.pdf (https://www.penflex.com/austenitic-steels-mechanical-properties-at-cryogenic-temperatures/scg.gov/pdf/lnms/lnm0811g2019.pdf)

Assuming your 520 is correct and that its ~2x the room temp yield strength then that brings up an interesting scenario in my mind.  When you're filling the tank you may get up to 3 bar before the top of the tank has cooled substantially in which case you may be over yield strength (hoop + longitudinal + structural).  Or maybe my perceived problem happens during reentry, its hard to envision all of the tank remaining at -320F.
   edit: oh, but I think we know the plan is for tank pressure to be reduced on return.

And... In looking up 304 cryo yield strength I came across this material which claims to have 2x the tensile properties of 304 while being otherwise similar.  And, it does show a 2x increase in t.s. at cryo temps.  Interesting.  Is this something that we armchairists have considered using in our design?  http://www.electralloy.com/images/pdf/Product_Sheets/Go_Carlson/Nitronic33.pdf (http://www.electralloy.com/images/pdf/Product_Sheets/Go_Carlson/Nitronic33.pdf)

This steel supplier gives a strength of 517 MPa at -196 C for annealed 301 SS:
https://www.aksteel.com/sites/default/files/2018-01/301201706_0.pdf

The nice thing about 301 at cryo temps is that very small deformations (even within the elastic range) lead to cold working which results in large increases in yield strength. If the steel yields at cryo temps it's basically cryoforming itself, which can quadruple the strength. It's the ultimate form of bend but don't break: the UTS at -196 C is 1900 MPa because of the cold-working effect. That is nearly 10 times the room temp yield strength.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Spindog on 03/20/2019 08:18 pm
Ok, I've been obsessing on the new hex tiles in the heatshield. What are they, some silica or carbon-carbon? Then it hit me. Inconel. Maybe even the new alloy they're using in the Raptor. Formed into sheets and tiles? It could take the heat and it's lighter than stainless steel (though certainly much more expensive)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/20/2019 08:33 pm
Ok, I've been obsessing on the new hex tiles in the heatshield. What are they, some silica or carbon-carbon? Then it hit me. Inconel. Maybe even the new alloy they're using in the Raptor. Formed into sheets and tiles? It could take the heat and it's lighter than stainless steel (though certainly much more expensive)

This sounds similar to the metal reusable TPS tiles designed for the X-33, which I think have already been posted on the Transpiration Cooling thread, which I think is the proper forum for discussing the Hex Tiles. Here's the post where livingjw brought up the X-33 tiles:

There have been several experimental designs for metallic TPS using very thin ('foil-gauge') metallic sandwich panels enclosing some sort of ceramic fiber insulation material. Since SpaceX is going for a hot-structure design, less insulation may be needed.

http://adsbit.harvard.edu//full/2006ESASP.631E..23F/0000023.002.html (http://adsbit.harvard.edu//full/2006ESASP.631E..23F/0000023.002.html)

Also:
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20040095922.pdf
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: JohnLloydJones on 03/20/2019 08:36 pm
Ok, I've been obsessing on the new hex tiles in the heatshield. What are they, some silica or carbon-carbon? Then it hit me. Inconel. Maybe even the new alloy they're using in the Raptor. Formed into sheets and tiles? It could take the heat and it's lighter than stainless steel (though certainly much more expensive)

This sounds similar to the metal reusable TPS tiles designed for the X-33, which I think have already been posted on the Transpiration Cooling thread, which I think is the proper forum for discussing the Hex Tiles. Here's the post where livingjw brought up the X-33 tiles:

There have been several experimental designs for metallic TPS using very thin ('foil-gauge') metallic sandwich panels enclosing some sort of ceramic fiber insulation material. Since SpaceX is going for a hot-structure design, less insulation may be needed.

http://adsbit.harvard.edu//full/2006ESASP.631E..23F/0000023.002.html (http://adsbit.harvard.edu//full/2006ESASP.631E..23F/0000023.002.html)

Also:
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20040095922.pdf
I seem to recall reading that the X33 tiles were inconel and Titanium.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/20/2019 08:48 pm
Ok, I've been obsessing on the new hex tiles in the heatshield. What are they, some silica or carbon-carbon? Then it hit me. Inconel. Maybe even the new alloy they're using in the Raptor. Formed into sheets and tiles? It could take the heat and it's lighter than stainless steel (though certainly much more expensive)

This sounds similar to the metal reusable TPS tiles designed for the X-33, which I think have already been posted on the Transpiration Cooling thread, which I think is the proper forum for discussing the Hex Tiles. Here's the post where livingjw brought up the X-33 tiles:

There have been several experimental designs for metallic TPS using very thin ('foil-gauge') metallic sandwich panels enclosing some sort of ceramic fiber insulation material. Since SpaceX is going for a hot-structure design, less insulation may be needed.

http://adsbit.harvard.edu//full/2006ESASP.631E..23F/0000023.002.html (http://adsbit.harvard.edu//full/2006ESASP.631E..23F/0000023.002.html)

Also:
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20040095922.pdf
I seem to recall reading that the X33 tiles were inconel and Titanium.

The paper here discusses two slightly different versions. One is Inconel honeycomb foil-saffil-titanium honeycomb, the other uses only one metal type (pretty sure Inconel, if I'm reading "superalloy" correctly). These correspond to figure 3 and 4 of the paper, respectively.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/20/2019 09:23 pm
Weather tomorrow doesn't look much better than today's, as far as I can tell. :(
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris Bergin on 03/20/2019 10:18 pm
Love that the X-33 has been brought up! :)

However, as per a report to mod, I think Hopper isn't really the TPS vehicle? Perhaps we need to split into a new thread here (someone start one) or if we have an Orbital Starship, that'd be a good place to continue.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ZChris13 on 03/20/2019 10:27 pm
Love that the X-33 has been brought up! :)

However, as per a report to mod, I think Hopper isn't really the TPS vehicle? Perhaps we need to split into a new thread here (someone start one) or if we have an Orbital Starship, that'd be a good place to continue.
There are, in fact, several threads about the engineering of starship, including one specifically about transpiration cooling
mods, feel free to kill this post
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/20/2019 11:47 pm
Love that the X-33 has been brought up! :)

However, as per a report to mod, I think Hopper isn't really the TPS vehicle? Perhaps we need to split into a new thread here (someone start one) or if we have an Orbital Starship, that'd be a good place to continue.
There are, in fact, several threads about the engineering of starship, including one specifically about transpiration cooling

Indeed. The Transpiration Cooling thread has been very active in discussion details about the new Hex tiles, including comparisons to X-33. Best to head there, as the collection of individuals most interested in that topic are actively commenting on relevant aspects!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/20/2019 11:57 pm
Weather tomorrow doesn't look much better than today's, as far as I can tell. :(
The weather looks much better tomorrow. It's about as clear and dry with as little wind as it's ever predicted to be in the winter here.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/21/2019 02:01 am
Weather tomorrow doesn't look much better than today's, as far as I can tell. :(
The weather looks much better tomorrow. It's about as clear and dry with as little wind as it's ever predicted to be in the winter here.
Ah good to hear!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/21/2019 03:05 am
Looks pretty good based on this
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marsbase on 03/21/2019 12:08 pm
Hop my pretty!  Hop!     

https://www.youtube.com/watch?v=m-H8PuweRVA
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: TechManiac on 03/21/2019 01:23 pm
Hello guys, what about the half foil cover of the Hopper?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MichaelBlackbourn on 03/21/2019 01:27 pm
The tin foil hat is no more. Hopper is now sporting the r2d2 look only. The pieces under construction at the tent are for the next vehicle.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/21/2019 01:27 pm
Thought - Might they just run the oxygen-y side or just run the methane-y side individually the first time?  Though I guess the methane would lightly toast the wires and such on the exterior of the gadget in a Delta launch kind of way.  This Raptor didn't stop in McGregor (or did it?).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: TechManiac on 03/21/2019 01:29 pm
Not the hat, just the topping  ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/21/2019 02:16 pm
Chrome dome
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: kessdawg on 03/21/2019 02:19 pm
Vapor visible on SPadre webcam!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: stinger729 on 03/21/2019 03:29 pm
Hey everyone, first post.. been watching this for quite some time now. Not sure if you guys saw this yet. A link to Austin's live stream on twitter, a bit of a different angle than the SPadre stream.
https://twitter.com/AstroSherie/status/1108764389560197120
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris Bergin on 03/21/2019 03:37 pm
Austin's great, so that's a good first post.

I do - as mentioned before - think today is about a WDR (Wet Dress Rehearsal), but it's always prudent to keep an eye on Hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThomasGadd on 03/21/2019 03:38 pm
This is the first time they have put LOX and fuel in it...  I suspect they have a long list to check.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Spindog on 03/21/2019 03:40 pm
Not to spoil the excitement but surely they'll just do gimbal and preburner tests at first. I doubt anything (except some venting) will be visible today.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wolfram66 on 03/21/2019 03:52 pm
Looking at SouthPadre webfeed, it looks like there are fewer vehicles in close proximity to the hopper
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: northstar on 03/21/2019 04:21 pm
Does anyone know if the pad that Hopper is sitting on is just straight concrete, or whether they have something like a steel plate protecting it from the exhaust from the Raptor?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NH22077 on 03/21/2019 04:24 pm
Does anyone know if the pad that Hopper is sitting on is just straight concrete, or whether they have something like a steel plate protecting it from the exhaust from the Raptor?
Just concrete & 3 day set at that.

Ned
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BunkerTheHusky on 03/21/2019 04:38 pm
How long does it take to secure a testing window? If nothing happens today, or they do in fact just do pre-burner / gimballing tests, when do you expect to see a new testing date?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/21/2019 04:42 pm
Does anyone know if the pad that Hopper is sitting on is just straight concrete, or whether they have something like a steel plate protecting it from the exhaust from the Raptor?
Just concrete & 3 day set at that.

Ned

I'm curious about this, and I think I remember reading something about it (maybe on the boca chica thread?). Some questions:

1. It was only set for 3 days before moving stuff onto it, but it's been much longer now. Do these "extra" days count as "setting", or once it's taking a load it changes/stops or something? Could it still be setting?
2. I don't know anything about different kinds of concrete. Is there a kind (perhaps used on flame trenches?) that would be capable of withstanding the blast?
3. If there's a very short fire, 1 sec or less, what would this do to "garden variety" concrete, or whatever our best guess is as to what kind this is?
4. If the pad gets destroyed, how will this happen? Under this kind of punishment, what is the failure mode of steel-reinforced concrete? Does it "melt", break apart in rocky chunks, or maybe vaporizes/turns into a powdery mess?

Obviously, most will be speculation, but it'd be nice to hear from people with knowledge about this stuff to get some concrete (see what I did there) limits as to what's possible with this pad. And, of course, we'll get to simply wait and see. :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BrianPeterson on 03/21/2019 05:00 pm
1. It was only set for 3 days before moving stuff onto it, but it's been much longer now. Do these "extra" days count as "setting", or once it's taking a load it changes/stops or something? Could it still be setting?
2. I don't know anything about different kinds of concrete. Is there a kind (perhaps used on flame trenches?) that would be capable of withstanding the blast?
3. If there's a very short fire, 1 sec or less, what would this do to "garden variety" concrete, or whatever our best guess is as to what kind this is?
4. If the pad gets destroyed, how will this happen? Under this kind of punishment, what is the failure mode of steel-reinforced concrete? Does it "melt", break apart in rocky chunks, or maybe vaporizes/turns into a powdery mess?

Obviously, most will be speculation, but it'd be nice to hear from people with knowledge about this stuff to get some concrete (see what I did there) limits as to what's possible with this pad. And, of course, we'll get to simply wait and see. :)

1 Concrete takes years to dry. Setting is just the time we let it along before it goes into use. I remember when I had a new porch poured the company told us that it would be 15 years at the thickness it was till it "dried". I believe that Hoover damn is actually still drying from a documentary I read once, all these decades later.

At 3 days Space X decided it was dry enough to start using for their needs.

2 There is high temperature concrete available. I just bought some to make a backyard foundry. I doubt that it was used for the pad.

3 Elon was already asked about the pad and said the engines would damage it. Initially it will probably withstand the engine testing but it will begin to degrade.

4 It will probably crumble and pot hole underneath the engines. A long enough sustained blast could start to glass the silicates in the concrete.

Since there is much debate over if they are going to launch from a sea platform or on land, I seriously doubt this pad was intended for long term use. My guess is it will be used long enough to test the hopper maybe a handfull of suborbital test and then be broken up and carted off for a new pad or the area grassed over.

Everything depends on where they are going to be launching, land or sea, and the permits.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Llian Rhydderch on 03/21/2019 05:01 pm
I'm not a concrete expert.

But I know that a hydrate of calcium and silicate forms as concrete cures.  And my understanding has always been that the nature of hydrated minerals is that they will fracture/spall in small bits when exposed to high heat for a sufficiently long period of time to heat the rock/mineral above a certain temperature.

So I would expect some issues, if long enough hot enough; not sure what to expect in a few second burst. 

I suspect we have many geologists and concrete experts who frequent the NSF forum who might help us on this matter.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/21/2019 05:04 pm
[pedantry]
Concrete doesn't dry.  It cures.
[/pedantry]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: BigDustyman on 03/21/2019 05:06 pm
I think it depends on blend of concrete is trapped air in concrete that causes spalling
and low air mix might reduce this signifcantly but probably impossible to get rid of all air pockets
You can vibrate out most air with vibrator
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: PM3 on 03/21/2019 05:06 pm
4 It will probably crumble and pot hole underneath the engines. A long enough sustained blast could start to glass the silicates in the concrete.

Firefly's Reaver made Popcrete  :D

https://twitter.com/Firefly_Space/status/1103667960294662144

(Includes Video)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RoboGoofers on 03/21/2019 05:08 pm
it gets stronger the longer it cures.
https://www.cement.org/learn/concrete-technology/concrete-construction/curing-in-construction
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MizaruSpaceXNut on 03/21/2019 05:34 pm
When heated fast, moist concrete will explode like pop rocks (Texan's name for petrified crinoid stems)!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NH22077 on 03/21/2019 05:34 pm
Does anyone know if the pad that Hopper is sitting on is just straight concrete, or whether they have something like a steel plate protecting it from the exhaust from the Raptor?
Just concrete & 3 day set at that.

Ned

I'm curious about this, and I think I remember reading something about it (maybe on the boca chica thread?). Some questions:

1. It was only set for 3 days before moving stuff onto it, but it's been much longer now. Do these "extra" days count as "setting", or once it's taking a load it changes/stops or something? Could it still be setting?
2. I don't know anything about different kinds of concrete. Is there a kind (perhaps used on flame trenches?) that would be capable of withstanding the blast?
3. If there's a very short fire, 1 sec or less, what would this do to "garden variety" concrete, or whatever our best guess is as to what kind this is?
4. If the pad gets destroyed, how will this happen? Under this kind of punishment, what is the failure mode of steel-reinforced concrete? Does it "melt", break apart in rocky chunks, or maybe vaporizes/turns into a powdery mess?

Obviously, most will be speculation, but it'd be nice to hear from people with knowledge about this stuff to get some concrete (see what I did there) limits as to what's possible with this pad. And, of course, we'll get to simply wait and see. :)


My knowledge is from laying a few pads and the floor of a warehouse. But I've asked a lot of questions while seeing concrete being laid and Google is your friend. Concrete that you can drive vehicles across after 3 days is type HE (high early strength). Which has a lower total strength then type GU (general use). GU concrete must set for 28 days before you can put weight on it.

1. And all concrete continues to set, depending on type.  I don't know for how long, but it always succumbs to the rusty rebar expanding & cracking it apart from inside.

2 & 3 They have a rain bird & plenty of water to sound deaden & cool the pad.
Weather or not it holds up to Hopper testing , who knows.

4. It will probably be big chunks if it starts breaking up.

Once I saw trucks parked on it after 3 days. I figured the pad was temporary. Till Hopper testing was done.

Ned
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ctjordan33 on 03/21/2019 05:36 pm
How long does it take to secure a testing window? If nothing happens today, or they do in fact just do pre-burner / gimballing tests, when do you expect to see a new testing date?

The next test window is tomorrow, 3/22 from 10a-4p Central.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Norm38 on 03/21/2019 06:03 pm
Everything I know about concrete comes from watching skyscrapers get built. Can learn a lot on those forums.
When concrete towers are built, they run as fast as one floor every 5-7 days. They are using high PSI concrete and tons of rebar. But basically 2-3 days after pouring they expect a floor to hold all the weight of the next floor being built above it. That includes massive steel formwork that probably weighs as much as the hopper does.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RocketLover0119 on 03/21/2019 06:04 pm
No updates would seem to indicate a firing today, seems like an issue arose during the WDR, would think it would be a 24 hr turnaround.

 This is why they WDR instead of firing blindly.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: intelati on 03/21/2019 06:11 pm
As long as you're conservative and don't damage the limited strength of the concrete (driving a tank over the pad at 5 days), you're free to work on the pad. As far as I remember, there wasn't much work on the ppad for a while....
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/21/2019 06:15 pm
These streaming cams leave something to be desired.  Oh if we only had someone with lots of dive gear, no fear, and a willingness to work in tidal pools.  Well that would just be magnificent.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: flyright on 03/21/2019 06:17 pm
They did something different with the concrete directly under the hopper than they did with the rest of the hopper pad. In the update thread there is an Austin Barnard picture that shows additional forms in the area that would be under the hopper.
Perhaps they used high temperature concrete in this area?

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1911235#msg1911235




Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HeartofGold2030 on 03/21/2019 06:18 pm
These streaming cams leave something to be desired.  Oh if we only had someone with lots of dive gear, no fear, and a willingness to work in tidal pools.  Well that would just be magnificent.

I think just a camera with a telephoto lens would suffice...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WormPicker959 on 03/21/2019 06:31 pm
These streaming cams leave something to be desired.  Oh if we only had someone with lots of dive gear, no fear, and a willingness to work in tidal pools.  Well that would just be magnificent.

Perhaps we could start a gofundme for a telephoto lens for Nomadd's flagpole?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: philw1776 on 03/21/2019 06:31 pm
Someone in a lift was just raised up to the Hopper over the last five minutes.

A human sacrifice to appease the Flight Gods?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/21/2019 06:37 pm
Probably wont have a static fire today with people on the pad and the window closing soonish.

As for pictures/video: SpaceX has at least 2 surveilance cameras near Hopper, on the water cannons. If they have a first fire, we are likely to get video bits from Elon.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: GregTheGrumpy on 03/21/2019 07:28 pm
They did something different with the concrete directly under the hopper than they did with the rest of the hopper pad. In the update thread there is an Austin Barnard picture that shows additional forms in the area that would be under the hopper.
Perhaps they used high temperature concrete in this area?

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1911235#msg1911235

I expect this represents a quickly replaceable section.  Chip it out after sufficient damage, put in another.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bubbinski on 03/21/2019 07:40 pm
Just got off the Austin Barnard YouTube broadcast. No test today as per a cop he was talking to a few minutes ago. He also said there was rain in tomorrow's forecast. Hope that's wrong
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NH22077 on 03/21/2019 07:42 pm
These streaming cams leave something to be desired.  Oh if we only had someone with lots of dive gear, no fear, and a willingness to work in tidal pools.  Well that would just be magnificent.

Perhaps we could start a gofundme for a telephoto lens for Nomadd's flagpole?
From the pictures NOMAD has posted. His RapterCam has a good lens on it.
He is limited by there being no highspeed internet access available in Boca Chica, TX.
I am sure he will correct me, if they just ran fiber or cable into the village. He tethers his phone to his
computer to upload to the forum.  I do remember him saying just a few days ago, he had hit his phone's data limit. And was on 2g now.

Ned
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: SpaceWoof on 03/21/2019 08:07 pm
What would be handy, is if he had a reasonable price, broadband, satellite constellation based internet service... I wonder if anyone could possibly be thinking about providing that? *wink*

Regarding the concrete pad, there is a type of concrete based on Magnesium Oxide cement that has good high temp refractory properties and very high strength.. :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/21/2019 08:19 pm
These streaming cams leave something to be desired.  Oh if we only had someone with lots of dive gear, no fear, and a willingness to work in tidal pools.  Well that would just be magnificent.

Perhaps we could start a gofundme for a telephoto lens for Nomadd's flagpole?
From the pictures NOMAD has posted. His RapterCam has a good lens on it.
He is limited by there being no highspeed internet access available in Boca Chica, TX.
I am sure he will correct me, if they just ran fiber or cable into the village. He tethers his phone to his
computer to upload to the forum.  I do remember him saying just a few days ago, he had hit his phone's data limit. And was on 2g now.

Ned
A little better than 2g. Reliable 600k.

This was the test for the optical zoom.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Kansan52 on 03/21/2019 08:58 pm
Beautiful shot. And the dish isn't pointed at you anymore!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: cppetrie on 03/21/2019 09:01 pm
Beautiful shot. And the dish isn't pointed at you anymore!
Those pictures are from January of last year
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AC in NC on 03/21/2019 09:12 pm
Just got off the Austin Barnard YouTube broadcast. No test today as per a cop he was talking to a few minutes ago. He also said there was rain in tomorrow's forecast. Hope that's wrong

15% Precipitation per this Source.  Not looking like a washout by any means

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: HeartofGold2030 on 03/21/2019 09:15 pm
Beautiful shot. And the dish isn't pointed at you anymore!
Those pictures are from January of last year

SPadre is saying SpaceX will have another attempt at a static fire tomorrow, can you confirm?
 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: iamScotty on 03/21/2019 09:34 pm
Just wondering -why would any rain effect the hopper?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: John Alan on 03/21/2019 09:52 pm
Just wondering -why would any rain effect the hopper?

My Guess...
There is a lot of exposed metal piping and the hopper shell itself is not insulated much...
In no rain or drizzle conditions... frost forms on the piping, etc and after some buildup tends to insulate the pipes with the trapped air in the frost...
Drizzle or rain and they may have a frozen mess on their hands in a hurry...
Also clean/dry lenses on their cameras at the pad may be a concern...

2 cents on subtopic...  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: strawwalker on 03/21/2019 11:24 pm
It looks like they've removed most of the slack from the leg tethers. Previous shots of the tethers have shown the clevis lying on the concrete. The hopper isn't going to move very far, though there could still be unseen slack in the lower Slingmax. It's hard to tell how directly the tether angle is pointed toward the manhole. Not that removal of the slack should be much of a surprise.

[labeled image of foil wrapped Slingmax]

I imagined the blanket and foil wrap were there to discourage tether melt, but the ends of the Slingmax ropes remain unprotected, suggesting that the main purpose is... to prevent chaffing?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: xyv on 03/22/2019 12:25 am
it gets stronger the longer it cures.
https://www.cement.org/learn/concrete-technology/concrete-construction/curing-in-construction

Yep.  In high school I broke concrete for a living.  What I mean by that was I drove to construction sites, and collected sample cylinders.  Each pour at a job cast three 6 inch diameter by 12 inch cylinders in cans.  I took them back to the lab, cut the can off, logged them and put them in a cattle trough ("moist cure")  At 7 and 28 days, I took a cylinder out, put square ends on it with molten sulfur and broke it with a calibrated hydraulic press.  At 28 days it was supposed to achieve strength (2K to 5K pounds depending on the application).  The third cylinder was for a failed 28 day test - a 'cheap' contractor (who cut corners on cement quantity) had another 7 days to pass or rip out the slab.

Unusual job for high school but definitely better that burger flipping.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/22/2019 12:28 am
 A LOX tanker pulled up to the hard checkpoint about 1100 and got turned back. I still haven't figured that one out.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Rocket Science on 03/22/2019 03:25 am
https://www.youtube.com/watch?v=pnJInGDH3Dc&t=155s
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: marokrile on 03/22/2019 10:11 am
Hi, is there any possibility from admin to crowdfund or make donate option to collect some funds for the better equipment for those persons at Boca Chica if they have interest to upgrade?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: fuchtherezer on 03/22/2019 10:50 am
Hi, is there any possibility from admin to crowdfund or make donate option to collect some funds for the better equipment for those persons at Boca Chica if they have interest to upgrade?

Both Nomadd and bocachicagal have afaik politely declined such offers in the past. If you would like to support Austin you can become a patreon at https://www.patreon.com/austinbarnard45
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: 50_Caliber on 03/22/2019 12:27 pm
These streaming cams leave something to be desired.  Oh if we only had someone with lots of dive gear, no fear, and a willingness to work in tidal pools.  Well that would just be magnificent.

Perhaps we could start a gofundme for a telephoto lens for Nomadd's flagpole?
From the pictures NOMAD has posted. His RapterCam has a good lens on it.
He is limited by there being no highspeed internet access available in Boca Chica, TX.
I am sure he will correct me, if they just ran fiber or cable into the village. He tethers his phone to his
computer to upload to the forum.  I do remember him saying just a few days ago, he had hit his phone's data limit. And was on 2g now.

Ned
A little better than 2g. Reliable 600k.

This was the test for the optical zoom.

Are you streaming this on Youtube Nomadd? That South Padre cam is frustratingly far away and low quality.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Duncan Idaho on 03/22/2019 12:35 pm
Another Cam is running.
Little bit shaky due to windy conditions but more Zoom.
LabPadre:
https://www.youtube.com/watch?v=vc4Pzu--rCw (https://www.youtube.com/watch?v=vc4Pzu--rCw)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Eer on 03/22/2019 12:48 pm
Another Cam is running.
Little bit shaky due to windy conditions but more Zoom.
LabPadre:
https://www.youtube.com/watch?v=vc4Pzu--rCw (https://www.youtube.com/watch?v=vc4Pzu--rCw)

Wish there was an in-line image stabilization filter they could insert - this is making me dizzy ...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Lampyridae on 03/22/2019 01:10 pm
Another Cam is running.
Little bit shaky due to windy conditions but more Zoom.
LabPadre:
https://www.youtube.com/watch?v=vc4Pzu--rCw (https://www.youtube.com/watch?v=vc4Pzu--rCw)

Wish there was an in-line image stabilization filter they could insert - this is making me dizzy ...

Looks like it's been knocked off its mount...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/22/2019 01:26 pm
Another Cam is running.
Little bit shaky due to windy conditions but more Zoom.
LabPadre:
https://www.youtube.com/watch?v=vc4Pzu--rCw (https://www.youtube.com/watch?v=vc4Pzu--rCw)

Wish there was an in-line image stabilization filter they could insert - this is making me dizzy ...

Looks like it's been knocked off its mount...
To the casual observer, that might sound a bit troubling. I'm going with your statement relates to the camera and NOT the BFH...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NH22077 on 03/22/2019 01:32 pm
Another Cam is running.
Little bit shaky due to windy conditions but more Zoom.
LabPadre:
https://www.youtube.com/watch?v=vc4Pzu--rCw (https://www.youtube.com/watch?v=vc4Pzu--rCw)

Wish there was an in-line image stabilization filter they could insert - this is making me dizzy ...

Digital stabalization would lower the resolution. They need a better mount. It's the wind making it bounce around. And this mount wasn't tightened enough. And the camera is now pointed down.
Ned
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NH22077 on 03/22/2019 01:51 pm
The 2nd video has been re-aimed.

(Edit) And the mount isn't holding, pointing down again. Till they fix it again.

Ned
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: mark_m on 03/22/2019 02:02 pm
Wish there was an in-line image stabilization filter they could insert - this is making me dizzy ...

Digital stabalization would lower the resolution. They need a better mount. It's the wind making it bounce around. And this mount wasn't tightened enough. And the camera is now pointed down.
Ned
I guess it depends on your definition of resolution, but digital stabilization doesn't necessarily lower it. Depending on the method, it could result in a somewhat cropped view, but within that view the image should be at the same resolution as the original. Still, a better mount would be nice.  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: NH22077 on 03/22/2019 02:11 pm
Reposting the shaky video to the last page https://youtu.be/vc4Pzu--rCw
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: moreno7798 on 03/22/2019 02:31 pm
Wish there was an in-line image stabilization filter they could insert - this is making me dizzy ...

Digital stabalization would lower the resolution. They need a better mount. It's the wind making it bounce around. And this mount wasn't tightened enough. And the camera is now pointed down.
Ned
I guess it depends on your definition of resolution, but digital stabilization doesn't necessarily lower it. Depending on the method, it could result in a somewhat cropped view, but within that view the image should be at the same resolution as the original. Still, a better mount would be nice.  ;)

Resolution = Size
Cropping = reducing the size = lower quality when upsizing

stabilizing will lower the quality because it crops the image. Resolution can stay the same by upsizing the cropped image.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: mark_m on 03/22/2019 03:26 pm
Wish there was an in-line image stabilization filter they could insert - this is making me dizzy ...

Digital stabalization would lower the resolution. They need a better mount. It's the wind making it bounce around. And this mount wasn't tightened enough. And the camera is now pointed down.
Ned
I guess it depends on your definition of resolution, but digital stabilization doesn't necessarily lower it. Depending on the method, it could result in a somewhat cropped view, but within that view the image should be at the same resolution as the original. Still, a better mount would be nice.  ;)

Resolution = Size
Cropping = reducing the size = lower quality when upsizing

stabilizing will lower the quality because it crops the image. Resolution can stay the same by upsizing the cropped image.

Rather than get into a discussion about the definition of resolution, how about we focus on this particular case, which is what can be resolved. As in discernible cm of the Hopper per pixel, or some similar measure. Digital stabilization shouldn't adversely affect that, we would be able to see just as much detail with or without it.

Sorry, this has veered off topic. (Unless of course the camera operator is reading this and has the option to switch on stabilization. Or can just stabilize the camera a bit better.)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MizaruSpaceXNut on 03/22/2019 03:28 pm
These streaming cams leave something to be desired.  Oh if we only had someone with lots of dive gear, no fear, and a willingness to work in tidal pools.  Well that would just be magnificent.

Perhaps we could start a gofundme for a telephoto lens for Nomadd's flagpole?
From the pictures NOMAD has posted. His RapterCam has a good lens on it.
He is limited by there being no highspeed internet access available in Boca Chica, TX.
I am sure he will correct me, if they just ran fiber or cable into the village. He tethers his phone to his
computer to upload to the forum.  I do remember him saying just a few days ago, he had hit his phone's data limit. And was on 2g now.

Ned
A little better than 2g. Reliable 600k.

This was the test for the optical zoom.

Are you streaming this on Youtube Nomadd? That South Padre cam is frustratingly far away and low quality.
   No matter how good your telescope is, high humidity degrades resolution!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: duke3k on 03/22/2019 03:33 pm
In case you forgot www.spadre.com has a live video link also:
https://spadre.com/ (https://spadre.com/)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: CardBoardBoxProcessor on 03/22/2019 03:44 pm
We need someone to attach a webcam to one of these cheap glorious things and stream it

https://www.ebay.com/i/223358167124?chn=ps

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: rcoppola on 03/22/2019 05:03 pm
Can we please refocus this thread? I mean who doesn't love technical, creative discussions of streaming, cameras, lenses, etc..etc..
Hell, I do it for a living. I'm in AfterFX and Final Cut hell as I write...but maybe start a Streaming thread?

Thanks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: freddo411 on 03/22/2019 05:24 pm
Wish there was an in-line image stabilization filter they could insert - this is making me dizzy ...

Digital stabalization would lower the resolution. They need a better mount. It's the wind making it bounce around. And this mount wasn't tightened enough. And the camera is now pointed down.
Ned
I guess it depends on your definition of resolution, but digital stabilization doesn't necessarily lower it. Depending on the method, it could result in a somewhat cropped view, but within that view the image should be at the same resolution as the original. Still, a better mount would be nice.  ;)

Resolution = Size
Cropping = reducing the size = lower quality when upsizing

stabilizing will lower the quality because it crops the image. Resolution can stay the same by upsizing the cropped image.

Not to be pedantic about this, but cropping an image doesn't reduce it's quality.     No need to "upsize" the cropped image.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/22/2019 05:40 pm
 Everyday astronaut is next to me trying to stream, but cell based internet is pretty sucky this morning. One advantage of the delays is that the picture should be much clearer later in the afternoon.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: prelator on 03/22/2019 05:50 pm
With cell service as bad as it is there, has anyone considered setting up a remote camera along the road with an analog video link to South Padre? I have a similar setup on my home built FPV RC plane that would work great for that application.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/22/2019 05:52 pm
Everyday astronaut is next to me trying to stream, but cell based internet is pretty sucky this morning. One advantage of the delays is that the picture should be much clearer later in the afternoon.

Is there any word on what the holdups are?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: kessdawg on 03/22/2019 05:54 pm
Everyday astronaut is next to me trying to stream, but cell based internet is pretty sucky this morning. One advantage of the delays is that the picture should be much clearer later in the afternoon.

Thanks to all of you for sating our hunger for updates!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris Bergin on 03/22/2019 06:14 pm
Careful (because people are reporting to mod) not to let this turn into a webcam thread ;) Everyone's doing the best they can.

PS I think we need a new thread again (82 pages and half a million views was pretty fast). I'll keep this one going until tomorrow morning so as not to interrupt things ;))
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: WindyCity on 03/22/2019 06:33 pm
The best live-cam I've found is https://www.space.com/spacex-starship-hopper-tests-livestream.html, coming from a South Padre surfing school 6.5 miles from the pad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nehkara on 03/22/2019 06:41 pm
The best live-cam I've found is https://www.space.com/spacex-starship-hopper-tests-livestream.html, coming from a South Padre surfing school 6.5 miles from the pad.

Probably easier to just link directly to the stream:

https://www.youtube.com/watch?v=L7zia2HqOOc
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: gnatdagnat on 03/22/2019 07:15 pm
New NOTAMS issued for Starhopper with a restriction of up to 1,000 feet, hops incoming it seems:

https://twitter.com/jeff_foust/status/1109177418466713601

Quote
New FAA NOTAM restricts airspace around SpaceX’s South Texas launch site Monday-Wednesday next week “for rocket launch and recovery”. Airspace restricted up to an altitude of 1,000 feet. Looks like they’re getting ready to hop… http://bit.ly/2JxnU5S

Notice the document shows it was issued 1822 UTC and is effective from 1400 UTC to 2300 UTC on the 25th, 26th, and 27th... I'm not sure if that changes things but to me it sounds like they plan to have testing on those days and we're left with nothing today. Anyone who knows better the implications of this please reply.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/22/2019 07:23 pm
Probably not expecting they'll be flying to 1k ft, more likely just protecting anyone from the radius of a potential fireball.  I'm surprised no NOTAMs for today.  If I'm understanding properly you could park a helicopter right over it with 500 ft. minimum clearance.  That would be a whole bunch of unsafe and should have been NOTAMed already.

edit: And I'd have in place some communication channel to quickly close all flights at all altitudes in case there's a large natural gas release that would go up and could be ignited by someone flying through it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nehkara on 03/22/2019 07:34 pm
Probably not expecting they'll be flying to 1k ft, more likely just protecting anyone from the radius of a potential fireball.  I'm surprised no NOTAMs for today.  If I'm understanding properly you could park a helicopter right over it with 500 ft. minimum clearance.  That would be a whole bunch of unsafe and should have been NOTAMed already.

edit: And I'd have in place some communication channel to quickly close all flights at all altitudes in case there's a large natural gas release that would go up and could be ignited by someone flying through it.

There was a NOTAM covering this week from Wednesday at 1500 to Friday (today) at 2300.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: MKremer on 03/22/2019 08:38 pm
I'm not sure if that changes things but to me it sounds like they plan to have testing on those days and we're left with nothing today. Anyone who knows better the implications of this please reply.
I would expect them to continue fueling tests (LCH4, LOX, and both together), all the way through engine conditioning tests, possibly through the weekend. Make sure everything prior to the engine firing command is working properly (like a WDR).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: billh on 03/22/2019 08:43 pm
Do we know where these Boca Chica tests are being controlled from? I haven't seen anything about a control room.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: tyrred on 03/22/2019 08:48 pm
They do have a nifty RV 😉
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/22/2019 09:01 pm
Thought - Might they just run the oxygen-y side or just run the methane-y side individually the first time?  Though I guess the methane would lightly toast the wires and such on the exterior of the gadget in a Delta launch kind of way.  This Raptor didn't stop in McGregor (or did it?).


About 20ea 70-100 second long jet engine sounds, not too loud. Could they be doing preburner testing?

Answers only on the discussion thread.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/22/2019 09:02 pm
Big flaring started.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/22/2019 09:04 pm
Or aircraft APU for to power something or another?  Maybe thrust vector actuators?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/22/2019 09:06 pm
Large long venting could atm.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: mgfitter on 03/22/2019 09:16 pm
Probably just me, or some weird visual effect of the heat haze, but in both streams the whole structure looks like it is leaning over at perhaps ~20 degrees.

-MG.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThomasGadd on 03/22/2019 09:17 pm
The flare stack has been continuous since 17:00 local time.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Tommyboy on 03/22/2019 09:19 pm
Hi, is there any possibility from admin to crowdfund or make donate option to collect some funds for the better equipment for those persons at Boca Chica if they have interest to upgrade?

Both Nomadd and bocachicagal have afaik politely declined such offers in the past. If you would like to support Austin you can become a patreon at https://www.patreon.com/austinbarnard45
Correct. BocaChicaGal wouldn't even accept a donation for her beer/wine fund.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/22/2019 09:27 pm
What would be really helpful on these live streams we're all(?) looking at would be if they had no sound until something happened then they could hit us with an alarm signal so that we could all get some work done until there's a significant event.  And if anyone is reading this that runs one of those streams I'd suggest a WWII movie submarine dive alarm.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: ThomasGadd on 03/22/2019 09:27 pm
When they are done today will they pump the CH4 and O2 into the storage tanks or leave it in the hopper?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/22/2019 09:30 pm
Burning methane and dumping oxygen.

This whole exercise over the last few months and today and into next week, its kind of parallel to one of Elon's other things, Burning Man where they build a giant thing and when its complete they set it on fire.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Electric Paint on 03/22/2019 09:57 pm
When they are done today will they pump the CH4 and O2 into the storage tanks or leave it in the hopper?

They definitely can't leave it in the hopper, it's hazardous to ground crew and it will be boiling off the whole time.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: PM3 on 03/22/2019 10:19 pm
New NOTAMS issued for Starhopper from Monday through Wednesday of next week with a restriction of up to 1,000 feet. Hops incoming it seems:

https://twitter.com/jeff_foust/status/1109177418466713601

Quote
New FAA NOTAM restricts airspace around SpaceX’s South Texas launch site Monday-Wednesday next week “for rocket launch and recovery”. Airspace restricted up to an altitude of 1,000 feet. Looks like they’re getting ready to hop… http://bit.ly/2JxnU5S

Center: Latitude: 25º59'16"N, Longitude: 97º11'12"W
Radius: 1.1 nautical miles

That's not around the pad, but around the place where the hopper was built. Pad is ~ 0,7 NM outside. ???

https://tfr.faa.gov/save_pages/sect_print_9_1046.html

https://www.google.com/maps/d/viewer?mid=1V-ZK8jINCViRqje7sm8OwlHIhw-zx6mc

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: DaddyBee on 03/22/2019 10:53 pm
Did anybody notice on the last 2 photo update pages that the hopper appears to me to have a noticeable Easterly lean? Am I seeing things or am I seeing things?   ???  :o

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Prettz on 03/22/2019 11:01 pm
Talk about them getting close to the first hop, next week... however, what about tethered tests? Do they issue NOTAMs for tethered rocket tests? Or are they really plowing ahead to real hops?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/23/2019 12:03 am
https://twitter.com/SpacePadreIsle/status/1109224038096912385
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/23/2019 12:06 am
Did anybody notice on the last 2 photo update pages that the hopper appears to me to have a noticeable Easterly lean? Am I seeing things or am I seeing things?   ???  :o

I'd seen that accusation earlier when watching the video and I convinced myself that it was an illusion based on the leg on the RH side being more prominent than the leg on the LH side which plays with your mind to average between the two sloping sides and come to that conclusion.  When I looked at the profile of the cylinder that is visible above the LH leg it seemed much closer to vertical.  I couldn't convince myself that it was absolutely vertical but it appeared close when I just focused on that.


I took these pics this morning but had trouble posting them.

I see in the top picture for the first time that they've added a steel safety cable to the potentially melty green lift strap.  But strangely there doesn't appear to be a steel safety cable on the other leg.  So if the green straps melt (and if thrust is greater than weight) the BFH won't head toward the sky, it'll only tip over.  But its tough, right?  Pull it back upright and replace some of the shiny panels.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: AU1.52 on 03/23/2019 12:13 am
Did anybody notice on the last 2 photo update pages that the hopper appears to me to have a noticeable Easterly lean? Am I seeing things or am I seeing things?   ???  :o

I'd seen that accusation earlier when watching the video and I convinced myself that it was an illusion based on the leg on the RH side being more prominent than the leg on the LH side which plays with your mind to average between the two sloping sides and come to that conclusion.  When I looked at the profile of the cylinder that is visible above the LH leg it seemed much closer to vertical.  I couldn't convince myself that it was absolutely vertical but it appeared close when I just focused on that.


I took these pics this morning but had trouble posting them.

I see in the top picture for the first time that they've added a steel safety cable to the potentially melty green lift strap.  But strangely there doesn't appear to be a steel safety cable on the other leg.  So if the green straps melt (and if thrust is greater than weight) the BFH won't head toward the sky, it'll only tip over.  But its tough, right?  Pull it back upright and replace some of the shiny panels.

Except the lower cable attached to the anchor appears to be same material - hope that cable does not melt!


Edit: I wonder if the extra silverly protection is against friction heat?It does not cover where it does into the metal u ring.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: OxCartMark on 03/23/2019 12:25 am
Except the lower cable attached to the anchor appears to be same material - hope that cable does not melt!


Edit: I wonder if the extra silverly protection is against friction heat?It does not cover where it does into the metal u ring.

I hadn't picked up on the fact that there is a second green strap in series with each one going from the shackle to the  subterranean mega anchor.  Actually a few things that I hadn't picked up on until I looked back.  I didn't see that BCG's pic (the one that I croppied above) included all three legs.  So only one leg has the steel.  And that steel is not only in parallel to the strap above the shackle but also in parallel with the strap below the shackle.  Solid steel from hopper to anchor on one leg and no steel cable on the other leg.  Hmm.  And another thing I didn't pick up - in her post test pic the equipment is too close to the gadget in my mind (although it may be a long lens distortion).

One potential take from the lack of steel cables on two legs and the close in equipment would be that they knew that this wasn't going be a day of fire and fury day and they are still in the process of installing steel backup cables.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: magnemoe on 03/23/2019 12:46 am
Except the lower cable attached to the anchor appears to be same material - hope that cable does not melt!


Edit: I wonder if the extra silverly protection is against friction heat?It does not cover where it does into the metal u ring.

I hadn't picked up on the fact that there is a second green strap in series with each one going from the shackle to the  subterranean mega anchor.  Actually a few things that I hadn't picked up on until I looked back.  I didn't see that BCG's pic (the one that I croppied above) included all three legs.  So only one leg has the steel.  And that steel is not only in parallel to the strap above the shackle but also in parallel with the strap below the shackle.  Solid steel from hopper to anchor on one leg and no steel cable on the other leg.  Hmm.  And another thing I didn't pick up - in her post test pic the equipment is too close to the gadget in my mind (although it may be a long lens distortion).

One potential take from the lack of steel cables on two legs and the close in equipment would be that they knew that this wasn't going be a day of fire and fury day and they are still in the process of installing steel backup cables.
The rope is flexible so it will not shock the hopper then constraining it.
the wire is for safety in the unlikely event the rope break or burn trough.
And to stop it going ballistic :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Johnnyhinbos on 03/23/2019 01:35 am
Except the lower cable attached to the anchor appears to be same material - hope that cable does not melt!


Edit: I wonder if the extra silverly protection is against friction heat?It does not cover where it does into the metal u ring.

I hadn't picked up on the fact that there is a second green strap in series with each one going from the shackle to the  subterranean mega anchor.  Actually a few things that I hadn't picked up on until I looked back.  I didn't see that BCG's pic (the one that I croppied above) included all three legs.  So only one leg has the steel.  And that steel is not only in parallel to the strap above the shackle but also in parallel with the strap below the shackle.  Solid steel from hopper to anchor on one leg and no steel cable on the other leg.  Hmm.  And another thing I didn't pick up - in her post test pic the equipment is too close to the gadget in my mind (although it may be a long lens distortion).

One potential take from the lack of steel cables on two legs and the close in equipment would be that they knew that this wasn't going be a day of fire and fury day and they are still in the process of installing steel backup cables.
The rope is flexible so it will not shock the hopper then constraining it.
the wire is for safety in the unlikely event the rope break or burn trough.
And to stop it going ballistic :)
It kinda reminds me of an inverter line on a lift bag. And in this case the term “inverter” would be apropos...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Nomadd on 03/23/2019 01:53 am
For some reason I'n reminded of the guy who was with us yesterday. He was a diver who had seen many Canaveral launches because he worked at the port there. A bit strange, but you know how divers are. Not a normal one in the bunch, but interesting and good to be around.
 He got to stay because his vehicle was stuck in the clay and tow trucks couldn't get past the hounds.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Bogeyman on 03/23/2019 05:16 am
When they are done today will they pump the CH4 and O2 into the storage tanks or leave it in the hopper?

They definitely can't leave it in the hopper, it's hazardous to ground crew and it will be boiling off the whole time.

So they let the methane just vent out in the open?  :o
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: RotoSequence on 03/23/2019 05:54 am
When they are done today will they pump the CH4 and O2 into the storage tanks or leave it in the hopper?

They definitely can't leave it in the hopper, it's hazardous to ground crew and it will be boiling off the whole time.

So they let the methane just vent out in the open?  :o

They burned it off. They have a flare stack for it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: docmordrid on 03/23/2019 05:55 am
When they are done today will they pump the CH4 and O2 into the storage tanks or leave it in the hopper?

They definitely can't leave it in the hopper, it's hazardous to ground crew and it will be boiling off the whole time.

So they let the methane just vent out in the open?  :o

There's a flare stack south of the pad where it burns off. Bottom left in this tweet

https://twitter.com/NASASpaceflight/status/1108137279787360261
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Jakusb on 03/23/2019 08:46 am
I took these pics this morning but had trouble posting them.

(Everyone hogging the 4G - the webcasts were struggling too - Chris).

Seems to me that this first test is really just a vertical raptor integration test. The hopper is not able to lift more then a couple of centimeters at most.
Not surprisingly though.

Will there be another attempt today?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: TorenAltair on 03/23/2019 11:25 am
[...]
Will there be another attempt today?

No beach closures at weekends as far as I understand.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Wargrim on 03/23/2019 12:09 pm
For some reason I'n reminded of the guy who was with us yesterday. He was a diver who had seen many Canaveral launches because he worked at the port there. A bit strange, but you know how divers are. Not a normal one in the bunch, but interesting and good to be around.
 He got to stay because his vehicle was stuck in the clay and tow trucks couldn't get past the hounds.
Sounds like the BocaChica ground keeps claiming more and more cars - Austin's Dad's car, the Divers's car and who knows how many more.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 3
Post by: Chris Bergin on 03/23/2019 01:00 pm
Careful (because people are reporting to mod) not to let this turn into a webcam thread ;) Everyone's doing the best they can.

PS I think we need a new thread again (82 pages and half a million views was pretty fast). I'll keep this one going until tomorrow morning so as not to interrupt things ;))

OK, on to Thread 4. I'll leave this one open for the rest of the day to allow quoting from Thread 3 to Thread 4, so no more posts on this thread, all on Thread 4.

Thread 4:
https://forum.nasaspaceflight.com/index.php?topic=47729.0

*I repeat, all posts now to Thread 4*

(Watch someone post on here ;D)

Thread 4! :)