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SpaceX Vehicles and Missions => SpaceX Mega Thread Archive Section => Topic started by: Chris Bergin on 01/05/2019 12:41 pm

Title: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Chris Bergin on 01/05/2019 12:41 pm
Thread 2 on what has become one of the biggest areas of interest over the last month or so (at time of writing).

Resources:

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

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):
https://forum.nasaspaceflight.com/index.php?topic=47107.0

---

Please remember, these threads run at 17,500 mph. A lot of people tend to have them on "notification" (an e-mail arrives with a new post). You can imagine how much they shout at the mods when that new post link sends them to "HA! It's SOOO shiny" ;) So aim to make your post useful/adding to the conversation.

Moderation here is never personal, it's just the foundation of the forum (we started it in 2005 at which point SDC - the main space forum of the time - was dying due to threads turning into food fights and moderators giving up in frustration). We'll annoy a few "I just want to chat!" types, but it's always got to be quality over quantity, especially during this era of the internet. I always said I'd never allow NSF's forum to turn into the dark days of SDC.

I'll shut up now and start the thread ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/05/2019 01:32 pm
Thanks for the new thread layout Chris!


And poor choice of words on my behalf when I asked for a comparison between the BFH and the Crew Dragon "stack". What I meant was the Dragon 2 mated to its trunk, as shown here. I think this would give a nice human scale reference between what essentially is the future of SpaceX crewed spaceships - kinda a Generation 1 (Dragon 2) and Generation 2 (BFS/Starship) side by side.


I just don't have the photo chops to do it justice myself...


John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: cuddihy on 01/05/2019 01:58 pm
Seen several comments along the lines of “SpaceX giving up on composites for BFS.” My bet is no, they haven’t.
Although structure and fuel tanks will be stainless, it’s possible the “people tank” will still be CF structure. If they develop a CF all-contained module for passengers, it likely would be significantly lighter and cheaper than all that structure out of metal, just as it was for the interstage on F9. A CF “passenger module” or “payload module” could be inserted into appropriate space, whether at the top or as many are speculating based on BFH so far just above the engine bay, as needed for a crew, cargo, or tanker BFS (with only bigger tanks instead).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/05/2019 02:11 pm
Nobody knows what the holes are for, but I'll suggest that if they are for RCS, then they are not "too low" in the body, since the bottom section is so much heavier.  If you were to multiply each linear vertical foot by the mass contained in it, the rocket will warp...  The bottom section will take a good 80-90% of the rocket, and the entire shiny section would be just a small nose cone... 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/05/2019 02:33 pm
Seen several comments along the lines of “SpaceX giving up on composites for BFS.” My bet is no, they haven’t.
Although structure and fuel tanks will be stainless, it’s possible the “people tank” will still be CF structure. If they develop a CF all-contained module for passengers, it likely would be significantly lighter and cheaper than all that structure out of metal, just as it was for the interstage on F9. A CF “passenger module” or “payload module” could be inserted into appropriate space, whether at the top or as many are speculating based on BFH so far just above the engine bay, as needed for a crew, cargo, or tanker BFS (with only bigger tanks instead).

The pax compartment will be constantly pressurized, for obvious reasons. The F9 interstage is not pressurized, so I don't think comparing those structurally will tell us much.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/05/2019 02:35 pm
Looks like it's about to get placed on the can!

50_Caliber, just wanted to remind you and others that when commenting on a post in an Update thread you should make sure to do it in the Discussion thread - NOT in the update thread. It's the only way we can preserve the update thread for, er, updates (and in this case photos that are in fact updates).

Otherwise you are breaking the hearts of literally thousands.

This post serves as an example.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/05/2019 02:38 pm
I think this counts as an update, as it's sent from Elon and is therefore more validation (though we don't need any more) this what is being built in Boca Chica is indeed a flight article.

https://twitter.com/elonmusk/status/1081573955591258113 (https://twitter.com/elonmusk/status/1081573955591258113)

(Mods please move to discussion if you deem more proper)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: NGC 4258 on 01/05/2019 02:47 pm
As seen in photos thread, an official render of the completed BFH.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: kevinof on 01/05/2019 02:54 pm
First hop in 4-8 weeks and maybe we were correct that it is a compromise bell on the Raptor to suit both sea-level and vacuum.

https://twitter.com/elonmusk/status/1081572521105707009
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AbuSimbel on 01/05/2019 02:58 pm
Quote from: Elon Musk
Engines currently on Starship hopper are a blend of Raptor development & operational parts. First hopper engine to be fired is almost finished assembly in California. Probably fires next month.
Quote from: Elon Musk
Aiming for 4 weeks, which probably means 8 weeks, due to unforeseen issues

Am I the only one that doesn't know how interpret these tweets together?

How can they expect to do flight tests in a month (or even 2) if the 'first hopper engine to be fired ... probably fires next month'?

Also I still don't understand from Elon's answer if the Raptors already mounted on the hopper are working engines or not.

The only logical explanation I can think of is that they ARE in fact working engines, but SpaceX is waiting to test fire a fourth one in McGregor before flying the hopper.
Is this possible?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/05/2019 02:58 pm
As seen in photos thread, an official render of the completed BFH.

Can anybody do some Kremlinology what the lack of a SpaceX logo means? Thinking SLS here...

Basically: That's not a SpaceX rocket, that's an American rocket...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/05/2019 03:02 pm
https://twitter.com/elonmusk/status/1081572521105707009
https://twitter.com/elonmusk/status/1081575156990894082

Am I the only one that doesn't know how interpret these tweets together?

How can they expect to do flight tests in a month (or even 2) if the 'first hopper engine to be fired ... probably fires next month'?

Also I still don't understand from Elon's answer if the Raptors already mounted on the hopper are working engines or not.
My takeaway (and for me it’s clear, but obviously subjective) is he used “engines” not bells, nozzles, or mockups, so those are actual engines mounted in there.

However because they’ve changed materials (SX500 stainless steel for example) and potentially other things on a new iteration that has yet to be fired, they may not be the actual flight engines used for hopping.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: su27k on 01/05/2019 03:09 pm
https://twitter.com/elonmusk/status/1081572521105707009
https://twitter.com/elonmusk/status/1081575156990894082

Am I the only one that doesn't know how interpret these tweets together?

How can they expect to do flight tests in a month (or even 2) if the 'first hopper engine to be fired ... probably fires next month'?

Also I still don't understand from Elon's answer if the Raptors already mounted on the hopper are working engines or not.

Yeah, this is a bit confusing. A direct interpretation is:
1. The current engines consists of real engine parts from dev Raptor(s), but they only serve as placeholder, they don't intend to use them.
2. The engine they intend to fly hopper with is still being assembled, they'll tested fire it and then install it on hopper (or maybe install it first then test fire?). Anyway this sounds like the engine is the critical path for the first flight. Also notice he used singular form for engine, so initial hop may use one engine.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AbuSimbel on 01/05/2019 03:11 pm
https://twitter.com/elonmusk/status/1081572521105707009
https://twitter.com/elonmusk/status/1081575156990894082

Am I the only one that doesn't know how interpret these tweets together?

How can they expect to do flight tests in a month (or even 2) if the 'first hopper engine to be fired ... probably fires next month'?

Also I still don't understand from Elon's answer if the Raptors already mounted on the hopper are working engines or not.
My takeaway (and for me it’s clear, but obviously subjective) is he used “engines” not bells, nozzles, or mockups, so those are actual engines mounted in there.

However because they’ve changed materials (SX500 stainless steel for example) and potentially other things on a new iteration that has yet to be fired, they may not be the actual flight engines used for hopping.

So if they want to fly the hopper in 1-2 months is it possible they intend to forgo acceptance testing of the engines on a test stand?

Edit: or maybe they're going to use just a single engine at first as su27k suggested...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MikeAtkinson on 01/05/2019 03:15 pm
It would make sense if Elon mis-tweeted and meant to say:

"Engines currently on Starship hopper are a blend of Raptor development & operational parts. First hopper
 Starship orbital engine to be fired is almost finished assembly in California. Probably fires next month."
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/05/2019 03:15 pm
https://twitter.com/elonmusk/status/1081572521105707009
https://twitter.com/elonmusk/status/1081575156990894082

Am I the only one that doesn't know how interpret these tweets together?

How can they expect to do flight tests in a month (or even 2) if the 'first hopper engine to be fired ... probably fires next month'?

Also I still don't understand from Elon's answer if the Raptors already mounted on the hopper are working engines or not.
My takeaway (and for me it’s clear, but obviously subjective) is he used “engines” not bells, nozzles, or mockups, so those are actual engines mounted in there.

However because they’ve changed materials (SX500 stainless steel for example) and potentially other things on a new iteration that has yet to be fired, they may not be the actual flight engines used for hopping.

So if they want to fly the hopper in 1-2 months is it possible they intend to forgo acceptance testing of the engines on a test stand?
Elon mentioned test firing next month, so gives four weeks after potential initial test fire to qualify and install in the BFH and still make the 8 week window. Conversely could do initial hop tests using installed engines as I would guess the plumbing connections etc would mostly stay the same.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/05/2019 03:16 pm
So if they want to fly the hopper in 1-2 months is it possible they intend to forgo acceptance testing of the engines on a test stand?

Edit: or maybe they're going to use just a single engine at first as su27k suggested...

It's just 450 miles from McGregor to Boca Chica. I can't imagine that they would risk their hopper just to save a few days.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lar on 01/05/2019 03:34 pm
The tyranny of Twitter is that no answer is ever as nuanced and detailed as one might wish it to be.

My guess is that these engines are placeholders.. all the connection points for plumbing, mounting, wiring, etc are correct, and their shape is correct, but they aren't intended to be functional since they are a "blend of development and operational parts". By having correct shape and correct interfaces a lot can be ensured to be correct. Engineering drawings don't always let you find every interference. Even if they are from solid models although that helps a lot.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/05/2019 03:34 pm
Replying to something from thread 1:
Quote
Do you think that for the production Starship they will return to FSW? Supposedly it delivers welds on stainless with better high temperature properties than more prosaic welding techniques.

No, for FSW you need to use a much harder tougher metal as the stirring tool, and as hard and tough as Stainless steel becomes when cold-worked there really aren't any viable materials.

If you want to go that route then ultrasonic welding (rubbing metal on metal at ~10-20kHz ~0.001mm oscillation) is the way to go.  Doesn't ruin the strength of the cold-worked (tough and hard) stainless being welded like MIG or TIG or laser welding does.

No, tungsten carbide is many times harder than stainless steel and is a common FSW tool material.  It'll FSW stainless just fine.  And toughness of the tool material is of little relevance.  I think where the difficulty comes in in FSWing this would be that stainless requires higher forces and because of the scale BFR very long structural members in the FSW apparatus (arms, gantries etc, however they would choose to do it) woud be needed to reach the areas being welded so a very large beefy machine would be needed.  But dooable it seems if that's the chosen path.

Edit/Lar; Edited in the quoted post as it's easier to read than the screenshot.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ajmarco on 01/05/2019 03:35 pm
https://twitter.com/elonmusk/status/1081572521105707009
https://twitter.com/elonmusk/status/1081575156990894082

Am I the only one that doesn't know how interpret these tweets together?

How can they expect to do flight tests in a month (or even 2) if the 'first hopper engine to be fired ... probably fires next month'?

Also I still don't understand from Elon's answer if the Raptors already mounted on the hopper are working engines or not.

Just another interpretation of Elon's comment is that he mentions hopper tests in 4 weeks but nothing about using the engines for that test. So both could be true.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cinder on 01/05/2019 03:37 pm
As seen in photos thread, an official render of the completed BFH.

Can anybody do some Kremlinology what the lack of a SpaceX logo means? Thinking SLS here...

Basically: That's not a SpaceX rocket, that's an American rocket...
IIRC there's precedent for Musk himself pointing out that some just released illustration was outdated/inaccurate on some details.  Ostensibly the flag is even more minor than a functional part.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ThomasGadd on 01/05/2019 03:40 pm
These engines will run in the test cells before being installed in the hopper.  Right?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DanielW on 01/05/2019 03:43 pm
As seen in photos thread, an official render of the completed BFH.

Is this known to be an official render or is it a fan render that he liked? There seem to be some marked differences with the legs. The current fin material seems to be in the middle of the leg triangle, not wrapping it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: tea monster on 01/05/2019 03:52 pm
Here's my take (cross-posted from the photo thread) on what the hopper would look like if assembled in it's current form. This isn't taking into account if they decide to fully enclose the legs, fill in the vents, add shocks to the legs or buff up the lower section to match the nose and tanks.
(https://i.imgur.com/GDAPyTB.jpg)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/05/2019 03:55 pm
Third link doesn't exist.

It's L2.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: lonestriker on 01/05/2019 03:56 pm
https://twitter.com/elonmusk/status/1081572521105707009
https://twitter.com/elonmusk/status/1081575156990894082

Am I the only one that doesn't know how interpret these tweets together?

How can they expect to do flight tests in a month (or even 2) if the 'first hopper engine to be fired ... probably fires next month'?

Also I still don't understand from Elon's answer if the Raptors already mounted on the hopper are working engines or not.
My takeaway (and for me it’s clear, but obviously subjective) is he used “engines” not bells, nozzles, or mockups, so those are actual engines mounted in there.

However because they’ve changed materials (SX500 stainless steel for example) and potentially other things on a new iteration that has yet to be fired, they may not be the actual flight engines used for hopping.

So if they want to fly the hopper in 1-2 months is it possible they intend to forgo acceptance testing of the engines on a test stand?
Elon mentioned test firing next month, so gives four weeks after potential initial test fire to qualify and install in the BFH and still make the 8 week window. Conversely could do initial hop tests using installed engines as I would guess the plumbing connections etc would mostly stay the same.

Another possibility, they can use these Franken-engines for some tests (maybe even hops), but not at full thrust:

"I met someone tonight who worked at SpaceX and she said they are real raptors on there but not full thrust."

https://www.reddit.com/r/spacex/comments/acm8sj/whats_going_on_with_spacexs_stainless_steel/ed9u3oc/

Can always swap the engines out later for final production versions when ready.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: su27k on 01/05/2019 03:57 pm
As seen in photos thread, an official render of the completed BFH.

Can anybody do some Kremlinology what the lack of a SpaceX logo means? Thinking SLS here...

Basically: That's not a SpaceX rocket, that's an American rocket...

This is a good observation, kind of strange to only have the flag there. But it could be for aesthetics reasons, the red/white color of the flag is well contrasted against the silver body, but SpaceX's blue and gray color may look less impressive.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rocambole on 01/05/2019 04:01 pm
As seen in photos thread, an official render of the completed BFH.

Can anybody do some Kremlinology what the lack of a SpaceX logo means? Thinking SLS here...

Basically: That's not a SpaceX rocket, that's an American rocket...

This is a good observation, kind of strange to only have the flag there. But it could be for aesthetics reasons, the red/white color of the flag is well contrasted against the silver body, but SpaceX's blue and gray color may look less impressive.

Also, weren't CBP and DHS wanting to survey the property for The Wall?  Good to be patriotic if so!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: IntoTheVoid on 01/05/2019 04:03 pm
Conversely could do initial hop tests using installed engines as I would guess the plumbing connections etc would mostly stay the same.

Another possibility, they can use these Franken-engines for some tests (maybe even hops), but not at full thrust:

As many have quoted already, Elon said "First hopper engine to be fired is ... in California", therefore the engines currently in Boca Chica won't be fired.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/05/2019 04:06 pm
Conversely could do initial hop tests using installed engines as I would guess the plumbing connections etc would mostly stay the same.

Another possibility, they can use these Franken-engines for some tests (maybe even hops), but not at full thrust:

As many have quoted already, Elon said "First hopper engine to be fired is ... in California", therefore the engines currently in Boca Chica won't be fired.

Bingo. These are placeholders.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: M.E.T. on 01/05/2019 04:08 pm
As seen in photos thread, an official render of the completed BFH.

Can anybody do some Kremlinology what the lack of a SpaceX logo means? Thinking SLS here...

Basically: That's not a SpaceX rocket, that's an American rocket...

This is a good observation, kind of strange to only have the flag there. But it could be for aesthetics reasons, the red/white color of the flag is well contrasted against the silver body, but SpaceX's blue and gray color may look less impressive.

A possible subtle attempt to leverage off potential angst that China's recent moon landing may have created, by demonstrating an American rocket in development that could compete with that? With the upcoming Crew Dragon test launch the added bit of substance providing a solid foundation to the, at first glance, "fanciful" Starship prototype?

A lot aligning at the start of 2019 that might influence the course of space exploration in the near future.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: NGC 4258 on 01/05/2019 04:11 pm
As seen in photos thread, an official render of the completed BFH.

Is this known to be an official render or is it a fan render that he liked? There seem to be some marked differences with the legs. The current fin material seems to be in the middle of the leg triangle, not wrapping it.

If a post directly from Elon is not official, I'm not sure what you want to see to be convinced.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ThomasGadd on 01/05/2019 04:12 pm
https://twitter.com/elonmusk/status/1081572521105707009
https://twitter.com/elonmusk/status/1081575156990894082

Am I the only one that doesn't know how interpret these tweets together?

How can they expect to do flight tests in a month (or even 2) if the 'first hopper engine to be fired ... probably fires next month'?

Also I still don't understand from Elon's answer if the Raptors already mounted on the hopper are working engines or not.
My takeaway (and for me it’s clear, but obviously subjective) is he used “engines” not bells, nozzles, or mockups, so those are actual engines mounted in there.

However because they’ve changed materials (SX500 stainless steel for example) and potentially other things on a new iteration that has yet to be fired, they may not be the actual flight engines used for hopping.

So if they want to fly the hopper in 1-2 months is it possible they intend to forgo acceptance testing of the engines on a test stand?
Elon mentioned test firing next month, so gives four weeks after potential initial test fire to qualify and install in the BFH and still make the 8 week window. Conversely could do initial hop tests using installed engines as I would guess the plumbing connections etc would mostly stay the same.

Another possibility, they can use these Franken-engines for some tests (maybe even hops), but not at full thrust:

"I met someone tonight who worked at SpaceX and she said they are real raptors on there but not full thrust."

https://www.reddit.com/r/spacex/comments/acm8sj/whats_going_on_with_spacexs_stainless_steel/ed9u3oc/

Can always swap the engines out later for final production versions when ready.

We don't know if installed engines are operational.  Even if they are they may wait for the new ones.  If they are delayed they could test with them.

I wouldn't expect the new engines to be full power they initially test at lower power and then increase as they get flight time just like the Merlin's.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: SpacePhileon on 01/05/2019 04:12 pm
https://twitter.com/elonmusk/status/1081572521105707009
https://twitter.com/elonmusk/status/1081575156990894082

Am I the only one that doesn't know how interpret these tweets together?

How can they expect to do flight tests in a month (or even 2) if the 'first hopper engine to be fired ... probably fires next month'?

Also I still don't understand from Elon's answer if the Raptors already mounted on the hopper are working engines or not.
My takeaway (and for me it’s clear, but obviously subjective) is he used “engines” not bells, nozzles, or mockups, so those are actual engines mounted in there.

However because they’ve changed materials (SX500 stainless steel for example) and potentially other things on a new iteration that has yet to be fired, they may not be the actual flight engines used for hopping.

So if they want to fly the hopper in 1-2 months is it possible they intend to forgo acceptance testing of the engines on a test stand?

Edit: or maybe they're going to use just a single engine at first as su27k suggested...

Perhaps (one of) the reason(s) for these somewhat contradictory information is the fast construction of the hopper. Perhaps Musk and SpaceX didn't expect this thing to evolve so quickly, because when Musk first tweeted about it, he hoped the first hopps would be in March/April, now he is talking of February/March which would mean the schedule moved one month to the left...

https://twitter.com/elonmusk/status/1076608579652616192

Quote
I will do a full technical presentation of Starship after the test vehicle we’re building in Texas flies, so hopefully March/April
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: janky on 01/05/2019 04:14 pm
i mean, we know they have working raptors... there's video, right? https://www.youtube.com/watch?v=efbq-ptd3ng (https://www.youtube.com/watch?v=efbq-ptd3ng)

maybe they will do static fires and short hops with the prototype engines before swapping out for the flight engines when they're ready?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: John Alan on 01/05/2019 04:37 pm
i mean, we know they have working raptors... there's video, right? https://www.youtube.com/watch?v=efbq-ptd3ng (https://www.youtube.com/watch?v=efbq-ptd3ng)

maybe they will do static fires and short hops with the prototype engines before swapping out for the flight engines when they're ready?
The engines installed on the Hopper are physically about 2.5 times the size of the engine firing in this video...
The prototype was like a 3/8 bolt... The production one is 1 inch!!
So they will NOT even fit... there are L2 pics to back this... (test stand being modified)

Please stop thinking this is even possible... thanks...  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Bananas_on_Mars on 01/05/2019 04:44 pm
Replying to something from thread 1:
Quote
Do you think that for the production Starship they will return to FSW? Supposedly it delivers welds on stainless with better high temperature properties than more prosaic welding techniques.

No, for FSW you need to use a much harder tougher metal as the stirring tool, and as hard and tough as Stainless steel becomes when cold-worked there really aren't any viable materials.

If you want to go that route then ultrasonic welding (rubbing metal on metal at ~10-20kHz ~0.001mm oscillation) is the way to go.  Doesn't ruin the strength of the cold-worked (tough and hard) stainless being welded like MIG or TIG or laser welding does.

No, tungsten carbide is many times harder than stainless steel and is a common FSW tool material.  It'll FSW stainless just fine.  And toughness of the tool material is of little relevance.  I think where the difficulty comes in in FSWing this would be that stainless requires higher forces and because of the scale BFR very long structural members in the FSW apparatus (arms, gantries etc, however they would choose to do it) woud be needed to reach the areas being welded so a very large beefy machine would be needed.  But dooable it seems if that's the chosen path.

IMO a joint can be engineered to work with cold-worked stainless steel and traditional welding techniques. For example as already seen on the hopper you can use a bandage(?) with spot welds for strength and have a buttweld for leak tightness. Can be combined with reinforcement hoops if they are necessary.

Welds can also be cold worked after welding for additional strength.

We will see what technique they will end up with (hopefully).


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Jcc on 01/05/2019 04:48 pm
It's still possible the Raptors currently bolted onto the Hopper were test fired, but they won't be fired on the Hopper. Why put them there? If it is for fit checks, that means they must be full size and have the same fittings.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/05/2019 04:51 pm
 There are flags on both sides.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/05/2019 04:54 pm
Here's my take (cross-posted from the photo thread) on what the hopper would look like if assembled in it's current form. This isn't taking into account if they decide to fully enclose the legs, fill in the vents, add shocks to the legs or buff up the lower section to match the nose and tanks.
(https://i.imgur.com/GDAPyTB.jpg)
You're going to have to change that by the end of the day.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: John Alan on 01/05/2019 04:56 pm
It's still possible the Raptors currently bolted onto the Hopper were test fired, but they won't be fired on the Hopper. Why put them there? If it is for fit checks, that means they must be full size and have the same fittings.

To quote Elon's tweet in part
Quote
Engines currently on Starship hopper are a blend of Raptor development & operational parts.

I take that as early full size parts that maybe have quality defects... Dimensional the cases and castings were good enough to assemble three "fit check" and "stand in" units...

They may even be missing key internal parts... It literally is just holding the nozzles in the right place and bolts to the Hopper base... That all that was required for now... 

The other issue known is the test stand mods are not done yet (again L2)... So I assure you none of these three engines have been fired...  ;)

On edit... source of the above quote... It's literally up above, so I originally did not source it...
https://forum.nasaspaceflight.com/index.php?topic=47113.msg1897298#msg1897298 (https://forum.nasaspaceflight.com/index.php?topic=47113.msg1897298#msg1897298)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jaxon9182 on 01/05/2019 04:59 pm
It's still possible the Raptors currently bolted onto the Hopper were test fired, but they won't be fired on the Hopper. Why put them there? If it is for fit checks, that means they must be full size and have the same fittings.

Well, if we knew more about the production process for Raptors it could make guessing a little easier. They will have to be building lots of them and fast, like Merlins. It seems possible they could have built some production plumbing, and structural components and then put those on a development engine so that they would have a complete engine, with production parts to test fittings for most of the engine. It would also help if we knew how different the production engine will be form the development one. We need more tweets
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/05/2019 05:07 pm
When referencing tweets please copy in the text or eventual images in your posting. Twitter uses all sorts of tricks to make browsing their pages difficult for non-users (just like Facebook). Copying in the texts makes for a much faster and more straightforward browsing experience of these threads.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: John Alan on 01/05/2019 05:09 pm
It's still possible the Raptors currently bolted onto the Hopper were test fired, but they won't be fired on the Hopper. Why put them there? If it is for fit checks, that means they must be full size and have the same fittings.

Well, if we knew more about the production process for Raptors it could make guessing a little easier. They will have to be building lots of them and fast, like Merlins. It seems possible they could have built some production plumbing, and structural components and then put those on a development engine so that they would have a complete engine, with production parts to test fittings for most of the engine. It would also help if we knew how different the production engine will be form the development one. We need more tweets

A piston from a 6.9L Cummins engine can not be tried in say a 1.8L Honda to "see if it will work"...
Again... 2.5 times bigger (est)... all dimensions... no interchangeable major parts is likely...  ???
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Doesitfloat on 01/05/2019 05:13 pm
Raptors physical size may stay the same just operate at higher thrust. Like the Merlin Ds.  Won't know until it shows up.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/05/2019 05:16 pm
It's still possible the Raptors currently bolted onto the Hopper were test fired, but they won't be fired on the Hopper. Why put them there? If it is for fit checks, that means they must be full size and have the same fittings.

Well, if we knew more about the production process for Raptors it could make guessing a little easier. They will have to be building lots of them and fast, like Merlins. It seems possible they could have built some production plumbing, and structural components and then put those on a development engine so that they would have a complete engine, with production parts to test fittings for most of the engine. It would also help if we knew how different the production engine will be form the development one. We need more tweets

A piston from a 6.9L Cummins engine can not be tried in say a 1.8L Honda to "see if it will work"...
Again... 2.5 times bigger (est)... all dimensions... no interchangeable major parts is likely...  ???

It's not 2.5x bigger. Maybe 15% bigger than the original Dev engines, and we don't even know if these are those. See jwliving's posts on the Raptor thread.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: John Alan on 01/05/2019 05:19 pm
It's still possible the Raptors currently bolted onto the Hopper were test fired, but they won't be fired on the Hopper. Why put them there? If it is for fit checks, that means they must be full size and have the same fittings.

Well, if we knew more about the production process for Raptors it could make guessing a little easier. They will have to be building lots of them and fast, like Merlins. It seems possible they could have built some production plumbing, and structural components and then put those on a development engine so that they would have a complete engine, with production parts to test fittings for most of the engine. It would also help if we knew how different the production engine will be form the development one. We need more tweets

A piston from a 6.9L Cummins engine can not be tried in say a 1.8L Honda to "see if it will work"...
Again... 2.5 times bigger (est)... all dimensions... no interchangeable major parts is likely...  ???

It's not 2.5x bigger. Maybe 15% bigger. See jwliving's posts on the Raptor thread.

I assume you have seen the L2 pics of the test stand mods envy887...
In my opinion, the engine mounting plate grew by 2.5x in scale!... Plus other major changes to the stand.
I guess we shall see in time...  :-\
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: flyright on 01/05/2019 05:19 pm
A UFO was spotted observing the Boca Chica flying water tank.

That's an Aerostat.
Tethered at South Padre Island?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: aero on 01/05/2019 05:27 pm
Regarding the latest image from Elon. It doesn't show Canards, when were they deleted from the design? Or is it simply that the Hopper doesn't need Canards? I would think that the saying "build/test as you fly" would be applicable, implying that the Canard control system needs to be tested on the Hopper, too.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ZachF on 01/05/2019 05:28 pm
Quote from: Elon Musk
Engines currently on Starship hopper are a blend of Raptor development & operational parts. First hopper engine to be fired is almost finished assembly in California. Probably fires next month.
Quote from: Elon Musk
Aiming for 4 weeks, which probably means 8 weeks, due to unforeseen issues

Am I the only one that doesn't know how interpret these tweets together?

How can they expect to do flight tests in a month (or even 2) if the 'first hopper engine to be fired ... probably fires next month'?

Also I still don't understand from Elon's answer if the Raptors already mounted on the hopper are working engines or not.

The only logical explanation I can think of is that they ARE in fact working engines, but SpaceX is waiting to test fire a fourth one in McGregor before flying the hopper.
Is this possible?

Is Elon adding an Elon time dilation factor to his own estimates?  ;) ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/05/2019 05:54 pm
It's still possible the Raptors currently bolted onto the Hopper were test fired, but they won't be fired on the Hopper. Why put them there? If it is for fit checks, that means they must be full size and have the same fittings.

Well, if we knew more about the production process for Raptors it could make guessing a little easier. They will have to be building lots of them and fast, like Merlins. It seems possible they could have built some production plumbing, and structural components and then put those on a development engine so that they would have a complete engine, with production parts to test fittings for most of the engine. It would also help if we knew how different the production engine will be form the development one. We need more tweets

A piston from a 6.9L Cummins engine can not be tried in say a 1.8L Honda to "see if it will work"...
Again... 2.5 times bigger (est)... all dimensions... no interchangeable major parts is likely...  ???

It's not 2.5x bigger. Maybe 15% bigger. See jwliving's posts on the Raptor thread.

I assume you have seen the L2 pics of the test stand mods envy887...
In my opinion, the engine mounting plate grew by 2.5x in scale!... Plus other major changes to the stand.
I guess we shall see in time...  :-\

Scaling an engine 2.5x linearly will increase its thrust 6.25x. Combined with the 50% pressure increase from the 1 MN demo Raptor that would put the production model at 9.4 MN, some 50% more thrust than the F-1. I don't think that's real likely.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Machdiamond on 01/05/2019 06:17 pm
My guess on the holes is that they are vents.

Check my math but I am estimating the following parameters:

- volume of air above the propulsion and tank section 1140 cubic meter (measured on a simple 3d model) which weighs about 1400 kg at sea level and 840 kg at 5000 m
- assuming a climb from sea level to 5000 m in 2.5 minutes (the FCC application quotes 6 minutes for the entire flight to 5 km and I subtract 1 min for the top of climb and near ground speeds) that means roughly 120 km/hr climb and descent speeds
- I am eyeballing the four holes to be 40 cm diameter each for a total area of 0.525 square meter

So this means that during climb and descent, the vent exit and entry speed would be about 25 to 28 km/hr (the high end on top).

This happens to be about the right size for these four vents, if that is what they are. If that nose volume is unpressurized, you definitely need vents somewhere.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mlindner on 01/05/2019 06:27 pm
Can't respond to OxCartMark directly (in response to his post here: https://forum.nasaspaceflight.com/index.php?topic=47022.msg1897056#msg1897056 ), but in response to the post about balloon posts Elon stated it here how they're not using balloon tanks (also look at what the posts are responses to):

https://twitter.com/elonmusk/status/1076595190658265088

and

https://twitter.com/elonmusk/status/1076606482332807168

and

https://twitter.com/elonmusk/status/1076607861952671744
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mlindner on 01/05/2019 06:33 pm
Quote from: Robotbeat
No he didn't exactly. He made clear it's pressure-stabilized exactly like balloon tanks, just that there's internal structure (which we've seen) that maintains the general shape and prevents the tank from collapsing when pressure is lost.

Please, please do not put words in Elon's mouth.


Sorry but you're the one putting words in Elon's mouth. He never mentioned it would be pressure-stabilized or anything related to that. See previous post.

I can't leave this thread for more than 24 hours before we get 5 additional pages and a new thread and the discussion has long moved past what we were talking about...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mhenderson on 01/05/2019 06:57 pm
What are the aerodynamic consequences if the slightly "dimpled" surface we see on the hopper is carried over to the ship?

For example, a golf ball (with a few hundred dimples) flies further than it would if it were a smooth sphere. 

Or consider the stitching on a baseball.  "The raised red cotton stitching that holds the cowhide covering of the ball together serves more than just an ornamental function. Without it, the ball wouldn't travel as far or as fast. When the ball is airborne, the stitching disturbs the boundary layer, the paper-thin layer of air closest to the surface of the ball. As the ball spins, some of this slightly turbulent air rotates with the ball."

I realize the relatively low speed hopper's aerodynamics won't be affected nearly as much as the transonic final article.  Will the final configuration need to be as smooth as the rendering that Elon tweeted?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/05/2019 07:04 pm
Ever shake sheet metal? 

Yeah, this thing is going to sound like rolling thunder...

https://youtu.be/m7hQ9dmiQ54
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: SirKeplan on 01/05/2019 07:08 pm
Is it me or are there some stray 1px lines on the hopper render, especially around the right hand Raptor.

It almost looks as if they have overlayed raptors with 2 different types on nozzle geometries on the render, maybe they forgot to delete some stray lines and wanted to post a quick and dirty render, could vaguely be indicative of different plans with the nozzles though?

Does anyone else see it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: livingjw on 01/05/2019 07:24 pm
What are the aerodynamic consequences if the slightly "dimpled" surface we see on the hopper is carried over to the ship?

For example, a golf ball (with a few hundred dimples) flies further than it would if it were a smooth sphere. 

Or consider the stitching on a baseball.  "The raised red cotton stitching that holds the cowhide covering of the ball together serves more than just an ornamental function. Without it, the ball wouldn't travel as far or as fast. When the ball is airborne, the stitching disturbs the boundary layer, the paper-thin layer of air closest to the surface of the ball. As the ball spins, some of this slightly turbulent air rotates with the ball."

I realize the relatively low speed hopper's aerodynamics won't be affected nearly as much as the transonic final article.  Will the final configuration need to be as smooth as the rendering that Elon tweeted?

Flow will be almost all turbulent in forward flight. In high angle of attack (~>45 deg) flight (if they do any) flow will separate further around on the cylindrical fuselage due to the roughness.

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: darkenfast on 01/05/2019 07:27 pm
Regarding the latest image from Elon. It doesn't show Canards, when were they deleted from the design? Or is it simply that the Hopper doesn't need Canards? I would think that the saying "build/test as you fly" would be applicable, implying that the Canard control system needs to be tested on the Hopper, too.

This Hopper appears to be just an up-and-down vehicle to test the Raptors and guidance systems for powered landings, the way that Grasshopper was used on Falcon 9.  The canards (as far as we have seen), are for the atmospheric "belly-flop" portion of the flight.  I would GUESS that they will tested by the first Starship prototype, which is presumably being built in Los Angeles.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AJW on 01/05/2019 07:38 pm
This seemed like a good time to go back and watch some of the Grasshopper test flights to put the BFH flights in perspective.   This is from one of the 1000m flights which it climbs to in about 60 seconds, so the top speed is roughly 35 mph.   Acceleration and deceleration are very smooth, so there should be minimal stress on the cap.  No RCS on grasshopper, but the final successful flight did have grid-fins.  It was a great reminder of just how exciting these tests were to watch and how the BFH hops will also be a thrill.  Maybe there will be live coverage.

Looking forward to the next few months.  I'll miss the cows though.

https://www.youtube.com/watch?v=ZwwS4YOTbbw

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: NGC 4258 on 01/05/2019 07:40 pm
With all the talk of engines, there are other questions that could be answered with this render.

For one, they took the care to place in background objects such as the tracking station. Does this give some clues to Hopper launchsite placement?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AJW on 01/05/2019 07:43 pm
And worth noting, no visible shock absorption system on the legs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mclumber1 on 01/05/2019 07:50 pm
And worth noting, no visible shock absorption system on the legs.

The shock absorber and landing foot may extend into the more vertical portion of the fin.   Before landing, the foot and piston assembly may be extended out a meter or so, and as the craft begins to touch down, the shock becomes compressed into the fin. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: dorkmo on 01/05/2019 07:55 pm
And worth noting, no visible shock absorption system on the legs.

The shock absorber and landing foot may extend into the more vertical portion of the fin.   Before landing, the foot and piston assembly may be extended out a meter or so, and as the craft begins to touch down, the shock becomes compressed into the fin.

thats my assumption too, but its also true that we dont see anything suggesting that something is installed
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Mark Lattimer on 01/05/2019 08:05 pm
With all the talk of engines, there are other questions that could be answered with this render.

For one, they took the care to place in background objects such as the tracking station. Does this give some clues to Hopper launchsite placement?

Given the alignment of the tracking antennas, coupled with the fact that the Tesla power packs are just behind them and off to the right, the rendered Hopper seems to be pretty much where the actual one is right now. Can't imagine that that would turn out to be a launchsite though.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: NGC 4258 on 01/05/2019 08:08 pm
With all the talk of engines, there are other questions that could be answered with this render.

For one, they took the care to place in background objects such as the tracking station. Does this give some clues to Hopper launchsite placement?

Given the alignment of the tracking antennas, coupled with the fact that the Tesla power packs are just behind them and off to the right, the rendered Hopper seems to be pretty much where the actual one is right now. Can't imagine that that would turn out to be a launchsite though.

At this point, we are watching a water tower turn into a rocket. I wouldn't be surprised if they decide to take the risks of launching it from there.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Mark Lattimer on 01/05/2019 08:15 pm
With all the talk of engines, there are other questions that could be answered with this render.

For one, they took the care to place in background objects such as the tracking station. Does this give some clues to Hopper launchsite placement?

Given the alignment of the tracking antennas, coupled with the fact that the Tesla power packs are just behind them and off to the right, the rendered Hopper seems to be pretty much where the actual one is right now. Can't imagine that that would turn out to be a launchsite though.

At this point, we are watching a water tower turn into a rocket. I wouldn't be surprised if they decide to take the risks of launching it from there.
I think they would take that risk, but the question is whether they're even allowed to do so and what the residents of Weems Street (some 1,500 feet away) would think. Mind you, if it was me, I'd let them light her up right in my backyard!

edit/lar: Fix quotes
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/05/2019 08:25 pm
I would have thought they could move the Starship by road. Obviously a difficult undertaking with a seriously oversized load but possible. Might need to close the road for a few hours or a day or so but I don't think there are any obstructions that would prohibit such a move. Does anyone know how wide the road is and how much of an overhang there would be?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: frostbit_canadian on 01/05/2019 08:33 pm
This seemed like a good time to go back and watch some of the Grasshopper test flights to put the BFH flights in perspective.   This is from one of the 1000m flights which it climbs to in about 60 seconds, so the top speed is roughly 35 mph.   Acceleration and deceleration are very smooth, so there should be minimal stress on the cap.  No RCS on grasshopper, but the final successful flight did have grid-fins.  It was a great reminder of just how exciting these tests were to watch and how the BFH hops will also be a thrill.  Maybe there will be live coverage.

Looking forward to the next few months.  I'll miss the cows though.

<removed link>

Even more perspective: the very first Grasshopper jump, which went up a grand total of six feet before coming back down. I wouldn't be shocked if the first Starhopper goes just as high on its first jump.

https://www.youtube.com/watch?v=pzXlUw2WhcE
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Mongo62 on 01/05/2019 08:45 pm
So the hopper will have the wavy skin, but the actual Starship will look much smoother:

https://twitter.com/NASASpaceflight/status/1081578399724916739

https://twitter.com/Mulymule/status/1081586947397697542

https://twitter.com/enn_nafnlaus/status/1081617473462521856

https://twitter.com/Yaru_Sasaki/status/1081662015339417601

https://twitter.com/elonmusk/status/1081662202124296192
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AJW on 01/05/2019 08:49 pm
And worth noting, no visible shock absorption system on the legs.

The shock absorber and landing foot may extend into the more vertical portion of the fin.   Before landing, the foot and piston assembly may be extended out a meter or so, and as the craft begins to touch down, the shock becomes compressed into the fin.

thats my assumption too, but its also true that we dont see anything suggesting that something is installed

I think that raises a question that should probably move to the engineering thread.   Do you want shock absorption?   If you come down tilted towards one leg, instead of having the immediate benefit of that leg pushing fully with the corrective measure, shock absorption would dampen the movement, but not correct it.   When the other two legs touch ground, they are now fully extended putting more force on the already compressed leg causing it to compress further and possibly exacerbating the problem.  Dampening is only half the solution, you then want to use the absorbed energy to return the compressed leg to an even position.

Autos use a combination of Shocks (hydraulic dampeners) and Springs to absorb the energy and then return it to the system.   Aircraft often use a mix of compressed gas and hydraulics.  Falcon 9 uses compressed helium to extend and lock the legs, and the legs contain an aluminum 'crush' core to absorb.  This has led to tilting rockets that walked their way around the ASDS.

A rigid leg may be the best approach.  Filling it with compressed gas may provide additional rigidity and strength without the weight penalty of a full dampener and energy absorption system.  It will also provide immediate force to correct any tilt.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DJPledger on 01/05/2019 08:51 pm
It's still possible the Raptors currently bolted onto the Hopper were test fired, but they won't be fired on the Hopper. Why put them there? If it is for fit checks, that means they must be full size and have the same fittings.

Well, if we knew more about the production process for Raptors it could make guessing a little easier. They will have to be building lots of them and fast, like Merlins. It seems possible they could have built some production plumbing, and structural components and then put those on a development engine so that they would have a complete engine, with production parts to test fittings for most of the engine. It would also help if we knew how different the production engine will be form the development one. We need more tweets

A piston from a 6.9L Cummins engine can not be tried in say a 1.8L Honda to "see if it will work"...
Again... 2.5 times bigger (est)... all dimensions... no interchangeable major parts is likely...  ???

It's not 2.5x bigger. Maybe 15% bigger. See jwliving's posts on the Raptor thread.

I assume you have seen the L2 pics of the test stand mods envy887...
In my opinion, the engine mounting plate grew by 2.5x in scale!... Plus other major changes to the stand.
I guess we shall see in time...  :-\

Scaling an engine 2.5x linearly will increase its thrust 6.25x. Combined with the 50% pressure increase from the 1 MN demo Raptor that would put the production model at 9.4 MN, some 50% more thrust than the F-1. I don't think that's real likely.
Superalloy foundry will allow rapid iteration of Raptor so it is not impossible for some future iteration of Raptor for the next generation larger dia. SH/SS system to have that sort of thrust. Hopper Raptor may have around 1.7-2MN of thrust. EM's recent tweet about 74.6MW(100,000HP) TP power could indicate that the production Raptor for 9m dia. SH/SS system could have around 3MN of thrust for 19 engines on SH and 5 engines on SS. Dual bell nozzle could allow throttling of Raptor at SL to <20% allowing engine out capability on landing for SS with only 5 engines.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: benbenwilde on 01/05/2019 08:55 pm
So the hopper will have the wavy skin, but the actual Starship will look much smoother

The hopper will definitely be smooth. There are tools for stretching/smoothing steel.



Sent from my iPhone using Tapatalk
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/05/2019 09:02 pm
What are the aerodynamic consequences if the slightly "dimpled" surface we see on the hopper is carried over to the ship?

For example, a golf ball (with a few hundred dimples) flies further than it would if it were a smooth sphere. 

Or consider the stitching on a baseball.  "The raised red cotton stitching that holds the cowhide covering of the ball together serves more than just an ornamental function. Without it, the ball wouldn't travel as far or as fast. When the ball is airborne, the stitching disturbs the boundary layer, the paper-thin layer of air closest to the surface of the ball. As the ball spins, some of this slightly turbulent air rotates with the ball."

I realize the relatively low speed hopper's aerodynamics won't be affected nearly as much as the transonic final article.  Will the final configuration need to be as smooth as the rendering that Elon tweeted?

The Spaceship is meant to fly in space and will spend very little time airborne in the thicker parts of the atmosphere. No reason for creating laminar flow with a dimpled skin.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: glennfish on 01/05/2019 09:42 pm
Question.

I can picture using shiny stainless steel for the hopper.

I can picture polishing it to make it shiny, for aesthetics.

I can't figure out why you'd add shiny wall paper to the lower portion unless it's pure aesthetics.

For a gizmo going at low speed as high as 5 km before landing, is there any plausible engineering reason to add the shiny sheets to the lower portion?

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/05/2019 09:53 pm
Question.

I can picture using shiny stainless steel for the hopper.

I can picture polishing it to make it shiny, for aesthetics.

I can't figure out why you'd add shiny wall paper to the lower portion unless it's pure aesthetics.

For a gizmo going at low speed as high as 5 km before landing, is there any plausible engineering reason to add the shiny sheets to the lower portion?



 Laser defense.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/05/2019 10:39 pm
Question.

I can picture using shiny stainless steel for the hopper.

I can picture polishing it to make it shiny, for aesthetics.

I can't figure out why you'd add shiny wall paper to the lower portion unless it's pure aesthetics.

For a gizmo going at low speed as high as 5 km before landing, is there any plausible engineering reason to add the shiny sheets to the lower portion?

What’s wrong with doing something just for aesthetics, after all Apple have been doing it for years and it has worked for them sales wise.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: John Alan on 01/05/2019 10:41 pm
It's still possible the Raptors currently bolted onto the Hopper were test fired, but they won't be fired on the Hopper. Why put them there? If it is for fit checks, that means they must be full size and have the same fittings.

Well, if we knew more about the production process for Raptors it could make guessing a little easier. They will have to be building lots of them and fast, like Merlins. It seems possible they could have built some production plumbing, and structural components and then put those on a development engine so that they would have a complete engine, with production parts to test fittings for most of the engine. It would also help if we knew how different the production engine will be form the development one. We need more tweets

A piston from a 6.9L Cummins engine can not be tried in say a 1.8L Honda to "see if it will work"...
Again... 2.5 times bigger (est)... all dimensions... no interchangeable major parts is likely...  ???

It's not 2.5x bigger. Maybe 15% bigger. See jwliving's posts on the Raptor thread.

I assume you have seen the L2 pics of the test stand mods envy887...
In my opinion, the engine mounting plate grew by 2.5x in scale!... Plus other major changes to the stand.
I guess we shall see in time...  :-\

Scaling an engine 2.5x linearly will increase its thrust 6.25x. Combined with the 50% pressure increase from the 1 MN demo Raptor that would put the production model at 9.4 MN, some 50% more thrust than the F-1. I don't think that's real likely.
Superalloy foundry will allow rapid iteration of Raptor so it is not impossible for some future iteration of Raptor for the next generation larger dia. SH/SS system to have that sort of thrust. Hopper Raptor may have around 1.7-2MN of thrust. EM's recent tweet about 74.6MW(100,000HP) TP power could indicate that the production Raptor for 9m dia. SH/SS system could have around 3MN of thrust for 19 engines on SH and 5 engines on SS. Dual bell nozzle could allow throttling of Raptor at SL to <20% allowing engine out capability on landing for SS with only 5 engines.

Ok.. I can buy that...
They are rebuilding the test stand to take up to the originally talked about "bigger then F-1" Raptor from several years ago, and will use adapter/spacers to adapt that mounting surface back down to whatever size engine they are working on today...  8)
Again... Tom Mueller (in my opinion) wants to be known for designing a family of FFSC LNG/LOX rocket engines, from small (1 MN) to large (10 MN), and likely (my guess) has pushed for a test stand upgrade that could fire a bigger then F-1 scale engine down the road. For the next gen 12 meter (or larger) BFR maybe...  ;)

Seeing a future ~10 MN Raptor in action will be eye watering, I know I will be like this->  :o  8)

I guess time will tell...  :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MizaruSpaceXNut on 01/05/2019 11:13 pm
My guess on the holes is that they are vents.

Check my math but I am estimating the following parameters:

- volume of air above the propulsion and tank section 1140 cubic meter (measured on a simple 3d model) which weighs about 1400 kg at sea level and 840 kg at 5000 m
- assuming a climb from sea level to 5000 m in 2.5 minutes (the FCC application quotes 6 minutes for the entire flight to 5 km and I subtract 1 min for the top of climb and near ground speeds) that means roughly 120 km/hr climb and descent speeds
- I am eyeballing the four holes to be 40 cm diameter each for a total area of 0.525 square meter

So this means that during climb and descent, the vent exit and entry speed would be about 25 to 28 km/hr (the high end on top).

This happens to be about the right size for these four vents, if that is what they are. If that nose volume is unpressurized, you definitely need vents somewhere.

That much air entering or leaving through one side will give a considerable impulse, won't it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: zhangmdev on 01/05/2019 11:24 pm

I can't figure out why you'd add shiny wall paper to the lower portion unless it's pure aesthetics.

For a gizmo going at low speed as high as 5 km before landing, is there any plausible engineering reason to add the shiny sheets to the lower portion?

To reduce heating a bit?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/05/2019 11:25 pm

I can't figure out why you'd add shiny wall paper to the lower portion unless it's pure aesthetics.

For a gizmo going at low speed as high as 5 km before landing, is there any plausible engineering reason to add the shiny sheets to the lower portion?

To reduce heating a bit?
Uh... Solar heating? Or what?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/05/2019 11:34 pm
That much air entering or leaving through one side will give a considerable impulse, won't it?
No. 1. If there are opposing holes, the net momentum which is a vector will be zero.
       2. Impulse = change in momentum. Momentum of all 1.4t of air from one hole a at 8m/s (29km/h) is only about 11000 kgm/s ..... even the empty hopper will be in the region of 40t so 1.4t of air over 3 mins will make little difference.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: joek on 01/06/2019 12:03 am
...
I can't figure out why you'd add shiny wall paper to the lower portion unless it's pure aesthetics.

For a gizmo going at low speed as high as 5 km before landing, is there any plausible engineering reason to add the shiny sheets to the lower portion?

I think aesthetics is a large part of the answer (although I can think of a number of marginal engineering reasons).

This is as much a sales-PR job as anything.  Musk wants to get people excited about it.  The incremental cost of adding a shiny coat to what would otherwise be humdrum construct is likely nil.

Musk is trying to sell a vision which takes us BEO and to Mars.  That needs some broad-based interest and excitement.  That is not going to happen with a typical fuddy-duddy rocket.

And I expect he is aiming his message at the same generations who grew up with similar images and promises of  spacecraft making trips to Mars and beyond.

He certainly has my attention. Tell me true he doesn't have yours?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: tea monster on 01/06/2019 12:04 am
Updated with wider fill in the legs and shiny-shiny lower section.
(https://i.imgur.com/0FVfJmF.jpg)

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: zhangmdev on 01/06/2019 12:18 am

To reduce heating a bit?
Uh... Solar heating? Or what?

Yes. Paint it white, or polished aluminum should reduce a bit heating from sitting in the sunlight. But wallpaper it seems to be the quicker way to cover it.

If this thing is going to be awesome and recorded for posterity, at least try not to make it a giant eyesore.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/06/2019 12:48 am
With all the talk of engines, there are other questions that could be answered with this render.

For one, they took the care to place in background objects such as the tracking station. Does this give some clues to Hopper launchsite placement?
They didn't take too much care. The dishes are reversed. Where is that from?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cinder on 01/06/2019 01:08 am
Is it me or are there some stray 1px lines on the hopper render, especially around the right hand Raptor.

It almost looks as if they have overlayed raptors with 2 different types on nozzle geometries on the render, maybe they forgot to delete some stray lines and wanted to post a quick and dirty render, could vaguely be indicative of different plans with the nozzles though?

Does anyone else see it?
It's hand drawn. Identical (one and the same) style as found in other concept art illustrations.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Machdiamond on 01/06/2019 02:18 am
That much air entering or leaving through one side will give a considerable impulse, won't it?

It won't. Assuming very conservatively a quarter of a second to accelerate that mass of air through the vent only gives you 100 Newtons or about the same as a man pushing on the side of the rocket.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Mike Borgelt on 01/06/2019 03:09 am
Nobody has commented on the feature on the nice rendering on Page 2 of the BFH.
The fins appear to be hinged well outboard of the body and there is a tapered section making the fin much thicker where it meets the body.
I didn't see it until I clicked on the image to make it full screen
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Mike Borgelt on 01/06/2019 03:13 am
Sorry, Page 1
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/06/2019 03:19 am
Nobody has commented on the feature on the nice rendering on Page 2 of the BFH.
The fins appear to be hinged well outboard of the body and there is a tapered section making the fin much thicker where it meets the body.
I didn't see it until I clicked on the image to make it full screen

EM has said "Similar" not "Exactly". So I wouldn't put too much credence into the render.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: benbenwilde on 01/06/2019 03:26 am
Nobody has commented on the feature on the nice rendering on Page 2 of the BFH.
The fins appear to be hinged well outboard of the body and there is a tapered section making the fin much thicker where it meets the body.
I didn't see it until I clicked on the image to make it full screen

EM has said "Similar" not "Exactly". So I wouldn't put too much credence into the render.


I'm not sure there is a hinge in the image but I do think the tapered section will indeed be on the hopper.

If you look at how they are applying the shiny sheets to the bottom section of the ship, there is quite a gap between it and where the leg meets the ship. The gaps line up with the tapered sections.


Sent from my iPhone using Tapatalk
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/06/2019 03:50 am
Nobody has commented on the feature on the nice rendering on Page 2 of the BFH.
The fins appear to be hinged well outboard of the body and there is a tapered section making the fin much thicker where it meets the body.
I didn't see it until I clicked on the image to make it full screen

EM has said "Similar" not "Exactly". So I wouldn't put too much credence into the render.


I'm not sure there is a hinge in the image but I do think the tapered section will indeed be on the hopper.

If you look at how they are applying the shiny sheets to the bottom section of the ship, there is quite a gap between it and where the leg meets the ship. The gaps line up with the tapered sections.


Sent from my iPhone using Tapatalk

I see what you're sying . . . It's possible they will add the taper covers but why wait until they have the Stainless steel sheets on the bottom section. I'd have thought they would have done that early during attachment of the legs/fins.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: benbenwilde on 01/06/2019 05:22 am
Nobody has commented on the feature on the nice rendering on Page 2 of the BFH.
The fins appear to be hinged well outboard of the body and there is a tapered section making the fin much thicker where it meets the body.
I didn't see it until I clicked on the image to make it full screen

EM has said "Similar" not "Exactly". So I wouldn't put too much credence into the render.


I'm not sure there is a hinge in the image but I do think the tapered section will indeed be on the hopper.

If you look at how they are applying the shiny sheets to the bottom section of the ship, there is quite a gap between it and where the leg meets the ship. The gaps line up with the tapered sections.


Sent from my iPhone using Tapatalk

I see what you're sying . . . It's possible they will add the taper covers but why wait until they have the Stainless steel sheets on the bottom section. I'd have thought they would have done that early during attachment of the legs/fins.


I would think the taper covers will be made of the same stuff as the top two parts of the ship, with the same kind of backing frame.

In Elon's tweet today he said that the final version will have a skin thickness that varies based on the load in different parts of the ship. So maybe thicker near the bottom and thinner as it goes up.

Looks like what they have done here is approximated/exceeded the target thickness in each part of the ship, but with only two thicknesses. The top is thinner but with 100% stainless steel, possibly 300 series, maybe even their special version of it, maybe not.

On the bottom there is a different metal, but it's much thicker (for the bigger loads in that section), and presumably cheaper. The special stuff is only the covering on the bottom of the hopper.

Assuming the hopper won't be used to test any meaningful atmospheric heating, the shiny stuff is just for looks. That also makes it less likely to be a special alloy at this point, but it's possible it is so that they can test how it handles load in the higher sections, but who knows.

The final version's skin will presumably be 100% shiny special stainless steel series 300 (yes that was 5 S's in a row), with different thicknesses in different areas (optimized for weight), and built using a more advanced method.


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Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MichaelBlackbourn on 01/06/2019 05:28 am
Nobody has commented on the feature on the nice rendering on Page 2 of the BFH.
The fins appear to be hinged well outboard of the body and there is a tapered section making the fin much thicker where it meets the body.
I didn't see it until I clicked on the image to make it full screen

There is no bottom taper. You're seeing reflections of the fins in the body.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ejb749 on 01/06/2019 06:26 am
https://twitter.com/Nomadd2029/status/1081731792103723010 (https://twitter.com/Nomadd2029/status/1081731792103723010)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mlindner on 01/06/2019 07:01 am
With all the talk of engines, there are other questions that could be answered with this render.

For one, they took the care to place in background objects such as the tracking station. Does this give some clues to Hopper launchsite placement?

That's a render overlayed on a photograph. So they didn't need to place any objects there.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RobLynn on 01/06/2019 07:09 am
They are rebuilding the test stand to take up to the originally talked about "bigger then F-1" Raptor from several years ago, and will use adapter/spacers to adapt that mounting surface back down to whatever size engine they are working on today...  8)
Again... Tom Mueller (in my opinion) wants to be known for designing a family of FFSC LNG/LOX rocket engines, from small (1 MN) to large (10 MN), and likely (my guess) has pushed for a test stand upgrade that could fire a bigger then F-1 scale engine down the road. For the next gen 12 meter (or larger) BFR maybe...  ;)

Seeing a future ~10 MN Raptor in action will be eye watering, I know I will be like this->  :o  8)

I guess time will tell...  :)

In all likelihood higher thrust engines will have worse thrust to weight ratios (flow path lengths grow causing increased weight), and worse problems with low cycle fatigue caused by transient thermal differential expansion in thick sections.  Would make sense for them to build vacuum test facilities for large diameter vacuum expansion Raptors if they want to get a lot of test and cycle hours on them.  Starship will likely eventually sport a number of high expansion ratio Raptors (maybe even all of them if use a stepped nozzle on 3 of them for earth landings)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Mike Borgelt on 01/06/2019 07:10 am
There actually is a taper. Look at the radius where the upper section of the tapered part meets the body. Very obvious. You need to view at large size.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: geza on 01/06/2019 07:45 am
With all the talk of engines, there are other questions that could be answered with this render.

For one, they took the care to place in background objects such as the tracking station. Does this give some clues to Hopper launchsite placement?
Probably, this is the view of the two tacking antennas at Boca Chica from the location of the assembly of the Hopper. So, this is a real place, but not the launchsite.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mlindner on 01/06/2019 07:46 am
There actually is a taper. Look at the radius where the upper section of the tapered part meets the body. Very obvious. You need to view at large size.

That model on page 2 of this thread is made by a forum user. It's not representative. I suggest you read more before insisting you're correct.

If you're instead confusing it with the one elon posted here: https://twitter.com/elonmusk/status/1081576707365064704 Yes the legs taper outward before connecting with the body. They obviously haven't added that part to the rocket yet. However there is no hinge there.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/06/2019 08:28 am
Won’t the fins need to get more substantial in reality than they are now to be more like the ones in the concept?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: zodiacchris on 01/06/2019 08:44 am
Hmmm, fin root and leading edge root fairings...🤔
Very neat! 😎
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: kevinof on 01/06/2019 09:00 am
here's the large size from the Twitter post above. It's interesting to see how the body appears to taper in just below the flag to accommodate the leg roots. Would be interesting to see this from a different viewpoint so get a better idea of the shape.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/06/2019 09:02 am
As much like a giant artillery shell in the body as anything.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Callezetter on 01/06/2019 10:57 am
Maybe add evenly distributed weight? Plus aesthetics.

Question.

I can picture using shiny stainless steel for the hopper.

I can picture polishing it to make it shiny, for aesthetics.

I can't figure out why you'd add shiny wall paper to the lower portion unless it's pure aesthetics.

For a gizmo going at low speed as high as 5 km before landing, is there any plausible engineering reason to add the shiny sheets to the lower portion?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: M.E.T. on 01/06/2019 11:45 am
So I'm trying to estimate how the passenger/cargo portion of the full size Starship compares to the above picture of the Hopper with the man figure next to it. I know the Hopper is shortened, but how large will the full size payload bay be compared to the current Hopper?

Half of its volume? Two thirds? Is there a handy picture which gives one a fair idea?

EDIT

I’m guessing the payload compartment on the full size Starship would stretch from the nose downto approximately where the top of the fin meets the Hopper body.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Jcc on 01/06/2019 12:04 pm
here's the large size from the Twitter post above. It's interesting to see how the body appears to taper in just below the flag to accommodate the leg roots. Would be interesting to see this from a different viewpoint so get a better idea of the shape.

I don't think the body tapers below the flag area, but there are shrouds added on the forward edge of the legs. We may see those added to our water tank.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DJPledger on 01/06/2019 12:11 pm
They are rebuilding the test stand to take up to the originally talked about "bigger then F-1" Raptor from several years ago, and will use adapter/spacers to adapt that mounting surface back down to whatever size engine they are working on today...  8)
Again... Tom Mueller (in my opinion) wants to be known for designing a family of FFSC LNG/LOX rocket engines, from small (1 MN) to large (10 MN), and likely (my guess) has pushed for a test stand upgrade that could fire a bigger then F-1 scale engine down the road. For the next gen 12 meter (or larger) BFR maybe...  ;)

Seeing a future ~10 MN Raptor in action will be eye watering, I know I will be like this->  :o  8)

I guess time will tell...  :)

In all likelihood higher thrust engines will have worse thrust to weight ratios (flow path lengths grow causing increased weight), and worse problems with low cycle fatigue caused by transient thermal differential expansion in thick sections.  Would make sense for them to build vacuum test facilities for large diameter vacuum expansion Raptors if they want to get a lot of test and cycle hours on them.  Starship will likely eventually sport a number of high expansion ratio Raptors (maybe even all of them if use a stepped nozzle on 3 of them for earth landings)
SpaceX probably won't need vacuum test cells for eventual Raptor vac. for future Starship upgrades. They test Merlin vac. in the open air.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: kevinof on 01/06/2019 12:30 pm
Ok more of a dimple than a taper and maybe I'm seeing things that aren't there - it's just a render with lots of shiny bits.

but right where the leg attaches it does appear to be recessed.


here's the large size from the Twitter post above. It's interesting to see how the body appears to taper in just below the flag to accommodate the leg roots. Would be interesting to see this from a different viewpoint so get a better idea of the shape.

I don't think the body tapers below the flag area, but there are shrouds added on the forward edge of the legs. We may see those added to our water tank.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: NH22077 on 01/06/2019 12:31 pm
They are rebuilding the test stand to take up to the originally talked about "bigger then F-1" Raptor from several years ago, and will use adapter/spacers to adapt that mounting surface back down to whatever size engine they are working on today...  8)
Again... Tom Mueller (in my opinion) wants to be known for designing a family of FFSC LNG/LOX rocket engines, from small (1 MN) to large (10 MN), and likely (my guess) has pushed for a test stand upgrade that could fire a bigger then F-1 scale engine down the road. For the next gen 12 meter (or larger) BFR maybe...  ;)

Seeing a future ~10 MN Raptor in action will be eye watering, I know I will be like this->  :o  8)

I guess time will tell...  :)

In all likelihood higher thrust engines will have worse thrust to weight ratios (flow path lengths grow causing increased weight), and worse problems with low cycle fatigue caused by transient thermal differential expansion in thick sections.  Would make sense for them to build vacuum test facilities for large diameter vacuum expansion Raptors if they want to get a lot of test and cycle hours on them.  Starship will likely eventually sport a number of high expansion ratio Raptors (maybe even all of them if use a stepped nozzle on 3 of them for earth landings)
SpaceX probably won't need vacuum test cells for eventual Raptor vac. for future Starship upgrades. They test Merlin vac. in the open air.

Yes they do test Merlin Vac in open air. Without the nozzle extention. Otherwise it would have flow separation & rud.

Ned
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Ludus on 01/06/2019 01:49 pm
What’s the Flag? If the design is bare polished metal for a reason, is the Flag just a painted exception? Is it intended to end up partially burned off by heating? Is it temporary like a magnetic attachment that comes off? I suppose the hopper won’t experience much heating so it doesn’t matter, but would it be present in the operational Starship?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: holmstar on 01/06/2019 01:52 pm
Ok more of a dimple than a taper and maybe I'm seeing things that aren't there - it's just a render with lots of shiny bits.

but right where the leg attaches it does appear to be recessed.

You’re being confused by the shininess of the shroud.  There is no dimple/recess.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: lonestriker on 01/06/2019 02:01 pm
What’s the Flag? If the design is bare polished metal for a reason, is the Flag just a painted exception? Is it intended to end up partially burned off by heating? Is it temporary like a magnetic attachment that comes off? I suppose the hopper won’t experience much heating so it doesn’t matter, but would it be present in the operational Starship?

We don't know if the flags will be the same for the actual Starship. We do know that they are there for the test BFH though, which will never experience reentry or the associated heating.  So no special precautions needed yet.

It's 2019 now and in about 7 months, we'll be celebrating the 50th anniversary of the Apollo 11 US moon landing.  I'm sure that has something to do with how Elon presents the BFH and Starship (when it's assembled).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cinder on 01/06/2019 02:18 pm
Ok more of a dimple than a taper and maybe I'm seeing things that aren't there - it's just a render with lots of shiny bits.

but right where the leg attaches it does appear to be recessed.

You’re being confused by the shininess of the shroud.  There is no dimple/recess.
It's hand drawn.. You can see the brush shapes there and elsewhere.  The accuracy of an actual (e.g.) ray traced render isn't there to read tea leaves from, instead you're likely to be misled as to the exact subtleties of the outer body shape by some inaccuracy of the reflection's hand drawn appearance.  Look at the bottom end of the hopper.  It's full of quick and dirty brush strokes.

It's an ideation sketch.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/06/2019 02:20 pm
What’s the Flag? If the design is bare polished metal for a reason, is the Flag just a painted exception? Is it intended to end up partially burned off by heating? Is it temporary like a magnetic attachment that comes off? I suppose the hopper won’t experience much heating so it doesn’t matter, but would it be present in the operational Starship?

We don't know if the flags will be the same for the actual Starship. We do know that they are there for the test BFH though, which will never experience reentry or the associated heating.  So no special precautions needed yet.

It's 2019 now and in about 7 months, we'll be celebrating the 50th anniversary of the Apollo 11 US moon landing.  I'm sure that has something to do with how Elon presents the BFH and Starship (when it's assembled).
Yup, to counter things like "America's ride to space" and what not.

Once this thing is standing proud and then hopping - capsules (and space planes) are going to look so obsolete.

Building one in plain view is such a smart move.

-----
ABCD: Always Be Counting Down

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Hauerg on 01/06/2019 02:25 pm
Maybe add evenly distributed weight? Plus aesthetics.

Question.

I can picture using shiny stainless steel for the hopper.

I can picture polishing it to make it shiny, for aesthetics.

I can't figure out why you'd add shiny wall paper to the lower portion unless it's pure aesthetics.

For a gizmo going at low speed as high as 5 km before landing, is there any plausible engineering reason to add the shiny sheets to the lower portion?
Measuring warming of the ship in the sun.
They need to keep it as cool as possible in space and even more so on Mars.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/06/2019 02:34 pm
More stainless has been added to the fins.

Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???

And one small observation - the cladding looks wrinkled in part because of its high reflectance, coupled with all the "stuff" laying around being reflected back at all angles. It'll probably look a lot less "wrinkled" once it's out on the pad (and after they use the heat shrink gun - kidding!).


Edit to add: And for those who were saying the upper and bottom half of the nosecone section wouldn't be permanently attached together, looks like they are welding on the horizontal strip around that seam...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Janter on 01/06/2019 02:55 pm
Assuming the Heavy Booster remains CF here is what it early tests may look like.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/06/2019 03:21 pm
[/font][/size]More stainless has been added to the fins.

Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???

And one small observation - the cladding looks wrinkled in part because of its high reflectance, coupled with all the "stuff" laying around being reflected back at all angles. It'll probably look a lot less "wrinkled" once it's out on the pad (and after they use the heat shrink gun - kidding!).


Edit to add: And for those who were saying the upper and bottom half of the nosecone section wouldn't be permanently attached together, looks like they are welding on the horizontal strip around that seam...

I said not long up thread that they must be going to add more steel to the fins. Why do some posters, and I am not referring to you here, seem surprised by stuff like this when it’s in the concept drawing EM posted only yesterday. The only thing he indicated would be different in reality is that the skin wouldn’t be as smooth as shown in the concept drawing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/06/2019 03:26 pm
Assuming the Heavy Booster remains CF here is what it early tests may look like.

No. The hopper would not survive reentry. It can't go on top of the booster. And, judging by the way it's being built: it does not have the mating equipment to interface with the booster.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mlindner on 01/06/2019 03:26 pm
here's the large size from the Twitter post above. It's interesting to see how the body appears to taper in just below the flag to accommodate the leg roots. Would be interesting to see this from a different viewpoint so get a better idea of the shape.

There is no taper. Please stop saying there's a taper. It's an artist's impression based on a hand drawing and there's no taper on the left side with a 3-pixel "taper" on the right side. This is something drawn and painted in photoshop (or similar). This is not a 3d model.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: cuddihy on 01/06/2019 03:29 pm

Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???


ok, I might be at risk for being the MOTO here, but...padeye covers with holes  that a hook fits through....
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/06/2019 03:33 pm

Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???


ok, I might be at risk for being the MOTO here, but...padeye covers with holes  that a hook fits through....

Look:
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mlindner on 01/06/2019 03:39 pm

Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???


ok, I might be at risk for being the MOTO here, but...padeye covers with holes  that a hook fits through....

Look:

I would assume those eye hooks are how they lifted the leg coverings into place.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: thxbmp3 on 01/06/2019 04:01 pm
SpaceX probably won't need vacuum test cells for eventual Raptor vac. for future Starship upgrades. They test Merlin vac. in the open air.

In Raptor's case I think they will? The vacuum regen-cooled nozzles will be an integral part of the engine and can't be removed willy nilly, unlike MVac's.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/06/2019 04:03 pm
[/font][/size]More stainless has been added to the fins.

Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???

And one small observation - the cladding looks wrinkled in part because of its high reflectance, coupled with all the "stuff" laying around being reflected back at all angles. It'll probably look a lot less "wrinkled" once it's out on the pad (and after they use the heat shrink gun - kidding!).


Edit to add: And for those who were saying the upper and bottom half of the nosecone section wouldn't be permanently attached together, looks like they are welding on the horizontal strip around that seam...

I said not long up thread that they must be going to add more steel to the fins. Why do some posters, and I am not referring to you here, seem surprised by stuff like this when it’s in the concept drawing EM posted only yesterday. The only thing he indicated would be different in reality is that the skin wouldn’t be as smooth as shown in the concept drawing.
... Because there isn't a single poster around here that has even a 20% hit ratio, even when basing their posts on Musk's statements.

-----
ABCD: Always Be Counting Down

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/06/2019 04:04 pm

Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???


ok, I might be at risk for being the MOTO here, but...padeye covers with holes  that a hook fits through....

Look:
LOL - in no way are those eyes for lifting a multiple ton structure.


For me at least, as an extreme geek, all of these small mysteries add up to a huge amount of enjoyment. With our remote eyes (Nomadd & BCGal) we'll probably see exactly how they both lift and transport the BFH.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Swedish chef on 01/06/2019 04:05 pm
Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???

I'm guessing they are going to use a Self-Propelled Modular Transporter for the journey out to the launch pad. If that is the case there would be no further lifting of the water-tower section instead it will be pushed up with the transporter.

(Adding a picture of the transporter I'm thinking of.)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/06/2019 04:06 pm
SpaceX probably won't need vacuum test cells for eventual Raptor vac. for future Starship upgrades. They test Merlin vac. in the open air.

In Raptor's case I think they will? The vacuum regen-cooled nozzles will be an integral part of the engine and can't be removed willy nilly, unlike MVac's.
Has a vacuum test cell of that size ever been built! Quite soon (if engines get larger) that will be a facility only possible in orbit, or on the moon!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AndrewSmith on 01/06/2019 04:17 pm
All of NASA's altitude engine test facilities (Stennis A2/A3, Plum Brook) are set up for LH2/LOX - so they would have to be modified for Methane.



Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/06/2019 04:24 pm
Looks like they stuffed some insulation, or contractor bags, or something else, along the gap between the base of the nosecone section and the top of the concrete jig. Why? To prevent us perverts from peeking in through the gaps? Or to keep the weather out, or some other nefarious reason?

Nomadd or BocaChicaGal - don't suppose they put a door or some kind of cover over the opening into the jig?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/06/2019 04:31 pm
Looks like they stuffed some insulation, or contractor bags, or something else, along the gap between the base of the nosecone section and the top of the concrete jig. Why? To prevent us perverts from peeking in through the gaps? Or to keep the weather out, or some other nefarious reason?

Nomadd or BocaChicaGal - don't suppose they put a door or some kind of cover over the opening into the jig?
The base is a little bigger than the ship, and the rocket scientists probably found out last night that's a good way to funnel rain in.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/06/2019 04:44 pm
With all the talk of engines, there are other questions that could be answered with this render.

For one, they took the care to place in background objects such as the tracking station. Does this give some clues to Hopper launchsite placement?

That's a render overlayed on a photograph. So they didn't need to place any objects there.
The whole thing is a render, and an inaccurate one.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/06/2019 04:54 pm

Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???


ok, I might be at risk for being the MOTO here, but...padeye covers with holes  that a hook fits through....

Look:
LOL - in no way are those eyes for lifting a multiple ton structure.


For me at least, as an extreme geek, all of these small mysteries add up to a huge amount of enjoyment. With our remote eyes (Nomadd & BCGal) we'll probably see exactly how they both lift and transport the BFH.

It's exactly where the lifting eyes are underneath. And these things are probably pretty big and strong. Somebody should do some pixel counting to get a measure.

We will see soon enough, when they lift the base segment again.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: sevenperforce on 01/06/2019 05:13 pm
If they are filling this even a fraction of the way with props, then it should have every capacity to go suborbital, reverse, and come back down.

I do wonder if they have found an EDL path that doesn't require articulation on the leg-fins. Articulation of those control surfaces is a major failure point.

With sufficient roll control provided by those centrally-located thrusters, perhaps they could pull EDL all the way from compressive-lift through into the aerodynamic transition by maintaining a controlled tailspin. Then it would just be a question of rolling one fin ventrally to kick AoA even higher and firing the engines to complete and control the flip.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/06/2019 05:27 pm
If they are filling this even a fraction of the way with props, then it should have every capacity to go suborbital, reverse, and come back down.

I do wonder if they have found an EDL path that doesn't require articulation on the leg-fins. Articulation of those control surfaces is a major failure point.

With sufficient roll control provided by those centrally-located thrusters, perhaps they could pull EDL all the way from compressive-lift through into the aerodynamic transition by maintaining a controlled tailspin. Then it would just be a question of rolling one fin ventrally to kick AoA even higher and firing the engines to complete and control the flip.

I would assume that the articulated fins are not going to be anymore of a failure point than the F9's grid  fins. They have performed magnificently so far.  By the way, the recent F9 landing failure was not attributed to the fins thmselves but to hydaulics. So, if you couple that with built-in hydraulics redundancy in the system, you get airline level reliability.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: loekf on 01/06/2019 05:47 pm
Stupid question, can this thing rise and drop completely stable ? You have three engines next to each other, in a line, not spread out like with 120 degrees between two. I know you do a kind of thrust vectoring, but with three engines in line ?

Oh this rocket is epic and a drastic change from the traditional booster and capsule design. Makes me wonder where’s Zefram Cochrane ;-)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/06/2019 05:49 pm
If they are filling this even a fraction of the way with props, then it should have every capacity to go suborbital, reverse, and come back down.

What do you mean by "this" in the above sentence?

The bottom part is clearly being built *much* stronger than the top two parts.  It seems very obvious to me that that's the tankage, and the top is just a nosecone (and full-scale standin for the (very large) cargo / passenger area).  I expect there to be a bulkhead installed inside the lower part, and a second bulkhead sticking up from it (intruding into the upper portion).

Remember that as big as this is, this isn't a full-scale Starship.  It'll be extended meaningfully in the final version, and all of that will be extra tankage.

It also seems obvious to me that the hopper isn't going to "have every capacity to go suborbital".  Their "extended" application is only to eventually go up to 5 km.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/06/2019 05:53 pm

Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???


ok, I might be at risk for being the MOTO here, but...padeye covers with holes  that a hook fits through....

Look:


More than likely they will just cut them out the same way they did the side vent holes...

(https://forum.nasaspaceflight.com/assets/47113.0/1537712.jpg)

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47113.0;attach=1537720;image)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/06/2019 05:54 pm
Assuming the Heavy Booster remains CF here is what it early tests may look like.

Super Heavy isn't going to be CF. It's going to be stainless, just like Starship.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/06/2019 05:59 pm

Yowza - okay, so I expected the entire thing to get wrapped, and after Elon's tweet image yesterday I expected that they would add the taper between legs and body, but what I _didn't_ expect was for them to cover the lifting eyes on top of the legs. How the heck are they going to pick this thing up now???


ok, I might be at risk for being the MOTO here, but...padeye covers with holes  that a hook fits through....

What’s happened here it’s attached my name to quote not by me, has this been edited?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/06/2019 06:11 pm
Stupid question, can this thing rise and drop completely stable ? You have three engines next to each other, in a line, not spread out like with 120 degrees between two. I know you do a kind of thrust vectoring, but with three engines in line ?

Yes. Why wouldn’t it? If one engine can balance it, why would it be harder with three? All engines gimbal to provide thrust vectoring, and they can do it independent of each other.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Norm38 on 01/06/2019 06:12 pm
Someone asked for a visual comparison between the Hopper and Dragon2. I found this one on Reddit.
https://www.reddit.com/r/SpaceXLounge/comments/ad51uu/i_designed_and_printed_a_starhopper_based_on_the/
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: uhuznaa on 01/06/2019 06:18 pm
Oh my. This has gone from "It's a water tower!" to "It's a space ship!" all too fast.

Can we reckon some rational development path? My take is this:

1. This thing is a pathfinder. It's there both for having something in halfway the right scale and shininess to show off as soon as possible (exploiting all the hopefully good press they get with DM-1) and to fly the 500 m landing tests once they have three flight-worthy Raptors ready. Do landings with one, two or three engines and explore failure modes and how to recover from them. Try to not destroy it, but if you have to, well, do it and learn from it.

2. While they'll be doing this they will build version 2 with movable wings, canards and bigger propellant tanks to fly the 5 km tests: launch, do a landing approach sideways to 1 km of height, move vertical with the moving wings and canards and RCS and land. Repeat with all kinds of failure modes and shake it down until it's routine.

3. While doing this build the version 3, with actual full size tanks and a heat shield (active cooling) to fly suborbital trajectories and to test reentry with increasing velocities and thermal loads. THIS SpaceX won't be able to pull off without money from the outside, but hopefully in one way or another they will get more money to do that with all the publicity they managed to provoke with 1. and 2.


I said this here more than once and do it again: SpaceX is (just as Tesla) an extremely high-risk undertaking. It basically surfs the wave in the hope of making it JUST all the way through, but it has to learn by doing and to soak up power from wherever it happens to end up. For commercial spaceflight cash flow and money is just as real as delta-V and thermal loads: You have to play the game and to stage things just right to get to orbit or to succeed as a business. In this terms Spacehopper is a bit desperate, "fake it until you make it", surely far away from the top-down approach spacecraft got built in the past and more than just a bit of PR.

But honestly, and I'm saying this again and again: SpaceX won't be able to develop and build a reusable Mars-going craft just from what they earn with their current business model. They even won't be able to launch and then earn money with StarLink, which they won't be able to launch and complete with F9, which would be much too expensive for that, just with what they have NOW. They need to start building StarLink and StarShip at the same time and have the latter take over launching the former at JUST the right moment. Just as you have to launch a rocket with the first stage and then have the second stage take over at just the right moment.

You can't repeat these words often enough: High risk. This is all about going in full speed, keeping your goal firmly in sight and rely on things lining up on the way because they want to anyway.

But honestly: This thing will never do anything but short hops. The fixed wings are a clear indication for that. It will go straight up, maybe translate a bit back and forth and then land. Testing your software and recovering from engine troubles and getting good PR is what this is all about. And so far it seems to work quite nicely!





Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/06/2019 06:20 pm
Someone asked for a visual comparison between the Hopper and Dragon2. I found this one on Reddit.
https://www.reddit.com/r/SpaceXLounge/comments/ad51uu/i_designed_and_printed_a_starhopper_based_on_the/

Good scale comaprison. Now, imagine the original 2017 12m ITS . . . and the even larger spaceships SpaceX is going to do in the future . . .
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Jcc on 01/06/2019 06:22 pm
Stupid question, can this thing rise and drop completely stable ? You have three engines next to each other, in a line, not spread out like with 120 degrees between two. I know you do a kind of thrust vectoring, but with three engines in line ?

Yes. Why wouldn’t it? If one engine can balance it, why would it be harder with three? All engines gimbal to provide thrust vectoring, and they can do it independent of each other.

If the Raptors can throttle down enough to hover, they should be able all kinds of subtle movements, rotations, translations with minimal tilt, etc.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/06/2019 06:51 pm
Someone asked for a visual comparison between the Hopper and Dragon2. I found this one on Reddit.
https://www.reddit.com/r/SpaceXLounge/comments/ad51uu/i_designed_and_printed_a_starhopper_based_on_the/
I was waiting for this one to happen...

Or in words, Dragons (or any of today's capsules) can serve as worthy landing feet for Starship...

-----
ABCD: Always Be Counting Down

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/06/2019 06:52 pm
... Spacehopper is a bit desperate, "fake it until you make it", surely far away from the top-down approach spacecraft got built in the past and more than just a bit of PR.

...But honestly, and I'm saying this again and again: SpaceX won't be able to develop and build a reusable Mars-going craft just from what they earn with their current business model.

...You can't repeat these words often enough: High risk. This is all about going in full speed, keeping your goal firmly in sight and rely on things lining up on the way because they want to anyway.


Well, I think you've pretty much described the beginnings of almost every successful company in existence today - from General Motors to Microsoft to Amazon. So what is your point?

A sensed a bit of passive pessimism here which is OK. But then again, risk aversion is the reason why $19B/year can't even get us a reusable rocket from NASA.

So . . . I'm not worried.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: IntoTheVoid on 01/06/2019 07:02 pm
Looks like they stuffed some insulation, or contractor bags, or something else, along the gap between the base of the nosecone section and the top of the concrete jig. Why? To prevent us perverts from peeking in through the gaps? Or to keep the weather out, or some other nefarious reason?

Nomadd or BocaChicaGal - don't suppose they put a door or some kind of cover over the opening into the jig?

Notice also that the ductwork seems to gone from the holes and there appears to be caps of some sort on the inside edge of the holes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: uhuznaa on 01/06/2019 07:07 pm
... Spacehopper is a bit desperate, "fake it until you make it", surely far away from the top-down approach spacecraft got built in the past and more than just a bit of PR.

...But honestly, and I'm saying this again and again: SpaceX won't be able to develop and build a reusable Mars-going craft just from what they earn with their current business model.

...You can't repeat these words often enough: High risk. This is all about going in full speed, keeping your goal firmly in sight and rely on things lining up on the way because they want to anyway.


Well, I think you've pretty much described the beginnings of almost every successful company in existance today - from General Motors to Microsoft to Amazon. So what is your point?

A sensed a bit of passive pessimism here which is OK. But then again, Risk aversion is the reason why $19B/year can't even get us a reusable rocket from NASA.

So . . . I'm not worried.

I'm not worried or risk averse or whatever. I'm just saying that it pays to be realistic and rational, because only then you're at your toes when you need to be exactly there.

I'm just saying that this thing will be never higher than 500 m, but will be at many websites and even now is there. This is a good thing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: IntoTheVoid on 01/06/2019 07:08 pm
It's exactly where the lifting eyes are underneath. And these things are probably pretty big and strong. Somebody should do some pixel counting to get a measure.

We will see soon enough, when they lift the base segment again.
This is not exactly "where the lifting eyes are underneath". If you look at the 1st picture here (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1897597#msg1897597), there is one leg shrouded and one not. The welded lift points are almost at the top edge, and the points on the shroud, (2 low, one high center) do line up at all.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DJPledger on 01/06/2019 07:15 pm
Assuming the Heavy Booster remains CF here is what it early tests may look like.

Can someone please redo this render with a stainless steel booster. SpaceX likely to make whole system out of stainless steel.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/06/2019 07:18 pm
... Spacehopper is a bit desperate, "fake it until you make it", surely far away from the top-down approach spacecraft got built in the past and more than just a bit of PR.

...But honestly, and I'm saying this again and again: SpaceX won't be able to develop and build a reusable Mars-going craft just from what they earn with their current business model.

...You can't repeat these words often enough: High risk. This is all about going in full speed, keeping your goal firmly in sight and rely on things lining up on the way because they want to anyway.


Well, I think you've pretty much described the beginnings of almost every successful company in existance today - from General Motors to Microsoft to Amazon. So what is your point?

A sensed a bit of passive pessimism here which is OK. But then again, Risk aversion is the reason why $19B/year can't even get us a reusable rocket from NASA.

So . . . I'm not worried.

I'm not worried or risk averse or whatever. I'm just saying that it pays to be realistic and rational, because only then you're at your toes when you need to be exactly there.

I'm just saying that this thing will be never higher than 500 m, but will be at many websites and even now is there. This is a good thing.

OK. I understand. What I am saying is that this hopper is built to do exactly what it was intended to do - 500 or so meter hops and test out various landing procedures. So I think they are very much on track with their plans to do what they have planned for years - dev of the BFR. I don't see how this is a risk. PR? Sure. Who can fault them for that?

As far as I'm concearned, the more widespread this story gets the better for the future of human spaceflight. Don't you think that we Aerospace enthusiasts and professionals have benefitted from it? I think so.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ThePonjaX on 01/06/2019 07:19 pm
But honestly, and I'm saying this again and again: SpaceX won't be able to develop and build a reusable Mars-going craft just from what they earn with their current business model. They even won't be able to launch and then earn money with StarLink, which they won't be able to launch and complete with F9, which would be much too expensive for that, just with what they have NOW. They need to start building StarLink and StarShip at the same time and have the latter take over launching the former at JUST the right moment. Just as you have to launch a rocket with the first stage and then have the second stage take over at just the right moment.


Elon thinks different:

https://twitter.com/elonmusk/status/1076614135138312192 (https://twitter.com/elonmusk/status/1076614135138312192)

"Starlink V1 on Falcon, V2+ on Starship. Basically, all future products will contain either the word “star” or “link” "


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Eerie on 01/06/2019 07:22 pm
Any idea why SpaceX need this hopper? What is there to learn that they don't already know from their Grasshopper and Falcon-9 experience?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/06/2019 07:24 pm
Can we reckon some rational development path? My take is this:

1. This thing is a pathfinder. It's there both for having something in halfway the right scale and shininess to show off as soon as possible (exploiting all the hopefully good press they get with DM-1) and to fly the 500 m landing tests once they have three flight-worthy Raptors ready. Do landings with one, two or three engines and explore failure modes and how to recover from them. Try to not destroy it, but if you have to, well, do it and learn from it.

[snip]

You have to play the game and to stage things just right to get to orbit or to succeed as a business. In this terms Spacehopper is a bit desperate, "fake it until you make it",

Contradictory statements.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/06/2019 07:25 pm
Any idea why SpaceX need this hopper? What is there to learn that they don't already know from their Grasshopper and Falcon-9 experience?

They have experience.  The F9 experience won't translate to SS without serious revalidation.  It's too expensive to blow up Test versions of SS.

SH gets you the test validations that let you start hopping with SS.  IIRC, the avionics software is starting from a clean sheet.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/06/2019 07:50 pm
Any idea why SpaceX need this hopper? What is there to learn that they don't already know from their Grasshopper and Falcon-9 experience?

They're using a new engine with a new combustion cycle (FFSC). It will have different characteristics, no separate turbine exhaust, different total thrust, throttle ability and power up time. Also different dimensions and hence different gambolling arrangements (even if similar). It will use a different fuel with a different mass and different flow rate running at cryogenic temperatures. It will be powering a much larger vehicle with different dimensions to F9.

The cost of making a mistake with a Starship is very large because it will need sophisticated active re-entry cooling, fancy flipperon controls, 7 raptor engines and will be a very large structure built to fine tolerances. Would be a shame if they managed to get it into orbit and return it to the launch site only to lose control in the last few km and have it crash because of some sea level engine control issue that had been overlooked.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: John Alan on 01/06/2019 08:01 pm
It's exactly where the lifting eyes are underneath. And these things are probably pretty big and strong. Somebody should do some pixel counting to get a measure.

We will see soon enough, when they lift the base segment again.
This is not exactly "where the lifting eyes are underneath". If you look at the 1st picture here (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1897597#msg1897597), there is one leg shrouded and one not. The welded lift points are almost at the top edge, and the points on the shroud, (2 low, one high center) do line up at all.

Maybe they have welded in a central, one place lifting point (or will soon) and the temporary construction eyelets are now retired...   ???

Honestly, that would save time and cost moving forward, as then no need for a spreader tri-bar and all that rigging...  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: weepingdragon on 01/06/2019 08:01 pm
Question for those who know/follow the legalities of these things.  Many on the forum (including myself) have a "rough" outline of all the paperwork and approvals required by multiple federal agencies involved in flights and testing above certain heights.

But does anything change if they're testing on a "barge'ish" platform past the 12 or 200 mile coastal boundaries? Less or more (international?) agencies/rules to deal with? Or no changes?

And if anyone knows/thinks of a better place to post this let me know. Thanks!

edit:missing words
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: joek on 01/06/2019 08:03 pm
Any idea why SpaceX need this hopper? What is there to learn that they don't already know from their Grasshopper and Falcon-9 experience?

What others have mentioned, plus... to test Raptor multi-engine and multi-altitude performance would otherwise require building new, or adapting existing facilities--likely an expensive proposition for limited scope.

Hopper gets them that and more, albeit with a bit more initial risk... maybe...  SpaceX's F9 experience should help reduce that risk.

In short, think of this hopper as a very mobile test facility/mule which can perform a variety of engine-related, aero and GNC tests at lower time and cost than discrete test facilities.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: HMXHMX on 01/06/2019 08:05 pm
Question for those who know/follow the legalities of these things.  Many on the forum (including myself) have a "rough" outline of all the paperwork and approvals required by multiple federal agencies involved in flights and testing above certain heights.

But does anything change if they're testing on a "barge'ish" platform past the 12 or 200 mile coastal boundaries? Less or agencies/rules to deal with? Or no changes?

And if anyone knows/thinks of a better place to post this let me know. Thanks!


No legal change whatever if the launching company is a US person.  In practice, sea launching might mean an easier path to a license regarding environmental or third-party risk analysis (as was the case for SeaLaunch) but this is a weak benefit.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: joek on 01/06/2019 08:14 pm
Question for those who know/follow the legalities of these things.  Many on the forum (including myself) have a "rough" outline of all the paperwork and approvals required by multiple federal agencies involved in flights and testing above certain heights.

But does anything change if they're testing on a "barge'ish" platform past the 12 or 200 mile coastal boundaries? Less or more (international?) agencies/rules to deal with? Or no changes?

Requirements and related paperwork will not change--which would fall under the FAA as SpaceX is a US company.  In the case of this hopper it would be an FAA launch permit (not license, unless they decide to start carrying for-pay payloads).  Launching it in the middle of nowhere would reduce the risk to the public--which is one of the FAA's primary concerns--which would presumably make it easier to obtain FAA approval.

edit: and what HMXHMX said.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/06/2019 08:30 pm
Any idea why SpaceX need this hopper? What is there to learn that they don't already know from their Grasshopper and Falcon-9 experience?

They have experience.  The F9 experience won't translate to SS without serious revalidation.  It's too expensive to blow up Test versions of SS.

Bingo, exactly. Most people just don’t seem to realize this. SpaceX could afford to throw away F9s with the tests... the missions were already paid for. But that is not the case here. This will be more like an airliner testing program. They can not afford to throw away test articles.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ludonope on 01/06/2019 08:31 pm
I was thinking about the current engines on the hopper, and in my opinion, these were used to test the interface with the water tower, but they might replace only the central one to do the first hops, and then add the two other ones in the future when they are built.

This would allow them to start testing way faster than having to wait for 3 raptors to be completed and tested and shipped and mounted.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/06/2019 08:39 pm
See if you agree with the argument given in this article.

Why is SpaceX Working Around the Clock on the Starship Prototype? (https://www.nextbigfuture.com/2019/01/why-is-spacex-working-around-the-clock-on-the-starship-prototype.html)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: magnemoe on 01/06/2019 08:46 pm
Any idea why SpaceX need this hopper? What is there to learn that they don't already know from their Grasshopper and Falcon-9 experience?

They have experience.  The F9 experience won't translate to SS without serious revalidation.  It's too expensive to blow up Test versions of SS.

Bingo, exactly. Most people just don’t seem to realize this. SpaceX could afford to throw away F9s with the tests... the missions were already paid for. But that is not the case here. This will be more like an airliner testing program. They can not afford to throw away test articles.
Yes, the F9 first stage was paid for and would crash after use anyway, why not play with it after separation.
BFR is another case they will use 30 something raptors and an rocket who will be build in small numbers.
Unlike the F9 first stage its not something you will want to risk, up to the level of sacrifice an tanker for an first stage.

And yes they will probably use hopper data for first stage landings to.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DigitalMan on 01/06/2019 09:05 pm
Any idea why SpaceX need this hopper? What is there to learn that they don't already know from their Grasshopper and Falcon-9 experience?

They have experience.  The F9 experience won't translate to SS without serious revalidation.  It's too expensive to blow up Test versions of SS.

SH gets you the test validations that let you start hopping with SS.  IIRC, the avionics software is starting from a clean sheet.

I suppose this is what happens.  SpaceX has success reusing F9 1st stage according to part of their goals (they have not yet achieved rapid fuel and go reuse), and people think it's simple.

Look at the complexity NASA is encountering building SLS and that is shuttle-based, something they had been flying for decades. 

Rapid, fuel and go reuse in conjunction with deep space exploration deserves a lot more respect than it is getting.  It reminds me of some folks from my mountain climbing days that didn't have any respect for the mountain, some of them are no longer with us.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/06/2019 09:07 pm
See if you agree with the argument given in this article.

Why is SpaceX Working Around the Clock on the Starship Prototype? (https://www.nextbigfuture.com/2019/01/why-is-spacex-working-around-the-clock-on-the-starship-prototype.html)

Quote
The top portion of the new rocket is the Starship portion.

Neither part is "the Starship portion".  It's a test vehicle.  The whole vehicle is designed to test various important aspects of the final product.  Much will change for the actual final product.

Structurally, the bottom is clearly vastly "sturdier" than the top - very thick steel sheet (just check out those welds), while the top is so thin and flimsy I can't imagine it taking loads any more significant than air resistance.  The bottom will be the tanks.  Its upper hemispheric bulkhead will intrude into the upper portion of the rocket.  That still leaves a massive amount of empty space in the upper portion.  And of course it does, because the cargo volume of Starship is to be freaking massive.

Given this, the tanks won't be very large.  But they're not supposed to be; the max target altitude is only 5km.  The final Starship will be longer, and all that extra length will be tankage.

The construction method is not how the final vehicle will be built (although the exact method is yet to be seen).  Elon responded to several of my posts (@enn_nafnlaus) on the subject recently, I recommend checking them out (short summary: final version won't have the "wrinkling" problem of this, but spiral winding is out because of the difficulty in varying the thickness).  Right now, the goal is to start gathering real-world data ASAP.

Quote
SpaceX has shifted to stainless steel to enable hot metal structures for re-entry.

Well, that's one reason.  Here's some more.

 * They're clearly going for a heat rejection, rather than heat radiating, approach.  You need a highly reflective material for this.  They'll still need to cool the steel on the hot side, despite the high max operating temperature.  I imagine they'll do this by spraying it with cryogenic propellant (but this is just my speculation).

 * While specific strength on CF is notably higher than stainless at room temperature, at cryogenic temperatures stainless is stronger, and at reentry temperatures it's much stronger.

 * Propellant must be able to be stored for months or years at a time for transit to Mars and other destinations further out in the solar system.  A key part of this is solar heat rejection.

Honestly, I'm thrilled with the design.  I've long been a Negative Nelly concerning the CF BFR concepts, for quite a few reasons. There's nothing about the new approach that I don't love.  Starship and Super Heavy are going to change everything.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ejb749 on 01/06/2019 09:39 pm
Assuming the Heavy Booster remains CF here is what it early tests may look like.

Super Heavy isn't going to be CF. It's going to be stainless, just like Starship.

Where did you get this information?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/06/2019 09:53 pm
If they are filling this even a fraction of the way with props, then it should have every capacity to go suborbital, reverse, and come back down.

It also seems obvious to me that the hopper isn't going to "have every capacity to go suborbital".  Their "extended" application is only to eventually go up to 5 km.

"Suborbital" is a low bar that's easy to obtain.  Back a few decades ago when I was flying model rockets I managed to get every one of them to go suborbital.  Most cats leaping after a bird can achieve suborbital trajectories.  Golf balls, field goals in American football etc. Fish leaping for a fly. Doesn't take much.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/06/2019 09:57 pm
Super Heavy isn't going to be CF. It's going to be stainless, just like Starship.

Where did you get this information?

Answering a question about both Super Heavy and Starship:
https://twitter.com/elonmusk/status/1071572534921900033

General comment on material properties:
https://twitter.com/elonmusk/status/1077111607564464129

Not explicitly stated, but strongly suggested.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/06/2019 09:59 pm
If they are filling this even a fraction of the way with props, then it should have every capacity to go suborbital, reverse, and come back down.

It also seems obvious to me that the hopper isn't going to "have every capacity to go suborbital".  Their "extended" application is only to eventually go up to 5 km.

"Suborbital" is a low bar that's easy to obtain.  Back a few decades ago when I was flying model rockets I managed to get every one of them to go suborbital.  Most cats leaping after a bird can achieve suborbital trajectories.  Golf balls, field goals in American football etc. Fish leaping for a fly. Doesn't take much.

Yeah, my fault for repeating their misleading terminology rather than making the correction you just made, despite considering doing so at the time I was posting  ;)  (I was operating on the premise that they were talking about "suborbital spaceflight", rather than mere atmospheric flight, given the context of what they wrote).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MikeAtkinson on 01/06/2019 10:35 pm
See if you agree with the argument given in this article.

Why is SpaceX Working Around the Clock on the Starship Prototype? (https://www.nextbigfuture.com/2019/01/why-is-spacex-working-around-the-clock-on-the-starship-prototype.html)

Why are they working round the clock? Because the hopper is on the critical path. I'm not sure why the hopper is on the critical path, though many suggestions have been made on various threads.

It is hard to underestimate how important speed is on a venture like this. Speed both cuts project costs (think of all the wages that need to be paid) and pulls forward revenue.

[Please take the figures below with a large grain of salt (perhaps a whole saltmine of salt), they are just there to illustrate how important speed is in monetary terms]

Ignoring staff involved on launches and starlink there are perhaps 4,000 engineers, production and testing staff for F9, FH and Dragon at a loaded labor rate of $150,000 / year (so $600 M / year or $50 M / month). Pulling forward SH/SS allows these costs to be charged to some other (hopefully revenue earning) project.

F9/FH will probably launch at about 2/month, at a cost to SpaceX of about $80 M /month.

Starlink is rumored to be on the order of $30 B / year revenue, or about $2500 M/ month and $800 M / month profit (full size constellation, starlink v2+), pulling this forward makes the revenue more certain and the profit higher due to first mover advantage, it brings in more revenue and profit because they ramp up quicker and reduces outgoing cash flow.

The profit from #Dearmoon and other potential lunar adventures is brought forward.

Keeping to the timetable for Mars also saves SpaceX a lot of cost.

It helps win business, increases the market size and stops that business going to rivals. Although hard to estimate this could be significant. I'm guessing a size of about 1/3 of NASA human spaceflight revenue (not all coming from NASA), so about $3 B / year revenue or $250 M / month.

It accelerates point-to-point, which is a business opportunity on the same scale as starlink. I'm fairly skeptical about this, lets guess that this has a 30% chance of working as a business, so guessing $10 B / year revenue and 3 B / year profit.

The amount of capital they need to raise is less because costs to break-even revenue are reduced.

Putting all of these together, each month that SH/SS can be brought forward is worth an extra (50 + 2500 + 250 + 800) $3.6 B revenue and well over $1 B profit.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DigitalMan on 01/06/2019 10:38 pm
The funny thing is you have folks doubting that SpaceX could make a 2022 launch date for Starship cargo launches to Mars and you also have people wondering why are they moving so fast?

Make up your mind.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MizaruSpaceXNut on 01/06/2019 10:55 pm
Even with all the night, weekend and overtime pay; SpaceX is probably getting the work done cheaper than

could be done in la la land! Many highly skilled workers go to the Valley in the winter as a tradition.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: NotOnImpact on 01/06/2019 11:23 pm
My thinking is that, after switching directions to the new architecture, they were left with a lot of extra cash already dedicated to the project.  Working with Carbon Fiber at this scale and especially trying to put pressurized, hot oxygen in a CF tank was going to be a very expensive endeavor. 

So if you have the resources allocated, why not use it to accelerate the schedule.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/06/2019 11:56 pm
Why are they working round the clock? Because the hopper is on the critical path. I'm not sure why the hopper is on the critical path, though many suggestions have been made on various threads.

It is hard to underestimate how important speed is on a venture like this. Speed both cuts project costs (think of all the wages that need to be paid) and pulls forward revenue.

Ok but let's think about this a second.  The hopper is basically a Raptor test platform.  And really just "final landing" Raptor test platform.  That includes engine out capability, various gimballing regimes, etc.  But other than that, whatever the physical resemblance the hopper has to the final form factor of the SpaceShip, it does not have the capability to test many of the most critical systems: TPS, EDL aerodynamics, vacuum operation, cargo processes, and certainly nothing related to crew.  So while obviously you need to have maximum reliability in your advanced super-high performance engine, that seems to be about all that this platform will test, and not much more.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: joek on 01/07/2019 12:07 am
...  So while obviously you need to have maximum reliability in your advanced super-high performance engine, that seems to be about all that this platform will test, and not much more.

Which I would argue "...that seems to be about all that this platform will test..." is enough at this point in time.  This is not necessarily the end-all test vehicle; it gets them to the next step.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: matthewkantar on 01/07/2019 12:35 am
The rush to build this thing suggests to me that they need the information it will provide to make an important decision. If they are at a fork in the road, they may need this data to continue.

On the other hand, they are wasting time hanging some non engineering bling on it, so how big can the rush be?

Matthew
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/07/2019 12:42 am
The rush to build this thing suggests to me that they need the information it will provide to make an important decision. If they are at a fork in the road, they may need this data to continue.

On the other hand, they are wasting time hanging some non engineering bling on it, so how big can the rush be?

Matthew

Rush?

I am going to assumen you have not kept up with EM's presentations over the past 3 years. Otherwise, I will assume you're trolling.

If they had decided to build the hopper 3 months ago I would have considered some validity to this argument.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/07/2019 12:46 am
Quote
So while obviously you need to have maximum reliability in your advanced super-high performance engine, that seems to be about all that this platform will test, and not much more.

 * First time flying a spacecraft with such a high diameter
 * First time landing a spacecraft with such a high diameter
 * If a weight-match for Starship, first time landing a spacecraft with such a high mass
 * First time operating a spacecraft with CH4 onboard
 * First time operating a steel-framed spacecraft
 * First time operating a spacecraft with steel in contact with cryogenic propellants
 * Numerous subsystems developed specifically for the craft which may be tested in flight.

Probably many more things.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: su27k on 01/07/2019 01:27 am
The funny thing is you have folks doubting that SpaceX could make a 2022 launch date for Starship cargo launches to Mars and you also have people wondering why are they moving so fast?

Make up your mind.

The two thoughts are not necessarily contradictory, you can hold both if you don't believe the hopper is on the critical path to a 2022 launch date. I don't think anyone figured out why hopper is on the critical path yet (assuming it is).

On a smaller scale, there's also the question why are they rushing the body work when the engine won't be ready for another month. It looks like the body would be done in a day or two, what's next?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: su27k on 01/07/2019 01:36 am
Oh my. This has gone from "It's a water tower!" to "It's a space ship!" all too fast.

Can we reckon some rational development path? My take is this:

1. This thing is a pathfinder. It's there both for having something in halfway the right scale and shininess to show off as soon as possible (exploiting all the hopefully good press they get with DM-1) and to fly the 500 m landing tests once they have three flight-worthy Raptors ready. Do landings with one, two or three engines and explore failure modes and how to recover from them. Try to not destroy it, but if you have to, well, do it and learn from it.

2. While they'll be doing this they will build version 2 with movable wings, canards and bigger propellant tanks to fly the 5 km tests: launch, do a landing approach sideways to 1 km of height, move vertical with the moving wings and canards and RCS and land. Repeat with all kinds of failure modes and shake it down until it's routine.

This hopper should be able to do #2 easily. DC-X was able to do this using just the main engines, no RCS or wings required:

https://www.youtube.com/watch?v=wv9n9Casp1o

Quote
3. While doing this build the version 3, with actual full size tanks and a heat shield (active cooling) to fly suborbital trajectories and to test reentry with increasing velocities and thermal loads. THIS SpaceX won't be able to pull off without money from the outside, but hopefully in one way or another they will get more money to do that with all the publicity they managed to provoke with 1. and 2.

They got close to $1B outside investment this year, I doubt money is a problem for building the orbital test vehicle. Besides, Elon said they're already building it at the San Pedro site, now we just need some photos to see what's going on.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cinder on 01/07/2019 01:41 am
If the BFH is the sine qua non precursor to all crew SSs, then you would want as much flight time as possible before putting humans in it, never mind high profile humans like the DearMoon crew. 

It may be an unanswered question to ask what good reason SpaceX could have to not work around the clock.  Maybe this SHSS work speed is only remarkable because it's the only publicly visible SHSS work.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lemurion on 01/07/2019 01:42 am
The funny thing is you have folks doubting that SpaceX could make a 2022 launch date for Starship cargo launches to Mars and you also have people wondering why are they moving so fast?

Make up your mind.

The two thoughts are not necessarily contradictory, you can hold both if you don't believe the hopper is on the critical path to a 2022 launch date. I don't think anyone figured out why hopper is on the critical path yet (assuming it is).

On a smaller scale, there's also the question why are they rushing the body work when the engine won't be ready for another month. It looks like the body would be done in a day or two, what's next?

I think that while the specifics may not be public knowledge, the base reason why the hopper is on the critical path is obvious:

It’s Raptor. If Raptor doesn’t work as designed, nothing else matters. The hopper is going to give them vital data on both takeoff and landing operations and landing is the hard part. Raptor has to be able to throttle down and land and SpaceX appears to think that the hopper is the best available, if not the only, way to demonstrate that functionality.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Mongo62 on 01/07/2019 01:47 am
The rush to build this thing suggests to me that they need the information it will provide to make an important decision. If they are at a fork in the road, they may need this data to continue.

On the other hand, they are wasting time hanging some non engineering bling on it, so how big can the rush be?

Matthew

Is it wasting time though? They presumably need to wait until the engines are ready, so they might as well make the hopper shiny in the meantime. The cost is tiny compared to the total SS/SH development cost, and the gain is considerable, in terms of positive public perception when video of the hopper flying goes public.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/07/2019 01:56 am
I’m curious as to what Jim’s thoughts are on the BFH. Jim, you out there? Be interesting to get your take...

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: GWH on 01/07/2019 02:03 am
I am sure there will still be a lot of time spent with actual SpaceX employees crawling around inside this thing wiring up various sensors and everything else to make it flight (hop?) worthy. The rush now is to get ahead of that.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: vaporcobra on 01/07/2019 02:19 am
Guys, the idea that this development is being rushed because of the hours worked is straight up blind to history and known operational facts. SpaceX runs almost every single one of its facilities - ranging from Hawthorne to Redmond to McGregor - 24/7 or nearly so, and pretty much universally has two shifts (10-12+ hours for two, 10-14+ hours for one) for most conceivable tasks.

This is a very normal pace for SpaceX, modified by the fact that they're building a purely experimental and less-than-full-fidelity test article with almost no red tape whatsoever. The Grasshopper/F9R programs proceeded at very similar speeds once they got into the actual process of building and assembling hardware.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AJW on 01/07/2019 02:34 am
One aspect of getting the hopper flying that is easy to overlook is the human factor.   Having a team without a real deadline teaches you little about how that team will work when they must meet hard targets.  Who are the real leaders.  Who on the team makes the right decisions, or the wrong ones.  Hopper is the rubber hitting the road and will represent the efforts of thousands.  Decisions made up to this point will soon face the toughest of judges.

The difference between theory and practice is that practice may not forgive you for forgetting something.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: georgegassaway on 01/07/2019 03:29 am

This hopper should be able to do #2 easily [test for change from belly flop mode to tail-first descent mode]. DC-X was able to do this using just the main engines, no RCS or wings required:

DC-X most definitely had aerodynamic flaps near the base which assisted in steering it. It also had strakes on the nose section to get a bit of aerodynamic "bite" when the flaps steered to produce an angle of attack (strakes acting sort of like very long skinny canards with no control surfaces).

(https://i.warosu.org/data/sci/img/0097/66/1527339957128.jpg)

And DC-X did not have huge fins trying to stabilize it nose-first thru the air. 

 This new hopper will be unable to get  data on the aerodynamic maneuvering of the "real" Starship to flip to tail-first descent, since it wont have the canard, two articulated fins for the belly-flop mode, and not the same shape (length), among other things (landing configuration CP/CG relationship need to be the same as well as mass).   Also, unless they really are going to pressurize the skin of the mid and nose sections or do something to stiffen it up more than the bare bones structure it seems to have, it's not likely to hold up to high aerodynamic side loads.

They are going to need a different vehicle to accurately test for that.

Although they'll be able to use thrust vectoring to maneuver sharply if they want to (up to the aerodynamic and structural limits), but not the same as the real Starship.  They can certainly get some rudimentary (hopefully not RUD-imentary) info on fuel slosh behavior
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/07/2019 03:40 am
EDIT - never mind
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Michel Van on 01/07/2019 08:03 am
Looking at what happen a SpaceX launch site Boca Chica
it remind me of this...
(https://pbs.twimg.com/media/DwKECeBX4AA-5JG.jpg)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: longboard1210 on 01/07/2019 08:44 am
one consideration for the 24/7 working is there is less likely to be things missed in the program as systems will not be assigned to just one person
kind of like a double double check if that makes sense

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: hallmh on 01/07/2019 09:30 am

Regarding the 'foil', it may be similar to material that I used a few years ago - thin stainless steel sheet (I used 0.1mm, but it does come thinner and of course thicker), mechanically polished on one face to a mirror finish.

Comes in rolls or sheets. Amazing stuff.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/07/2019 10:13 am
I agree that it looks like somewhere around 0,1mm stainless. That said, you're not going to build tanks out of 0,1mm stainless for such a large rocket.  Falcon 9's skin is 4,7mm alumium, for comparison.

I'm 95% sure that only the bottom portion is tankage (and it'll end up with a big hemispheric bulkhead intruding into the upper portion, as well as an internal bulkhead). The bottom portion is clearly built far sturdier than the top portion. Yes, that leaves a truly massive empty area at the top, but that's the point - Starship's passenger / cargo volume is supposed to be truly massive..  Final Starship will be significantly extended vs. the hopper, and all of that extra length will be tankage.

The key thing to look for going forward is bulkheads. Is there any sign of work being done on them?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Llian Rhydderch on 01/07/2019 11:13 am
Looking at what happen a SpaceX launch site Boca Chica
it remind me of this...

--- snipped out the image expansion---

"Amazing Stories"  cover art, "October"  "25 cents"
https://pbs.twimg.com/media/DwKECeBX4AA-5JG.jpg


If NSF is going to put up images from some magazine cover artwork website from time to time, I think we should be crediting that source and providing a link to it, not merely grabbing the artwork and adding it to our site.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: woods170 on 01/07/2019 12:01 pm
I’m curious as to what Jim’s thoughts are on the BFH. Jim, you out there? Be interesting to get your take...



Jim hasn't been active here since Dec 26th, 2018.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/07/2019 12:04 pm
Looking at what happen a SpaceX launch site Boca Chica
it remind me of this...

--- snipped out the image expansion---

"Amazing Stories"  cover art, "October"  "25 cents"
https://pbs.twimg.com/media/DwKECeBX4AA-5JG.jpg


If NSF is going to put up images from some magazine cover artwork website from time to time, I think we should be crediting that source and providing a link to it, not merely grabbing the artwork and adding it to our site.

How about this one: Amazing Stories, April 1947  (http://www.isfdb.org/cgi-bin/pl.cgi?56201)

(http://www.philsp.com/data/images/a/amazing_stories_194704.jpg)(https://forum.nasaspaceflight.com/assets/47120.0/1537593.jpg)

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ctjordan33 on 01/07/2019 02:16 pm
Assuming the Heavy Booster remains CF here is what it early tests may look like.

Can someone please redo this render with a stainless steel booster. SpaceX likely to make whole system out of stainless steel.

Someone on Reddit did this and it is gorgeous.
https://www.reddit.com/r/SpaceXLounge/comments/adgm77/fullstack_stainless_steel_starship_super_heavy/

(https://i.redd.it/2rx75mrsez821.png)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rocket Science on 01/07/2019 03:21 pm
Assuming the Heavy Booster remains CF here is what it early tests may look like.

Can someone please redo this render with a stainless steel booster. SpaceX likely to make whole system out of stainless steel.

Someone on Reddit did this and it is gorgeous.
https://www.reddit.com/r/SpaceXLounge/comments/adgm77/fullstack_stainless_steel_starship_super_heavy/

(https://i.redd.it/2rx75mrsez821.png)
Great first post, welcome to the forum! :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/07/2019 04:17 pm
Assuming the Heavy Booster remains CF here is what it early tests may look like.

Can someone please redo this render with a stainless steel booster. SpaceX likely to make whole system out of stainless steel.

Someone on Reddit did this and it is gorgeous.
https://www.reddit.com/r/SpaceXLounge/comments/adgm77/fullstack_stainless_steel_starship_super_heavy/

(https://i.redd.it/2rx75mrsez821.png)

How Magritte!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Ludus on 01/07/2019 04:36 pm
Maybe the window glass in gold metallic mirror finish? Cut down on harsh direct sunlight and would look cool.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: edzieba on 01/07/2019 04:44 pm
BFH (Star Hopper has an acronym collision with Super heavy) being on the critical path makes perfect sense: to test any other aspect of Starship, Starship needs to be able to land. No landing, no economically viable test program, including testing Starship landing. The only way out of that Catch 22 is to be able to test landing without using an extremely expensive Starship, hence the rather cheap Starship Like Object.

Lifting: the existing spreader bar triangle lifting assembly used to move the base section off of the concrete form would comfortable fit within the shiny foil aeroshell. The drone shots clearly show the leg mounting points extend through the outer wall to internal bracing that lift points could also be mounted to. The nose cap is already made of structural steel with a lifting hardpoint (as has already been used to lift the upper assembly). There is nothing to stop the entire BFH being lifted via a hardpoint in the nosecap other than a propensity to swing about in high winds.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/07/2019 04:49 pm
Which I would argue "...that seems to be about all that this platform will test..." is enough at this point in time.  This is not necessarily the end-all test vehicle; it gets them to the next step.

I don't disagree, however it doesn't necessarily answer the question of why they are grinding so hard on this particular branch of the development tree when there are others that are arguably far more complicated (TPS, life support, power, etc.).  Between the grind and some of the aesthetic decisions, I'm thinking they really want something to "show" soon.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mme on 01/07/2019 05:00 pm
Which I would argue "...that seems to be about all that this platform will test..." is enough at this point in time.  This is not necessarily the end-all test vehicle; it gets them to the next step.

I don't disagree, however it doesn't necessarily answer the question of why they are grinding so hard on this particular branch of the development tree when there are others that are arguably far more complicated (TPS, life support, power, etc.).  Between the grind and some of the aesthetic decisions, I'm thinking they really want something to "show" soon.
Clearly SpaceX wants this thing to look good and to show it off. But the only reason we know about it is because it's being built out in the open and we have eyeballs on it. We have no idea how hard they are "grinding" on anything else.

We know there will be an active TPS, so people must be working on that. We know a new full scale production Raptor will be on the test stand soon, so people are clearly working on that. We know that people are actively working on "Starship Mk 1" in the factory. On and on, don't assume what we can not see happening in a field is not happening.

SpaceX has over 7,000 employees now. We get to "see" about 1% [1] of what they are doing.

[1] Totally made up percentage purely for illustrative purposes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/07/2019 05:22 pm
Clearly SpaceX wants this thing to look good and to show it off. But the only reason we know about it is because it's being built out in the open and we have eyeballs on it. We have no idea how hard they are "grinding" on anything else.

We know there will be an active TPS, so people must be working on that. We know a new full scale production Raptor will be on the test stand soon, so people are clearly working on that. We know that people are actively working on "Starship Mk 1" in the factory. On and on, don't assume what we can not see happening in a field is not happening.

SpaceX has over 7,000 employees now. We get to "see" about 1% [1] of what they are doing.

[1] Totally made up percentage purely for illustrative purposes.

I never said they weren't working on other things.  Would you at least concede in the breadth of technologies and testing that will be needed to make Starship work, that Raptor engine and hover testing are among some of the more "known" quantities given their experience in the Falcon/Merlin/Grasshopper world?  I'm not making assumptions around what other work is being done on different/new technologies, but it is surprising to see them paying people around the clock (including likely holiday overtime, which is $$$) on an aspect of the testing regime that from a admitted-layman's perspective seems like they have plenty of time to work out even on an accelerated development roadmap.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: philw1776 on 01/07/2019 05:29 pm
Clearly SpaceX wants this thing to look good and to show it off. But the only reason we know about it is because it's being built out in the open and we have eyeballs on it. We have no idea how hard they are "grinding" on anything else.

We know there will be an active TPS, so people must be working on that. We know a new full scale production Raptor will be on the test stand soon, so people are clearly working on that. We know that people are actively working on "Starship Mk 1" in the factory. On and on, don't assume what we can not see happening in a field is not happening.

SpaceX has over 7,000 employees now. We get to "see" about 1% [1] of what they are doing.

[1] Totally made up percentage purely for illustrative purposes.

I never said they weren't working on other things.  Would you at least concede in the breadth of technologies and testing that will be needed to make Starship work, that Raptor engine and hover testing are among some of the more "known" quantities given their experience in the Falcon/Merlin/Grasshopper world?  I'm not making assumptions around what other work is being done on different/new technologies, but it is surprising to see them paying people around the clock (including likely holiday overtime, which is $$$) on an aspect of the testing regime that from a admitted-layman's perspective seems like they have plenty of time to work out even on an accelerated development roadmap.

I think you miss the critical point that without validating and characterizing the rocket engine, in this case Raptor, the entire rest of the spacecraft development is moot or greatly affected.  Rockets are designed based on the engine(s) capabilities and characteristics, not the other way around.
Testing Raptor is smack dab on the critical schedule path.  Thus git 'er done ASAP.

I agree with the speculation that there is something new and unique about Raptor then need flight verified beyond simulation.  I think it's a new to SpaceX variable engine geometry we see hints of in the stand in engine photos.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: adrianwyard on 01/07/2019 05:29 pm
The test vehicle we see being built doesn't appear to have any way to absorb landing loads - the BFS renders have retracting legs on the fins but there's almost no vertical travel available in this vehicle. So I guess they're either confident all landings will be really soft. Or … perhaps they are going to try an early version of an active (moving/load-damping) landing pad - as has been anticipated before now for the final vehicles.

Speculating: Precision landing can be assumed these days, so I suppose all that's needed is a biggish Pica-X surface, raised on actuating hydraulic legs? It seems easier to just put legs on this test vehicle, but if the final vehicle(s) will need to land on a pad this would give some initial real world experience.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/07/2019 05:36 pm
I never said they weren't working on other things.  Would you at least concede in the breadth of technologies and testing that will be needed to make Starship work, that Raptor engine and hover testing are among some of the more "known" quantities given their experience in the Falcon/Merlin/Grasshopper world?  I'm not making assumptions around what other work is being done on different/new technologies, but it is surprising to see them paying people around the clock (including likely holiday overtime, which is $$$) on an aspect of the testing regime that from a admitted-layman's perspective seems like they have plenty of time to work out even on an accelerated development roadmap.

Here's the reconciliation (TL;DR:    They are overtiming this because it's crtical path to the next phases)

YES.  Absolutely.  What they are about to test is the one of the "most known" factors.

HOWEVER.  They have settled on material.  It permits faster iteration.  They are committed and can proceed. They have a SS in progress.  It will be an expensive test article.  No one is paying for them so they can't iterate on customer-paid HW like F9.  SS will be ready soon and can test those other "more unknown" aspects provided they are comfortable they aren't going to crash it.  Extraordinary number of factors different between F9 hopping and SS hopping.

THEREFORE, for many reasons and since it's so cheap to work on BFH ... it makes sense to crush out BFH fast so you can do the validations necessary to pivot testing to a full-up SS by the summer.

The 2022 synod permits little slack in the schedule AND every month delaying Starlink is Texas$$$
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Norm38 on 01/07/2019 05:43 pm
https://twitter.com/Nomadd2029/status/1081731792103723010 (https://twitter.com/Nomadd2029/status/1081731792103723010)

For the discussion on lift points, see how easy it is for their bucket lifts to reach the hardpoints at the tops of the legs?  To connect and disconnect cables?  How would they get someone to the very top of the nosecone?  Else what? Design some auto-clasp?

Nah, I think they'll just use the spreader and lift from the legs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mme on 01/07/2019 05:53 pm
Clearly SpaceX wants this thing to look good and to show it off. But the only reason we know about it is because it's being built out in the open and we have eyeballs on it. We have no idea how hard they are "grinding" on anything else.

We know there will be an active TPS, so people must be working on that. We know a new full scale production Raptor will be on the test stand soon, so people are clearly working on that. We know that people are actively working on "Starship Mk 1" in the factory. On and on, don't assume what we can not see happening in a field is not happening.

SpaceX has over 7,000 employees now. We get to "see" about 1% [1] of what they are doing.

[1] Totally made up percentage purely for illustrative purposes.

I never said they weren't working on other things.  Would you at least concede in the breadth of technologies and testing that will be needed to make Starship work, that Raptor engine and hover testing are among some of the more "known" quantities given their experience in the Falcon/Merlin/Grasshopper world?  I'm not making assumptions around what other work is being done on different/new technologies, but it is surprising to see them paying people around the clock (including likely holiday overtime, which is $$$) on an aspect of the testing regime that from a admitted-layman's perspective seems like they have plenty of time to work out even on an accelerated development roadmap.
They've never restarted a Raptor in free fall. They've never done a two engine hover slam with a third engine as a backup (or however they plan to do "human rated" propulsive landings.) This thing is cheap even with all the overtime. Loosing the real prototype because of some unexpected issue with the GNC or Raptor would be really expensive in time and money.

I've said it before, I'll say it again. Landing an F9 is a post mission bonus. Landing the SS is the mission.

I agree that they want to show this thing off and are rushing. I don't know when/why they want to show it off. But I think it has real value as a test mule that will inform engine and GNC development that needs to be rock solid before Starship Mk 1 flies. And I think they probably are working feverishly on every "gating" technology but that is an assumption on my part.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/07/2019 06:05 pm
How would they get someone to the very top of the nosecone?  Else what? Design some auto-clasp?
Big cranes tend to have a main line and a secondary line.  You put someone in a basket and raise him on the secondary line to connect the main line.

I'm having some problem with the lift by crane methods I've seen proposed here.  The covered up hook points on top of the legs are great for moving the hopper pot but once you put the nose cone on there'd be too much wiggle swing of the BFH and too little clearance to the cables.  If as someone said there is now an internal load spreader (or any other internal hook point) in the hopper and a cable will continue up through the top of the nose cone it seems the nose cone wouldn't be able to take the side load.  Not the side loads from wind so much as those transient side loads from the crane bumping over uneven terrain no matter how slowly.  The new hook points on the leg covers look to be too light and connected to thin tin skin so not likely to be a lifting point for the whole thing (but then again what else could they have put them there for?).  There's been talk that the largest crane on site has outriggers so it couldn't move the BFH by driving.  But what about if it can get the job done by driving if the boom extension isn't all that high and if the load is a small percentage of its rated load and if the load is directly in front or directly in back of the crane truck body?  Hmm, I'm going to guess it gets moved in pieces by the crane and they're hoping for no re-moves (off pad landings) once it gets to the launch pad in pieces and assembled.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/07/2019 06:07 pm
I agree that they want to show this thing off and are rushing. I don't know when/why they want to show it off. But I think it has real value as a test mule that will inform engine and GNC development that needs to be rock solid before Starship Mk 1 flies. And I think they probably are working feverishly on every "gating" technology but that is an assumption on my part.

Definitely has value and makes sense from an engine testing standpoint, but the rush is quite something.  I would have loved to be a fly on the wall when Elon asked them to make it in ~weeks!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: uhuznaa on 01/07/2019 06:09 pm
The test vehicle we see being built doesn't appear to have any way to absorb landing loads - the BFS renders have retracting legs on the fins but there's almost no vertical travel available in this vehicle. So I guess they're either confident all landings will be really soft. Or … perhaps they are going to try an early version of an active (moving/load-damping) landing pad - as has been anticipated before now for the final vehicles.

I guess the legs will get feet with shock absorbers.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ThereIWas3 on 01/07/2019 06:10 pm
That render from Reddit looks great, but I should not be surprised if the nose greenhouse does not make the final cut.  It is non-functional and too risky.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: toren on 01/07/2019 06:11 pm
Assuming they want to static fire this beast before turning it loose to fly, there's going to have be some sort of hold down mechanism.  We haven't seen that either.  (Unless they are going to dangle it from a BF crane, a la the Dragon pad test.)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rsdavis9 on 01/07/2019 06:13 pm
I agree that they want to show this thing off and are rushing. I don't know when/why they want to show it off. But I think it has real value as a test mule that will inform engine and GNC development that needs to be rock solid before Starship Mk 1 flies. And I think they probably are working feverishly on every "gating" technology but that is an assumption on my part.

Definitely has value and makes sense from an engine testing standpoint, but the rush is quite something.  I would have loved to be a fly on the wall when Elon asked them to make it in ~weeks!

And don't forget that this "engine test platform" can have many "bolt on" mods.

10 ton gaseous thrusters
autogenous pressurization
etc
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: adrianwyard on 01/07/2019 06:17 pm
The test vehicle we see being built doesn't appear to have any way to absorb landing loads - the BFS renders have retracting legs on the fins but there's almost no vertical travel available in this vehicle. So I guess they're either confident all landings will be really soft. Or … perhaps they are going to try an early version of an active (moving/load-damping) landing pad - as has been anticipated before now for the final vehicles.

I guess the legs will get feet with shock absorbers.

Seems likely. But if so, why were they not shown in the render?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rsdavis9 on 01/07/2019 06:17 pm
Assuming they want to static fire this beast before turning it loose to fly, there's going to have be some sort of hold down mechanism.  We haven't seen that either.  (Unless they are going to dangle it from a BF crane, a la the Dragon pad test.)

They could static fire one engine at a time without hold downs.
I would assume a full propellant load would be heavy enough for one engine thrust.

I am guessing we are going to see a minimal pad. This would be a good way to test what they will encounter on mars. Flexible fuel hoses, Maybe a flame trench, prepared surface so debris isn't launched into rocket.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: dror on 01/07/2019 06:44 pm
Quote
News of the updated assembly – which included the possible integration of three Raptor engines – began making the rounds after a series of photos were posted on NASA Spaceflight’s board on Dec. 31st. These were taken by a member of the National Space Foundation (NSF) – who goes by the handle bocachicagal – and drew attention to the three nozzles that were apparent on the aft section.
:o
https://www.universetoday.com/141076/the-spacex-starhopper-has-three-raptor-engines-on-the-bottom/
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/07/2019 06:45 pm
Quote
News of the updated assembly – which included the possible integration of three Raptor engines – began making the rounds after a series of photos were posted on NASA Spaceflight’s board on Dec. 31st. These were taken by a member of the National Space Foundation (NSF) – who goes by the handle bocachicagal – and drew attention to the three nozzles that were apparent on the aft section.
:o
https://www.universetoday.com/141076/the-spacex-starhopper-has-three-raptor-engines-on-the-bottom/ (https://www.universetoday.com/141076/the-spacex-starhopper-has-three-raptor-engines-on-the-bottom/)
All Hail the National Space Foundation!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ThereIWas3 on 01/07/2019 06:46 pm
Definately some sort of flame trench.  In a video Tom Mueller said that the engine exhaust will eat right through concrete.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RobLynn on 01/07/2019 06:53 pm
Assuming they want to static fire this beast before turning it loose to fly, there's going to have be some sort of hold down mechanism.  We haven't seen that either.  (Unless they are going to dangle it from a BF crane, a la the Dragon pad test.)

They could static fire one engine at a time without hold downs.
I would assume a full propellant load would be heavy enough for one engine thrust.

I am guessing we are going to see a minimal pad. This would be a good way to test what they will encounter on mars. Flexible fuel hoses, Maybe a flame trench, prepared surface so debris isn't launched into rocket.

Agree regarding a flame trench - they will need to do a fair amount of pre-flight static firing.

I think they should run fueling lines up through one or more of the legs rather than have a short launch tower.  Flexible and durable cryogen hoses that fall to the ground and into the rocket exhaust wash aren't so easy to do.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/07/2019 06:57 pm
Definately some sort of flame trench.  In a video Tom Mueller said that the engine exhaust will eat right through concrete.

I'm pretty sure that was for a long-duration burn like a full-length merlin qualification burn. For a couple seconds, concrete will be fine. Raptor isn't that much bigger than the M1D on F9R dev1 which flew off a simple pad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Inoeth on 01/07/2019 06:59 pm
Definately some sort of flame trench.  In a video Tom Mueller said that the engine exhaust will eat right through concrete.

are you referring to the video posted on r/spacex the other day where he was talking about Merlin development? he did say that with the addition of water suppression those issues of the exhaust were dealt with... tho yes I'm sure there will be some form of flame trench built at the pad - the whole pad is built on a mound after all- plenty of space to build said flame trench.

To me my biggest question is what there plans are for the BC test pad once the hopper tests are done... perhaps they'll test launch the full size Starship there as well, but, that to me says the whole pad will only be used for a couple years unless it's built to eventually launch the full stack for real missions... That's a lot of time/money not to mention state support (Texas/Brownsville gave some subsidies/tax incentives i think) with the expectation that this whole complex will be used for years to come...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/07/2019 07:09 pm
I guess the legs will get feet with shock absorbers.

Seems likely. But if so, why were they not shown in the render?

Because it's a lazy render.  Not just in that regard.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DigitalMan on 01/07/2019 07:12 pm
Assuming they want to static fire this beast before turning it loose to fly, there's going to have be some sort of hold down mechanism.  We haven't seen that either.  (Unless they are going to dangle it from a BF crane, a la the Dragon pad test.)

They could static fire one engine at a time without hold downs.
I would assume a full propellant load would be heavy enough for one engine thrust.

I am guessing we are going to see a minimal pad. This would be a good way to test what they will encounter on mars. Flexible fuel hoses, Maybe a flame trench, prepared surface so debris isn't launched into rocket.

Agree regarding a flame trench - they will need to do a fair amount of pre-flight static firing.

I think they should run fueling lines up through one or more of the legs rather than have a short launch tower.  Flexible and durable cryogen hoses that fall to the ground and into the rocket exhaust wash aren't so easy to do.

My expectation is that another element the StarHopper will test is launch/landing on unprepared surfaces.  Elon has already said Starship will do this.

There is very little discussion about this although I am pretty sure launch/landing such a large spacecraft on unprepared surfaces is untested with little or no data available.  The belief that has floated around that hopper serves no purpose could imply that this scenario is well understood or will be tested on a more expensive iteration of Starship.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/07/2019 07:35 pm
Assuming they want to static fire this beast before turning it loose to fly, there's going to have be some sort of hold down mechanism.  We haven't seen that either.  (Unless they are going to dangle it from a BF crane, a la the Dragon pad test.)

They could static fire one engine at a time without hold downs.
I would assume a full propellant load would be heavy enough for one engine thrust.

I am guessing we are going to see a minimal pad. This would be a good way to test what they will encounter on mars. Flexible fuel hoses, Maybe a flame trench, prepared surface so debris isn't launched into rocket.

Agree regarding a flame trench - they will need to do a fair amount of pre-flight static firing.

I think they should run fueling lines up through one or more of the legs rather than have a short launch tower.  Flexible and durable cryogen hoses that fall to the ground and into the rocket exhaust wash aren't so easy to do.

My expectation is that another element the StarHopper will test is launch/landing on unprepared surfaces.  Elon has already said Starship will do this.

There is very little discussion about this although I am pretty sure launch/landing such a large spacecraft on unprepared surfaces is untested with little or no data available.  The belief that has floated around that hopper serves no purpose could imply that this scenario is well understood or will be tested on a more expensive iteration of Starship.
They might use the BFH for landings on unprepared surfaces to give them information on the likely effects of a Mars landing on the engines, but they won't do this until they have exhausted all other testing they want to do as it will be very risky. If they don't break the BFH first they might want to try landings on increasingly rough terrain until disaster strikes. Not sure what the authorities would make of such a crash test though. Not sure of the licence you would need.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RobLynn on 01/07/2019 07:50 pm
They might use the BFH for landings on unprepared surfaces to give them information on the likely effects of a Mars landing on the engines, but they won't do this until they have exhausted all other testing they want to do as it will be very risky. If they don't break the BFH first they might want to try landings on increasingly rough terrain until disaster strikes. Not sure what the authorities would make of such a crash test though. Not sure of the licence you would need.

I note that they have changed the landing legs/fins to not have the axial landing feet tubes at ends.  Might we be looking at a design change made specifically so that SpaceX can incorporate very long, possibly even disposable, telescopic extension legs for landing on Mars to prevent entrained debris damage?

[Edit] Also, with 2-3m of leg suspension travel you can safely hover, cut engines, and drop 10-20m onto Martian surface.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/07/2019 07:54 pm
They could static fire one engine at a time without hold downs.
I would assume a full propellant load would be heavy enough for one engine thrust.

I'm not sure that's a safe assumption as you'd need to take into account the loss in mass from fuel consumption as well.  They can do static fires on the stand at MacGregor anyway?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: magnemoe on 01/07/2019 07:56 pm
Assuming they want to static fire this beast before turning it loose to fly, there's going to have be some sort of hold down mechanism.  We haven't seen that either.  (Unless they are going to dangle it from a BF crane, a la the Dragon pad test.)

They could static fire one engine at a time without hold downs.
I would assume a full propellant load would be heavy enough for one engine thrust.

I am guessing we are going to see a minimal pad. This would be a good way to test what they will encounter on mars. Flexible fuel hoses, Maybe a flame trench, prepared surface so debris isn't launched into rocket.
Don't think they will use holddowns with the hopper, they will use it for the BFR as on falcon 9 to check that all engines are running before the go. its an safety if something is wrong during takeoff.
The hopper is cheap and live dangerous.
For an second hopper who go suborbital they might use an real pad and holddown.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/07/2019 07:59 pm
The test vehicle we see being built doesn't appear to have any way to absorb landing loads - the BFS renders have retracting legs on the fins but there's almost no vertical travel available in this vehicle. So I guess they're either confident all landings will be really soft. Or … perhaps they are going to try an early version of an active (moving/load-damping) landing pad - as has been anticipated before now for the final vehicles.

I guess the legs will get feet with shock absorbers.

Seems likely. But if so, why were they not shown in the render?

It’s not a render. It’s an artist impression. (As states by Elon when he tweeted it)

Zoom in and you will see. You can see the individual photoshop brush strokes. It is hand painted in digital form. Not a 3d render.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DusanC on 01/07/2019 08:06 pm
They might use the BFH for landings on unprepared surfaces to give them information on the likely effects of a Mars landing on the engines, but they won't do this until they have exhausted all other testing they want to do as it will be very risky. If they don't break the BFH first they might want to try landings on increasingly rough terrain until disaster strikes. Not sure what the authorities would make of such a crash test though. Not sure of the licence you would need.

I note that they have changed the landing legs/fins to not have the axial landing feet tubes at ends.  Might we be looking at a design change made specifically so that SpaceX can incorporate very long, possibly even disposable, telescopic extension legs for landing on Mars to prevent entrained debris damage?
For human flight to Mars and BFH I like the passive legs design, no telescopic shock absorbers, just plain rigid tubular legs with very hard tips.
Deep throttling engines make BFS hover and as BFS has relatively low COG so it easily lands on prepared site.

Why prepared site and fixed legs:
1. Prepared launch and landing sites diminish the risk of something flying from engine exhaust and hitting the engines;
2. Fixed legs exclude one big failure point, that's telescopic legs that went through reentry heating.

Fixed legs can have crumple zones ofc.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ncb1397 on 01/07/2019 08:42 pm
The test vehicle we see being built doesn't appear to have any way to absorb landing loads - the BFS renders have retracting legs on the fins but there's almost no vertical travel available in this vehicle. So I guess they're either confident all landings will be really soft. Or … perhaps they are going to try an early version of an active (moving/load-damping) landing pad - as has been anticipated before now for the final vehicles.

I guess the legs will get feet with shock absorbers.

Seems likely. But if so, why were they not shown in the render?

It’s not a render. It’s an artist impression. (As states by Elon when he tweeted it)

Zoom in and you will see. You can see the individual photoshop brush strokes. It is hand painted in digital form. Not a 3d render.

Quote
3. represent or depict artistically.

....

COMPUTING
process (an outline image) using color and shading in order to make it appear solid and three-dimensional.
https://www.google.com/search?q=render+definition

The toolset doesn't matter, it can still be considered a render.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/07/2019 08:43 pm
The test vehicle we see being built doesn't appear to have any way to absorb landing loads - the BFS renders have retracting legs on the fins but there's almost no vertical travel available in this vehicle. So I guess they're either confident all landings will be really soft. Or … perhaps they are going to try an early version of an active (moving/load-damping) landing pad - as has been anticipated before now for the final vehicles.

I guess the legs will get feet with shock absorbers.

Seems likely. But if so, why were they not shown in the render?

Again, "Similar" <> "Exactly"
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: zodiacchris on 01/07/2019 08:47 pm
A few hundred tonnes of SS landing without suspension? In off-nominal situations that’d convert the whole leg into an unintentional crumple zone. Specifically as two of them are also actuating fins, and you do not want to overstress those. Heavy aircraft are landing on smooth runways every minute, and do they ever need their suspension! Check out an A380 or 747 landing.

So yes, there not being dampened landing gear of sorts is very unlikely. And crusher cores are single use, so no go...

2c
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wargrim on 01/07/2019 09:16 pm
I am now going to take two unconfirmed assumptions and combine them, forming a highly speculative idea:

- If the Hopper really does not get any dampeners/shock absorbers added to the lags later, and
- If the rumours that the landing pad would be concave concrete are true

... then while my earlier idea speculation of a water-flooded "soup bowl" launch pad for launch vibration dampening was shot down, i propose the possibility of a water-flooded "soup bowl" landing pad for dampening the last few km/h remaining after a very, very carefully timed landing burn.

After all, SpaceX has plenty of water landing experience.

And no, i am not proposing that for production Starship / Mars landings.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/07/2019 09:30 pm
I am now going to take two unconfirmed assumptions and combine them, forming a highly speculative idea:

- If the Hopper really does not get any dampeners/shock absorbers added to the lags later, and
- If the rumours that the landing pad would be concave concrete are true

... then while my earlier idea speculation of a water-flooded "soup bowl" launch pad for launch vibration dampening was shot down, i propose the possibility of a water-flooded "soup bowl" landing pad for dampening the last few km/h remaining after a very, very carefully timed landing burn.

After all, SpaceX has plenty of water landing experience.

And no, i am not proposing that for production Starship / Mars landings.
If they can land the hopper accurately which seems reasonable is it possible that the pad will be smaller than the span of the legs and just used as a flame deflector allowing legs to touch down into a layer of some softer material beyond (mud/wet sand/soft clay/wood)? So put the damping into the ground instead of carrying it on-board the legs? No idea if this is even remotely practical, just a thought.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DigitalMan on 01/07/2019 09:38 pm
I am now going to take two unconfirmed assumptions and combine them, forming a highly speculative idea:

- If the Hopper really does not get any dampeners/shock absorbers added to the lags later, and
- If the rumours that the landing pad would be concave concrete are true

... then while my earlier idea speculation of a water-flooded "soup bowl" launch pad for launch vibration dampening was shot down, i propose the possibility of a water-flooded "soup bowl" landing pad for dampening the last few km/h remaining after a very, very carefully timed landing burn.

After all, SpaceX has plenty of water landing experience.

And no, i am not proposing that for production Starship / Mars landings.

Perhaps Nomadd can clarify I thought he only said he heard the pad was going to be concave.  Concrete was not mentioned.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rpapo on 01/07/2019 11:25 pm
I am now going to take two unconfirmed assumptions and combine them, forming a highly speculative idea:

- If the Hopper really does not get any dampeners/shock absorbers added to the lags later, and
- If the rumours that the landing pad would be concave concrete are true

... then while my earlier idea speculation of a water-flooded "soup bowl" launch pad for launch vibration dampening was shot down, i propose the possibility of a water-flooded "soup bowl" landing pad for dampening the last few km/h remaining after a very, very carefully timed landing burn.

After all, SpaceX has plenty of water landing experience.

And no, i am not proposing that for production Starship / Mars landings.

Perhaps Nomadd can clarify I thought he only said he heard the pad was going to be concave.  Concrete was not mentioned.
The notion of a concave pad was something bandied about on this site.  No more than that.  It's just an idea, not any sort of confirmed plan.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rakaydos on 01/08/2019 12:39 am
A few hundred tonnes of SS landing without suspension? In off-nominal situations that’d convert the whole leg into an unintentional crumple zone. Specifically as two of them are also actuating fins, and you do not want to overstress those. Heavy aircraft are landing on smooth runways every minute, and do they ever need their suspension! Check out an A380 or 747 landing.

So yes, there not being dampened landing gear of sorts is very unlikely. And crusher cores are single use, so no go...

2c
Alternatively, you have 3 relatively sharp points coming down with hundreds of tons of force on unimproved ground when landing on mars. Something is going to give, and it may well be the martian regolith instead of the steel landing legs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/08/2019 12:44 am
The ship needs to land back on earth too.

No it is pretty obvious that the legs on this hopper (and the real Starship) will have A) a real foot and B) dampening.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RotoSequence on 01/08/2019 12:53 am
The ship needs to land back on earth too.

No it is pretty obvious that the legs on this hopper (and the real Starship) will have A) a real foot and B) dampening.

Given that this was obviously a water tower before it turned out to be their initial test vehicle, I wouldn't be too sure about anything at this point.  ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/08/2019 01:22 am
Regarding landing feet, not so sure on this hopper, maybe I fall into the 'soft earth' camp, but on the real Mars landing vehicle (slightly off topic in this thread but I'm drawn in by others' comments on Mars landing) you'll need some conformability either by hydraulics or screw jack or something so that those folks won't be living in the leaning tower of Mars for 2 years at a time.  That would be a very poor weight and complexity vs. crew living conditions tradeoff.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Llian Rhydderch on 01/08/2019 02:22 am
Regarding landing feet, not so sure on this hopper, maybe I fall into the 'soft earth' camp, but on the real Mars landing vehicle (slightly off topic in this thread but I'm drawn in by others' comments on Mars landing) you'll need some conformability either by hydraulics or screw jack or something so that those folks won't be living in the leaning tower of Mars for 2 years at a time.  That would be a very poor weight and complexity vs. crew living conditions tradeoff.

I think you are in the wrong thread.  This is about a test article, getting built to be tested in South Texas. 

Mars design tradeoffs have many other threads where they might be discussed with folks who come to the thread to talk Mars design tradeoffs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: kkattula on 01/08/2019 02:24 am
Regarding fast pace of construction, it could simply be that it costs a lot per day to rent all that equipment, (cranes, lifts, generators, etc.).

So overtime (or two shifts) is much less expensive.

The rentals could also be cheaper over the holiday period as many other operations shut down.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/08/2019 02:25 am
They can still punch a vertical hole in the leg joint and insert a cylinder+foot.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: dorkmo on 01/08/2019 02:45 am
could they just land on soft dirt and not worry about feet?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/08/2019 02:47 am
could they just land on soft dirt and not worry about feet?

Yes, but why would they?  It's nonsensical.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Scylla on 01/08/2019 02:50 am
https://mobile.twitter.com/austinbarnard45/status/1082414650791264256
Do the holes have covers now?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Restless on 01/08/2019 03:06 am
It's clear the hopper is being built with some urgency, but how is it going to be launched?

Assuming it is tested on land, it can only be done safely down at the launch area near the beach. Here are some of my observations:

1. There needs to be a launch pad to handle the total weight - concrete or densely packed road base, or?
2. The long horizontal LNG and LOX tanks must be moved to within a few hundred feet of the launch pad with proper foundations, a LOX & LNG truck unloading spot to fill the tanks, cryogenic fuel and LOX transfer pumps, and vacuum insulated loading lines to the BFH.
3. Generator sets for launch power
4. Telemetry to the control room
5. Some sort of large (500 bbl) water tank with pumps for pad cooling, general use, and fire fighting
6. Etc....

Keep in mind it took the better part of a year just to rebuild LC-40. So how can all this stuff be ready in a month or two? Or am I just missing something obvious?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AJW on 01/08/2019 04:08 am
The ship needs to land back on earth too.

No it is pretty obvious that the legs on this hopper (and the real Starship) will have A) a real foot and B) dampening.

To be clear on terminology, dampening is for absorbing vibration, and I don't think you are arguing for that.  Falcon 9 legs are locked and each leg has a single use crush zone for absorbing energy as a last resort to prevent the legs from failing.  These may only have been necessary for open ocean landings where waves can be many meters high causing the ASDS to heave, sway, surge, roll, pitch and yaw unpredictably.

What I am having difficulty understanding is how it is obvious that dampening or even crush zones are even required.  For reference, I've attached a video link to the Falcon Heavy twin landing and I'm looking for the energy that you believe needs to be either dampened or absorbed.  I've been looking at landings for commercial planes, especially in cross-winds, and rocket landings may be exceptionally gentle by comparison.

This did bring up another use for BFH and that would be for testing the the ability to land under high winds.  A returning ship should be able to divert to a backup landing site, but it is good to know under what conditions this would be necessary.

https://www.youtube.com/watch?v=u0-pfzKbh2k
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: launchwatcher on 01/08/2019 04:38 am
Keep in mind it took the better part of a year just to rebuild LC-40. So how can all this stuff be ready in a month or two? Or am I just missing something obvious?
1) They don't have to do a hazmat cleanup, mishap investigation, and demolition and removal of wreckage before they can start building.   

2) Compare the amount of GSE required by a full F9 with the amount of GSE visible in the Grasshopper videos.   The single-stage hopper stands on its own feet; it doesn't need hold-downs, it doesn't need upper stage & payload umbilicals and a structure to get them out of the way at launch time.   
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Skye882 on 01/08/2019 05:37 am
I would have thought they could move the Starship by road. Obviously a difficult undertaking with a seriously oversized load but possible. Might need to close the road for a few hours or a day or so but I don't think there are any obstructions that would prohibit such a move. Does anyone know how wide the road is and how much of an overhang there would be?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mwood on 01/08/2019 05:57 am
I would have thought they could move the Starship by road. Obviously a difficult undertaking with a seriously oversized load but possible. Might need to close the road for a few hours or a day or so but I don't think there are any obstructions that would prohibit such a move. Does anyone know how wide the road is and how much of an overhang there would be?

The road appears to be about 35 ft wide all the way to launch site which is a little wider than rocket body excluding legs. I'm just viewing in Google Earth so there may have been changes since the images were taken. They probably just need to make sure there aren't any road signs in the way that might hit the legs. That's an easily fixable problem so moving to launch site shouldn't pose any serious problem.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Semmel on 01/08/2019 06:32 am
The BFH fins are of considerably different design compared to the Starship fins. It makes little sense to draw conclusions from one to the other.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: adrianwyard on 01/08/2019 06:39 am
The SpaceX landings are impressively gentle, but here's that Falcon Heavy booster landing zoomed in with a scale reference.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lampyridae on 01/08/2019 07:35 am
Maybe the window glass in gold metallic mirror finish? Cut down on harsh direct sunlight and would look cool.

The spacesuit gold visors are because they are designed to cut down the unfiltered IR leaking in which can damage the retina, and also cuts down a bit on UV. The visor itself is made of polycarbonate which is great at blocking UV but is transparent to IR. The gold also cuts down on the amount of raw sunlight entering the suit, reducing visual glare and heating (which is a big issue for a suit).

The space shuttle on the other hand had fused silica windows, with an aluminosilicate inner pressure pane. There was a red reflector to cut out the IR that came in. I'm not sure how the UV is dealt with; pure silica is somewhat transparent to it but regular glass blocks UV-C (280-100nm) and some UV-B (315-280nm). What you rarely saw on the shuttle was that the windows were equipped with shades if the sun glare became a bit much for the crew. Presumably there will be some kind of internal shade system.

Having a permanent gold coating would look snazzy but it would pose a couple of problems. First and foremost, it would be like having sunglasses permanently on. Convenient during the day, but it would make it much harder to see out at night. The view through the gold is also kind of brownish/yellow IIRC. Also, in the case of an emergency, looking into the ship to assess the condition of the passengers/crew, or for them to visually signal out would be almost impossible. From a marketing standpoint, I think it would be preferable to have photos showing the passengers floating around inside the ship. If the ship window is catching some rays, it would probably be time to break out the sunglasses.

The thickness of the windows will also help cut down on radiation: experiments with shielding on the ISS showed that the 1.5cm thick Zarya window glass was as effective as the 5gm/cm^2 polymer shielding they were using.

On a side note, apparently the Mercury and Gemini suits were silvered for no other reason than to look cool:

https://www.youtube.com/watch?v=IcVUXhefYvc&feature=youtu.be&list=WL
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: octavo on 01/08/2019 09:06 am

On a side note, apparently the Mercury and Gemini suits were silvered for no other reason than to look cool:

https://www.youtube.com/watch?v=IcVUXhefYvc&feature=youtu.be&list=WL

Thank you for that link - I've got a soda and 51 minutes of youtube ahead of me :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cinder on 01/08/2019 10:34 am
...
...
...
It’s not a render. It’s an artist impression. (As states by Elon when he tweeted it)

Zoom in and you will see. You can see the individual photoshop brush strokes. It is hand painted in digital form. Not a 3d render.

Quote
3. represent or depict artistically.

....

COMPUTING
process (an outline image) using color and shading in order to make it appear solid and three-dimensional.
https://www.google.com/search?q=render+definition

The toolset doesn't matter, it can still be considered a render.
Why prefer ambiguous wording, when illustration for 2D and render for 3D are so much more fool proof?  Esp. germaine when the specific differences between those two (a human drawing 2D that looks 3D will effectively always be less reliable than 3D render*) were the cause of erroneous hypotheses WRT what BFH is/will be.

*never mind when it's one done as this one, where parts that aren't focal points get only rough details.  This works great for other types of concept art, but in this particular case it actually adds noise to the data.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Norm38 on 01/08/2019 12:46 pm
It’s not a render. It’s an artist impression. (As states by Elon when he tweeted it)
toolset doesn't matter, it can still be considered a render.

Not to be too picky, but as I've been corrected in the past on other sites I'll do the same here.

Render is a verb, just like draw is a verb.  Rendering is the image, as drawing is the image.
You wouldn't say "A 3D draw" would you?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/08/2019 01:49 pm
I would have thought they could move the Starship by road. Obviously a difficult undertaking with a seriously oversized load but possible. Might need to close the road for a few hours or a day or so but I don't think there are any obstructions that would prohibit such a move. Does anyone know how wide the road is and how much of an overhang there would be?

The road appears to be about 35 ft wide all the way to launch site which is a little wider than rocket body excluding legs. I'm just viewing in Google Earth so there may have been changes since the images were taken. They probably just need to make sure there aren't any road signs in the way that might hit the legs. That's an easily fixable problem so moving to launch site shouldn't pose any serious problem.
But wait!

The ship can be placed on a turn-table, and then the signs will gently rotate it as it advances by them, by slowly pushing on the fins - just like carrying a dinner table through a narrow door.

Unless of course, through lack of foresight, two road signs were placed on both sides of the road at the same location, in which case all is lost.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: adrianwyard on 01/08/2019 06:26 pm
This video shows more clearly that this FH booster touches down at ~1-2 m/s. Thankfully the compressed Helium in the legs damps that out in the subsequent bounce. If it were perfectly rigid all that energy would be absorbed by structure (as depicted on left). So I think we can be confident the hopper will have *some* means of damping landing loads. I imagine we'll see soon enough.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/08/2019 07:04 pm
The two sections have been put together. Still working on the final fit.

I mean...don't they have more stuff to stick inside ???
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: John Alan on 01/08/2019 07:10 pm
The two sections have been put together. Still working on the final fit.

I mean...don't they have more stuff to stick inside ???

My opinion... this is a test fit, dry run putting the top nose cone on...
Yes... There is still at least the top tank dome (seen elsewhere on other pics (L2)) to be welded it...
Lets just sit back, and let this play out...  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/08/2019 07:13 pm
The two sections have been put together. Still working on the final fit.

I mean...don't they have more stuff to stick inside ???

My opinion... this is a test fit, dry run putting the top nose cone on...
Yes... There is still at least the top tank dome (seen elsewhere on other pics (L2)) to be welded it...
Lets just sit back, and let this play out...  ;)
Note the symmetry of the four holes about the unclad leg, as well as the fact that the four gar or electric or whatever lines are directly in line with that leg and remain attached.


I don't think it's a dry fit. They already fit the first section of the top part to the top of the water tank prior to wrapping it in foil and added the tabs / drilled the holes where the two halves will bolt together, so they know it will properly fit.



Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/08/2019 07:28 pm

There are no tanks and no (real) engines, so either it's a fit test and they will take it back off, or they plan on somehow installing everything from the bottom?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RotoSequence on 01/08/2019 07:30 pm

There are no tanks and no (real) engines, so either it's a fit test and they will take it back off, or they plan on somehow installing everything from the bottom?

The lower structure probably is fuel tanks. They had what looked to be bulkhead sections brought in a while back.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/08/2019 07:42 pm
I will venture a guess as to why SpaceX has been working three shifts, including weekends on the BFH. First off, Eric, I agree that SpaceX works multiple shifts in their Hawthorne plant and elsewhere - born out by the bustle during F9 launches, regardless of local time. However I believe we're looking at mainly local contractors building the BFH. I don't know if second and third shifts are too common for these guys and their unions. I would say this is an unusual occurrence. So why?

Well my take is it's many faceted. However one big reason is connected to the SLS and the need for SpaceX to get some serious investment. Last we've heard, they had secured roughly 50% of the $500MM capital round. So another $250MM to go. What shows serious intent better than hardware flying (hopping) - some seriously large hardware, and I might add, with some serious bling. It doesn't take much effort to look at SLS's glacial progress (slowed even further by the government shutdown) and incredibly low flight rate and compare it to the incredibly rapid developments down at BC. Yes, the SLS isn't vying for commercial customers, but it definitely provides a stark comparison for potential SpaceX investors. Add to that potential government contracts and this thing _could_ be one huge marketing bonanza for SpaceX (provided it works as planned). New Glenn also takes a hit as a bonus  - since perception is everything. Time is, as they say, of the essence. SpaceX is getting out ahead of the competitors and they're letting everyone know it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: docmordrid on 01/08/2019 07:49 pm
bocachicagal does it again

The two sections have been put together. Still working on the final fit.

2K crop, BCG's upload is 5K
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MizaruSpaceXNut on 01/08/2019 07:55 pm
Well, the framing, siding and roof is done! Now, likely, comes the slow stuff, finishing!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Restless on 01/08/2019 07:57 pm
From my earlier post,
Assuming it is tested on land, it can only be done safely down at the launch area near the beach. Here are some of my observations:

1. There needs to be a launch pad to handle the total weight - concrete or densely packed road base, or?
2. The long horizontal LNG and LOX tanks must be moved to within a few hundred feet of the launch pad with proper foundations, a LOX & LNG truck unloading spot to fill the tanks, cryogenic fuel and LOX transfer pumps, and vacuum insulated loading lines to the BFH.
3. Generator sets for launch power
4. Telemetry to the control room
5. Some sort of large (500 bbl) water tank with pumps for pad cooling, general use, and fire fighting
6. Etc....
Keep in mind it took the better part of a year just to rebuild LC-40. So how can all this stuff be ready in a month or two? Or am I just missing something obvious?
1) They don't have to do a hazmat cleanup, mishap investigation, and demolition and removal of wreckage before they can start building.   

2) Compare the amount of GSE required by a full F9 with the amount of GSE visible in the Grasshopper videos.   The single-stage hopper stands on its own feet; it doesn't need hold-downs, it doesn't need upper stage & payload umbilicals and a structure to get them out of the way at launch time.   

Yes, the pad GSE would be minimal for BFH, but the LNG and LOX tanks do need to be moved to the launch site, set on some sort of foundation, with the truck unloading facilities and BFH fueling lines installed. This is all vacuum insulated piping with cryogenic valves and safety interlock instrumentation. If it were installed today it could take a month to go through commissioning, de-bugging, and dry runs before BFH test flights. And there is still items 1, 3, 4, 5, etc from above to get done.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Restless on 01/08/2019 08:09 pm
According to Nomadd yesterday, they're still pushing dirt around at the launch site.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wudizzle on 01/08/2019 08:17 pm
From my earlier post,
Assuming it is tested on land, it can only be done safely down at the launch area near the beach. Here are some of my observations:

1. There needs to be a launch pad to handle the total weight - concrete or densely packed road base, or?
2. The long horizontal LNG and LOX tanks must be moved to within a few hundred feet of the launch pad with proper foundations, a LOX & LNG truck unloading spot to fill the tanks, cryogenic fuel and LOX transfer pumps, and vacuum insulated loading lines to the BFH.
3. Generator sets for launch power
4. Telemetry to the control room
5. Some sort of large (500 bbl) water tank with pumps for pad cooling, general use, and fire fighting
6. Etc....
Keep in mind it took the better part of a year just to rebuild LC-40. So how can all this stuff be ready in a month or two? Or am I just missing something obvious?
1) They don't have to do a hazmat cleanup, mishap investigation, and demolition and removal of wreckage before they can start building.   

2) Compare the amount of GSE required by a full F9 with the amount of GSE visible in the Grasshopper videos.   The single-stage hopper stands on its own feet; it doesn't need hold-downs, it doesn't need upper stage & payload umbilicals and a structure to get them out of the way at launch time.   

Yes, the pad GSE would be minimal for BFH, but the LNG and LOX tanks do need to be moved to the launch site, set on some sort of foundation, with the truck unloading facilities and BFH fueling lines installed. This is all vacuum insulated piping with cryogenic valves and safety interlock instrumentation. If it were installed today it could take a month to go through commissioning, de-bugging, and dry runs before BFH test flights. And there is still items 1, 3, 4, 5, etc from above to get done.

Maybe. That's what current logic says. 3 weeks ago logic said don't build a stainless steel flying water tower rocket ship in a field.

Pragmatically, my logic says working 3 shifts through weekends and holidays to finish a rocket so it can sit around doing nothing is colossally terrible project management. I'm guessing there is a plan. I would like to know the plan. I'm excited to watch the plan unfold.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AJW on 01/08/2019 08:22 pm
This video shows more clearly that this FH booster touches down at ~1-2 m/s. Thankfully the compressed Helium in the legs damps that out in the subsequent bounce. If it were perfectly rigid all that energy would be absorbed by structure (as depicted on left). So I think we can be confident the hopper will have *some* means of damping landing loads. I imagine we'll see soon enough.

It is my understanding that helium is only used to extend and lock the F9 legs, and the compressed gas is not used to absorb the shock.  And you are correct, we won't have to wait long.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: uhuznaa on 01/08/2019 08:31 pm
This video shows more clearly that this FH booster touches down at ~1-2 m/s. Thankfully the compressed Helium in the legs damps that out in the subsequent bounce. If it were perfectly rigid all that energy would be absorbed by structure (as depicted on left). So I think we can be confident the hopper will have *some* means of damping landing loads. I imagine we'll see soon enough.

The compressed helium in the legs doesn't have anything to do with that, the leg segments are locked and don't move at all anymore once the legs are extended. Apart from the crushable elements in the last segment any "bounce" is coming out of elasticity in the legs itself or the tank they're connected to.

And yes, I think there will be some shock absorbers in the feet that will be mounted later.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Kenp51d on 01/08/2019 08:34 pm
On the one hand we can assume there is still a lot of labor left, plumbing, wiring, ECT left.
One the other hand we can only see the outside. There may already have been a thrust structure made. Maybe already had the engine standins installed complete with wiring and plumbing.
I will say they are going full out, pedal to the metal. WOW! And dang, but but it is pretty.

Ken
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/08/2019 08:37 pm
This video shows more clearly that this FH booster touches down at ~1-2 m/s. Thankfully the compressed Helium in the legs damps that out in the subsequent bounce. If it were perfectly rigid all that energy would be absorbed by structure (as depicted on left). So I think we can be confident the hopper will have *some* means of damping landing loads. I imagine we'll see soon enough.

The compressed helium in the legs doesn't have anything to do with that, the leg segments are locked and don't move at all anymore once the legs are extended. Apart from the crushable elements in the last segment any "bounce" is coming out of elasticity in the legs itself or the tank they're connected to.

No, I'm not sure that's right. The "crush cores" are just there to absorb excessive landing force. (see notes about hard landings in the past where they noted that the crush cores in the legs were used up) There does appear to be a hydraulic or pneumatic shock absorption for the F9 legs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ThereIWas3 on 01/08/2019 08:41 pm
It will be interesting to find out the explanation for the shiny cladding added to the base section.  Just for appearances to match the rest?  The shiny part is clearly not structural.  Will the final SS be layered like this?  Can we tell how thick the cladding is?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: intamin on 01/08/2019 08:43 pm
https://forum.nasaspaceflight.com/index.php?topic=47022.msg1896315#msg1896315

https://forum.nasaspaceflight.com/index.php?topic=47022.msg1896319#msg1896319
https://forum.nasaspaceflight.com/index.php?topic=47022.msg1896320#msg1896320
https://forum.nasaspaceflight.com/index.php?topic=47022.msg1896322#msg1896322
https://forum.nasaspaceflight.com/index.php?topic=47022.msg1896327#msg1896327

Based on Bocachicagal's latest photo clearly showing two layers of metal (one dull, one shiny), where do I collect my prize? ;)

https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=47120.0;attach=1537643;image
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: launchwatcher on 01/08/2019 08:46 pm
Yes, the pad GSE would be minimal for BFH, but the LNG and LOX tanks do need to be moved to the launch site, set on some sort of foundation, with the truck unloading facilities and BFH fueling lines installed. This is all vacuum insulated piping with cryogenic valves and safety interlock instrumentation. If it were installed today it could take a month to go through commissioning, de-bugging, and dry runs before BFH test flights. And there is still items 1, 3, 4, 5, etc from above to get done.
Think about how to compress the schedule.

If their test plan is similar to the plan for Grasshopper, the first few flights won't last very long or go very high - they won't need the full tank capacity right away   A couple tanker trucks will will do for those tests.   If things go badly wrong the resulting kaboom will be smaller and it will be easier to find all the pieces, knock out a few dents and refly it.

Full-scale fuelling infrastructure can be built in parallel with the first few flights.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/08/2019 08:47 pm

Is it possible they are doing first few flights from where it sits now?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/08/2019 08:49 pm
Based on Bocachicagal's latest photo clearly showing two layers of metal (one dull, one shiny), where do I collect my prize? ;)

Based on no rivets and no dull layer under the TFH upper section, you don't.   ::)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MizaruSpaceXNut on 01/08/2019 08:49 pm
Some questions answered, the nose is stacked on top of the base!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: glennfish on 01/08/2019 09:26 pm

Is it possible they are doing first few flights from where it sits now?

If they take the tent down first, yes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/08/2019 09:32 pm

Is it possible they are doing first few flights from where it sits now?

VERY unlikely. Too close to residences and other buildings.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Restless on 01/08/2019 09:33 pm
Yes, the pad GSE would be minimal for BFH, but the LNG and LOX tanks do need to be moved to the launch site, set on some sort of foundation, with the truck unloading facilities and BFH fueling lines installed. This is all vacuum insulated piping with cryogenic valves and safety interlock instrumentation. If it were installed today it could take a month to go through commissioning, de-bugging, and dry runs before BFH test flights. And there is still items 1, 3, 4, 5, etc from above to get done.
Think about how to compress the schedule.

If their test plan is similar to the plan for Grasshopper, the first few flights won't last very long or go very high - they won't need the full tank capacity right away   A couple tanker trucks will will do for those tests.   If things go badly wrong the resulting kaboom will be smaller and it will be easier to find all the pieces, knock out a few dents and refly it.

Full-scale fuelling infrastructure can be built in parallel with the first few flights.

Well, I guess we'll have to see how it all works out - seat of the pants or proper space launch approach.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/08/2019 09:40 pm
Fire/lift from current location. No chance!

Safety and exclusion zone - close to boca Chia village. !!!
Not consistent with the plans in the EIS etc!

So as an outsider, with no knowledge of how these work.... it sounds impossible from a regulation and safety pov. to fire or hop from where it was built.

But with the current tempo, the hat has to come off so the tank dome (and what else?) can be fitted. The move to the official pad should be easy. A good slab of concrete as a (flat) initial pad could be fairly quick, and temporary partial fuelling arrangements using tanks on lorries is conceivable. ! Will a very small hop - like 10 feet be done before Dragon 2 flies - probably late Feb due to p*l***cs! ?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MizaruSpaceXNut on 01/08/2019 09:51 pm
Fire/lift from current location. No chance!

Safety and exclusion zone - close to boca Chia village. !!!
Not consistent with the plans in the EIS etc!

So as an outsider, with no knowledge of how these work.... it sounds impossible from a regulation and safety pov. to fire or hop from where it was built.

But with the current tempo, the hat has to come off so the tank dome (and what else?) can be fitted. The move to the official pad should be easy. A good slab of concrete as a (flat) initial pad could be fairly quick, and temporary partial fuelling arrangements using tanks on lorries is conceivable. ! Will a very small hop - like 10 feet be done before Dragon 2 flies - probably late Feb due to p*l***cs! ?
You could be right? Most of the guesses from folks on this site have been wrong, including mine! I've been

involved in many projects and from experience, I'll say they'll have to step on it to meet your timetable!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MTom on 01/08/2019 10:06 pm
What I don't understand: the whole surface is (more or less) ready, but this vertical line is like a long opening between the two half part. What could it be?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: zhangmdev on 01/08/2019 10:08 pm
What I don't understand: the whole surface is (more or less) ready, but this vertical line is like a long opening between the two half part. What could it be?

That dark vertical line is reflection of the crane, I think.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Kenp51d on 01/08/2019 10:09 pm
Might be a reflection artifact, maybe of the lefting boom.

Ken
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MTom on 01/08/2019 10:12 pm
another part of the opening/reflection.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: zhangmdev on 01/08/2019 10:15 pm
another part of the opening/reflection.

Check the latest photo

https://forum.nasaspaceflight.com/index.php?topic=47120.msg1898584

You can see the yellow part of the crane in the reflection.

Anyway, is there anyone think proportionally the hopper is more visually appealing than the "real" spaceship? Or just me?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: freddo411 on 01/08/2019 11:12 pm
another part of the opening/reflection.


 anyone think proportionally the hopper is more visually appealing than the "real" spaceship? Or just me?


I like the dimensions a lot.  It's beautiful.

The wrinkling of the SS skin is off putting to me at first.   I wonder if the actual starship will have visual oddities or not.   Atlas didn't have wrinkles, but it also wasn't so shiny.   https://commons.wikimedia.org/wiki/File:LOC-63C-1556.jpg
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: FutureMartian97 on 01/08/2019 11:18 pm
It was together and now it is back apart!

I wonder if it was just a fit check?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/08/2019 11:26 pm
another part of the opening/reflection.
Maybe there is some final adjustment, or tightening planned along this open seam. When that has been done then the stainless sheet can be finished off like it is around the rest of the diameter. This makes a little sense, where it fits ofer the rigid "watertank" But ISTM there is no reason to take the join to the top!. However if there is 10s of cm  adjustment in the circumference, then the seam would have to go to the top or distortions would show.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RotoSequence on 01/08/2019 11:30 pm
It was together and now it is back apart!

I wonder if it was just a fit check?

Looks like it might have some issues in that department.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ejb749 on 01/08/2019 11:41 pm
Missed it by that much.
 *from BCGs photo*

Yeah, but scale matters.  That much is a lot!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: SPadre on 01/08/2019 11:43 pm
Drive by this afternoon...

https://www.youtube.com/watch?v=lMceVIYsUZQ
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Jaghond on 01/08/2019 11:48 pm
Hi everyone from Italy!
Looking at this wonderful models, I'm trying to figure out the rationals for a 40mt, midsize hopper, instead of a full lenght (we can assume that should be very fast to add 15mt, easy and inexpensive like the nosecone was).

My guess is pretty go-ahead.
Premises:
- Spacex needs to put in place Starlink Asap
- Major competitive advantage comparing internet satellite competitors is in the launch costs
- Starlink needs almost +100 FH launches (estimate)
- We know that the big booster is under construction in LA

Given that, could be possible that for first the next Starship would be in fact a reusable second stage for carrying satellites, a cargo with enormous turning fairings. But an orbital hopper at the same time.
Two options in this case for the smaller lenght: the hopper will simulate landing of a 55mt with a proper center of mass (engine and tanks stuff plus satellite release structure light when empty); or, this is in fact the hopper of the cargo Starship, smaller because this size fits with the goal (the goal could be to save 30-40% launches for Starlink) but anyway useful in terms of data.

This could be also the safest approach to the real life testing and landing of such a big thing.
If this theory is correct, they want to validate this first Starship, avionics and the hardest part, the landing. After the validation, they can incredibly reuse this hopper for the second iteration, the real Starship, they only have to change the thin nosecone, starting with a lot of data from the previous cargo. At the same time Starlink cargo could start his work and collect experience.

What do you think?


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/08/2019 11:49 pm
What I don't understand: the whole surface is (more or less) ready, but this vertical line is like a long opening between the two half part. What could it be?

Surely you are joking.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/08/2019 11:55 pm
What I don't understand: the whole surface is (more or less) ready, but this vertical line is like a long opening between the two half part. What could it be?

Surely you are joking.

In a post near this:
another part of the opening/reflection.
The "gap" really does look like a real gap and not a reflection. The metal is folded and the edge not fastened. ISTM this gap is to allow to movement, which will be needed as on final fit it will be tensioned around the outside of the ridgid water tank section, then the loose edge will be fastened, like the rest of the upper skin.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Taxidermista on 01/08/2019 11:57 pm
IT IS a reflection.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/09/2019 12:06 am
What I don't understand: the whole surface is (more or less) ready, but this vertical line is like a long opening between the two half part. What could it be?

Surely you are joking.

In a post near this:
another part of the opening/reflection.
The "gap" really does look like a real gap and not a reflection. The metal is folded and the edge not fastened. ISTM this gap is to allow to movement, which will be needed as on final fit it will be tensioned around the outside of the ridgid water tank section, then the loose edge will be fastened, like the rest of the upper skin.

So I have found the pic from the second quote, and cropped it closer. That part is definitely an unfastened sheet. The shadow it makes to the right follows the profile of the unfastened edge including the sharpish bend. I admit this does not prove that its still a gap towards the top of the vehicle.)

Edit: It is much clearer if you examine the original picture by following this link back:
another part of the opening/reflection.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/09/2019 12:46 am
So I have found the pic from the second quote, and cropped it closer. That part is definitely an unfastened sheet. The shadow it makes to the right follows the profile of the unfastened edge including the sharpish bend. I admit this does not prove that its still a gap towards the top of the vehicle.)

It's not unfastened.  Just a shadow.  Notice the same "dimple" from January 5th that contributes to the impression that it's unfastened.

There is a sheet that looks like a spot weld popped in an L2 image but this one isn't it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Chris_Pi on 01/09/2019 12:51 am
From my earlier post,
Assuming it is tested on land, it can only be done safely down at the launch area near the beach. Here are some of my observations:

1. There needs to be a launch pad to handle the total weight - concrete or densely packed road base, or?
2. The long horizontal LNG and LOX tanks must be moved to within a few hundred feet of the launch pad with proper foundations, a LOX & LNG truck unloading spot to fill the tanks, cryogenic fuel and LOX transfer pumps, and vacuum insulated loading lines to the BFH.
3. Generator sets for launch power
4. Telemetry to the control room
5. Some sort of large (500 bbl) water tank with pumps for pad cooling, general use, and fire fighting
6. Etc....
Keep in mind it took the better part of a year just to rebuild LC-40. So how can all this stuff be ready in a month or two? Or am I just missing something obvious?
1) They don't have to do a hazmat cleanup, mishap investigation, and demolition and removal of wreckage before they can start building.   

2) Compare the amount of GSE required by a full F9 with the amount of GSE visible in the Grasshopper videos.   The single-stage hopper stands on its own feet; it doesn't need hold-downs, it doesn't need upper stage & payload umbilicals and a structure to get them out of the way at launch time.   

Yes, the pad GSE would be minimal for BFH, but the LNG and LOX tanks do need to be moved to the launch site, set on some sort of foundation, with the truck unloading facilities and BFH fueling lines installed. This is all vacuum insulated piping with cryogenic valves and safety interlock instrumentation. If it were installed today it could take a month to go through commissioning, de-bugging, and dry runs before BFH test flights. And there is still items 1, 3, 4, 5, etc from above to get done.

The delay in getting the piping installed and checked out could be sidestepped a bit by doing both projects in parallel. The first (Short, Low fuel load) test hops could be loaded directly from tankers while fuel handling equipment is still being worked on.

 As far as earlier items:

1) Mostly-flat concrete and possibly a shallow flame trench won't be that far different than a F9 landing pad, Except for needing to support a bit more weight. I don't think those took long and weren't built with a short schedule in mind. This could go pretty fast.

2) Looking at the McGregor Raptor test cell, The unload area and pump/storage is just the access road, One 30' square sheet metal building, and a half-dozen trucked-in tanks for storage. And 1800' of piping to reach the test cell itself. So distance isn't a big problem and where the tanks are now may be fine as long as piping doesn't need to be run somewhere crazy like across future HIF or crawlerway.

3) Trucked-in equipment on relatively small foundations could work for this and would go from nothing to done quickly.

4) Telemetry/control could be a couple trailers parked next to the existing tracking dishes. Likely won't know until it's installed, And pointed out as such.

5) Long-term a water tower makes sense, But a group of smaller pressure-fed tanks could work short term and potentially reused for a firefighting system later - LZ-1 has this sort of setup. (One old tank, Not multiples.)

This whole setup has to go together fast to avoid delays in test flights, But only has to be good enough in time for the first few test flights. Finished could come much later.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: joek on 01/09/2019 01:02 am
So I have found the pic from the second quote, and cropped it closer. That part is definitely an unfastened sheet. The shadow  ...
Step back a ways (to the original image)... that looks like a reflection of the crane, not a shadow.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/09/2019 01:06 am
What I don't understand: the whole surface is (more or less) ready, but this vertical line is like a long opening between the two half part. What could it be?

Surely you are joking.

In a post near this:
another part of the opening/reflection.
The "gap" really does look like a real gap and not a reflection. The metal is folded and the edge not fastened. ISTM this gap is to allow to movement, which will be needed as on final fit it will be tensioned around the outside of the ridgid water tank section, then the loose edge will be fastened, like the rest of the upper skin.

So I have found the pic from the second quote, and cropped it closer. That part is definitely an unfastened sheet. The shadow it makes to the right follows the profile of the unfastened edge including the sharpish bend. I admit this does not prove that its still a gap towards the top of the vehicle.)

Edit: It is much clearer if you examine the original picture by following this link back:
another part of the opening/reflection.
Everyone please, it’s a reflection. It’s is 100% a reflection and only a reflection.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ludonope on 01/09/2019 01:22 am
Drive by this afternoon...

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

Nice video :)

We can see the "dome" being assembled on your footage. Since they are already assembling the whole hopper, I thought that it might be used to put the actual raptors. "Just" remove the actual one with the "mockup" engines, and put this one instead with the real ones.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Chris_Pi on 01/09/2019 01:32 am
The thought crossed my mind that this thing's so obnoxiously reflective nobody's really seen much of it. Just reflections of sky, clouds, and whatever else happens to be nearby. All distorted enough that the where it is is visible, but not the hopper itself. From the air it probably looks like a wavy patch of grass, dirt, or whatever else is near.

There's possibly a Romulan somewhere laughing about what's clearly the worst cloaking device ever built - Nobody can figure out what it is, But there it is for sure.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: hrissan on 01/09/2019 01:32 am
Regarding lack of huge shock absorbers - if BFR is going to land back onto pad, very precise landing is required, so starship mock-up might be a good opportunity to test it as early as possible.

For BFR to land at desired X-Y (into launch pad) in the presence of changing wind, it seems the set of powerfull side thrusters must be added with thrust equal to total wind force (~8000 kg per 700 square meters of BFR for 10m/s wind).

Unlikely, but can the round holes in the middle of starship be for the set of those new methane thrusters? Each thruster is just a thrust chamber and 2 valves feeding from single/multiple raptor engine (thruster will work only when main engine is running). Not unlike SuperDraco but with different propellants.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: WannaWalnetto on 01/09/2019 04:15 am
Humm .... could the “rush” to fully assemble the shiny water tower have anything to do with President Trump’s announced plan to visit the Texas / Mexico border later this week?  Didn’t DHS just request to tour the BC site?

I guess we’ll know for sure if the BFH push is primarily for a photo-op if the locals spot a fleet of black SUV’s in the next day or so. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/09/2019 04:20 am
Humm .... could the “rush” to fully assemble the shiny water tower have anything to do with President Trump’s announced plan to visit the Texas / Mexico border later this week?  Didn’t DHS just request to tour the BC site?

I guess we’ll know for sure if the BFH push is primarily for a photo-op if the locals spot a fleet of black SUV’s in the next day or so.

No way in h-e-doublehockeysticks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: SPadre on 01/09/2019 04:46 am
My pup thinks yall are barking up the wrong tree...  it is a giant fire hydrant  ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Restless on 01/09/2019 04:58 am
From my earlier post,
Assuming it is tested on land, it can only be done safely down at the launch area near the beach. Here are some of my observations:

1. There needs to be a launch pad to handle the total weight - concrete or densely packed road base, or?
2. The long horizontal LNG and LOX tanks must be moved to within a few hundred feet of the launch pad with proper foundations, a LOX & LNG truck unloading spot to fill the tanks, cryogenic fuel and LOX transfer pumps, and vacuum insulated loading lines to the BFH.
3. Generator sets for launch power
4. Telemetry to the control room
5. Some sort of large (500 bbl) water tank with pumps for pad cooling, general use, and fire fighting
6. Etc....
Keep in mind it took the better part of a year just to rebuild LC-40. So how can all this stuff be ready in a month or two? Or am I just missing something obvious?
1) They don't have to do a hazmat cleanup, mishap investigation, and demolition and removal of wreckage before they can start building.   

2) Compare the amount of GSE required by a full F9 with the amount of GSE visible in the Grasshopper videos.   The single-stage hopper stands on its own feet; it doesn't need hold-downs, it doesn't need upper stage & payload umbilicals and a structure to get them out of the way at launch time.   

Yes, the pad GSE would be minimal for BFH, but the LNG and LOX tanks do need to be moved to the launch site, set on some sort of foundation, with the truck unloading facilities and BFH fueling lines installed. This is all vacuum insulated piping with cryogenic valves and safety interlock instrumentation. If it were installed today it could take a month to go through commissioning, de-bugging, and dry runs before BFH test flights. And there is still items 1, 3, 4, 5, etc from above to get done.

The delay in getting the piping installed and checked out could be sidestepped a bit by doing both projects in parallel. The first (Short, Low fuel load) test hops could be loaded directly from tankers while fuel handling equipment is still being worked on.

 As far as earlier items:

1) Mostly-flat concrete and possibly a shallow flame trench won't be that far different than a F9 landing pad, Except for needing to support a bit more weight. I don't think those took long and weren't built with a short schedule in mind. This could go pretty fast.

2) Looking at the McGregor Raptor test cell, The unload area and pump/storage is just the access road, One 30' square sheet metal building, and a half-dozen trucked-in tanks for storage. And 1800' of piping to reach the test cell itself. So distance isn't a big problem and where the tanks are now may be fine as long as piping doesn't need to be run somewhere crazy like across future HIF or crawlerway.

3) Trucked-in equipment on relatively small foundations could work for this and would go from nothing to done quickly.

4) Telemetry/control could be a couple trailers parked next to the existing tracking dishes. Likely won't know until it's installed, And pointed out as such.

5) Long-term a water tower makes sense, But a group of smaller pressure-fed tanks could work short term and potentially reused for a firefighting system later - LZ-1 has this sort of setup. (One old tank, Not multiples.)

This whole setup has to go together fast to avoid delays in test flights, But only has to be good enough in time for the first few test flights. Finished could come much later.

1. They're still pushing dirt around at the launch site. If concrete were poured today it would take a month at least to develop enough strength for BFH.
2. The LNG and LOX tanks are just parked at the existing lay down pad. They must moved to the launch site to protect the residential area for safety. LNG is serious stuff. If not done right major leaks could occur with fire/explosion/loss of life. The Texas Environmental Agency will not approve a permit for a facility unless LNG emissions are minimized. That means LNG boil-off has to be captured and sent back to the storage tank. All this and more.
3. 4. and 5. are relatively easy but still need to be done.

So building BFH may be easier than launching it........

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/09/2019 05:06 am

Between the yet-to-be-test-fired engines and the (lack of a) pad, it looks like the structure of the hopper is going to be done well ahead of time.  Makes it that much more head-scratching that they pushed to assemble it so fast.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lampyridae on 01/09/2019 06:24 am

Between the yet-to-be-test-fired engines and the (lack of a) pad, it looks like the structure of the hopper is going to be done well ahead of time.  Makes it that much more head-scratching that they pushed to assemble it so fast.

Probably so that they can get on with all the interior fluff work. Sensors, plumbing, last minute modifications to the internal structure etc. Stuff like that tends to be quite time consuming.

Plus: PR.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: kkattula on 01/09/2019 07:13 am

Between the yet-to-be-test-fired engines and the (lack of a) pad, it looks like the structure of the hopper is going to be done well ahead of time.  Makes it that much more head-scratching that they pushed to assemble it so fast.

I still think it's probably just about minimizing heavy equipment hire costs.  Any contractor tries to schedule together everything that needs lifting with a crane.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/09/2019 10:23 am

Between the yet-to-be-test-fired engines and the (lack of a) pad, it looks like the structure of the hopper is going to be done well ahead of time.  Makes it that much more head-scratching that they pushed to assemble it so fast.

Probably so that they can get on with all the interior fluff work. Sensors, plumbing, last minute modifications to the internal structure etc. Stuff like that tends to be quite time consuming.

Plus: PR.

Heck, forget about "fluff work" - has anyone seen any signs whatsoever of bulkheads yet?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/09/2019 10:40 am

Between the yet-to-be-test-fired engines and the (lack of a) pad, it looks like the structure of the hopper is going to be done well ahead of time.  Makes it that much more head-scratching that they pushed to assemble it so fast.

Probably so that they can get on with all the interior fluff work. Sensors, plumbing, last minute modifications to the internal structure etc. Stuff like that tends to be quite time consuming.

Plus: PR.

Heck, forget about "fluff work" - has anyone seen any signs whatsoever of bulkheads yet?

Glad you asked.

High resolution images of the dome like structure, posted by John Randolph @ SpaceX Boca Chica, Texas Facebook group (https://www.facebook.com/groups/1541938906124567/permalink/2218201841831600/).

So: Is this a bulkhead? And is this the reason they did not yet permanently connect the two remaining segments of the BFH?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/09/2019 10:47 am
Looks like it might well be a bulkhead, good catch!  :)  There should be two - one for inside the bottom part, and the other most likely rising up from the bottom part into the top.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/09/2019 11:26 am

Between the yet-to-be-test-fired engines and the (lack of a) pad, it looks like the structure of the hopper is going to be done well ahead of time.  Makes it that much more head-scratching that they pushed to assemble it so fast.

They might have more or less finished the shell but what about the inner workings? Would have thought that might take longer to finish off and work would not be visable
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: cuddihy on 01/09/2019 11:43 am

Between the yet-to-be-test-fired engines and the (lack of a) pad, it looks like the structure of the hopper is going to be done well ahead of time.  Makes it that much more head-scratching that they pushed to assemble it so fast.

They might have more or less finished the shell but what about the inner workings? Would have thought that might take longer to finish off and work would not be visable

This is a "ship", not just a rocket. Sea-going ships often have all the steel on the outer hull before they are even halfway complete (in terms of time remaining) for launching (much less commissioning).

I'd expect the interior and pad work to take the full remaining 7 weeks even if they are currently effectively "done" on the outside. With tank bulkheads sitting outside the ship, no doubt there's at least a week before it's together, even if they leave all the plumbing for work after the hull is complete.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MaxTeranous on 01/09/2019 01:33 pm
Wiring up the thousands of sensors this thing will have will take a month on it's own. This is a test article, it'll be festooned with data capture devices.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: CuddlyRocket on 01/09/2019 01:52 pm
... I'm trying to figure out the rationals for a 40mt, midsize hopper, instead of a full lenght (we can assume that should be very fast to add 15mt, easy and inexpensive like the nosecone was).

My guess is pretty go-ahead.
Premises:
- Spacex needs to put in place Starlink Asap
- Major competitive advantage comparing internet satellite competitors is in the launch costs
- Starlink needs almost +100 FH launches (estimate)
- We know that the big booster is under construction in LA

Given that, could be possible that for first the next Starship would be in fact a reusable second stage for carrying satellites, a cargo with enormous turning fairings. But an orbital hopper at the same time.

The Hopper would need very substantial modifications to enable it to survive re-entry. It would probaby be cheaper to build a Starship. But it got me thinking as to whether it could be used as an expendable second stage to launch Starlink satellites (or anything else). There's a good chance that the Super Heavy may be ready before the Starship as it's a relatively straightforward larger version of the F9 first stage.

This would depend on whether the Hopper can both survive launch and have the performance to reach the necessary orbit with a useful payload and the cost per Starlink satellite launched compared with the FH.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/09/2019 02:09 pm
It has moved again. Looks like a perfect fit.

Is the suspected bulkhead  (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1898757#msg1898757)still lying around?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/09/2019 02:12 pm
Wiring up the thousands of sensors this thing will have will take a month on it's own. This is a test article, it'll be festooned with data capture devices.

Or so one would assume. But so far SpaceX seems to enjoy breaking all the rules...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/09/2019 02:22 pm

Is it possible they are doing first few flights from where it sits now?

VERY unlikely. Too close to residences and other buildings.

Oh I'm sure Nomadd's house will hold up just fine...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/09/2019 02:24 pm
Looks like the vertical rip has spread all the way down into the base section...  ;D ;D ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/09/2019 02:36 pm
Hi everyone from Italy!
Looking at this wonderful models, I'm trying to figure out the rationals for a 40mt, midsize hopper, instead of a full lenght (we can assume that should be very fast to add 15mt, easy and inexpensive like the nosecone was).

My guess is pretty go-ahead.
Premises:
- Spacex needs to put in place Starlink Asap
- Major competitive advantage comparing internet satellite competitors is in the launch costs
- Starlink needs almost +100 FH launches (estimate)
- We know that the big booster is under construction in LA

Given that, could be possible that for first the next Starship would be in fact a reusable second stage for carrying satellites, a cargo with enormous turning fairings. But an orbital hopper at the same time.
Two options in this case for the smaller lenght: the hopper will simulate landing of a 55mt with a proper center of mass (engine and tanks stuff plus satellite release structure light when empty); or, this is in fact the hopper of the cargo Starship, smaller because this size fits with the goal (the goal could be to save 30-40% launches for Starlink) but anyway useful in terms of data.

This could be also the safest approach to the real life testing and landing of such a big thing.
If this theory is correct, they want to validate this first Starship, avionics and the hardest part, the landing. After the validation, they can incredibly reuse this hopper for the second iteration, the real Starship, they only have to change the thin nosecone, starting with a lot of data from the previous cargo. At the same time Starlink cargo could start his work and collect experience.

What do you think?


Ciao Jaghond and welcome to the site! Grazie per il tuo contributo molto interessante.

Musk hasn't mentioned anything about it, but I think your idea is intrigueing. An initial short Starship followed by a "stretched" full-length version does make a lot of sense, development-wise, as I see it. Just the way they do many airliners. Maybe the orbital-class reentry test article will be a sort of short Starship v. 1.0.

Also goes well with the tried and true SpaceX method of incremental development.

Of course the fact that nothing like this has been mentioned by Musk yet speaks against the idea. However, with the twists and turns in this development saga I wouldn't bet against it. In any case I am pretty sure that the first Starship that flies will be a bare-bones (Starlink-) launch vehicle. Manrating and outfitting it for crew is very complex and can come later, after they have flown it a lot, and maybe blown up a few ships.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: edzieba on 01/09/2019 02:49 pm
The legs and feet are beefy enough that SpaceX could well just weld some oleo struts from a large aircraft to the bottom to provide shock absorption for landing. It'd look a little ponderous to sit on 'stilt' legs, but no reason it would not work structurally.
Looks like it might well be a bulkhead, good catch!  :)  There should be two - one for inside the bottom part, and the other most likely rising up from the bottom part into the top.
Three, including the common bulkhead between Methane and LOX tank sections.
My pup thinks yall are barking up the wrong tree...  it is a giant fire hydrant  ;D
With all the cranes around it, it looks like it's sitting in a Soyuz launch cradle!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/09/2019 02:52 pm
My presumption (I could be totally wrong) was that the bottom bulkhead is already present.

I agree that oleo struts (or similar) added at a later date are the most likely option. It's not like it's hard for them to lift up the vehicle to attach struts under the legs. I think speculation on this front so far has been much ado about nothing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/09/2019 03:12 pm
Out of curiosity  - those who are thinking that the dome under construction is part of the BFH, such as a common bulkhead for propellant - how do you suggest it would be installed inside the BFH? Assuming they split the two halves apart again, where will it be installed?


Why I ask: take a look at this photo. And you also need to assume the bottom tubes of the leg-fins also have the same bracing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MikeAtkinson on 01/09/2019 03:15 pm
How do people get inside the BFH now? Are there human sized openings?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MikeAtkinson on 01/09/2019 03:19 pm
Out of curiosity  - those who are thinking that the dome under construction is part of the BFH, such as a common bulkhead for propellant - how do you suggest it would be installed inside the BFH? Assuming they split the two halves apart again, where will it be installed?


Why I ask: take a look at this photo. And you also need to assume the bottom tubes of the leg-fins also have the same bracing.

The dome would have been above the bracing. The bracing would have been in the tank, but that is thick steel so OK if cleaned.

It seems that the dome will not be installed in the BFH, it could possibly just be the bottom of a water tank. Which would be amusing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: John Alan on 01/09/2019 03:21 pm
The bulkhead still on the ground is likely the top one and likely will be welded in ABOVE the braces...

I see NO reason why the braces can't cross inside thru the LOX tank...  ;)

In fact... I expect to see a dome top and a central tube large enough for a human to climb down into sticking out the top of the base BEFORE they finally put the top dome on for flight...  ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: edzieba on 01/09/2019 03:23 pm
The third fin is now receiving it's stainless finish.
Looks like they were waiting in order to encapsulate the cabling/pipe from the top segment under the leg wrap.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/09/2019 03:26 pm
How do people get inside the BFH now? Are there human sized openings?
If you look around the BFH construction site you will see metal stairs and platforms scattered about. I am beginning to wonder if these were procured to provide access to the BFH via the business end.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: su27k on 01/09/2019 03:29 pm
The dome does have a ladder on it, this can be seen from one of bocachicagal's fit check photos from yesterday.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/09/2019 03:37 pm
The dome does have a ladder on it, this can be seen from one of bocachicagal's fit check photos from yesterday.
From other images - perhaps L2 - I think that ladder is just hooked to the top of the dome. I think it's a work ladder and not part of the dome.


The Jefferies Tubes (the tubes with the ladder inside) are very rusty and kind of banged up. I still think it's the downpipe for a water tank. However I would be happy to be wrong.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/09/2019 03:45 pm
Even if a ladder were somehow inseparable from the top of the upper bulkhead, that wouldn't be that important. There is no incentive to try to make the vehicle as lightweight as possible; it's not going to space. It just needs to be balanced.

You know what would be really amusing... if the test hopper was a great success, never crashed, was retired... and then was turned into a water tower   ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: NH22077 on 01/09/2019 03:51 pm
Even if a ladder were somehow inseparable from the top of the upper bulkhead, that wouldn't be that important. There is no incentive to try to make the vehicle as lightweight as possible; it's not going to space. It just needs to be balanced.

You know what would be really amusing... if the test hopper was a great success, never crashed, was retired... and then was turned into a water tower   ;)

That would be funny. But I bet it ends up at a museum, if it survives.

Ned
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/09/2019 03:55 pm
But I bet it ends up at a museum, if it survives.

Just have to get it there. It's falcon big, after all.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cheapchips on 01/09/2019 04:03 pm

Is the dome disappeared after the 2nd hat lift or is it still there?  I couldn't tell from the most recent photos (or the conversations above).

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/09/2019 04:06 pm
... I'm trying to figure out the rationals for a 40mt, midsize hopper, instead of a full lenght (we can assume that should be very fast to add 15mt, easy and inexpensive like the nosecone was).

My guess is pretty go-ahead.
Premises:
- Spacex needs to put in place Starlink Asap
- Major competitive advantage comparing internet satellite competitors is in the launch costs
- Starlink needs almost +100 FH launches (estimate)
- We know that the big booster is under construction in LA

Given that, could be possible that for first the next Starship would be in fact a reusable second stage for carrying satellites, a cargo with enormous turning fairings. But an orbital hopper at the same time.

The Hopper would need very substantial modifications to enable it to survive re-entry. It would probaby be cheaper to build a Starship. But it got me thinking as to whether it could be used as an expendable second stage to launch Starlink satellites (or anything else). There's a good chance that the Super Heavy may be ready before the Starship as it's a relatively straightforward larger version of the F9 first stage.

This would depend on whether the Hopper can both survive launch and have the performance to reach the necessary orbit with a useful payload and the cost per Starlink satellite launched compared with the FH.

They aren't going to be launching Starlink on expendable hoppers.  Come on.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: glennfish on 01/09/2019 04:15 pm
With the two parts mated at this point, I suspect the tanks are already inside or can be installed from the bottom.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/09/2019 04:17 pm
With the two parts mated at this point, I suspect the tanks are already inside or can be installed from the bottom.
See this post...


https://forum.nasaspaceflight.com/index.php?topic=47113.msg1898845#msg1898845
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/09/2019 04:19 pm
My bet is that they will install smaller tanks inside the hopper, if they aren't already there. They will fit inside through the bottom as will the rocket engines.

Could somebody perhaps guesstimate how much fuel would be needed to send the hopper to 5 km. and have it land with a good-sized margin?

Can't wait for Elon to post some pics of the innards of this beast...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/09/2019 04:48 pm
The third fin is now receiving it's stainless finish.

In case somebody else was wondering: https://www.portoco.com/  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/09/2019 04:57 pm
Looks like the vertical rip has spread all the way down into the base section...  ;D ;D ;D

Chomper!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/09/2019 05:22 pm
Out of curiosity  - those who are thinking that the dome under construction is part of the BFH, such as a common bulkhead for propellant - how do you suggest it would be installed inside the BFH? Assuming they split the two halves apart again, where will it be installed?
One way would be to have the tank be installed above the triangle of bracing with a smaller diameter support going down through the bracing.


How do people get inside the BFH now? Are there human sized openings?
I see them getting in from the bottom using ~Jefftubeswithladders to ascend within the thing.  Through a tank???  To get to the bottom they could use the man lift or if it'll be a longer term need they'd use the white ladders and platforms that are scattered around the site.


The bulkhead still on the ground is likely the top one and likely will be welded in ABOVE the braces...

I see NO reason why the braces can't cross inside thru the LOX tank...  ;)

In fact... I expect to see a dome top and a central tube large enough for a human to climb down into sticking out the top of the base BEFORE they finally put the top dome on for flight...  ;D
Yea, that's the spirit.


The Jefferies Tubes (the tubes with the ladder inside) are very rusty and kind of banged up. I still think it's the downpipe for a water tank. However I would be happy to be wrong.
Assuming those tubes with ladders are standard water tower parts, I think you have a picture of the tube being filled with water when in normal water tower use so the ladder would be in water.   That's OK, you are a diver.  But I think that the way they make them is to have the man sized tube be dry and within it not only the ladder but a smaller ~8"? pipe for the water.

And, as I posted about a week ago...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Chris Bergin on 01/09/2019 05:39 pm
Tim's video of current status:
https://twitter.com/Erdayastronaut/status/1083061513802399744
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Hauerg on 01/09/2019 06:13 pm
What I don't understand: the whole surface is (more or less) ready, but this vertical line is like a long opening between the two half part. What could it be?
A reflection!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Kenp51d on 01/09/2019 06:53 pm
What I don't understand: the whole surface is (more or less) ready, but this vertical line is like a long opening between the two half part. What could it be?
A reflection!
A reflection of a lift boom for men, or a reflection of a crane boom.
This darn thing is shinny like a mirror. It has eregular surfaces due to be bent in compound curves, and even minor surface eregularlairties will destort the reflections, causing image  bending, twisting , and various distortions.
Zoom out. There is always the presence of some sort of boom device or crane.

Ken

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/09/2019 07:13 pm
Hauerg and Kenp51d, the reflection thing has been cleared up a few pages back in this thread. Pls read to the end before posting...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Jaghond on 01/09/2019 07:25 pm
...
Given that, could be possible that for first the next Starship would be in fact a reusable second stage for carrying satellites, a cargo with enormous turning fairings. But an orbital hopper at the same time.

... Ciao Jaghond and welcome to the site! Grazie per il tuo contributo molto interessante.

Musk hasn't mentioned anything about it, but I think your idea is intrigueing. An initial short Starship followed by a "stretched" full-length version does make a lot of sense, development-wise, as I see it. Just the way they do many airliners. Maybe the orbital-class reentry test article will be a sort of short Starship v. 1.0.

Also goes well with the tried and true SpaceX method of incremental development.

Of course the fact that nothing like this has been mentioned by Musk yet speaks against the idea. However, with the twists and turns in this development saga I wouldn't bet against it. In any case I am pretty sure that the first Starship that flies will be a bare-bones (Starlink-) launch vehicle. Manrating and outfitting it for crew is very complex and can come later, after they have flown it a lot, and maybe blown up a few ships.

Thanks for the warm welcome! You totally got my point.

I just think Starlink is a priority, Mars program needs the money. So the Starship 1.0 could be cargo, short or not. Following this path, in order to optimise money and r&d time, also would be reusable. Onestly I have no experience in engineering, so I can't guess how a relatively light and empty structure could land.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wargrim on 01/09/2019 08:31 pm
The third fin is now receiving it's stainless finish.

In case somebody else was wondering: https://www.portoco.com/  ;)

Ah, in situ Methane production!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/09/2019 08:36 pm


Pics showing some stages of the dome assembly.

Dammit. This really, really looks like a bulkhead. And they are welding it. How are they going to get this inside now that the hopper is assembled?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/09/2019 08:41 pm
...
Given that, could be possible that for first the next Starship would be in fact a reusable second stage for carrying satellites, a cargo with enormous turning fairings. But an orbital hopper at the same time.

... Ciao Jaghond and welcome to the site! Grazie per il tuo contributo molto interessante.

Musk hasn't mentioned anything about it, but I think your idea is intrigueing. An initial short Starship followed by a "stretched" full-length version does make a lot of sense, development-wise, as I see it. Just the way they do many airliners. Maybe the orbital-class reentry test article will be a sort of short Starship v. 1.0.

Also goes well with the tried and true SpaceX method of incremental development.

Of course the fact that nothing like this has been mentioned by Musk yet speaks against the idea. However, with the twists and turns in this development saga I wouldn't bet against it. In any case I am pretty sure that the first Starship that flies will be a bare-bones (Starlink-) launch vehicle. Manrating and outfitting it for crew is very complex and can come later, after they have flown it a lot, and maybe blown up a few ships.

Thanks for the warm welcome! You totally got my point.

I just think Starlink is a priority, Mars program needs the money. So the Starship 1.0 could be cargo, short or not. Following this path, in order to optimise money and r&d time, also would be reusable. Onestly I have no experience in engineering, so I can't guess how a relatively light and empty structure could land.

I think it boils down to how big a cargo hold the Starship would need in order to make maximum use of its launch lift capacity with Starlink. I also suspect that the standard 4m cargo hatch could easily be used to deploy internally stored satellites via some form of magazine arrangement.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/09/2019 08:48 pm
By the way - based on recent pic from BocaChicaGal as well as a little thought, it's possible that the Jefferies Tube is nothing more than another jig. It's not easy to form a spherical structure in thin air. It's possible this tube is nothing more that a properly sized diameter tube that allows the metal petals to stay in alignment for welding.

We're all guilty of it - but sometimes this forum falls prey to a version of "if the only tool you have is a hammer, everything begins to look like a nail"...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: flyright on 01/09/2019 09:00 pm

I agree. The tube is just an assembly tool (for watertank domes).  :D


Pics showing some stages of the dome assembly.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DJPledger on 01/09/2019 09:07 pm


Pics showing some stages of the dome assembly.

Dammit. This really, really looks like a bulkhead. And they are welding it. How are they going to get this inside now that the hopper is assembled?
Remove the placeholder Raptors, lift Star Hopper off the ground with a crane, move completed tank assembly consisting of LOX and LHC4 tanks directly under suspended Star Hopper, then gently lower Star Hopper over the tank assembly, then attach it inside Star Hopper. Once all Star Hopper internals have been completed then install flight Raptors after they have been tested at McGregor.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Space OurSoul on 01/09/2019 09:08 pm


Pics showing some stages of the dome assembly.

Dammit. This really, really looks like a bulkhead. And they are welding it. How are they going to get this inside now that the hopper is assembled?
The dome construction images were taken before the moment of hopper hull assembly. Note that in the last-but-one image of the dome construction, you can still see the middle silver section attached to the concrete jig.
I don't think we have a picture showing a completed hopper hull with a dome section outside of it... (not that I'm certain the dome is inside the hull at this point).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wolfram66 on 01/09/2019 09:30 pm
By the way - based on recent pic from BocaChicaGal as well as a little thought, it's possible that the Jefferies Tube is nothing more than another jig. It's not easy to form a spherical structure in thin air. It's possible this tube is nothing more that a properly sized diameter tube that allows the metal petals to stay in alignment for welding.

We're all guilty of it - but sometimes this forum falls prey to a version of "if the only tool you have is a hammer, everything begins to look like a nail"...

How confusing will it be if they build The StarShipHopper AND a water tower out of these pieces..?. #Boom #MindBlown... LOL #Snarkasm
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/09/2019 09:33 pm
How confusing will it be if they build The StarShipHopper AND a water tower out of these pieces..?. #Boom #MindBlown... LOL #Snarkasm

https://www.google.com/search?q=Where+can+I+buy+a+flying+water+tower?&kgmid=/m/03fkyw&kponly
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wolfram66 on 01/09/2019 09:37 pm
How confusing will it be if they build The StarShipHopper AND a water tower out of these pieces..?. #Boom #MindBlown... LOL #Snarkasm

https://www.google.com/search?q=Where+can+I+buy+a+flying+water+tower?&kgmid=/m/03fkyw&kponly

Shakes head in wonderment, but no.... 1 hopper and 1 Water Tower ... not interchangeable... To quote LARS... Hoppers and Water towers and not LEGOS
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/09/2019 09:54 pm
I think we should all step back and just appreciate how wonderful it is that SpaceX is constructing this behemoth in full view. Could you imagine any other aerospace entity doing this? Nope: it would never happen.

Also: how much FUN must it be to work as an engineer on this project?

You get to build a huge big rocket.

However, you have to do it on a shoe-string budget...

- But it will be BUILT in weeks!

"Priceless". 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/09/2019 10:04 pm
Can anyone identify the hardware around the portholes in this pic by bocachicagal? 1) The tubes attached to the skin between the two right-most portholes in the picture and 2) the little thingamajig under the left-most porthole.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/09/2019 10:08 pm
Can anyone identify the hardware around the portholes in this pic by bocachicagal? 1) The tubes attached to the skin between the two right-most portholes in the picture and 2) the little thingamajig under the left-most porthole.
I _believe_ the thingamajig is a downward facing camera clamped to the flange of the porthole, leading me to think about a potential construction video that maybe SpaceX is thoughtfully making...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/09/2019 10:13 pm

I _believe_ the thingamajig is a downward facing camera clamped to the flange of the porthole

That is my thought as well.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/09/2019 10:48 pm
Can anyone identify the hardware around the portholes in this pic by bocachicagal? 1) The tubes attached to the skin between the two right-most portholes in the picture and 2) the little thingamajig under the left-most porthole.
I _believe_ the thingamajig is a downward facing camera clamped to the flange of the porthole, leading me to think about a potential construction video that maybe SpaceX is thoughtfully making...

Well, I guess this right.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/09/2019 11:08 pm

I agree. The tube is just an assembly tool (for watertank domes).  :D


Pics showing some stages of the dome assembly.


Looks like it. They removed it once the dome was together.



Pics showing some stages of the dome assembly.

Dammit. This really, really looks like a bulkhead. And they are welding it. How are they going to get this inside now that the hopper is assembled?
The dome construction images were taken before the moment of hopper hull assembly. Note that in the last-but-one image of the dome construction, you can still see the middle silver section attached to the concrete jig.
I don't think we have a picture showing a completed hopper hull with a dome section outside of it... (not that I'm certain the dome is inside the hull at this point).
The dome is still on the ground.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Zed_Noir on 01/09/2019 11:20 pm
Can anyone identify the hardware around the portholes in this pic by bocachicagal? 1) The tubes attached to the skin between the two right-most portholes in the picture and 2) the little thingamajig under the left-most porthole.
I _believe_ the thingamajig is a downward facing camera clamped to the flange of the porthole, leading me to think about a potential construction video that maybe SpaceX is thoughtfully making...

The paranoid in me think those cameras are for security surveillance. Of course SpaceX could compiled such footage after construction for our amusement.  ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: sfxtd on 01/09/2019 11:51 pm
I think we should all step back and just appreciate how wonderful it is that SpaceX is constructing this behemoth in full view. Could you imagine any other aerospace entity doing this? Nope: it would never happen.

Also: how much FUN must it be to work as an engineer on this project?

You get to build a huge big rocket.

However, you have to do it on a shoe-string budget...

- But it will be BUILT in weeks!

"Priceless". 

I have been thinking about the welders on this project. What was it like when they told them what they would be making?This will be the project they talk about forever.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Zed_Noir on 01/09/2019 11:58 pm
Have a wacky idea. SpaceX could build a flight fidelity Orbital Water Tower (AKA Star Hopper V3, BFH V3) as interim Starlink delivery vehicle/research vehicle.

Basically use OML of the Flying Water Tower for a reusable SSTO launcher. Omitted everything internal on top of the LOX tank. Put a 10 unit capacity carousal satellite launcher on top of the LOX tank along with a single Starlink ejection egress hull hatch.

This Orbital Water Tower will be much lighter than Starship with the same propellant load. Can the nominal propellant load in the Starship (BFS) design along with 7 Raptors in the Orbital Water Tower form factor have enough Delta-V to get about 5 tonnes of payload to LEO plus enough propellant reserves to landed maybe down range?

Of course you could put something like this on the Super Heavy as semi-expendable test vehicle.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Zed_Noir on 01/10/2019 12:09 am
.... 

I have been thinking about the welders on this project. What was it like when they told them what they would be making?This will be the project they talk about forever.

Because the welders are now honorary SpaceX rocket mechanics assembling flight hardware.  8)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/10/2019 12:48 am
Have a wacky idea. SpaceX could build a flight fidelity Orbital Water Tower (AKA Star Hopper V3, BFH V3) as interim Starlink delivery vehicle/research vehicle.

Basically use OML of the Flying Water Tower for a reusable SSTO launcher. Omitted everything internal on top of the LOX tank. Put a 10 unit capacity carousal satellite launcher on top of the LOX tank along with a single Starlink ejection egress hull hatch.

This Orbital Water Tower will be much lighter than Starship with the same propellant load. Can the nominal propellant load in the Starship (BFS) design along with 7 Raptors in the Orbital Water Tower form factor have enough Delta-V to get about 5 tonnes of payload to LEO plus enough propellant reserves to landed maybe down range?

Of course you could put something like this on the Super Heavy as semi-expendable test vehicle.

You are outhinking this.  SSTO is hard.  EM stated SS can do it with no payload.  They aren't just going to "back into" a Field Welded SSTO for meaningful payload.  Just not going to happen.  I have no idea how it would get back and if it can't then it's a non-starter.

There is most likely to be a single "generation" of BFH.  Quick and dirty similar to what they've got.  Maybe only this single BFH if they don't blow it up.  If I were them I might go ahead and build a 2nd one while they are at it, perhaps full size which can serve as an interior fit-check article if it's not blown up as a hopper. 

SS is coming soon and will be hopping as soon at possible.  SH will follow shortly thereafter with a similar test program.

Starlink will deploy when the satellites are ready on existing Falcon platform and on SS when SH can boost it.  Not before on anything else.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: WindyCity on 01/10/2019 12:58 am
Even if a ladder were somehow inseparable from the top of the upper bulkhead, that wouldn't be that important. There is no incentive to try to make the vehicle as lightweight as possible; it's not going to space. It just needs to be balanced.

You know what would be really amusing... if the test hopper was a great success, never crashed, was retired... and then was turned into a water tower   ;)

That would be funny. But I bet it ends up at a museum, if it survives.

I am reminded of a venerable Bill Murray and Steve Martin skit from SNL's days of yore:  https://www.liveleak.com/view?i=872_1313749431
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: su27k on 01/10/2019 02:07 am
Have a wacky idea. SpaceX could build a flight fidelity Orbital Water Tower (AKA Star Hopper V3, BFH V3) as interim Starlink delivery vehicle/research vehicle.

Basically use OML of the Flying Water Tower for a reusable SSTO launcher. Omitted everything internal on top of the LOX tank. Put a 10 unit capacity carousal satellite launcher on top of the LOX tank along with a single Starlink ejection egress hull hatch.

This Orbital Water Tower will be much lighter than Starship with the same propellant load. Can the nominal propellant load in the Starship (BFS) design along with 7 Raptors in the Orbital Water Tower form factor have enough Delta-V to get about 5 tonnes of payload to LEO plus enough propellant reserves to landed maybe down range?

Of course you could put something like this on the Super Heavy as semi-expendable test vehicle.

SSTO is very sensitive to dry mass/propellant mass fraction, building one from water tower is just not feasible.

What you're thinking is Starship V1, the orbital test vehicle they're building at L.A. It would not have much in common with hopper/water tower, but it will probably be massively overbuilt like a battleship in a similar spirit. It can't do SSTO but can go to very high mach number in suborbital test flight, and can deliver Starlink when used with SuperHeavy V1, which will also be massively overbuilt.

Anyway that's my guess as to how they can get a SuperHeavy/Starship stack to launch in 2020, basically trading mass/payload capability for development/construction speed, it will be the largest LV in history by liftoff thrust and mass, but will have a rather wimpy payload capability, which is perfectly fine as long as it's cheaper to reuse than Falcon 9.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/10/2019 03:37 am
Can anyone identify the hardware around the portholes in this pic by bocachicagal? 1) The tubes attached to the skin between the two right-most portholes in the picture and 2) the little thingamajig under the left-most porthole.
I _believe_ the thingamajig is a downward facing camera clamped to the flange of the porthole, leading me to think about a potential construction video that maybe SpaceX is thoughtfully making...
Twould be a fabulous video if they had the entire build sequence unfold from beginning to end whilst chronologically synchronized text from the NSF guessing squad, reddit, etc was to be placed on screen.  It would make a laughing stock of us all.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/10/2019 04:04 am
I wonder if by adding the thin shiny stainless sheets if they now have a lot of pieces that after a Kaboom would flutter and float much further from the kaboom location than the less ballitsically challenged parts that comprise the rest of the gadget and thus have pinned themselves into a smaller safe operating volume of airspace.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: joek on 01/10/2019 04:40 am
I wonder if by adding the thin shiny stainless sheets if they now have a lot of pieces that after a Kaboom would flutter and float much further from the kaboom location than the less ballitsically challenged parts that comprise the rest of the gadget and thus have pinned themselves into a smaller safe operating volume of airspace.

Maybe... but FAA is pretty strict about debris area controls and boundaries--and the consequences should those boundaries be breached.  Basically same as a mishap report on steroids, with consequent investigation, paperwork and delays.  Similar rationale for not unzipping F9 on RTLS return should something bad happen.  Better to keep the potential debris field controlled and limited (even though individual impact energies may be higher), rather than uncontrolled impact over a wider area.  Then again, if the launch-land area is in the middle of nowhere, that would help mitigate risks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: biosehnsucht on 01/10/2019 05:38 am
Seems more likely the skin would travel less distance than the higher mass parts, as they will be slowed more rapidly by air resistance.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Zed_Noir on 01/10/2019 05:56 am
....

What you're thinking is Starship V1, the orbital test vehicle they're building at L.A. It would not have much in common with hopper/water tower, but it will probably be massively overbuilt like a battleship in a similar spirit. It can't do SSTO but can go to very high mach number in suborbital test flight, and can deliver Starlink when used with SuperHeavy V1, which will also be massively overbuilt.


Was thinking of a shorten 40 meter high Starship minus the decks for cargo and passengers with nominal Starship propellant tankage.

I think the Starship and the Hopper will not be much different up to the level just above the  top of the LOX tank in the outer mold line. We will see in a few months if my speculation is correct or not.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: docmordrid on 01/10/2019 06:01 am
From the engineering thread,

Confirmation  Super Heavy is also stainless steel?

tetragrammaton @ruboyad
Replying to @elonmusk
Will Super Heavy also be shiny as Starship?
|
Elon Musk

@elonmusk
Yes 🚀
1:41 AM - Jan 10, 2019

https://twitter.com/elonmusk/status/1083252590689820672
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: QuantumG on 01/10/2019 07:10 am
Pics showing some stages of the dome assembly.

So yeah, they're making the common bulkhead the same way they made the outer skin. Crazy like a fox.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/10/2019 07:25 am
Pics showing some stages of the dome assembly.

So yeah, they're making the common bulkhead the same way they made the outer skin. Crazy like a fox.

Yeah. But it will require some really crazy magic to get it inside unless they take the hopper apart again.

¯\_(ツ)_/¯
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/10/2019 07:31 am
Pics showing some stages of the dome assembly.

So yeah, they're making the common bulkhead the same way they made the outer skin. Crazy like a fox.

Yeah. But it will require some really crazy magic to get it inside unless they take the hopper apart again.

¯\_()_/¯
I think it's a Monty Python joke, like when they forgot to get into the Trojan rabbit.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Semmel on 01/10/2019 07:47 am
Pics showing some stages of the dome assembly.

So yeah, they're making the common bulkhead the same way they made the outer skin. Crazy like a fox.

After the water tower fiasco, I dont want to say its not a common bulkhead. I would just be proven wrong. But how does LOX not make a bright torch out of a common bulkhead with rusty pieces sticking out like that?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: PaulVla on 01/10/2019 11:54 am
Pics showing some stages of the dome assembly.

So yeah, they're making the common bulkhead the same way they made the outer skin. Crazy like a fox.

After the water tower fiasco, I dont want to say its not a common bulkhead. I would just be proven wrong. But how does LOX not make a bright torch out of a common bulkhead with rusty pieces sticking out like that?

Could just be for strength, lining it on the inside like they are doing the outside with a thin layer of SS?

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/10/2019 01:32 pm
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: magnemoe on 01/10/2019 01:46 pm
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?
Not excactly new, think seadragon also used steel. Some stuff are easier as you scale up.
Only real issue I see is reentry.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/10/2019 02:04 pm
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Cladding doesn't solve anything. Stainless is only useful as a hot structure, and has considerable fabrication issues to get to the EFH stage necessary for superior specific strength in the necessary geometry.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: matthewkantar on 01/10/2019 02:42 pm
Pics showing some stages of the dome assembly.

So yeah, they're making the common bulkhead the same way they made the outer skin. Crazy like a fox.

After the water tower fiasco, I dont want to say its not a common bulkhead. I would just be proven wrong. But how does LOX not make a bright torch out of a common bulkhead with rusty pieces sticking out like that?

I think those "rusty pieces sticking out" are cleats temporarily welded on so that clamps can be used to pull the joint tight for welding.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/10/2019 03:03 pm
LOX material compatibility:

https://apps.dtic.mil/dtic/tr/fulltext/u2/613553.pdf

Quote
Liquid oxygen is considered to be noncorrosive to most metals. In particular, nickel, Monel, Inconel, copper, aluminum, the 300 series of stainless steels, brass, and silver solder are used in liquid-oxygen-handling equipment.

Several instances have been reported of violent reactions of titanium and liquid oxygen which appeared to be related to impact. The impact sensitivity of LOX has been investigated rather extensively. It appears that the ignition of titanium under impact occurs in the following sequence:

(1) The Impact exposes fresh metal and results in some gaseous oxygen being formed at the point of impact.
(2) The gaseous oxygen reacts with the fresh metal in an exothermic reaction.
(3) The heat generated raises the metal temperature sufficiently to result in localized dissolution of any TiO2 film that might form.
(4) Thus a protective oxide film does not build up and the reaction proceeds rapidly.

Ignition of massive titanium is observed in gaseous oxygen at liquid-oxygen temperatures at pressures of about 100 psi and above. This critical pressure limit is lowered only slightly as the temperature of the oxygen is raised to ambient temperature.

Massive aluminum exhibits ignition under severe detonation in LOX. The frequency is not so great nor is the propagation so severe as it is with titanium under the same conditions. Magnesium also ignites under detonation at shock levels higher than those for titanium but lower than those for aluminum.

Organic materials should be avoided with both liquid and gaseous oxygen because of possibilities of explosions. Currently, there is no single test or group of tests which gives a reliable compatibility rating for organic materials in liquid oxygen service. It is recommended that organic materials be avoided wherever possible and used only with caution. No completely compatible lubricants have been found. Thread antiseize sealants of graphite in chlorinated organic carrier and halogen paraffin with pour points as low as -100 F have been used in LOX systems. Teflon, Mylar, and certain chloroprene and Buna-N compounds have been used as static seals while Kel-F-300, Kel-F-500, Kel-F-240, Fluorothene FYTD, Fluozother.e FYTS, and certain chloroprene and Buna-N compounds have been used in dynamic seals.

Many organic and plastic materials exhibit impact sensitivity in LOX including:

(1) Synthetic elastomers and Thiokols
(2) Cellulose-based papers
(3) Silicone- and silicate-based oils and greases
(4) Thermoplastics such as nylon and phenolics
(5) Thermosetting resins (phenolics, silicones, epoxies, ec.)
(6) Petroleum-based oils and greases.

The fluorocarbon plastics are probably the best choice with respect to impact sensitivity. These, however, should not be used with aluminum. A number of other organic materials right be used, but specific conditions should be carefully studied.
The list of references on ignition in LOX contains the results of many impact tests on organic materials, which can be used as a guide to selection.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: clongton on 01/10/2019 04:02 pm
But it will require some really crazy magic to get it inside unless they take the hopper apart again.

Not if they also build a TE for the Hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/10/2019 04:35 pm
But it will require some really crazy magic to get it inside unless they take the hopper apart again.

Not if they also build a TE for the Hopper.
I doubt if this thing will ever be horizontal.
 Now if I could get Semmel to agree with me, we could be sure that it will go horizontal. Probably by the end of the day.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Tuna-Fish on 01/10/2019 05:23 pm
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Not the first such plan by far. The issue is that hot structure stainless steel only really makes sense if you dare to build very big, and there has not been enough big things built meant for orbital re-entry for this to have ever been tried before.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: geza on 01/10/2019 05:44 pm
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Not the first such plan by far. The issue is that hot structure stainless steel only really makes sense if you dare to build very big, and there has not been enough big things built meant for orbital re-entry for this to have ever been tried before.
Why is this?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: r4mir3zx on 01/10/2019 07:19 pm
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Not the first such plan by far. The issue is that hot structure stainless steel only really makes sense if you dare to build very big, and there has not been enough big things built meant for orbital re-entry for this to have ever been tried before.
Why is this?

I'm just guessing: maybe because it's not exactly engineering problem but psychological?
Maybe it's something like it took some thousand years to get from Archimedes' law to metal ships? :)

Edit: That's what this situation with this new shiny Starship reminds me...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rsdavis9 on 01/10/2019 07:38 pm
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Not the first such plan by far. The issue is that hot structure stainless steel only really makes sense if you dare to build very big, and there has not been enough big things built meant for orbital re-entry for this to have ever been tried before.
Why is this?

I know I will get this wrong...

For weight:
Maybe shielding with metal goes as the area therefore square of size.
Whereas orbital lift and fuel and eventual payload goes as cube of size.
So bigger means shielding is less important as to total weight.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/10/2019 07:42 pm
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Not the first such plan by far. The issue is that hot structure stainless steel only really makes sense if you dare to build very big, and there has not been enough big things built meant for orbital re-entry for this to have ever been tried before.
Why is this?

This is a different kind of vehicle than what as been re-entered before. Larger but with lighter overall loading. This allows some new ideas to be tried, and old discarded ideas to be re-evaluated.

SpaceX is also not as conservative as others in the business.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: bob the martian on 01/10/2019 08:30 pm
.... 

I have been thinking about the welders on this project. What was it like when they told them what they would be making?This will be the project they talk about forever.

Because the welders are now honorary SpaceX rocket mechanics assembling flight hardware.  8)

Stainless-steely-eyed missile men. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/10/2019 09:36 pm
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Not the first such plan by far. The issue is that hot structure stainless steel only really makes sense if you dare to build very big, and there has not been enough big things built meant for orbital re-entry for this to have ever been tried before.
Why is this?
Getting into orbit has always been very difficult and very expensive. The enphasis has always been on getting mass into orbit to do things rather than getting volume into orbit to do things in, as mass is critical to cost. Now we are seeing the advent of reusability the need for volume (or area) has taken a higher profile for use as an aid to re-entry.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mattstep on 01/11/2019 03:10 am
Elon just tweeted an image of the finished hopper. (https://twitter.com/elonmusk/status/1083567087983964160)

Quote
Elon Musk ✔ @elonmusk
Starship test flight rocket just finished assembly at the @SpaceX Texas launch site. This is an actual picture, not a rendering.
10:31 PM - Jan 10, 2019

So, does that look like a launchpad to anyone else? Is there any other reason for surrounding it with concrete rather than just gravel?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: QuantumG on 01/11/2019 03:12 am
Suborbital only, not surprising but y'all can stop speculating now.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/11/2019 03:16 am
So, does that look like a launchpad to anyone else? Is there any other reason for surrounding it with concrete rather than just gravel?

For a couple reasons, I'm thinking that's an actual picture photoshopped onto a pad with a separate background added.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: su27k on 01/11/2019 03:17 am
Should be done with first orbital prototype around June (https://twitter.com/elonmusk/status/1083575233423003648)

Well, I guess that's why they are rushing the hopper so hard, the orbital test vehicle is not far behind.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ngkiwi on 01/11/2019 03:17 am
I guess all we have to wait for is repositioning, fuelling and go.

The speculation has been fantastic, now the fun (serious) starts

ng
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: lonestriker on 01/11/2019 03:23 am
Should be done with first orbital prototype around June (https://twitter.com/elonmusk/status/1083575233423003648)

Well, I guess that's why they are rushing the hopper so hard, since the orbital test vehicle is not far behind.

I don't know what's crazier:  that they assembled the BFH in a field in a few weeks or that the prototype of the real deal is only 6 months away?  Makes me almost happy that I didn't start following SpaceX until later in their life, after they got F9 running.  It must have been torture to wait and watch the F1's inaugural flights.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rocket Surgeon on 01/11/2019 03:33 am
Should be done with first orbital prototype around June (https://twitter.com/elonmusk/status/1083575233423003648)

Well, I guess that's why they are rushing the hopper so hard, since the orbital test vehicle is not far behind.

I don't know what's crazier:  that they assembled the BFH in a field in a few weeks or that the prototype of the real deal is only 6 months away?  Makes me almost happy that I didn't start following SpaceX until later in their life, after they got F9 running.  It must have been torture to wait and watch the F1's inaugural flights.

There is nothing more un-satisfying then seeing a rocket light it's engines on the launch pad...then not go anywhere...

Especially if you stayed up late to see it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/11/2019 03:34 am
Should be done with first orbital prototype around June (https://twitter.com/elonmusk/status/1083575233423003648)

Well, I guess that's why they are rushing the hopper so hard, since the orbital test vehicle is not far behind.

I don't know what's crazier:  that they assembled the BFH in a field in a few weeks or that the prototype of the real deal is only 6 months away?  Makes me almost happy that I didn't start following SpaceX until later in their life, after they got F9 running.  It must have been torture to wait and watch the F1's inaugural flights.

It was quite the time...

Throughout, I had zero doubt that it'll pan out. What I didn't imagine was just how fast and far.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: intrepidpursuit on 01/11/2019 03:48 am
https://twitter.com/elonmusk/status/1083576980010881024

So we can put to bed that the water tower tank is indeed the fuel tank. I would guess someone looked at water tower specs and found that they could actually hold the PSI they needed. Clearly it took a while for someone to timidly raise their hand and say "How about we just put engines on the bottom of a water tower, fill it with fuel, and fly it?" But once they did it started a whirlwind.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: CardBoardBoxProcessor on 01/11/2019 03:54 am
Hi. How the devil did they smooth it out??
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: FutureMartian97 on 01/11/2019 04:01 am
Hi. How the devil did they smooth it out??

Photoshop
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: intrepidpursuit on 01/11/2019 04:02 am
Hi. How the devil did they smooth it out??

They didn't. Elon's picture is suspiciously smooth compared to the many pictures from other sources. The sun is glinting just right and perhaps there was a touch of photoshop. Still looks like it just got out of a long bath.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: docmordrid on 01/11/2019 04:08 am
Hi. How the devil did they smooth it out??

They didn't. Elon's picture is suspiciously smooth compared to the many pictures from other sources. The sun is glinting just right and perhaps there was a touch of photoshop. Still looks like it just got out of a long bath.

Or they slightly pressurized it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: intrepidpursuit on 01/11/2019 04:15 am
Hi. How the devil did they smooth it out??

They didn't. Elon's picture is suspiciously smooth compared to the many pictures from other sources. The sun is glinting just right and perhaps there was a touch of photoshop. Still looks like it just got out of a long bath.

Or they slightly pressurized it.

I know this whole thing is already crazy, but no way that top section holds fuel. We'll only see fuel in the water tower section.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Robotbeat on 01/11/2019 04:17 am
Suborbital only, not surprising but y'all can stop speculating now.
That was never in question. The question was Karman Line or not (considering they're building the orbital version in June, I would suspect "not" but technically it might be capable of it).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Robotbeat on 01/11/2019 04:17 am
Hi. How the devil did they smooth it out??

They didn't. Elon's picture is suspiciously smooth compared to the many pictures from other sources. The sun is glinting just right and perhaps there was a touch of photoshop. Still looks like it just got out of a long bath.

Or they slightly pressurized it.

I know this whole thing is already crazy, but no way that top section holds fuel. We'll only see fuel in the water tower section.
Doesn't mean they wouldn't pressurize it (slightly).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: docmordrid on 01/11/2019 04:18 am
Hi. How the devil did they smooth it out??

They didn't. Elon's picture is suspiciously smooth compared to the many pictures from other sources. The sun is glinting just right and perhaps there was a touch of photoshop. Still looks like it just got out of a long bath.

Or they slightly pressurized it.

I know this whole thing is already crazy, but no way that top section holds fuel. We'll only see fuel in the water tower section.

I didn't say it (the nose cone) holds propellants, just hinted that it may be airtight enough to hold pressure for stabilization and/or to smooth the skin.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/11/2019 04:49 am
 The ship could look like that if the sun was out in the south, the sky was overcast in the west, they took the picture from close up and corrected for perspective distortion.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: pathfinder_01 on 01/11/2019 05:27 am
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Not the first such plan by far. The issue is that hot structure stainless steel only really makes sense if you dare to build very big, and there has not been enough big things built meant for orbital re-entry for this to have ever been tried before.
Why is this?

This is a different kind of vehicle than what as been re-entered before. Larger but with lighter overall loading. This allows some new ideas to be tried, and old discarded ideas to be re-evaluated.

SpaceX is also not as conservative as others in the business.

Hot structure and active cooling are old ideas, it is just that for most spacecraft prior to BFR(or Startship or whatever Elon wants to call it this week) the mass and complexity of it didn't trade well against passive heat shielding. The trouble is that metals that can resist the heat of reentry can be expensive(not sure about the steel he intends to use) and  heavy. Plus the amount of cooling fluid needed for active cooling(like water) would be a lot of dead weight.

BFR is built very differently than say a small capsule that needs to be lifted by rocket, come down on parachute  and float in the ocean or a spacecraft that needs to glide on wings to a runway as well as carry a payload into orbit. The trades on it could yield quite different outcomes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lampyridae on 01/11/2019 05:57 am
Hi. How the devil did they smooth it out??

They didn't. Elon's picture is suspiciously smooth compared to the many pictures from other sources. The sun is glinting just right and perhaps there was a touch of photoshop. Still looks like it just got out of a long bath.

Or they slightly pressurized it.

Choice of location, angles, lighting, location of nearby objects and lenses make a big difference. Standing far away, with the cranes up close, you get reflections of grounds and what look like rips in the metal. Up close, on the property, the rocket you look up at reflects mostly blue sky and subtle imperfections in the metal become irrelevant.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: tea monster on 01/11/2019 06:47 am
Hi. How the devil did they smooth it out??

They didn't. If you look at the surface, it's just as bumpy. They've either subtly photoshopped it to reduce contrast or chosen their time of photography very carefully.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Semmel on 01/11/2019 08:46 am
But it will require some really crazy magic to get it inside unless they take the hopper apart again.

Not if they also build a TE for the Hopper.
I doubt if this thing will ever be horizontal.
 Now if I could get Semmel to agree with me, we could be sure that it will go horizontal. Probably by the end of the day.

Not going to... say it! You are right though, my track record is almost perfectly -100% lately, meaning the opposite of what I say comes true. But this time, I will keep my mouth shut. Saying the opposite of what I think is true would just jinx it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/11/2019 09:00 am
Did the Dear Moon flight money allow this sudden explosive progress and/or the government shutdown allow them to pull employees from other projects to work on this?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: dglow on 01/11/2019 09:09 am
But it will require some really crazy magic to get it inside unless they take the hopper apart again.

Not if they also build a TE for the Hopper.
I doubt if this thing will ever be horizontal.
 Now if I could get Semmel to agree with me, we could be sure that it will go horizontal. Probably by the end of the day.

Not going to... say it! You are right though, my track record is almost perfectly -100% lately, meaning the opposite of what I say comes true. But this time, I will keep my mouth shut. Saying the opposite of what I think is true would just jinx it.

Semmel, what's the extent of your position re: horizontal? Just for Hopper, Starship in general, Super Heavy?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Tuna-Fish on 01/11/2019 09:16 am
Did the Dear Moon flight money allow this sudden explosive progress and/or the government shutdown allow them to pull employees from other projects to work on this?

I don't think this progress is particularly explosive for SpaceX, it's just for once happening in the open where we can see it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/11/2019 09:56 am
Did the Dear Moon flight money allow this sudden explosive progress and/or the government shutdown allow them to pull employees from other projects to work on this?

I don't think this progress is particularly explosive for SpaceX, it's just for once happening in the open where we can see it.

Maybe I’ve just got used to launcher projects taking forever being built.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Jcc on 01/11/2019 10:29 am
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Not the first such plan by far. The issue is that hot structure stainless steel only really makes sense if you dare to build very big, and there has not been enough big things built meant for orbital re-entry for this to have ever been tried before.

Skylon also plans to make use of the low ballistic coefficient of empty fuel tanks to renter with minimal TPS, but they are a long way from building it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: niwax on 01/11/2019 10:56 am
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Not the first such plan by far. The issue is that hot structure stainless steel only really makes sense if you dare to build very big, and there has not been enough big things built meant for orbital re-entry for this to have ever been tried before.

Skylon also plans to make use of the low ballistic coefficient of empty fuel tanks to renter with minimal TPS, but they are a long way from building it.

And suddenly going steel for ease of manufacturing isn't an option for SSTOs. By the time any of the proposed SSTOs come online, I expect SpaceX or Blue Origin to have pushed the additional cost for launching on a booster to under a million $.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: blasphemer on 01/11/2019 11:09 am
Considering the apparently simple construction of the new BFR (stainless steel, methalox as propellant), would it be possible to build and operate it back in the 60s? Replace Raptor with a gas generator if needed, payload mass should still be acceptable. Would there be any technological showstopper (vertical landing maybe)?

Just wondering if this thing pans out, whether we have lost half a century chasing technological ghosts..
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: schaban on 01/11/2019 11:13 am
Considering the apparently simple construction of the new BFR (stainless steel, methalox as propellant), would it be possible to build and operate it back in the 60s? Replace Raptor with a gas generator if needed, payload mass should still be acceptable. Would there be any technological showstopper (vertical landing maybe)?

Just wondering if this thing pans out, whether we have lost half a century chasing technological ghosts..

Don't think so
All this was made possible by advancement in electronics and software
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: 50_Caliber on 01/11/2019 11:15 am
Should be done with first orbital prototype around June (https://twitter.com/elonmusk/status/1083575233423003648)

Well, I guess that's why they are rushing the hopper so hard, since the orbital test vehicle is not far behind.

I don't know what's crazier:  that they assembled the BFH in a field in a few weeks or that the prototype of the real deal is only 6 months away?  Makes me almost happy that I didn't start following SpaceX until later in their life, after they got F9 running.  It must have been torture to wait and watch the F1's inaugural flights.

I didn't think of SpaceX as anything more than an efficient version of ULA, doing a few things better than they did. Then the IAC 2017 speech was when I realized we were experiencing a real-life DD Harriman, in fact Musk is arguably in pursuit of an even bolder vision than DD.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/11/2019 11:20 am
A hundred years of rocketry and only now do we realise than every problem can be solved with shiny stainless steel cladding?

Not the first such plan by far. The issue is that hot structure stainless steel only really makes sense if you dare to build very big, and there has not been enough big things built meant for orbital re-entry for this to have ever been tried before.

Skylon also plans to make use of the low ballistic coefficient of empty fuel tanks to renter with minimal TPS, but they are a long way from building it.

And suddenly going steel for ease of manufacturing isn't an option for SSTOs. By the time any of the proposed SSTOs come online, I expect SpaceX or Blue Origin to have pushed the additional cost for launching on a booster to under a million $.

I am not sure why people feel the need to make speculative and probably unlikely to be true any time soon statements like this as it doesn’t really help anyone.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: uhuznaa on 01/11/2019 11:36 am
Considering the apparently simple construction of the new BFR (stainless steel, methalox as propellant), would it be possible to build and operate it back in the 60s? Replace Raptor with a gas generator if needed, payload mass should still be acceptable. Would there be any technological showstopper (vertical landing maybe)?

Just wondering if this thing pans out, whether we have lost half a century chasing technological ghosts..

Don't think so
All this was made possible by advancement in electronics and software

I think reusable two stages would still have been totally possible much earlier, but it would have been harder to develop and more expensive. In the first place there was no perceived need for it and no motivation to try with the necessary funding.

In fact without SpaceX nobody would try even today. Nobody else has any interest in furthering low-cost spaceflight at all (except BO maybe of course). Where's the point in that if you can just as well make billions and billions by doing ever more expensive launchers and just throwing them away after a few minutes?

And make no mistake: What SpaceX is trying to achieve is still very risky as a business. If you can go to orbit for cheaper and even can go to Mars you still need somebody to pay you for delivering their payloads, and lots of them. With StarLink (if it should materialize) SpaceX will be at least its own customer for quite a lot of LEO launches, but the EXISTING market for LEO (or even Mars) launches is quite limited.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lampyridae on 01/11/2019 11:42 am
Did the Dear Moon flight money allow this sudden explosive progress and/or the government shutdown allow them to pull employees from other projects to work on this?

I don't think this progress is particularly explosive for SpaceX, it's just for once happening in the open where we can see it.

Maybe I’ve just got used to launcher projects taking forever being built.

Well, the Shuttle Generation got a space shuttle whose economics were justified by fiction, a heat shield protected by hope and an escape system fuelled with nope.

Mercury had hand-written instrumenation labels, and it was still safer than the shuttle. Space is still really, really hard but the fact is you don't need a billion dollars to throw a used car at Mars.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: glennfish on 01/11/2019 11:56 am
Did the Dear Moon flight money allow this sudden explosive progress and/or the government shutdown allow them to pull employees from other projects to work on this?

I don't think this progress is particularly explosive for SpaceX, it's just for once happening in the open where we can see it.

If this was done by a water tower company using water tower construction techniques, then the net cost of construction was between 1.2 and 4.5 million net.  Probably at the low end.  The construction speed was about 2-3 times faster than a water tower, but most of the time is spent waiting for parts to arrive.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: schaban on 01/11/2019 11:57 am
Considering the apparently simple construction of the new BFR (stainless steel, methalox as propellant), would it be possible to build and operate it back in the 60s? Replace Raptor with a gas generator if needed, payload mass should still be acceptable. Would there be any technological showstopper (vertical landing maybe)?

Just wondering if this thing pans out, whether we have lost half a century chasing technological ghosts..

Don't think so
All this was made possible by advancement in electronics and software

I think reusable two stages would still have been totally possible much earlier, but it would have been harder to develop and more expensive. In the first place there was no perceived need for it and no motivation to try with the necessary funding.

In fact without SpaceX nobody would try even today.

This is not correct

Multiple companies and NASA itself were working on developing technologies SpaceX almost perfected

If not SpaceX then someone else would succeed. Perhaps not as cheap or quick but eventually would get there

What made Musk to be stand out is that he showed that what is physically possible could be made cheap enough to be economically viable. Just have to think deep and long enough.

Not only in SpaceX but Tesla or Boring or Hyperloop...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/11/2019 12:07 pm
Considering the apparently simple construction of the new BFR (stainless steel, methalox as propellant), would it be possible to build and operate it back in the 60s? Replace Raptor with a gas generator if needed, payload mass should still be acceptable. Would there be any technological showstopper (vertical landing maybe)?

Just wondering if this thing pans out, whether we have lost half a century chasing technological ghosts..

Don't think so
All this was made possible by advancement in electronics and software

I think reusable two stages would still have been totally possible much earlier, but it would have been harder to develop and more expensive. In the first place there was no perceived need for it and no motivation to try with the necessary funding.

In fact without SpaceX nobody would try even today.

This is not correct

Multiple companies and NASA itself were working on developing technologies SpaceX almost perfected

If not SpaceX then someone else would succeed. Perhaps not as cheap or quick but eventually would get there

What made Musk to be stand out is that he showed that what is physically possible could be made cheap enough to be economically viable. Just have to think deep and long enough.

Not only in SpaceX but Tesla or Boring or Hyperloop...

Nobody else is working on a reusable upper stage like Starship. NASA got halfway there with the Shuttle Orbiter and then gave up and went back to fully expendable SLS.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: magnemoe on 01/11/2019 12:45 pm
Considering the apparently simple construction of the new BFR (stainless steel, methalox as propellant), would it be possible to build and operate it back in the 60s? Replace Raptor with a gas generator if needed, payload mass should still be acceptable. Would there be any technological showstopper (vertical landing maybe)?

Just wondering if this thing pans out, whether we have lost half a century chasing technological ghosts..

Don't think so
All this was made possible by advancement in electronics and software

I think reusable two stages would still have been totally possible much earlier, but it would have been harder to develop and more expensive. In the first place there was no perceived need for it and no motivation to try with the necessary funding.

In fact without SpaceX nobody would try even today. Nobody else has any interest in furthering low-cost spaceflight at all (except BO maybe of course). Where's the point in that if you can just as well make billions and billions by doing ever more expensive launchers and just throwing them away after a few minutes?

And make no mistake: What SpaceX is trying to achieve is still very risky as a business. If you can go to orbit for cheaper and even can go to Mars you still need somebody to pay you for delivering their payloads, and lots of them. With StarLink (if it should materialize) SpaceX will be at least its own customer for quite a lot of LEO launches, but the EXISTING market for LEO (or even Mars) launches is quite limited.
It was some ideas back in the 60s. The problem was that most went into the SSTO trap.
The marked was missing and all rocket technology was very new.

Now if the space race had lasted longer and been more intense we probably got it earlier.

Look at the delta clipper, again an SSTO trap and not made here. SSTO trap in that it could easy be used as an reusable first stage.

Now however the cat is pretty much out of the bag, Pretty sure Blue Origin think a lot about reusable second stages as its the next goalpost.
You have to be that high to play the game.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/11/2019 12:54 pm
Considering the apparently simple construction of the new BFR (stainless steel, methalox as propellant), would it be possible to build and operate it back in the 60s? Replace Raptor with a gas generator if needed, payload mass should still be acceptable. Would there be any technological showstopper (vertical landing maybe)?

Just wondering if this thing pans out, whether we have lost half a century chasing technological ghosts..

Don't think so
All this was made possible by advancement in electronics and software

I think reusable two stages would still have been totally possible much earlier, but it would have been harder to develop and more expensive. In the first place there was no perceived need for it and no motivation to try with the necessary funding.

In fact without SpaceX nobody would try even today. Nobody else has any interest in furthering low-cost spaceflight at all (except BO maybe of course). Where's the point in that if you can just as well make billions and billions by doing ever more expensive launchers and just throwing them away after a few minutes?

And make no mistake: What SpaceX is trying to achieve is still very risky as a business. If you can go to orbit for cheaper and even can go to Mars you still need somebody to pay you for delivering their payloads, and lots of them. With StarLink (if it should materialize) SpaceX will be at least its own customer for quite a lot of LEO launches, but the EXISTING market for LEO (or even Mars) launches is quite limited.
It was some ideas back in the 60s. The problem was that most went into the SSTO trap.
The marked was missing and all rocket technology was very new.

Now if the space race had lasted longer and been more intense we probably got it earlier.

Look at the delta clipper, again an SSTO trap and not made here. SSTO trap in that it could easy be used as an reusable first stage.

Now however the cat is pretty much out of the bag, Pretty sure Blue Origin think a lot about reusable second stages as its the next goalpost.
You have to be that high to play the game.
I think Blue's next goal should be launching something into orbit.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: tea monster on 01/11/2019 12:56 pm
Reusable space craft have been proposed since the 1950s. Even Chrysler motors put forward a giant reusable booster called SERV (as just one of many examples). Everyone has known what needed to be done to reduce the cost of spaceflight. Nobody up until Elon and Jeff has actually stumped up the cash and made it happen. Any of the big aerospace contractors could have made such a craft. They have had people like Bono suggesting designs for decades. No interest has been shown at all by any of them.

NASA and others have started projects, but they always were cancelled - sometimes just before flying. The X-33 and the NASP are just two of the many dead projects littering the 90s. Apart from that, the 'new space age' has only existed in power point presentations.

If it wasn't for SpaceX (and, maybe, Blue Origin), we may have had some kind of reusable spacecraft operational at some time, but with NASA's current obsession with "Apollo on steroids", you may have had to wait a LONG time to see anything like what SpaceX is doing come to pass. 

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Llian Rhydderch on 01/11/2019 12:58 pm

Multiple companies and NASA itself were working on developing technologies SpaceX almost perfected

If not SpaceX then someone else would succeed. Perhaps not as cheap or quick but eventually would get there

What made Musk to be stand out is that he showed that what is physically possible could be made cheap enough to be economically viable. Just have to think deep and long enough.

Not only in SpaceX but Tesla or Boring or Hyperloop...

Let' get some perspective.

The really big factor is that the incentive structure is entirely different for the companies developing spaceflight technology on their own dime.  Such companies, SpaceX, Blue Origin, Rocket Lab, OneSpace, and others are primarily developing this technology with private capital.  Thus, they face a variety of standard choice metrics that face companies that endeavor to develop new technology that will eventually sustainably pay for itself.  They are principally driven by economic incentives, just like companies that make new cars or new marine vessels.

The legacy model for spaceflight tech development had been for a few nation states to pursue spaceflight technology, originally for exclusively geopolitical interests.  Later, although there were commercial applications (commsats in the Clarke Belt), the launch vehicle technology used was all originally developed by nation states.  Heck, in the first five decades that humans have possessed the technology of spaceflight, only six nation states had ever got any object to orbit.  In all of those government space technology dev programs, program funding and program decision making are primarily driven by political incentives

Change the incentive structure, and one can get entirely different results.  SpaceX put the first object into orbit on a privately funded launch vehicle in 2008, right at the end of that fifth decade of humans possessing spaceflight tech.  Now in 2018, at the end of the sixth decade, that one company facing these different incentives has made reusable booster technology a real thing, and reduced the price of space launch services sufficiently to be already eating the commercial market (https://en.wikipedia.org/wiki/Space_launch_market_competition#2010s:_Competition_and_pricing_pressure). 

And they are not stopping there.  The next generation launch vehicle technology based on a methalox engine development program started in 2012 and a large vehicle program (https://en.wikipedia.org/wiki/BFR_(rocket)) unveiled a few years later is still aiming for program objectives that no nation state is even contemplating for their government programs:  fully and rapidly reusable vehicles at a price point well below existing lowest-price Falcon 9 orbital payload technology.  The first article test vehicle--Starship hopper--for low-altitude testing is now complete in its vehicle structure, for tests within months in early 2019 (notably, on approx. the schedule that would be required to support the program aspirational dates unveiled in 2016 and 2017).  When both Starship and Super Heavy are put together, with the requisite ground infrastructure advancements to support faster launch and land turnaround, SpaceX is aiming for an announced marginal cost on launch that is a small fraction of their already world-beating tech. 

Will they succeed?  We don't know. 

This is standard entrepreneurial development of the private sector.  One invests resources to develop technological ideas and concepts,  If successful, growth and profit follow; if not, the entrepreneur discovers that the business idea is unsustainable and it is shut down. 

But these economic incentives are driving entirely different behavior over the political incentives we are used to in the "space sector" of the economy, and that is the fundamental difference that will deliver the very different results we see in the 2010s.

And we get to watch!   8)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/11/2019 01:03 pm
I wonder if the four portholes and four associated power lines are for four blowers that are there for nothing more than to provide slight positive pressure to the foil n frame for the photo op, which was taken of the opposite side. That would make sense to me.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/11/2019 01:48 pm

Multiple companies and NASA itself were working on developing technologies SpaceX almost perfected

If not SpaceX then someone else would succeed. Perhaps not as cheap or quick but eventually would get there

What made Musk to be stand out is that he showed that what is physically possible could be made cheap enough to be economically viable. Just have to think deep and long enough.

Not only in SpaceX but Tesla or Boring or Hyperloop...

Let' get some perspective.

The really big factor is that the incentive structure is entirely different for the companies developing spaceflight technology on their own dime.  Such companies, SpaceX, Blue Origin, Rocket Lab, OneSpace, and others are primarily developing this technology with private capital.  Thus, they face a variety of standard choice metrics that face companies that endeavor to develop new technology that will eventually sustainably pay for itself.  They are principally driven by economic incentives, just like companies that make new cars or new marine vessels.

The legacy model for spaceflight tech development had been for a few nation states to pursue spaceflight technology, originally for exclusively geopolitical interests.  Later, although there were commercial applications (commsats in the Clarke Belt), the launch vehicle technology used was all originally developed by nation states.  Heck, in the first five decades that humans have possessed the technology of spaceflight, only six nation states had ever got any object to orbit.  In all of those government space technology dev programs, program funding and program decision making are primarily driven by political incentives

Change the incentive structure, and one can get entirely different results.  SpaceX put the first object into orbit on a privately funded launch vehicle in 2008, right at the end of that fifth decade of humans possessing spaceflight tech.  Now in 2018, at the end of the sixth decade, that one company facing these different incentives has made reusable booster technology a real thing, and reduced the price of space launch services sufficiently to be already eating the commercial market (https://en.wikipedia.org/wiki/Space_launch_market_competition#2010s:_Competition_and_pricing_pressure). 

And they are not stopping there.  The next generation launch vehicle technology based on a methalox engine development program started in 2012 and a large vehicle program (https://en.wikipedia.org/wiki/BFR_(rocket)) unveiled a few years later is still aiming for program objectives that no nation state is even contemplating for their government programs:  fully and rapidly reusable vehicles at a price point well below existing lowest-price Falcon 9 orbital payload technology.  The first article test vehicle--Starship hopper--for low-altitude testing is now complete in its vehicle structure, for tests within months in early 2019 (notably, on approx. the schedule that would be required to support the program aspirational dates unveiled in 2016 and 2017).  When both Starship and Super Heavy are put together, with the requisite ground infrastructure advancements to support faster launch and land turnaround, SpaceX is aiming for an announced marginal cost on launch that is a small fraction of their already world-beating tech. 

Will they succeed?  We don't know. 

This is standard entrepreneurial development of the private sector.  One invests resources to develop technological ideas and concepts,  If successful, growth and profit follow; if not, the entrepreneur discovers that the business idea is unsustainable and it is shut down. 

But these economic incentives are driving entirely different behavior over the political incentives we are used to in the "space sector" of the economy, and that is the fundamental difference that will deliver the very different results we see in the 2010s.

And we get to watch!   8)

I would agree, but I think there is also another factor at work with SpaceX and possible some of the other private companies that has not been seen previously. And that is what you might call a personal vision incentive. Musk realy wants to get to Mars as he sees it as the destiny of mankind and wants to make humanity a multiplanetary secies. When he says that he realy means it. It's his equivalent of climbing Mount Everest and would be a lifetimes achievement.

Reaching this goal is what drives Musk rather than money. Although he sees money as a vitaly important means, its only a means to the ultimate end of getting to Mars and establishing a human prescence there not an end in its own right as it appears to be to many rich people.

Without this personal incentive I don't think SpaceX would exist. As Musk himself said he thought the chances of making a success of SpaceX were low, but that it was worth the try as no one else was doing it. Not the thought processs you would expect from a multi millionare wanting to expand his fortune.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Llian Rhydderch on 01/11/2019 02:03 pm

The really big factor is that the incentive structure is entirely different for the companies developing spaceflight technology on their own dime.  Such companies, SpaceX, Blue Origin, Rocket Lab, OneSpace, and others are primarily developing this technology with private capital.  Thus, they face a variety of standard choice metrics that face companies that endeavor to develop new technology that will eventually sustainably pay for itself.  They are principally driven by economic incentives, just like companies that make new cars or new marine vessels.


I would agree, but I think there is also another factor at work with SpaceX and possible some of the other private companies that has not been seen previously. And that is what you might call a personal vision incentive. Musk realy wants to get to Mars as he sees it as the destiny of mankind and wants to make humanity a multiplanetary secies. When he says that he realy means it. It's his equivalent of climbing Mount Everest and would be a lifetimes achievement.


Exactly.  And that "personal vision incentive" is just another example of an economic incentive (one of choice by the actor who  can take action).  "Economic incentive" does not mean a financial only incentive, or a return on investment incentive.  The study of economics is the study of human choice, and it's consequences.  Oftentimes, the unintended consequences (like the price system and market prices) are the most important; but so are all factors that humans consider in making choice.  And material, or monetary/pecuniary returns, are always only a part of the calculus that good economists study when they study economic incentives.

The point is that these sorts of incentives are very different than the political incentives that have primarily driven government space programs for many many decades.

So your are supporting my point:  economic incentives bring about entirely different actions and outcomes than political incentives of thr traditional government space programs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/11/2019 02:19 pm
Plus, Musk is a unique individual.

A lot of what SpaceX does right is because of this.  Few people have the ability to think as freely as he does, but also lead and manage large real projects and bring them to fruition.

That, plus the grand Mars vision, makes him probably unique from a historical perspective.

Add to that a bunch of early good hires, and the ability to fire bad ones, and there you have it.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/11/2019 02:28 pm
 I keep hearing various estimates for size of 120-130 feet or so, but I'm pretty sure the peak of that tent is almost exactly 50 feet, and when I measure a long shot to eliminate perspective, I'm getting close to 150 feet for this beast, about 14' of it being legs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/11/2019 02:48 pm
I keep hearing various estimates for size of 120-130 feet or so, but I'm pretty sure the peak of that tent is almost exactly 50 feet, and when I measure a long shot to eliminate perspective, I'm getting close to 150 feet for this beast, about 14' of it being legs.
Is there work still going on there? Recent photos don’t seem to show much going on, but that could be misleading.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: WindyCity on 01/11/2019 02:56 pm
What SpaceX is trying to achieve is still very risky as a business. If you can go to orbit for cheaper and even can go to Mars you still need somebody to pay you for delivering their payloads, and lots of them. With StarLink (if it should materialize) SpaceX will be at least its own customer for quite a lot of LEO launches, but the EXISTING market for LEO (or even Mars) launches is quite limited.
To use a baseball analogy, "Build it and they will come." SpaceX are risking that their efficient launch technology will stimulate a wave of non-traditional customers whose business proposals have been made feasible by SpaceX's relatively low prices.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Eric Hedman on 01/11/2019 02:58 pm
Some nice pictures in this article:

https://www.marketwatch.com/story/elon-musk-shows-off-spacexs-massive-starship-test-rocket-2019-01-10 (https://www.marketwatch.com/story/elon-musk-shows-off-spacexs-massive-starship-test-rocket-2019-01-10)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: WindyCity on 01/11/2019 03:12 pm
Plus, Musk is a unique individual.

A lot of what SpaceX does right is because of this.  Few people have the ability to think as freely as he does, but also lead and manage large real projects and bring them to fruition.

That, plus the grand Mars vision, makes him probably unique from a historical perspective.

Add to that a bunch of early good hires, and the ability to fire bad ones, and there you have it.
From all that I've read about our real-life D.D. Harriman/Tony Stark, he believes that if the laws of physics don't preclude the existence of a technology, then he refuses to back off when conventional thinkers tell him it can't be done. Door handles flush to the body that pop out when you walk up to the car? Make it so! Reusable rocket boosters? Just do it! If it's not impossible, it's, well, possible. His motto is, "Never say never." He's also a hard-a$$.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: PaulVla on 01/11/2019 03:15 pm
In December 2017 I got to visit the Hawthorne factory, I'm by no means willing (or able) to provide you with any technical details of semi-assembled Merlin engines but I can tell a thing or two about the atmosphere in the company and why I believe SpaceX is able to hire some of the business' brightest but also why they are willing to work day and night for a paycheck which could be much higher in different companies.

The place is littered with past successes and what is too large or dangerous to suspend from the ceiling or walls like trophies can be seen from screens all over the place, replaying launches/landings of Falcon 9 and or showing teasers/renders of Falcon Heavy/BFR. Some of the workplaces are in between the assembly stations of the engines themselves!

I can not imagine anyone sitting behind a desk and not be intrinsically motivated and pumped.
It felt almost like a religion and the place where they are working towards is heavenly Mars.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/11/2019 03:31 pm
I keep hearing various estimates for size of 120-130 feet or so, but I'm pretty sure the peak of that tent is almost exactly 50 feet, and when I measure a long shot to eliminate perspective, I'm getting close to 150 feet for this beast, about 14' of it being legs.

I'm all over the place with estimates from 107'-164'
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: uhuznaa on 01/11/2019 03:32 pm
What SpaceX is trying to achieve is still very risky as a business. If you can go to orbit for cheaper and even can go to Mars you still need somebody to pay you for delivering their payloads, and lots of them. With StarLink (if it should materialize) SpaceX will be at least its own customer for quite a lot of LEO launches, but the EXISTING market for LEO (or even Mars) launches is quite limited.
To use a baseball analogy, "Build it and they will come." SpaceX are risking that their efficient launch technology will stimulate a wave of non-traditional customers whose business proposals have been made feasible by SpaceX's relatively low prices.

Yes, but it's still a matter of faith. "Build it and they will come" normally is something that makes you run away when you read it in a business plan. It's a vision and it's a high risk, not something you can really rely on in any way. Nothing wrong with that of course, but traditional businesses wouldn't do things this way, SpaceX is totally unique in this regard.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RonM on 01/11/2019 03:37 pm
Considering the apparently simple construction of the new BFR (stainless steel, methalox as propellant), would it be possible to build and operate it back in the 60s? Replace Raptor with a gas generator if needed, payload mass should still be acceptable. Would there be any technological showstopper (vertical landing maybe)?

Just wondering if this thing pans out, whether we have lost half a century chasing technological ghosts..

Don't think so
All this was made possible by advancement in electronics and software

Could have been done in the 1990s. See DC-X testing. Problem back then was people wanted SSTO, a difficult thing to do. SpaceX is getting it right by using two stages. So, we could have done this 20 years ago.

Elon Musk's greatest talent is revisiting old ideas and figuring out which ones will work today.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/11/2019 03:51 pm
Elon Musk's greatest talent is revisiting old ideas and figuring out which ones will work today.

Theoretically, anyway.  EDL on this thing is going to be some interesting engineering.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RDMM2081 on 01/11/2019 04:13 pm
One of the least interesting parts of this build I'm sure, but the SpaceX sticker'd RV present on the 9th in the first photo by BCG in this post:

It has moved again. Looks like a perfect fit.

Is no longer seen in yesterdays photo of the tent/building/structure:


Roger Holt @RogerLewisHolt
 The Join is complete , no crane! @John_Gardi @Avron_p @JaneidyEve @DrPhiltill @austinbarnard45
:📷Tyler Thomas Rasmussen
2:40 AM - Jan 10, 2019

twitter.com/RogerLewisHolt/status/1083267259785719810

I'm sure it's all quite uninteresting compared to the mighty SS standing tall and complete*, but it could also mean something about the continuing pace of work on this test article.

Or they just need to go dump the tanks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rocambole on 01/11/2019 04:17 pm
Plus, Musk is a unique individual.

A lot of what SpaceX does right is because of this.  Few people have the ability to think as freely as he does, but also lead and manage large real projects and bring them to fruition.

That, plus the grand Mars vision, makes him probably unique from a historical perspective.

Add to that a bunch of early good hires, and the ability to fire bad ones, and there you have it.
From all that I've read about our real-life D.D. Harriman/Tony Stark, he believes that if the laws of physics don't preclude the existence of a technology, then he refuses to back off when conventional thinkers tell him it can't be done. Door handles flush to the body that pop out when you walk up to the car? Make it so! Reusable rocket boosters? Just do it! If it's not impossible, it's, well, possible. His motto is, "Never say never." He's also a hard-a$$.

I think of him more as Tom Swift (combination of Junior and Senior). He's got his Rocket Ship (Starship):
http://www.tomswift.info/homepage/rocket2.html

his Electric Runabout (Tesla):
http://tomswift.net/ts1.htm#5

and his soon to be Giant Tunnel (Boring Company):
http://tomswift.net/ts1.htm#19

For those not familiar with Tom Swift - here are some of his various incarnations over the years:
http://tomswift.net/index.html


or perhaps he is the Brains behind International Rescue from "Thunderbirds" (Thai cave rescue):
http://thunderbirds.wikia.com/wiki/Brains

and their Mole (Boring Company's Godot, Line-Storm, and soon Prufrock):
http://thunderbirds.wikia.com/wiki/The_Mole

and even Thunderbird 2 (Starship/Super Heavy for point to point transportation of cargo/personnel):
http://thunderbirds.wikia.com/wiki/Thunderbird_2
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: birdman on 01/11/2019 04:35 pm
or perhaps he is the Brains behind International Rescue from "Thunderbirds" (Thai cave rescue):
http://thunderbirds.wikia.com/wiki/Brains

I'm as much of an Elon lover as the next guy, and this is getting offtopic, but let's not pretend he did much of substance there. He was developing a backup plan, which is cool, luckily it wasn't needed. But he also went and called someone a pedo for no reason just because he criticized Musk's submarine.

Back to the BFH, man that picture he posted is beautiful. I think it's almost poetic that the first mock-up, if you will, finished (I know it's not close to flight readiness yet but it looks the part at least) on the same day that F9 completed its biggest order ever so far, Iridium. It could be argued that Iridum and Desch really kickstarted the program with half a billion and a lot of faith in 2008.


Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: freddo411 on 01/11/2019 04:58 pm
Elon Musk's greatest talent is revisiting old ideas and figuring out which ones will work today.

Theoretically, anyway.  EDL on this thing is going to be some interesting engineering.

It's a certain kind of brilliance to use existing tech in a new recipe to make a reliable, efficient service.

BFR appears to be pushing well beyond existing tech in the reentry area.   Other than that, it looks to be well grounded in existing experience base of rocketry.   
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: joncz on 01/11/2019 05:47 pm
I wonder if the four portholes and four associated power lines are for four blowers that are there for nothing more than to provide slight positive pressure to the foil n frame for the photo op, which was taken of the opposite side. That would make sense to me.

So... BouncyCastle reborn?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wargrim on 01/11/2019 06:13 pm
Some of the latest post are veering more into a "General Elon Discussion" - direction, but i think there is a lot of interesting Hopper stuff still to be talked on.

Like, i think in the latest Teslarati article it was claimed that they already weldes metal strips over the seam between "Water Tower" and "Tinfoil Hat" sections. Do we have a zoomed in picture of that area? Is the Hopper definitely not coming apart one more time? Elon calling the assembly finished certainly supports the idea that it stays as one piece. (RUDs excuded of course.)

Speaking of assembly finished, what does this really mean? Wiring and sensors and such all done? I somewhat doubt that, cause Elon confirmed legs will get some sort of shock absorbers, Frankenraptors will still need to be switched out, so it looks like some more interior work to be done.

And what about the mystery half dome? Bottom drop in? Not even part of the Hopper? Is it a part of an GSE element?

What can we expect to see in the near future before production Raptors arrive? Tanking tests? What would be necessary preparation steps, apart from building some sort of launch pad, that we could possibly see happening outside of the hull?

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/11/2019 06:18 pm
I can’t recall where it was posted but the photo in Musk’s tweet has no cranes but someone in a SpaceX spacesuit.
So yeah, it’s Photoshopped
It is not clear how that’s any more incredible than the real photos above and in L2.
The future IS so bright we have to wear shades. 😎
And it’s here now.

You mean this image? Why would you say it's Photoshopped? Musk could easily have shipped a suit there and told someone to put it on and stand around under the rocket for the photo.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rsdavis9 on 01/11/2019 06:21 pm
Some of the latest post are veering more into a "General Elon Discussion" - direction, but i think there is a lot of interesting Hopper stuff still to be talked on.

Like, i think in the latest Teslarati article it was claimed that they already weldes metal strips over the seam between "Water Tower" and "Tinfoil Hat" sections. Do we have a zoomed in picture of that area? Is the Hopper definitely not coming apart one more time? Elon calling the assembly finished certainly supports the idea that it stays as one piece. (RUDs excuded of course.)

Speaking of assembly finished, what does this really mean? Wiring and sensors and such all done? I somewhat doubt that, cause Elon confirmed legs will get some sort of shock absorbers, Frankenraptors will still need to be switched out, so it looks like some more interior work to be done.

And what about the mystery half dome? Bottom drop in? Not even part of the Hopper? Is it a part of an GSE element?

What can we expect to see in the near future before production Raptors arrive? Tanking tests? What would be necessary preparation steps, apart from building some sort of launch pad, that we could possibly see happening outside of the hull?

I think the outer hull is complete and therefore a "dry" environment to work in.
Now comes the real work of putting the guts in.
Sort of like how a house is constructed.
Also hides details of what they put in.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Eric Hedman on 01/11/2019 06:25 pm
Best image I found:

(https://pbs.twimg.com/media/DwmagBZX4AEbUN-.jpg)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: burger on 01/11/2019 06:55 pm
And what about the mystery half dome? Bottom drop in? Not even part of the Hopper? Is it a part of an GSE element?


Not sure of the source, but I read that someone had talked to one of the welders and they said it was for a deluge tank... So an actual water tower this time. No idea how reliable that statement is but would be pretty hilarious.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: calapine on 01/11/2019 06:55 pm
Sorry if I missed the explanation anywhere, but what is the reason for the "foil" tacked onto the structure?

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: WindyCity on 01/11/2019 06:56 pm
Best image I found:

(https://pbs.twimg.com/media/DwmagBZX4AEbUN-.jpg)
That thang's dang dog gone big, ain't it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/11/2019 07:10 pm
Sorry if I missed the explanation anywhere, but what is the reason for the "foil" tacked onto the structure?

To give it a more pleasing and uniform appearance, which is also closer to the look of the final Starship? (minus wrinkles)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mme on 01/11/2019 07:12 pm
Sorry if I missed the explanation anywhere, but what is the reason for the "foil" tacked onto the structure?

To give it a more pleasing and uniform appearance, which is also closer to the look of the final Starship? (minus wrinkles)
That's my theory too. Musk wants people excited about spaceflight and this beast is able to give people a sense of scale for the endeavor for almost no cost (in the scheme of things) by making the test mule look similar to the intended spacecraft.

Some people will find that frivolous.  Those people are no fun at parties. ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cheapchips on 01/11/2019 07:15 pm
Sorry if I missed the explanation anywhere, but what is the reason for the "foil" tacked onto the structure?

It's so it looks good in photos and closer to the final Starship. Elon is fickle about presentation.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/11/2019 07:23 pm
Sorry if I missed the explanation anywhere, but what is the reason for the "foil" tacked onto the structure?

It's always funny to see expressions like "foil tacked on to the structure", because they evidence the problem for all of us who haven't seen the BFH in person. We just cannot really comprehend how big it is. That is not "foil" but huge steel plates! Yet, they look like foil at this scale...

Regarding "economic incentives": it might be a specific term supposedly encompassing a lot of other incentives, but in the case of Musk it just sounds wrong. His incentives are anything but economy-driven. As they say, "if you want to become a millionaire in the space launch business... you just start as a billionaire."

Musk is a visionary and has repeatedly stated that all his money-making ventures serve one purpose only: to establish a sustainable human presence on Mars.   
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: agusaf on 01/11/2019 07:28 pm
I'm scratching my head at this hopper.  First, for a hopper, why are there no feet, and why does it look like its embedded into the concrete base?  Second, I find it odd this flight hardware was built in the open air, next to a sandy beach with expensive, high performance rocket engines exposed to the elements.  Could it be a mock-up perhaps? 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OnWithTheShow on 01/11/2019 07:30 pm
Are the cryo tanks that had previously arrived to Boca Chica still accounted for? Could they have gone into the structure early on unnoticed?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/11/2019 07:33 pm
I'm scratching my head at this hopper.  First, for a hopper, why are there no feet, and why does it look like its embedded into the concrete base?  Second, I find it odd this flight hardware was built in the open air, next to a sandy beach with expensive, high performance rocket engines exposed to the elements.  Could it be a mock-up perhaps?

Doesn't have flight engines installed yet.  All indications are that this is not a mock-up but an actual test article.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: groundbound on 01/11/2019 07:46 pm
I'm scratching my head at this hopper.  First, for a hopper, why are there no feet, and why does it look like its embedded into the concrete base?  Second, I find it odd this flight hardware was built in the open air, next to a sandy beach with expensive, high performance rocket engines exposed to the elements.  Could it be a mock-up perhaps?

Musk has stated quite clearly otherwise in his tweets on more than one occasion. It is difficult to come up with a sensible motivation for him to be lying about this.

OTOH it is not going to orbit or anywhere near the Karman line. That has been stated as well.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/11/2019 08:01 pm
I'm scratching my head at this hopper.  First, for a hopper, why are there no feet, and why does it look like its embedded into the concrete base?  Second, I find it odd this flight hardware was built in the open air, next to a sandy beach with expensive, high performance rocket engines exposed to the elements.  Could it be a mock-up perhaps?

First of all, it is not complete. The real engines will be installed next month(?), and the feet will have shock absorbers installed:

https://twitter.com/elonmusk/status/1083571038619922432

Quote
@Erdayastronaut Will there be some kind of shock absorbers installed on the feet of the landing legs?
@elonmusk Yes
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/11/2019 08:13 pm
I keep hearing various estimates for size of 120-130 feet or so, but I'm pretty sure the peak of that tent is almost exactly 50 feet, and when I measure a long shot to eliminate perspective, I'm getting close to 150 feet for this beast, about 14' of it being legs.
So it seems to me that you are measuring overall height as ground to tip and they're measuring rocket body base to tip only, neglecting that 14 feet.  Which one might have a tendency to do if their corporate background was F9 where the length of the vehicle is base of rocket body to tip and the legs come along later and raise that base a bit higher after the official measurement is done.  That still doesn't get the numbers into perfect alignment but close enough that a 'conversational numbers' exemption may cover the difference.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nehkara on 01/11/2019 08:29 pm
I'm scratching my head at this hopper.  First, for a hopper, why are there no feet, and why does it look like its embedded into the concrete base?  Second, I find it odd this flight hardware was built in the open air, next to a sandy beach with expensive, high performance rocket engines exposed to the elements.  Could it be a mock-up perhaps?

It's not embedded in a concrete base.

It only has placeholder engines right now, flight engines going in later.

They will be adding shock absorbing feet to it.

Elon has stated repeatedly that this vehicle is a suborbital hopper.  From the filings it sounds like 5 km max altitude.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/11/2019 08:34 pm
I'm scratching my head at this hopper.  First, for a hopper, why are there no feet, and why does it look like its embedded into the concrete base?  Second, I find it odd this flight hardware was built in the open air, next to a sandy beach with expensive, high performance rocket engines exposed to the elements.  Could it be a mock-up perhaps?

It's absolutely not an undoctored photograph.  There is no pad where the BFH stands now.  The feet have not been put on.  They took a picture of BFH where it stands currently, photoshopped the OML onto some "pad photo" and probably photoshopped that composite onto a background with the Dishes in the distance.  And they chopped in an astronaut
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/11/2019 08:37 pm
I keep hearing various estimates for size of 120-130 feet or so, but I'm pretty sure the peak of that tent is almost exactly 50 feet, and when I measure a long shot to eliminate perspective, I'm getting close to 150 feet for this beast, about 14' of it being legs.
So it seems to me that you are measuring overall height as ground to tip and they're measuring rocket body base to tip only, neglecting that 14 feet.  Which one might have a tendency to do if their corporate background was F9 where the length of the vehicle is base of rocket body to tip and the legs come along later and raise that base a bit higher after the official measurement is done.  That still doesn't get the numbers into perfect alignment but close enough that a 'conversational numbers' exemption may cover the difference.

I've been following estimations closely.  Usually they include the heigh of the concrete base/legs.  Estimates have been all over the place.  Early today I had 107 feet.

Just now based on an L2 photo from Nomadd, I'm closer to 140 feet which fits close with Nomadd's estimate.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nehkara on 01/11/2019 08:43 pm
I'm scratching my head at this hopper.  First, for a hopper, why are there no feet, and why does it look like its embedded into the concrete base?  Second, I find it odd this flight hardware was built in the open air, next to a sandy beach with expensive, high performance rocket engines exposed to the elements.  Could it be a mock-up perhaps?

It's absolutely not an undoctored photograph.  There is no pad where the BFH stands now.  The feet have not been put on.  They took a picture of BFH where it stands currently, photoshopped the OML onto some "pad photo" and probably photoshopped that composite onto a background with the Dishes in the distance.  And they chopped in an astronaut

This is incorrect, at least to a degree.

There IS a concrete pad where it stands now:

(https://i.imgur.com/Ewhcxe4.jpg)

Nomadd mentioned they took down the fence for the picture so it was a picture where the hopper is standing.  The background is not photoshopped in.

I don't know if they photoshopped in the spacesuit or whether they actually got one out there for the picture.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wargrim on 01/11/2019 08:44 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in. If that is true, then i doubt they welded strips over the seam. So someone is wrong here.

I think imagination is not just running wild here, but everywhere where people are following the construction of this huge shiny thing. :D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/11/2019 09:03 pm
It's absolutely not an undoctored photograph.  There is no pad where the BFH stands now.
This is incorrect, at least to a degree.  There IS a concrete pad where it stands now.
out there for the picture.

*** sigh ***   .... There is no "pad in the picture" where BFH stands now ... the pad that the scratchee's conjectured BFH Legs would've been embedded in.

I think the background is a separate photo onto which the "circular-ish pristine" pad, astronaut, and BFH were shopped onto.  I just don't see how you take a picture and get that crisp close background where they would've had to have taken the photo.  It generally lines up except the concrete area looks nothing like that, there's no gravel skirt, there's equipment everywhere, and the landscaping is much farther away.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/11/2019 09:09 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in. If that is true, then i doubt they welded strips over the seam. So someone is wrong here.

I think imagination is not just running wild here, but everywhere where people are following the construction of this huge shiny thing. :D
The cover strips (and the shiny sheeting also for that matter) are just tack welded on.  Quickly removable and replaceable.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/11/2019 09:11 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in. If that is true, then i doubt they welded strips over the seam. So someone is wrong here.

I think imagination is not just running wild here, but everywhere where people are following the construction of this huge shiny thing. :D

Awesome. That explains the last missing piece of the puzzle.  Hopper comes apart. Bulkheads get welded into the lower tank section, forming two small tanks. Rocket stays apart to complete plumbing, engines, and fitting out misc. flight hardware and instrumentation.  Rocket put back together. Finishing work is then completed.  Shock absorbers can be either before or after reassembly.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/11/2019 09:12 pm
The cover strips (and the shiny sheeting also for that matter) are just tack welded on.  Quickly removable and replaceable.

Yeah, I've been operating on the assumption that they're going to weld everything better together than tacks, both for the top and bottom portions.  Otherwise, there's this image in my head of sheet flying everywhere...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/11/2019 09:24 pm
It's absolutely not an undoctored photograph.  There is no pad where the BFH stands now.
This is incorrect, at least to a degree.  There IS a concrete pad where it stands now.
out there for the picture.

*** sigh ***   .... There is no "pad in the picture" where BFH stands now ... the pad that the scratchee's conjectured BFH Legs would've been embedded in.
"Pad" just means a slab of concrete around here, which there is.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/11/2019 09:27 pm
 I just used the supremely accurate method of backing off the Caldwell trailer until a nickel at arm's length exactly covered the 8 foot wide end and measuring the dome at Jefferson's chin less than 4 nickels wide. I had to move around a little so couldn't get the whole setup in one picture.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/11/2019 09:32 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in. If that is true, then i doubt they welded strips over the seam. So someone is wrong here.

I think imagination is not just running wild here, but everywhere where people are following the construction of this huge shiny thing. :D

Awesome. That explains the last missing piece of the puzzle.  Hopper comes apart. Bulkheads get welded into the lower tank section, forming two small tanks. Rocket stays apart to complete plumbing, engines, and fitting out misc. flight hardware and instrumentation.  Rocket put back together. Finishing work is then completed.  Shock absorbers can be either before or after reassembly.

Two purposes then putting it together now a fit check &amp; photo opportunity.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MizaruSpaceXNut on 01/11/2019 09:34 pm
I just used the supremely accurate method of backing off the Caldwell trailer until a nickel at arm's length exactly covered the 8 foot wide end and measuring the dome at Jefferson's chin less than 4 nickels wide. I had to move around a little so couldn't get the whole setup in one picture.
Sounds like a crude method of measuring but actually is not.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/11/2019 09:41 pm
"Pad" just means a slab of concrete around here, which there is.

Understand.  But the requisite precondition for it being a meaningful distinction is the assumption anyone thought they were building it on bare ground after nearly a month of pictures showing just the opposite.  A nit in search of a gnat so to speak.  It was a relatively simple post that didn't require any such deconstruction.  Over and out on that tangent.   ;D
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OneSpeed on 01/11/2019 09:54 pm
I keep hearing various estimates for size of 120-130 feet or so, but I'm pretty sure the peak of that tent is almost exactly 50 feet, and when I measure a long shot to eliminate perspective, I'm getting close to 150 feet for this beast, about 14' of it being legs.

We have one truly orthographic rendering of the StarHopper already, from SpaceX. If the fuselage diameter is 9m, then the total height of the ship is 39.55m or 129.76'.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: WindyCity on 01/11/2019 09:56 pm
Hopper comes apart. Bulkheads get welded into the lower tank section, forming two small tanks. Rocket stays apart to complete plumbing, engines, and fitting out misc. flight hardware and instrumentation.

Wouldn't they then have to protect it from the elements while they install its innards? A tent or something to shield it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: KSHavre on 01/11/2019 09:59 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in. If that is true, then i doubt they welded strips over the seam. So someone is wrong here.

I think imagination is not just running wild here, but everywhere where people are following the construction of this huge shiny thing. :D

Awesome. That explains the last missing piece of the puzzle.  Hopper comes apart. Bulkheads get welded into the lower tank section, forming two small tanks. Rocket stays apart to complete plumbing, engines, and fitting out misc. flight hardware and instrumentation.  Rocket put back together. Finishing work is then completed.  Shock absorbers can be either before or after reassembly.

Two purposes then putting it together now a fit check &amp; photo opportunity.

And, possibly, easier to move to the pad before it all goes back together?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/11/2019 10:01 pm
Do we have any official graphics that give us a sense of how much taller the final Starship (e.g. all the extra propellant) will be?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/11/2019 10:04 pm
Hopper comes apart. Bulkheads get welded into the lower tank section, forming two small tanks. Rocket stays apart to complete plumbing, engines, and fitting out misc. flight hardware and instrumentation.

Wouldn't they then have to protect it from the elements while they install its innards? A tent or something to shield it?

Possibly. Nobody here knows their construction plans.  Perhaps they'll just raise the top bulkhead first, weld it in place, and then do all further lifts from the underside, with the crane's cables coming through the centre of the top bulkhead.  They could then keep the internals weathertight just by putting a temporary cover over the hole.   But who knows?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/11/2019 10:07 pm
I keep hearing various estimates for size of 120-130 feet or so, but I'm pretty sure the peak of that tent is almost exactly 50 feet, and when I measure a long shot to eliminate perspective, I'm getting close to 150 feet for this beast, about 14' of it being legs.

We have one truly orthographic rendering of the StarHopper already, from SpaceX. If the fuselage diameter is 9m, then the total height of the ship is 39.55m or 129.76'.

Doing that way, I'm getting 5 x 22 ratio, so 130' sounds right.
 (Just realized that 5 x 22 is it's size in fathoms)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: tea monster on 01/12/2019 09:57 am
I got a side-on picture of the hopper and loaded it into Blender's viewport to compare with my 3D model that I made. I've adjusted the proportions of the model to exactly match that of the picture of the real StarHopper.

The width of the airframe of the model is exactly to scale at 9 meters wide, which is what Elon has stated the width of the hopper's airframe is.  As the height of the model matches the height of the rocket in the picture,we should be able to get the height of the model and be pretty sure that it matches the height of the real vehicle.

Blender reports that the height of the model is 40.6 meters, which comes out at 133.2 feet from tip to tail.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Peter.Colin on 01/12/2019 10:58 am
Has anyone noticed that the three Raptors of the hopper are in-line with a fin, and at the dear moon presentation they where not?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: HVM on 01/12/2019 11:23 am
Has anyone noticed that the three Raptors of the hopper are in-line with a fin, and at the dear moon presentation they where not?

Moon-composite one had seven engines; all symmetrically placed compared to the fins, each fin had three engines in-line. Somebody skipped geometry classes?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Peter.Colin on 01/12/2019 02:19 pm
I said it wrong, sorry for the confusion  :-[   I meant: it seems that they where in line with a fin at dear moon, and now are not?

The engines seem to be equally far in this pic from the viewer, which means they are not in line of a fin,
and not according to your nice pic.

Edit: is see the render guys also noticed the difference
https://forum.nasaspaceflight.com/index.php?topic=47144.msg1899433#msg1899433




Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/12/2019 02:42 pm
 A little perspective. This is the first time I noticed a short water tank by the tent. It appeared overnight and I have no idea what it already had inside. I was also gone the 2nd half of December and they could have installed all kinds of things inside I never saw. Point being, that huge metal triangle where the upper part of the legs are attached doesn't look like it's going to allow anything big to be lowered in, and even the top dome would have to pretty much sit on top of the lower section unless that triangle comes out, which doesn't seem likely. Maybe if they raised the concrete base so they could take the weight off the legs or something.

 That was November 23. Seven weeks from that to this.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Llian Rhydderch on 01/12/2019 02:52 pm
A little perspective. This is the first time I noticed a short water tank by the tent. It appeared overnight and I have no idea what it already had inside.
 That was November 23. Seven weeks from that to this.

Yeah, more of shipyard construction techniques than traditional aerospace manufacturing techniques!

I saw a bunch of photos on L2 that I thought were yours, capturing the concrete form building and concrete pumping into the forms, one of them with the "Caldwell" (water tank construction company) crew equipment and logo in it.  Perhaps a couple of those, with dates, ought to be added to the public side photo history of this very public facing and unusual rocket build process; for context and completeness.  The dates of those activities is obviously a part of the history of this important (and humongous) test rocket:  the BFWT.  ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JAFO on 01/12/2019 03:46 pm
-thread drift-
WRT photographers being asked/told to move along by Space X security, I'm assuming you're on public land and not scaling fences, using drones, etc. My wife is a retired international photojournalist (one of the good ones) and often ran into that problem post 9/11 when a "spooky" aircraft would be parked in plain sight at a public airport, or even taking pictures of buildings in NYC and DC, and was occasionally threatened with arrest if she took a photo of the plane or building (how do you hide a building in downtown NYC?). I'm a card carrying Space Geek since the Gemini missions and I realize we all want to stay on the good side of Space X, but there are limits as to what they can ask you to do.

https://www.aclu.org/issues/free-speech/photographers-rights (https://www.aclu.org/issues/free-speech/photographers-rights)
/thread drift

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MikeAtkinson on 01/12/2019 04:58 pm
I saw an old tweet from Elon today, he must have been amused with the alternative reading:

https://twitter.com/elonmusk/status/1060282495541727234

Quote
No, we’re building a BFR dev ship to do supersonic through landing tests in Boca Chica, Texas

which could mean it is doing the tests in Boca Chica, or that it is being built in Boca Chica. Everyone seems to have assumed the first meaning.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Restless on 01/12/2019 05:13 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in. If that is true, then i doubt they welded strips over the seam. So someone is wrong here.

I think imagination is not just running wild here, but everywhere where people are following the construction of this huge shiny thing. :D

Awesome. That explains the last missing piece of the puzzle.  Hopper comes apart. Bulkheads get welded into the lower tank section, forming two small tanks. Rocket stays apart to complete plumbing, engines, and fitting out misc. flight hardware and instrumentation.  Rocket put back together. Finishing work is then completed.  Shock absorbers can be either before or after reassembly.

Ok, so Falcon 9's are assembled in climate-controlled ultra-clean buildings to assure reliability. So how is this hopper going to be finished out standing in the open in a marine environment during wet winter weather? Some possibilities are:

1. Rotate horizontal and place under an enclosed tent to finish out.
2. Prefabricate the Raptor propulsion unit complete with mini-fuel tanks, avionics, etc and insert up thru the tail. This would also require rotation to the horizontal.
3. Or what?   
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Joffan on 01/12/2019 05:51 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in. If that is true, then i doubt they welded strips over the seam. So someone is wrong here.

I think imagination is not just running wild here, but everywhere where people are following the construction of this huge shiny thing. :D

Awesome. That explains the last missing piece of the puzzle.  Hopper comes apart. Bulkheads get welded into the lower tank section, forming two small tanks. Rocket stays apart to complete plumbing, engines, and fitting out misc. flight hardware and instrumentation.  Rocket put back together. Finishing work is then completed.  Shock absorbers can be either before or after reassembly.

Ok, so Falcon 9's are assembled in climate-controlled ultra-clean buildings to assure reliability. So how is this hopper going to be finished out standing in the open in a marine environment during wet winter weather? Some possibilities are:

1. Rotate horizontal and place under an enclosed tent to finish out.
2. Prefabricate the Raptor propulsion unit complete with mini-fuel tanks, avionics, etc and insert up thru the tail. This would also require rotation to the horizontal.
3. Or what?   

My current thinking is that they will assemble innards in accordance with your #2, then put them on the concrete rotunda and lower the Hopper over them. And weld up.

There would also need to be a prior stage, possibly also a lift on/off the rotunda, where the existing fit-check innards are removed, which would be a chance to put in some structure higher up in the Hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/12/2019 05:53 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in. If that is true, then i doubt they welded strips over the seam. So someone is wrong here.

I think imagination is not just running wild here, but everywhere where people are following the construction of this huge shiny thing. :D

Awesome. That explains the last missing piece of the puzzle.  Hopper comes apart. Bulkheads get welded into the lower tank section, forming two small tanks. Rocket stays apart to complete plumbing, engines, and fitting out misc. flight hardware and instrumentation.  Rocket put back together. Finishing work is then completed.  Shock absorbers can be either before or after reassembly.

Ok, so Falcon 9's are assembled in climate-controlled ultra-clean buildings to assure reliability. So how is this hopper going to be finished out standing in the open in a marine environment during wet winter weather? Some possibilities are:

1. Rotate horizontal and place under an enclosed tent to finish out.
2. Prefabricate the Raptor propulsion unit complete with mini-fuel tanks, avionics, etc and insert up thru the tail. This would also require rotation to the horizontal.
3. Or what?   
Or perhaps rockets don't need to be assembled in climate-controlled ultra-clean buildings to assure reliability.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: adrianwyard on 01/12/2019 06:20 pm
My $0.02: What we've seen built out in the open so far is primarily a mockup aeroshell that is representative of the outer-mold line of the Starship vehicle.

I suspect early Starship (Raptor) VTVL tests *could* have been done with no aeroshell at all, just stand-in tanks on a thrust structure. BUT if it's quick and easy - and it clearly was - it's much better to test flying with representative aerodynamics. After all wind will be a factor in the final vehicles control systems (those fins are sails).

And of course it looks cool and gets people talking = free publicity and good will.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: KSHavre on 01/12/2019 06:21 pm
1. Rotate horizontal and place under an enclosed tent to finish out.
2. Prefabricate the Raptor propulsion unit complete with mini-fuel tanks, avionics, etc and insert up thru the tail. This would also require rotation to the horizontal.
3. Or what?   

I recall a SpaceX member saying that F9 engines/assemblies are easier to work on (repairs at Vandy?) when vertical rather than horizontal. SpaceX might be designing assemblies that take advantage of that learning and simply build the vehicle that way; rotation would not be required for #2.

EDIT: My take on #2:

A. Prefabricate and wrap the Raptor propulsion unit in hepta/septa web and avionics assemblies
B. Move the sub-assemblies into the WT base, and put the StarHopper bottom 1/3 back onto the base (the fuel tanks are already being assembled inside).
C. Seal and clean the 'room' inside concrete base.
D. Remove he wrapping and assemble the parts/pieces.
E. Lift and move the StarHopper bottom 1/3 (tanks with propulsion unit assembled) to the Pad.
F. Move the top 2/3 to the pad, and StarHopper final assembly.
G. Hop!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/12/2019 06:32 pm
 Why would the suppository method require horizontal rotation? Everything about that would be more difficult than vertical. If they need a climate controlled place to finish things up, once the upper dome is on they can just put the section back over the concrete base and skirt off the gap. As for middle or bottom bulkheads, which may or may not already be there, lifting the whole section onto them might sound like a joke, but it's 30 minutes with a crane.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: docmordrid on 01/12/2019 06:33 pm
1. Rotate horizontal and place under an enclosed tent to finish out.
2. Prefabricate the Raptor propulsion unit complete with mini-fuel tanks, avionics, etc and insert up thru the tail. This would also require rotation to the horizontal.
3. Or what?   

I recall a SpaceX member saying that F9 engines/assemblies are easier to work on (repairs at Vandy?) when vertical rather than horizontal. SpaceX might be designing assemblies that take advantage of that learning and simply build the vehicle that way; rotation would not be required for #2.

Yup. How would you rotate Starship to do repairs on Mars? You likely wouldn't, but may well design it for vertical repairs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/12/2019 06:34 pm
WRT photographers being asked/told to move along by Space X security, I'm assuming you're on public land and not scaling fences, using drones, etc. [...] I'm a card carrying Space Geek since the Gemini missions and I realize we all want to stay on the good side of Space X, but there are limits as to what they can ask you to do.

I don't think it is about pressing legal points. It is about avoiding that SpaceX starts putting up tarps and goes behind hangar doors. They are much more open than other aerospace companies and that should be treasured and respected.

Also, everybody who drives by out there is only doing it to have a look at what SpaceX is doing...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: IntoTheVoid on 01/12/2019 07:13 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in.
If anyone doubted that the hopper is coming apart again:
I just noticed in Nomadd's latest RaptorCam pic that they never put the 'foil' sheeting on the top root and tubular portion of the third leg (the leg with the flag directly above it). Since the foil at the top root extends well above the 'water tower' rim, leaving it off (for now) provides an area to swing the top in and out from without risking the much thinner metal.
This leg is the back leg in the official SpaceX pic.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/12/2019 08:08 pm
I'm scratching my head at this hopper.  First, for a hopper, why are there no feet, and why does it look like its embedded into the concrete base?  Second, I find it odd this flight hardware was built in the open air, next to a sandy beach with expensive, high performance rocket engines exposed to the elements.  Could it be a mock-up perhaps?

It's absolutely not an undoctored photograph.  There is no pad where the BFH stands now.  The feet have not been put on.  They took a picture of BFH where it stands currently, photoshopped the OML onto some "pad photo" and probably photoshopped that composite onto a background with the Dishes in the distance.  And they chopped in an astronaut

This is incorrect, at least to a degree.

Welp.  I need to eat some crow and in the interest of owning my mistakes, I need to offer you an apology as well as agusaf.  I was pretty aggressive in my interpretation based on all I thought I knew but subsequent pictures reveal the truth.

1)  They have poured placed something that looks like a new concrete slab where the BFH sits now.

2)  The "slab" seems to have been poured placed around the bottom of the fins which have them sitting on ground rather than "slab".

3)  With the area cleared and a better drone picture, it is obvious BFH, pad, and background are most very likely a single picture as all the angles and surroundings fit very well with the perspective.

4)  The Elon pic pad seems a little more pristine than the Drone pic pad so I suspect they tweaked the pic a bit in Photoshop.

5)  The Astronaut seems photoshopped in as he stands 8' 4" tall based on a pixel height vs. BFH diameter (relative to whatever perspective discrepancies skew that number slightly).


References:

Elon Pic: https://twitter.com/elonmusk/status/1083567087983964160/photo/1 (http://Elon Musk)
Drone Pic: https://twitter.com/RogerLewisHolt/status/1084179354190516227/photo/1 (http://@RogerLewisHolt)
bocachicagal foot Pic:  https://forum.nasaspaceflight.com/index.php?topic=47120.msg1900195#msg1900195
perspective pic from Raul's "Google Map":  https://www.google.com/maps/d/viewer?mid=1wvgFIPuOmI8da9EIB88tHo9vamo&hl=en_US&ll=25.989817746513534%2C-97.18293114278697&z=16


EDIT:  Crisped up some statments based on what is knowable.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: SgtPoivre on 01/12/2019 08:11 pm
Quote
Or perhaps rockets don't need to be assembled in climate-controlled ultra-clean buildings to assure reliability.
Rockets not necessarily. Liquid rocket's fluidic propulsion systems yes. Especially if they use liquid oxygen.

Edit/lar: Fixed this so it at least looks like a quote... but it is not properly attributed. In future please use the Quote function of the interface rather than doing it by hand.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Restless on 01/12/2019 08:27 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in. If that is true, then i doubt they welded strips over the seam. So someone is wrong here.

I think imagination is not just running wild here, but everywhere where people are following the construction of this huge shiny thing. :D



Awesome. That explains the last missing piece of the puzzle.  Hopper comes apart. Bulkheads get welded into the lower tank section, forming two small tanks. Rocket stays apart to complete plumbing, engines, and fitting out misc. flight hardware and instrumentation.  Rocket put back together. Finishing work is then completed.  Shock absorbers can be either before or after reassembly.

Ok, so Falcon 9's are assembled in climate-controlled ultra-clean buildings to assure reliability. So how is this hopper going to be finished out standing in the open in a marine environment during wet winter weather? Some possibilities are:

1. Rotate horizontal and place under an enclosed tent to finish out.
2. Prefabricate the Raptor propulsion unit complete with mini-fuel tanks, avionics, etc and insert up thru the tail. This would also require rotation to the horizontal.
3. Or what?   
Or perhaps rockets don't need to be assembled in climate-controlled ultra-clean buildings to assure reliability.

It's been said many times in these forums that space is REALLY, REALLY hard. But now the feeling seems to be that the hopper can be made flight-worthy quickly and easily out in the open in a marine environment in a month or two.
IMHO, this hopper will be no different than any other rocket-driven craft: it will be really, really hard, and first hop will be July 4th or later.
I will be happy to eat my words if I'm wrong; I'm just as excited about this as anyone!
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/12/2019 08:27 pm
5)  The Astronaut seems photoshopped in as he stands 8' 4" tall based on a pixel height vs. BFH diameter.

The astronaut is standing closer to the camera than the centerline of the Hopper, he is going to look bigger due to perspective.

Also, I thought we estimated the bottom of the Hopper to be about 13 feet off the ground? The astronaut is less than 1/2 that height, which would put him in the 6 foot range.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/12/2019 08:28 pm
It's been said many times in these forums that space is REALLY, REALLY hard. But now the feeling seems to be that the hopper can be made flight-worthy quickly and easily out in the open in a marine environment in a month or two.
IMHO, this hopper will be no different than any other rocket-driven craft: it will be really, really hard, and first hop will be July 4th or later.
I will be happy to eat my words if I'm wrong; I'm just as excited about this as anyone!

Space is hard, but the first hop is only going to be a meter or 2 and this thing is never going to get anywhere near space.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: archae86 on 01/12/2019 09:26 pm
1)  They have poured a new concrete slab where the BFH sits now.

2)  The slab seems to have been poured around the bottom of the fins which have them sitting on ground rather than slab.
Is it clear that surface is concrete?  On reviewing a January 8 bocachicagal photo in your post at full resolution, it seems to me there is evidence that the surface is made of hastily placed panels.  I think I see said panels buckling up a bit under the tires of the BlueLine Rental crane, and possibly a not yet used stack of said panels to the right of the crane in front of a pickup truck.  Something a little like "sheet rock', maybe just for cosmetic purposes?

[edited later to add: I'll leave my original post intact for humility's sake, but recognize here that AC in NC has convincingly argued that my panels and stack are a side issue likely related to crane operation, and that there is evidence of a recently poured slab edge--I'll go back to lurking)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: billh on 01/12/2019 09:33 pm
1)  They have poured a new concrete slab where the BFH sits now.

2)  The slab seems to have been poured around the bottom of the fins which have them sitting on ground rather than slab.
This is a detail from a photo BocaChicaGal took on Jan 8. (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1900195#msg1900195)

I agree it looks like the slab was poured around the feet. We no longer see the bottom of the foot, and there seems to be a bit of dirt piled up beside the foot. The hopper is sitting on the ground, not the slab.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/12/2019 09:34 pm
5)  The Astronaut seems photoshopped in as he stands 8' 4" tall based on a pixel height vs. BFH diameter.

The astronaut is standing closer to the camera than the centerline of the Hopper, he is going to look bigger due to perspective.

Also, I thought we estimated the bottom of the Hopper to be about 13 feet off the ground? The astronaut is less than 1/2 that height, which would put him in the 6 foot range.

Certainly that's some of it but it doesn't account for all.  If we're going to acknowledge the perspective on the astronaut, we also have to measure relative to an appropriate point on the pad relative to the bottom of the skirt.


Is it clear that surface is concrete?  On reviewing a January 8 bocachicagal photo in your post at full resolution, it seems to me there is evidence that the surface is made of hastily placed panels.  I think I see said panels buckling up a bit under the tires of the BlueLine Rental crane, and possibly a not yet used stack of said panels to the right of the crane in front of a pickup truck.  Something a little like "sheet rock', maybe just for cosmetic purposes?

I'm pretty sure the panels under the Orange machine are plywood from the stack to the right of the leg, not panels from the "pad".  The front right corner of the pad running off to the right looks like a poured edge to me but I suppose they could be pre-fab.  I thought Nomadd or someone though indicated they were pouring concrete.  The plywood panels suggest they aren't pre-fab though IMO.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/12/2019 10:16 pm
5)  The Astronaut seems photoshopped in as he stands 8' 4" tall based on a pixel height vs. BFH diameter.

The astronaut is standing closer to the camera than the centerline of the Hopper, he is going to look bigger due to perspective.

Also, I thought we estimated the bottom of the Hopper to be about 13 feet off the ground? The astronaut is less than 1/2 that height, which would put him in the 6 foot range.
I don't understand why there's always someone yelling Photoshop.

If SpaceX has a space suit that they're using to take shots off, why wouldn't they bring it to BC for the photoshoot?

And if they did Photoshop it, why make it over 8' tall?  To make the rocket look smaller?

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wargrim on 01/12/2019 10:17 pm
Austin Barnard reports a border guard said that the Hopper is coming apart again to get the tanks in.
If anyone doubted that the hopper is coming apart again:
I just noticed in Nomadd's latest RaptorCam pic that they never put the 'foil' sheeting on the top root and tubular portion of the third leg (the leg with the flag directly above it). Since the foil at the top root extends well above the 'water tower' rim, leaving it off (for now) provides an area to swing the top in and out from without risking the much thinner metal.
This leg is the back leg in the official SpaceX pic.

Jea, the latest drone shots also show the seam did not have metal strips welded over it. So the "hat" - section can still come down again if needed.

I also notice there is currently no scissor lift or work platform or anything under the Hopper. If anyone was currently working inside the hull, i would expect some access method to be visible. Seems that after the photo shooting, work is focussing on stuff outside the Hopper hull.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: pyromatter on 01/12/2019 10:44 pm
In regards to Starman

In this video by Maria Pointer you can see Starman

https://www.facebook.com/maria.pointer/videos/pcb.2065261196873808/2065255760207685/?type=3&theater&ifg=1
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/12/2019 11:05 pm
In this video by Maria Pointer you can see Starman

Perhaps.  Compelling place for a white sillouette but hard to say for sure.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Restless on 01/13/2019 12:24 am
It's been said many times in these forums that space is REALLY, REALLY hard. But now the feeling seems to be that the hopper can be made flight-worthy quickly and easily out in the open in a marine environment in a month or two.
IMHO, this hopper will be no different than any other rocket-driven craft: it will be really, really hard, and first hop will be July 4th or later.
I will be happy to eat my words if I'm wrong; I'm just as excited about this as anyone!

Space is hard, but the first hop is only going to be a meter or 2 and this thing is never going to get anywhere
near space.

I'm referring to that first meter or two.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Okie_Steve on 01/13/2019 12:36 am
So, did they pour slab around the legs leaving a small circle around each one for now? If so, I expect once it has cured enough they will lift it with a crane and rotate 60 degrees and then patch the holes. Let's them compress the time line while doing other stuff in parallel with concrete curing.

The real question I'm my mind is why have a slab THERE to begin with. Seems too close to other structures to fly off of.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/13/2019 12:42 am
Quiet day here. Just about everyone had a well deserved day off. A cold front moved in this afternoon.
That one might help settle the "picture, not a render" debate. The variations of this thing depending on the sky and angle are endless.
 (1st photo is bocachicagal's last post)

Thanks for that.
People here are too young to know what a disco ball is :)

In the video posted above, the suit (Starman's less famous brother) looks a lot sharper than in the extracted image, btw.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: QuantumG on 01/13/2019 02:47 am
Suborbital only, not surprising but y'all can stop speculating now.
That was never in question. The question was Karman Line or not (considering they're building the orbital version in June, I would suspect "not" but technically it might be capable of it).

Also said subsonic only, so no Karman line for you.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Scylla on 01/13/2019 03:00 am
Finally settled. New drone pictures show the pad under the hopper is prefab panels with squares cut out for the hopper feet.
https://forum.nasaspaceflight.com/index.php?topic=47070.msg1900561#msg1900561
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Swedish chef on 01/13/2019 03:53 am
Finally settled. New drone pictures show the pad under the hopper is prefab panels with squares cut out for the hopper feet.
https://forum.nasaspaceflight.com/index.php?topic=47070.msg1900561#msg1900561

Where there not some concrete trucks on the site a couple of days ago? If so it would be much easier to pour a slab than using precast concrete, especially placing these precast pieces under a rocket. The lines one could see in the slab is probably man made and is used to steer cracks in the concrete as it cures.

(I have only followed this part of the debate with one eye open so my apologies if I missed something pertinent)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Robotbeat on 01/13/2019 03:56 am
Suborbital only, not surprising but y'all can stop speculating now.
That was never in question. The question was Karman Line or not (considering they're building the orbital version in June, I would suspect "not" but technically it might be capable of it).

Also said subsonic only, so no Karman line for you.
Cite?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: catdlr on 01/13/2019 04:51 am
1)  They have poured a new concrete slab where the BFH sits now.

2)  The slab seems to have been poured around the bottom of the fins which have them sitting on ground rather than slab.
This is a detail from a photo BocaChicaGal took on Jan 8. (https://forum.nasaspaceflight.com/index.php?topic=47120.msg1900195#msg1900195)

I agree it looks like the slab was poured around the feet. We no longer see the bottom of the foot, and there seems to be a bit of dirt piled up beside the foot. The hopper is sitting on the ground, not the slab.

So this lower end of the landing foot both taken from a previous Elon's twitter post, seems to be an axle joint for the landing PAD?) and all of that leg components are under soil surrounded by the cement slab?

Reference of current condition (https://forum.nasaspaceflight.com/index.php?topic=47113.msg1900498#msg1900498)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AJW on 01/13/2019 05:54 am
So this lower end of the landing foot both taken from a previous Elon's twitter post, seems to be an axle joint for the landing PAD?) and all of that leg components are under soil surrounded by the cement slab?
Reference of current condition (https://forum.nasaspaceflight.com/index.php?topic=47113.msg1900498#msg1900498)

That wheel/axle was discussed when the photo was originally posted and consensus was that it belongs to one of the orange lifts in the photo.

(Added link)
https://www.gumtree.co.za/a-machinery-vehicles/east-london/cherry-pickers-and-scissor-lifts-for-hire/1001219162080910270106409
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: QuantumG on 01/13/2019 06:27 am
Also said subsonic only, so no Karman line for you.
Cite?

I probably conflated suborbital and subsonic, sorry. I was also thinking about the comment where he talked about keeping the tests simple as anything else would be too dangerous... and now I can't find that tweet.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/13/2019 06:45 am
So from the recent images from around the BFH construction site, and seemingly confirmed by the recent drone shots, the BFC is gone, as would also appear with the load spreader (tho that’s easier to shove someplace off screen).

Nomadd or BCGal, have you seen the BFC get broken back down and driven off? If it’s gone it would indicate the BFH isn’t moving any time soon. The light upper 2/3s of the hopper can be lifted by the boom cranes on site, but needs the BFC to pick up entire assembly. 

Summarize the newly poured concrete serves two purposes:

1) Setting proper visual for SpaceX beauty shot

2) It’s where the BFM will be parked (Big Falcon Mover) eventually for when the BFH is transported to the launch pad. &lt;- primary reason

Therefore, a signal the entire BFH stack, or even just the water tank base (aft section), will be moved will be when the BFC showed up (or if still on-site then when she lifts her huge head and spreads her wings (outrigger guys)) - cause the hopper ain’t moving without it...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Step55 on 01/13/2019 07:52 am
Finally settled. New drone pictures show the pad under the hopper is prefab panels with squares cut out for the hopper feet.
https://forum.nasaspaceflight.com/index.php?topic=47070.msg1900561#msg1900561

Those are cast-in-situ concrete with contraction joints.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: shuttlelegs on 01/13/2019 08:21 am
We all know this is no Rocket ?
Looks to me to be a water tank specially with those vent holes for over filling. And the shell appears to be stainless steel which makes it way to heavy with a wrapping of insulation foil .
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: CuddlyRocket on 01/13/2019 08:22 am
Quiet day here. Just about everyone had a well deserved day off. A cold front moved in this afternoon.

Have they stopped because of the weather or because they're ahead of schedule (or other people are behind) and they're having to wait or slow down for something else that needs to happen? If there's no point in going at full pace on the BFH then it's presumably financially wise to stop work at the weekends (I assume overtime is still more expensive on the weekends!). Time will tell.

Nomadd or BCGal, have you seen the BFC get broken back down and driven off? If it’s gone it would indicate the BFH isn’t moving any time soon. The light upper 2/3s of the hopper can be lifted by the boom cranes on site, but needs the BFC to pick up entire assembly.

Is the attachment point at the top of the BFH strong enough to bear the weight of the entire assembly?

In any event, there are other ways to pick up and move the BFH. People have speculated about using the skills of house movers, for example - which basically seems to mean jacking it up and moving a wheeled transporter underneath.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/13/2019 09:10 am



Have they stopped because of the weather or because they're ahead of schedule (or other people are behind) and they're having to wait or slow down for something else that needs to happen?

One hypothesis for the initial frantic pace was the rent cost for the heavy equipment. The crane is now gone, so that would not longer be a factor and a slower pace makes sense.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/13/2019 09:19 am



Have they stopped because of the weather or because they're ahead of schedule (or other people are behind) and they're having to wait or slow down for something else that needs to happen?

One hypothesis for the initial frantic pace was the rent cost for the heavy equipment. The crane is now gone, so that would not longer be a factor and a slower pace makes sense.

Ask yourself the question what would they be doing now if they were working fast? What would we expect to see different?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/13/2019 09:28 am
We all know this is no Rocket ?
Looks to me to be a water tank specially with those vent holes for over filling. And the shell appears to be stainless steel which makes it way to heavy with a wrapping of insulation foil .

How would you like your hat done, good Sir?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: shuttlelegs on 01/13/2019 10:17 am
Well done with sauce . The future will tell.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Axiom on 01/13/2019 11:10 am
Quiet day here. Just about everyone had a well deserved day off. A cold front moved in this afternoon.

Have they stopped because of the weather or because they're ahead of schedule (or other people are behind) and they're having to wait or slow down for something else that needs to happen? If there's no point in going at full pace on the BFH then it's presumably financially wise to stop work at the weekends (I assume overtime is still more expensive on the weekends!). Time will tell.

Nomadd or BCGal, have you seen the BFC get broken back down and driven off? If it’s gone it would indicate the BFH isn’t moving any time soon. The light upper 2/3s of the hopper can be lifted by the boom cranes on site, but needs the BFC to pick up entire assembly.

Is the attachment point at the top of the BFH strong enough to bear the weight of the entire assembly?

In any event, there are other ways to pick up and move the BFH. People have speculated about using the skills of house movers, for example - which basically seems to mean jacking it up and moving a wheeled transporter underneath.

Just another crazy idea that popped into my head, but could SpaceX purge/fill the SS with helium. How much lighter would it get? enough to move it with just a small crane? Anyone cares to do the calculation (I'm no rocket scientist:). There used to be metal-skin dirigibles back around 1900's.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/13/2019 11:33 am
Quiet day here. Just about everyone had a well deserved day off. A cold front moved in this afternoon.

Have they stopped because of the weather or because they're ahead of schedule (or other people are behind) and they're having to wait or slow down for something else that needs to happen? If there's no point in going at full pace on the BFH then it's presumably financially wise to stop work at the weekends (I assume overtime is still more expensive on the weekends!). Time will tell.

Nomadd or BCGal, have you seen the BFC get broken back down and driven off? If it’s gone it would indicate the BFH isn’t moving any time soon. The light upper 2/3s of the hopper can be lifted by the boom cranes on site, but needs the BFC to pick up entire assembly.

Is the attachment point at the top of the BFH strong enough to bear the weight of the entire assembly?

In any event, there are other ways to pick up and move the BFH. People have speculated about using the skills of house movers, for example - which basically seems to mean jacking it up and moving a wheeled transporter underneath.

Just another crazy idea that popped into my head, but could SpaceX purge/fill the SS with helium. How much lighter would it get? enough to move it with just a small crane? Anyone cares to do the calculation (I'm no rocket scientist:). There used to be metal-skin dirigibles back around 1900's.
BOTE: replacing the enclosed air with helium would save about 2 tonnes.
(assuming an enclosed volume of 2200 m^3).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Dappa on 01/13/2019 11:46 am

Just another crazy idea that popped into my head, but could SpaceX purge/fill the SS with helium. How much lighter would it get? enough to move it with just a small crane? Anyone cares to do the calculation (I'm no rocket scientist:). There used to be metal-skin dirigibles back around 1900's.
BOTE: replacing the enclosed air with helium would save about 2 tonnes.
(assuming an enclosed volume of 2200 m^3).
I got about the same result, my BOTE got me 1900kg.  If you're really that close to the load limit of a crane of this size, it might be better to just get a bigger crane.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wargrim on 01/13/2019 11:55 am
They still need to install the leg shock absorbers at some point. If i had to chose between doing that with the Hopper dangling from a crane, or with the Hopper jacked up on hydraulic stands, i would chose the hydraulic stands. And those would also benefit from a nice level concrete base.

[wishful thinking] Look at how fast that concrete base appeared, if only the launch/landing pad concrete was similarly fast... [/wishful thinking]
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/13/2019 12:59 pm



Have they stopped because of the weather or because they're ahead of schedule (or other people are behind) and they're having to wait or slow down for something else that needs to happen?

One hypothesis for the initial frantic pace was the rent cost for the heavy equipment. The crane is now gone, so that would not longer be a factor and a slower pace makes sense.

It occurs to me that many of the workers on the BFWT (BFH) were external contractors, not SX employees. There are several hypothetical reasons for such a rush and then a sudden stop.
0) A certain contracted point has been reached.
1) Fixed price work. If its was a fixed price, the team and company benefit by working all out, getting the job done quickly.
2) Rewards/penalties for finishing to a certain point by a certain date.
3) If the contractors are paying for the heavy crane etc... then reducing its hire time increases their bottom line.
4) The contractors have other projects they have also promised completion on, (and maybe they were prevailed upon to squeeze the SX job in over Christmas so other projects are now time-compromised)
5) Progress is now awaiting components and staff from SX, and the contractors have switched to another project until SX does their bit... possibly internal installations.
6) There is disagreement over quality controll and payment.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/13/2019 01:11 pm
They still need to install the leg shock absorbers at some point. If i had to chose between doing that with the Hopper dangling from a crane, or with the Hopper jacked up on hydraulic stands, i would chose the hydraulic stands. And those would also benefit from a nice level concrete base.

[wishful thinking] Look at how fast that concrete base appeared, if only the launch/landing pad concrete was similarly fast... [/wishful thinking]

As someone said the concrete base will enable lifting from below. IMO this will be an SPMT rig. (with spacers/jacks etc to lift the edge and protect the engine bells)
Maybe this could be set up, the BFH lifted, then left like that for a few days whilst the "feet etc" are fitted, before being driven to the launch pad.

However lifting with hydraulic jacks alone is also likely, without an SPMT. The engines need switching, but I assume the BFH has sufficient ground clearance that a lift is not needed for this.

SX may also be planning what equipment will be needed to routinely lift (and move) the Starship prototypes and final ships. So will we see a custom SPMT-like rig built/adapted as a BFH transporter. IMO yes, but maybe not yet.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/13/2019 03:08 pm
So from the recent images from around the BFH construction site, and seemingly confirmed by the recent drone shots, the BFC is gone, as would also appear with the load spreader (tho that’s easier to shove someplace off screen).

Nomadd or BCGal, have you seen the BFC get broken back down and driven off? If it’s gone it would indicate the BFH isn’t moving any time soon. The light upper 2/3s of the hopper can be lifted by the boom cranes on site, but needs the BFC to pick up entire assembly. 

They hauled off the main part, but the boom is still there. No idea if it just needs service or they'll get the boom later. But, like DistantTemple says, those things ain't cheap.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/13/2019 03:12 pm



Have they stopped because of the weather or because they're ahead of schedule (or other people are behind) and they're having to wait or slow down for something else that needs to happen?

One hypothesis for the initial frantic pace was the rent cost for the heavy equipment. The crane is now gone, so that would not longer be a factor and a slower pace makes sense.

It occurs to me that many of the workers on the BFWT (BFH) were external contractors, not SX employees. There are several hypothetical reasons for such a rush and then a sudden stop.
0) A certain contracted point has been reached.
1) Fixed price work. If its was a fixed price, the team and company benefit by working all out, getting the job done quickly.
2) Rewards/penalties for finishing to a certain point by a certain date.
3) If the contractors are paying for the heavy crane etc... then reducing its hire time increases their bottom line.
4) The contractors have other projects they have also promised completion on, (and maybe they were prevailed upon to squeeze the SX job in over Christmas so other projects are now time-compromised)
5) Progress is now awaiting components and staff from SX, and the contractors have switched to another project until SX does their bit... possibly internal installations.
6) There is disagreement over quality controll and payment.

Add "risk" You don't want those huge, unfinished lightweight sections sitting around when a 60 mph wind hits. Storms can come out of nowhere fast around here.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: landlubber on 01/13/2019 03:22 pm
All of this inactivity and gazing at a silent, inactive spaceship, wondering what will happen next reminds me of a very famous novel and several films from the 1950s onwards.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/13/2019 03:30 pm



Have they stopped because of the weather or because they're ahead of schedule (or other people are behind) and they're having to wait or slow down for something else that needs to happen?

One hypothesis for the initial frantic pace was the rent cost for the heavy equipment. The crane is now gone, so that would not longer be a factor and a slower pace makes sense.

It occurs to me that many of the workers on the BFWT (BFH) were external contractors, not SX employees. There are several hypothetical reasons for such a rush and then a sudden stop.
0) A certain contracted point has been reached.
1) Fixed price work. If its was a fixed price, the team and company benefit by working all out, getting the job done quickly.
2) Rewards/penalties for finishing to a certain point by a certain date.
3) If the contractors are paying for the heavy crane etc... then reducing its hire time increases their bottom line.
4) The contractors have other projects they have also promised completion on, (and maybe they were prevailed upon to squeeze the SX job in over Christmas so other projects are now time-compromised)
5) Progress is now awaiting components and staff from SX, and the contractors have switched to another project until SX does their bit... possibly internal installations.
6) There is disagreement over quality controll and payment.

Or they're still working at a frantic pace but we simply can't see what's going on inside with the internal plumbing, wiring, sensors and other fittings.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: NGC 4258 on 01/13/2019 10:29 pm
https://twitter.com/RGVaerialphotos/status/1084250424415264768 (https://twitter.com/RGVaerialphotos/status/1084250424415264768)

Some new drone shots of Starhopper and the Boca Chica launchpad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Llian Rhydderch on 01/13/2019 10:48 pm
In the first picture, we see the finished dome, full hemisphere, on the ground.

Possibly even more important, are those even more dome sections to the right and foreground of the dome?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Okie_Steve on 01/14/2019 12:20 am
If they do install the domes for a 12m tank I suppose they could use it for water ballast and slosh testing and keep propellant in separate small tanks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: QuantumG on 01/14/2019 12:27 am
They need at least two... one to separate the LOX from the Methane, one to seal the bottom of the tank. If they don't intend the nose-cone to hold propellant, they'll need one up there too.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: edkyle99 on 01/14/2019 12:31 am
I've been staring at these photos for weeks now.  I still don't get it.

 - Ed Kyle
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: QuantumG on 01/14/2019 12:34 am
I've been staring at these photos for weeks now.  I still don't get it.

What don't you get? A big redneck rocketship to do low altitude, subsonic hops with is a great way to "make it real", as Elon said.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: livingjw on 01/14/2019 12:44 am
I've been staring at these photos for weeks now.  I still don't get it.

 - Ed Kyle

Me neither.

John
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: daveklingler on 01/14/2019 12:58 am
I've been staring at these photos for weeks now.  I still don't get it.

 - Ed Kyle

Me neither.

John

My take is that they could have built a flying bedstead, but they chose to dress it up a bit.

What makes my brow furrow is how they keep sand out of all the many widgets that don't react well to sand.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: philw1776 on 01/14/2019 01:09 am
I've been staring at these photos for weeks now.  I still don't get it.

 - Ed Kyle

Me neither.

John

My take is that they could have built a flying bedstead, but they chose to dress it up a bit.

What makes my brow furrow is how they keep sand out of all the many widgets that don't react well to sand.

Exactly.
This purpose built Raptor engine tester could have been a crude open pipe frame containing visible propellant tanks with engines mounted below.  Only goes up 5Km.  OK more likely it would have been sheathed with something.  But Musk's Tesla history is infused with showmanship and style. He's trying to capture imaginations of the public, potential customers and yes, no strings attached government money.

As to the issues with sand, etc.  We know that the real, possibly shrink wrapped Raptors are not yet installed.  I don't think we've seen the drop in propellant tanks either.  They don't need to be large for this 5Km hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Llian Rhydderch on 01/14/2019 01:11 am

What makes my brow furrow is how they keep sand out of all the many widgets that don't react well to sand.

They kind of have to design the lower part of the rocket engines for that anyway.  Later versions of these engines will land on unprepared rock/dust/regolith on Mars, and will have to still work when the vehicle departs and ascends the Martian (sometimes dusty) atmosphere for the trip back to Earth.

Might as well get started on the design requirements for that environment, and the testing, now.

This is not your father's pristine aerospace manufacturing environment.   ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/14/2019 02:13 am
I've been staring at these photos for weeks now.  I still don't get it.

 - Ed Kyle

Me neither.

John

My take is that they could have built a flying bedstead, but they chose to dress it up a bit.

What makes my brow furrow is how they keep sand out of all the many widgets that don't react well to sand.
This one has the full fuel system installed as well, including the autogenous pressure system.

I bet it will spend the first tests just getting the whole system to the point where they can even spin up the pumps.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: edkyle99 on 01/14/2019 02:56 am
I've been staring at these photos for weeks now.  I still don't get it.

What don't you get? A big redneck rocketship to do low altitude, subsonic hops with is a great way to "make it real", as Elon said.

OK, I understand the dressed up hopper idea, but why is this thing now set firmly into concrete?  Why does it have dummy engines and dummy legs?  Why did they build it far from where a real hopper would need to go, with no readily apparent way to get it there?  Whey are they building tank domes nearby, now, after finishing the supposedly flying thing with no tank domes?  Why not finish a launch/landing site first before building a shiny rocket shaped thing?  Etc.  When I first saw this I thought about the old "Battleship" test articles from Saturn days.  That idea seems possible to me - something to be used for nonflying tests, but I'm not willing to bet on anything about this.   Maybe it is a billboard.  Maybe a rocket ship.  It will all make sense someday, hopefully, but I don't see it yet.

Even the Falcon 9 "protovehicle", which mostly served as a prop in the end, arrived at a pad that already had poured concrete, a flame trench, etc.

 - Ed Kyle 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/14/2019 03:08 am
But why is this thing now set firmly into concrete? 
Why does it have dummy engines and dummy legs? 
Why did they build it far from where a real hopper would need to go,
[Why] no readily apparent way to get it there? 
Why are they building tank domes nearby, now, after finishing the supposedly flying thing with no tank domes? 
Why not finish a launch/landing site first before building a shiny rocket shaped thing? 

1)  It's not set firmly in concrete.
2)  For the picture
3)  Because they don't have a place to build it near the pad.
4)  There's a readily apparent road
5)  Because it was easy to assemble the stack for a photo and take it apart later
6)  Timeline

Why do people need to question what EM has stated unequivocally?

https://twitter.com/elonmusk/status/1083582184005533697
https://twitter.com/elonmusk/status/1081572521105707009
https://twitter.com/elonmusk/status/1083567087983964160
https://twitter.com/elonmusk/status/1076612033011826688
https://twitter.com/elonmusk/status/1081573955591258113
https://twitter.com/elonmusk/status/1083568315656822784
https://twitter.com/elonmusk/status/1081576707365064704
https://twitter.com/elonmusk/status/1081575156990894082
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: docmordrid on 01/14/2019 03:24 am
I've been staring at these photos for weeks now.  I still don't get it.

What don't you get? A big redneck rocketship to do low altitude, subsonic hops with is a great way to "make it real", as Elon said.

OK, I understand the dressed up hopper idea, but why is this thing now set firmly into concrete? 

Temporary slabs, laid out around the legs & removable before the big move?

Quote
Why does it have dummy engines and dummy legs?

Development engines for fit checks, rudimentary fin/legs because the full ones aren't needed until Starship Mk-1.

Quote
Why did they build it far from where a real hopper would need to go, with no readily apparent way to get it there?

It'd be in the way at the pad construction site, and house moving equipment can handle the moving job cheaply.

Quote
Whey are they building tank domes nearby, now, after finishing the supposedly flying thing with no tank domes?

Either they'll lift it and install them from below, or they're building parts for another Hopper in case the first RUD's so the program isn't delayed.

Quote
Why not finish a launch/landing site first before building a shiny rocket shaped thing?

Maybe they'll test it at the pad site, which is currently under construction. Given the uprated Raptor tests start soon, per Musk, the pad may be finished by the time those tests are completed. Just In Time Delivery.

Quote
>
Maybe a rocket ship.  It will all make sense someday, hopefully, but I don't see it yet.

 - Ed Kyle

Turn around.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: edkyle99 on 01/14/2019 03:32 am
Why do people need to question what EM has stated unequivocally?
Elon has said many things over the years.  The things he says will happen often do happen, but not always in the exact way, and rarely in the time frame, that his words originally suggested they would happen.  I have no doubt that a BF Hopper is going to fly down there in Texas.  I'm just not sure yet how or if this particular fabrication turns into something that flies. 

 - Ed Kyle
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/14/2019 03:40 am
Elon has said many things over the years.  The things he says will happen often do happen, but not always in the exact way, and rarely in the time frame, that his words originally suggested they would happen.

Stipulated.  However it shouldn't be like pulling teeth for you to recognize this case is different.  You are simply making up objections/questions where there are clearly obvious answers.

Kremlinology is hard.  This isn't Kremlinology.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rockets4life97 on 01/14/2019 04:10 am
Elon has said many things over the years.  The things he says will happen often do happen, but not always in the exact way, and rarely in the time frame, that his words originally suggested they would happen. 

I'd agree if there wasn't a well-documented hopper sitting down in Boca Chica. It is possible they'll abandon it or it is a set piece, but it seems unlikely.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Andre Infante on 01/14/2019 05:37 am
Yup. Sometimes timelines slip and sometimes plans change. That's rocketry for you. But for this vehicle to be a placeholder, Musk and SpaceX would need to be actively, maliciously lying about what it is and what it's for. I don't think there are any documented examples of them doing that in the past, and I don't think there's any basis to think that's what's going on now.

People are simply suffering from a failure of imagination. Because this isn't happening in a way that's familiar, it simply must not be happening. Except, of course, it very obviously is.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/14/2019 05:55 am
Why do people need to question what EM has stated unequivocally?
Elon has said many things over the years.  The things he says will happen often do happen, but not always in the exact way, and rarely in the time frame, that his words originally suggested they would happen.  I have no doubt that a BF Hopper is going to fly down there in Texas.  I'm just not sure yet how or if this particular fabrication turns into something that flies. 

 - Ed Kyle
Oh come on. Plans change...  And that's a good thing.

But he's pretty damn accurate as per the information available at the time, so if he's describing what they're building, then that's what it is.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/14/2019 06:07 am

What makes my brow furrow is how they keep sand out of all the many widgets that don't react well to sand.

They kind of have to design the lower part of the rocket engines for that anyway.  Later versions of these engines will land on unprepared rock/dust/regolith on Mars, and will have to still work when the vehicle departs and ascends the Martian (sometimes dusty) atmosphere for the trip back to Earth.

Might as well get started on the design requirements for that environment, and the testing, now.

This is not your father's pristine aerospace manufacturing environment.   ;)

NASA punk'd the public into thinking that clean rooms are actually sterile. In any case, no need for that here. This is a garage vehicle - built to do what it's intended to do. Nothing more, nothing less.

BTW, I bet Starship hopper is going to hop from right there where it stands, to the new hopping site once it's ready to start testing - it's just a hop away! (pun intended).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Andre Infante on 01/14/2019 06:10 am
I think unlikely. That's, what, 100,000 kg or so of methalox? The energy content there in TNT-equivalence is pretty wild. You probably want more of a buffer zone between it and other people's property, for both safety (if it explodes) and noise reasons. It's gonna be a while before the concrete sets, so I think they have time to move it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/14/2019 06:18 am
I've been staring at these photos for weeks now.  I still don't get it.

What don't you get? A big redneck rocketship to do low altitude, subsonic hops with is a great way to "make it real", as Elon said.

OK, I understand the dressed up hopper idea, but why is this thing now set firmly into concrete?  Why does it have dummy engines and dummy legs?  Why did they build it far from where a real hopper would need to go, with no readily apparent way to get it there?  Whey are they building tank domes nearby, now, after finishing the supposedly flying thing with no tank domes?  Why not finish a launch/landing site first before building a shiny rocket shaped thing?  Etc.  When I first saw this I thought about the old "Battleship" test articles from Saturn days.  That idea seems possible to me - something to be used for nonflying tests, but I'm not willing to bet on anything about this.   Maybe it is a billboard.  Maybe a rocket ship.  It will all make sense someday, hopefully, but I don't see it yet.

Even the Falcon 9 "protovehicle", which mostly served as a prop in the end, arrived at a pad that already had poured concrete, a flame trench, etc.

 - Ed Kyle

Why?...

Because you're not Elon Musk and you don't work at spaceX. Therefore you don not have the slightest idea what the plan is.

So just chill, wait, and enjoy the ride.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: woods170 on 01/14/2019 06:49 am
I've been staring at these photos for weeks now.  I still don't get it.

 - Ed Kyle

Me neither.

John

My take is that they could have built a flying bedstead, but they chose to dress it up a bit.

What makes my brow furrow is how they keep sand out of all the many widgets that don't react well to sand.

Remember: the ultimate version of this thing is to land on Mars, on unprepared surface and lift-off again a year later without any cleaning.
Both engines and structure must be capable of withstanding sand.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/14/2019 06:50 am
Yup. Sometimes timelines slip and sometimes plans change. That's rocketry for you. But for this vehicle to be a placeholder, Musk and SpaceX would need to be actively, maliciously lying about what it is and what it's for. I don't think there are any documented examples of them doing that in the past, and I don't think there's any basis to think that's what's going on now.

People are simply suffering from a failure of imagination. Because this isn't happening in a way that's familiar, it simply must not be happening. Except, of course, it very obviously is.

More than  a failure of imagination, it is one of the rarest cases of engineering denial I've witness.

Wake up people! It's 2019! This is not a NASA rocket, nor is it a government or a scientific project (and it should not be any of those things). This is a private project. A project to bring space to the masses and the masses to space. The private sector can move as fast as it wants, whenever it wants, and whereever it wants. That's how you truly bring dreams to life.

But the more mundane reason that this is unfolding the way it is may be that they need to get Starlink up and running soon.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: woods170 on 01/14/2019 07:08 am
I've been staring at these photos for weeks now.  I still don't get it.

What don't you get? A big redneck rocketship to do low altitude, subsonic hops with is a great way to "make it real", as Elon said.

OK, I understand the dressed up hopper idea, but why is this thing now set firmly into concrete?  Why does it have dummy engines and dummy legs?  Why did they build it far from where a real hopper would need to go, with no readily apparent way to get it there?  Whey are they building tank domes nearby, now, after finishing the supposedly flying thing with no tank domes?  Why not finish a launch/landing site first before building a shiny rocket shaped thing?  Etc.  When I first saw this I thought about the old "Battleship" test articles from Saturn days.  That idea seems possible to me - something to be used for nonflying tests, but I'm not willing to bet on anything about this.   Maybe it is a billboard.  Maybe a rocket ship.  It will all make sense someday, hopefully, but I don't see it yet.

Even the Falcon 9 "protovehicle", which mostly served as a prop in the end, arrived at a pad that already had poured concrete, a flame trench, etc.

 - Ed Kyle 

IMO you need to reset your frame of reference.
Remember the original grasshopper?
That was a prototype F9 v1.0 tankset retrofitted with an engine that didn't belong to it (Merlin-1D - again a prototype engine) and some rigged-up landing gear.
The entire contraption was integrated on the spot at McGregor, out in the open, and launched and landed from a flat slab of concrete.

Hoppers don't need flame trenches.

Hoppers don't need cleanroom environments for construction.

Hoppers don't require cleanroom environments for maintenance.

Hoppers can withstand sand, rain, wind, etc.

SpaceX did a repeat of that with F9R-Dev1. Which was again constructed at McGregor out in the open, with a fixed version of the now well-known landing gear, lauching from a flat slab of concrete and being stored out in the open, out in the elements.

Again:

Hoppers don't need flame trenches.

Hoppers don't need cleanroom environments for construction.

Hoppers don't require cleanroom environments for maintenance.

Hoppers can withstand sand, rain, wind, etc.


Oh, and uh, Elon already mentioned that this hopper will have shock-absorbers installed on the feet of the legs. Expect that work to be done in the two months to come when the real engines go in, as well as the associated remaining plumbing, electronics, etc. And all that will happen out in the open.
And eventually SpaceX will stick a SPMT under it, roll it to the launch pad slab and have it do what hoppers do best: Hop.
This is not your fathers government-built, uber-expensive, high-fidelity prototype but a one-off (relatively) cheap garage-build to get a specific job done.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: clongton on 01/14/2019 08:27 am
I'm just not sure yet how or if this particular fabrication turns into something that flies. 

 - Ed Kyle

It's going to do one thing and one thing only - test vtol. That's what he said it is for. I don't expect this "hopper" to do anything else. But I do *suspect* that its first true hop may be to a poured slab. Beyond that I don't think it will do anything else, just hop around to repeatedly test vtol - nothing more.

Elon says a lot of things that can cause much speculation and elaboration, which generates lots of confusion. It's a lot safer to just stick to what he actually says and then chill.

https://twitter.com/elonmusk/status/1083568315656822784 (https://twitter.com/elonmusk/status/1083568315656822784)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: tyrred on 01/14/2019 10:17 am
I'm just not sure yet how or if this particular fabrication turns into something that flies. 

 - Ed Kyle

It's going to do one thing and one thing only - test vtol. That's what he said it is for. I don't expect this "hopper" to do anything else. But I do *suspect* that its first true hop may be to a poured slab. Beyond that I don't think it will do anything else, just hop around to repeatedly test vtol - nothing more.

Elon says a lot of things that can cause much speculation and elaboration, which generates lots of confusion. It's a lot safer to just stick to what he actually says and then chill.

https://twitter.com/elonmusk/status/1083568315656822784 (https://twitter.com/elonmusk/status/1083568315656822784)

This.  What could also inspire much confidence and provide many data points is an extended campaign a la Masten experience with Xombie, at a MUCH larger scale.  Perhaps multiple hops from prepared pad, to a target altitude/ attitude, to minimally/un-prepared surfaces of various compositions for wider data anlysis.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: VCompact on 01/14/2019 11:04 am
confirmation of bulkhead for fuel tank!

https://twitter.com/elonmusk/status/1084737144394903552 (https://twitter.com/elonmusk/status/1084737144394903552)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/14/2019 11:43 am
Yup. Sometimes timelines slip and sometimes plans change. That's rocketry for you. But for this vehicle to be a placeholder, Musk and SpaceX would need to be actively, maliciously lying about what it is and what it's for. I don't think there are any documented examples of them doing that in the past, and I don't think there's any basis to think that's what's going on now.

People are simply suffering from a failure of imagination. Because this isn't happening in a way that's familiar, it simply must not be happening. Except, of course, it very obviously is.

More than  a failure of imagination, it is one of the rarest cases of engineering denial I've witness.

Wake up people! It's 2019! This is not a NASA rocket, nor is it a government or a scientific project (and it should not be any of those things). This is a private project. A project to bring space to the masses and the masses to space. The private sector can move as fast as it wants, whenever it wants, and whereever it wants. That's how you truly bring dreams to life.

But the more mundane reason that this is unfolding the way it is may be that they need to get Starlink up and running soon.
How many times have you heard "it's not proven" over things that are clearly happening?

Both ULA and Arianne corporate strategy hinged on that, with predictable results.

Denial is very common with respect to SpaceX.

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: clongton on 01/14/2019 01:31 pm
How many times have you heard "it's not proven" over things that are clearly happening?
Both ULA and Arianne corporate strategy hinged on that, with predictable results.
Denial is very common with respect to SpaceX.

Yea. Usually the people that don't see it are the same people that don't want to see it :(
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/14/2019 01:41 pm
...I don't see it yet.

Because you only see what past experiences have conditioned you to expect to see, instead of what is actually there.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: su27k on 01/14/2019 01:58 pm
Come on people, there's no need to beat up Ed, the construction sequence of this hopper is definitely odd, I know I was puzzled by some of the choices made. It looks like they really really want the exterior ready by early January, probably for the photo ops, so some tasks are out of order. I think Ed will see it once they start welding in the tank domes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: edkyle99 on 01/14/2019 02:17 pm
...I don't see it yet.

Because you only see what past experiences have conditioned you to expect to see, instead of what is actually there.
But that's the point.  I do see what is actually there.  It is not a functional flying machine.  Not yet.  Why waste resources building a photo prop?

 - Ed Kyle
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/14/2019 02:22 pm
...I don't see it yet.

Because you only see what past experiences have conditioned you to expect to see, instead of what is actually there.
But that's the point.  I do see what is actually there.  It is not a functional flying machine.  Not yet.  Why waste resources building a photo prop?

 - Ed Kyle

Are you just splitting hairs now?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/14/2019 02:31 pm
...I don't see it yet.

Because you only see what past experiences have conditioned you to expect to see, instead of what is actually there.
But that's the point.  I do see what is actually there.  It is not a functional flying machine.  Not yet.  Why waste resources building a photo prop?

 - Ed Kyle

You've been told what it is, and that it's not a photo prop.

You choose to believe it's a photo prop.

That's ok, you're entitled to your opinion.

But when you ask "why build a photo prop it makes no sense", that's where it gets weird, since you're just saying that your opinion, (to which you're entitled but which contradicts the stated purpose of the thing) doesn't make sense.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wolfram66 on 01/14/2019 02:41 pm
Pics of the bells and the bottom of a fin. Taken on 1-8-19 during the fit test excitement.

Using BocaChicaGal's photo, focusing on left 2 Raptors: Enhanced to show additional Raptor components through gap in the leg.

Note**  that the left bell and expander section are mismatched in O.D. ... whereas center is much smoother transition.

Peeking around leg, we can see part of the thrust chamber and lack of plumbing. This confirms EM's statement that thee were not flight ready units but development test articles being used as boiler plate fit check and alignment units...

Thanks for the great work BCG/Nomadd/Austin... and many others..
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: cambrianera on 01/14/2019 02:48 pm
...I don't see it yet.

Because you only see what past experiences have conditioned you to expect to see, instead of what is actually there.
But that's the point.  I do see what is actually there.  It is not a functional flying machine.  Not yet.  Why waste resources building a photo prop?

 - Ed Kyle

This: https://forum.nasaspaceflight.com/index.php?topic=47176.msg1900274#msg1900274
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/14/2019 02:50 pm
...I don't see it yet.

Because you only see what past experiences have conditioned you to expect to see, instead of what is actually there.
But that's the point.  I do see what is actually there.  It is not a functional flying machine.  Not yet.  Why waste resources building a photo prop?

 - Ed Kyle

You said the legs are embedded in the concrete, which they clearly are not. You said they have no way to move it to the pad, when it's right by the road leading to the pad area.

If you can't see things that are evident in other photos, how can you be so sure that what you see as "not a flying machine" is actually that?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/14/2019 02:53 pm
 Last time I saw somebody dogpiled like Ed's getting was when some nitwit suggested a watertank was going to be a flying rocket.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/14/2019 02:58 pm
Last time I saw somebody dogpiled like Ed's getting was when some nitwit suggested a watertank was going to be a flying rocket.

Yeah. Removed my somewhat lame attempt at humor. But the point still stands: When does a water tower with engines become a "functional flying machine"?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/14/2019 03:10 pm
Why waste resources building a photo prop?

They aren't wasting resources.  Absolutely no support for this statement.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: HVM on 01/14/2019 03:12 pm
Last time I saw somebody dogpiled like Ed's getting was when some nitwit suggested a watertank was going to be a flying rocket.

Yeah. Removed my somewhat lame attempt at humor. But the point still stands: When does a water tower with engines become a "functional flying machine"?

When its have working engines instead of mock-ups, avionics and plumbing installed...

(When pigs water towers fly)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ncb1397 on 01/14/2019 03:20 pm
SpaceX did a repeat of that with F9R-Dev1. Which was again constructed at McGregor out in the open, with a fixed version of the now well-known landing gear, lauching from a flat slab of concrete and being stored out in the open, out in the elements.

Again:

Hoppers don't need flame trenches.

Hoppers don't need cleanroom environments for construction.

Hoppers don't require cleanroom environments for maintenance.

Hoppers can withstand sand, rain, wind, etc.

Well, not so much the F9R-Dev1 as it was destroyed due to a blocked sensor (probably FOD???).
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/14/2019 03:26 pm
SpaceX did a repeat of that with F9R-Dev1. Which was again constructed at McGregor out in the open, with a fixed version of the now well-known landing gear, lauching from a flat slab of concrete and being stored out in the open, out in the elements.

Again:

Hoppers don't need flame trenches.

Hoppers don't need cleanroom environments for construction.

Hoppers don't require cleanroom environments for maintenance.

Hoppers can withstand sand, rain, wind, etc.

Well, not so much the F9R-Dev1 as it was destroyed due to a blocked sensor (probably FOD???).

After accomplishing the necessary testing, since its replacement was never finished or launched. So "didn't need" still applies.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/14/2019 03:27 pm
...I don't see it yet.

Because you only see what past experiences have conditioned you to expect to see, instead of what is actually there.
But that's the point.  I do see what is actually there.  It is not a functional flying machine.  Not yet.  Why waste resources building a photo prop?

 - Ed Kyle

This: https://forum.nasaspaceflight.com/index.php?topic=47176.msg1900274#msg1900274

That’s just you wading into tinfoil hat territory.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rsdavis9 on 01/14/2019 03:31 pm
Last time I saw somebody dogpiled like Ed's getting was when some nitwit suggested a watertank was going to be a flying rocket.

Yeah. Removed my somewhat lame attempt at humor. But the point still stands: When does a water tower with engines become a "functional flying machine"?

When its have working engines instead of mock-ups, avionics and plumbing installed...

(When pigs water towers fly)

Maybe this hopper should be called dumbo.
 :)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Doesitfloat on 01/14/2019 03:37 pm
Back in the day, before there were rockets that could be used more than once;  we didn't have to test the landing cycle.  The rockets just burned up and crashed.  Now with these new fangled "reusable rockets" well they have to land in a controlled operation.  If the landing doesn't preserve the integrity of the rocket and all of it's systems.  Well that landing is no better than the old standard flaming crash.
 I guess the question is " is there a benifit to pefecting the final approach and landing of a reusable rocket before sending one into orbit?"

The answer from the 3 companies that achieved it ( Spacex, Blue, Masten) yes!!

 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/14/2019 03:38 pm
Last time I saw somebody dogpiled like Ed's getting was when some nitwit suggested a watertank was going to be a flying rocket.

Yeah. Removed my somewhat lame attempt at humor. But the point still stands: When does a water tower with engines become a "functional flying machine"?
When it lands for the first time without a RUD
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/14/2019 03:40 pm
Why waste resources building a photo prop?

They aren't wasting resources.  Absolutely no support for this statement.

If you really want to know why the photo op, then listen to what Musk says very carefully in the video below. It's a bit of a window into the vision of SpaceX and why they do things the way they do.

When it's all said and done, someday in the far off future, I truly believe Elon will take a place among Edison, Tesla, Ford, and yes . . . Christopher Columbus.

Yeah. Columbus. That's not a typo.

https://www.youtube.com/watch?v=uRgzd-nHcxU
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/14/2019 03:44 pm
Why waste resources building a photo prop?

They aren't wasting resources.  Absolutely no support for this statement.

If you really want to know why the photo op, then listen to what Musk says very carefully in the video below. It's a bit of a window into the vision of SpaceX and why they do things the way they do.

When it's all said and done, someday in the far off future, I truly believe Elon will take a place among Edison, Tesla, Ford, and yes . . . Christopher Columbus.

Yeah. Columbus. That's not a typo.

https://www.youtube.com/watch?v=uRgzd-nHcxU

Columbus would not be a bad name for the first manned Mars-bound Starship.  Actually Mayflower would be even better.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wargrim on 01/14/2019 03:45 pm
The order of how things are being assembled is interesting indeed. And we lack the insight for clear conclusions, but there are a number of possible reasons:

- Finishing a watertight shell first makes interior work easier
- The Water Tower building company was available right there and then
- Elon really wanted the photo opportunity done before something else happens
- All the outer Hopper parts assembled free up space on the assembly site for further operations/assembly
- Stuff simply got put together in the order of availability
- A combination of the above
- Something else we are not aware of. Maybe the launch/landing pad construction was simply delayed by something and was supposed to be up before the Hopper? But stopping/delaying all the plans for the Hopper would have made no sense? Plenty of room for speculation.

Regardless, there are many steps towards first flight to come. Pad, GSE, Feet, production Raptors, Hopper Movement and so on. And if someone cant believe it until it hops, that's ok. I for example am still puzzled how a water tower is LOX - rated. Maybe the requirements are lower than i thought, or this is no ordinary water tower steel. Or they are coating it on the inside. Some are still wondering if this thing flies, most here wonder about how it flies.

But in terms of working under unusual conditions: The history of early rocketry is full of that. Nobody in the early days had the clean rooms and stuff of today. And the rockets still flew somehow. Aviation is full of DO-X/Spruce Goose moments. (Bad analogy hopefully, this here should be more like a 747 precursor.)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/14/2019 03:52 pm
Why waste resources building a photo prop?

They aren't wasting resources.  Absolutely no support for this statement.

If you really want to know why the photo op, then listen to what Musk says very carefully in the video below. It's a bit of a window into the vision of SpaceX and why they do things the way they do.

When it's all said and done, someday in the far off future, I truly believe Elon will take a place among Edison, Tesla, Ford, and yes . . . Christopher Columbus.

Yeah. Columbus. That's not a typo.

https://www.youtube.com/watch?v=uRgzd-nHcxU

Columbus would not be a bad name for the first manned Mars-bound Starship.  Actually Mayflower would be even better.

Yeah, I like Columbus. It would be very fitting for the first human spaceship to land on a new world.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jeffreycornish on 01/14/2019 03:56 pm
Regarding building if a company that constructs water towers could construct a LOX tank, lets check in with the experts, someone who actually fabricates (or has fabricated for them) LOx tanks,

https://www.gasworld.com/an-introduction-to-cryogenic-tanks/4599.article

"The double wall tanks consist of two cylindrical vessels, a stainless steel inner tank (the pressure vessel) and an outer jacket in carbon steel. The air in the space between the inner and outer vessel is known as the annular space, which is evacuated by means of a pump to create a vacuum."

So, the hopper will not be using insulation, as the propellant will be consumed shortly after loading,

as long as the welds are good, and the design can handle the 2-3 atmospheres of pressure, it should be fine.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/14/2019 03:56 pm
(When pigs water towers fly)

Quote
With sufficient thrust, pigs fly just fine.

Now I have to repost the YouTube link I just removed:

https://www.youtube.com/watch?v=6RgGNiDUROw
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/14/2019 03:56 pm
Pics of the bells and the bottom of a fin. Taken on 1-8-19 during the fit test excitement.

Using BocaChicaGal's photo, focusing on left 2 Raptors: Enhanced to show additional Raptor components through gap in the leg.

Note**  that the left bell and expander section are mismatched in O.D. ... whereas center is much smoother transition.

Peeking around leg, we can see part of the thrust chamber and lack of plumbing. This confirms EM's statement that thee were not flight ready units but development test articles being used as boiler plate fit check and alignment units...

Thanks for the great work BCG/Nomadd/Austin... and many others..

Nice! The plumbing details also show that they are at least partly real hardware and not just sheet metal hacked into a engine shape.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: alexterrell on 01/14/2019 04:00 pm

Columbus would not be a bad name for the first manned Mars-bound Starship.  Actually Mayflower would be even better.
Wouldn't Mayflower be the name for the one carrying the first permanent settlers?

Alternatively, the first colony ship could be called the "Caravel" after Cortes' ship, which he allegedly burnt on arrival in the New World. Then it could be turned into a fuel store.

However, seeing how SpaceX name their barges, might I suggest "About bloody time" as the name of the first ship?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: meekGee on 01/14/2019 04:07 pm

Columbus would not be a bad name for the first manned Mars-bound Starship.  Actually Mayflower would be even better.
Wouldn't Mayflower be the name for the one carrying the first permanent settlers?

Alternatively, the first colony ship could be called the "Caravel" after Cortes' ship, which he allegedly burnt on arrival in the New World. Then it could be turned into a fuel store.

However, seeing how SpaceX name their barges, might I suggest "About bloody time" as the name of the first ship?

About bloody time!  It's settled then.

Oh wait, that's not a bad name either.  :)

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/14/2019 04:08 pm

Columbus would not be a bad name for the first manned Mars-bound Starship.  Actually Mayflower would be even better.
Wouldn't Mayflower be the name for the one carrying the first permanent settlers?

Alternatively, the first colony ship could be called the "Caravel" after Cortes' ship, which he allegedly burnt on arrival in the New World. Then it could be turned into a fuel store.

However, seeing how SpaceX name their barges, might I suggest "About bloody time" as the name of the first ship?

We are getting dangerously off-topic, but here is the official statement:
https://twitter.com/elonmusk/status/777985245731696640

Elon Musk To Name SpaceX Mars Ship “Heart Of Gold” (https://www.valuewalk.com/2016/09/elon-musk-spacex-mars-ship/)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: HMXHMX on 01/14/2019 04:15 pm
Back in the day, before there were rockets that could be used more than once;  we didn't have to test the landing cycle.  The rockets just burned up and crashed.  Now with these new fangled "reusable rockets" well they have to land in a controlled operation.  If the landing doesn't preserve the integrity of the rocket and all of it's systems.  Well that landing is no better than the old standard flaming crash.
 I guess the question is " is there a benifit to pefecting the final approach and landing of a reusable rocket before sending one into orbit?"

The answer from the 3 companies that achieved it ( Spacex, Blue, Masten) yes!!

 


You forgot McDonnell-Douglas, i.e., the DC-X.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: sghill on 01/14/2019 04:21 pm
Last time I saw somebody dogpiled like Ed's getting was when some nitwit suggested a watertank was going to be a flying rocket.

...or Jim's initial opinions on reuse. ;)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: matthewkantar on 01/14/2019 04:45 pm
Here is what I think is a less controversial way to say what Ed is getting at: Isn't it a shame resources have to be spent on show rather the go? SpaceX has a better handle on show/go ratio than I do. For me it is a little painful to see rare and precious developement bucks spent on showmanship.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/14/2019 04:49 pm
Here is what I think is a less controversial way to say what Ed is getting at: Isn't it a shame resources have to be spent on show rather the go? SpaceX has a better handle on show/go ratio than I do. For me it is a little painful to see rare and precious developement bucks spent on showmanship.

It is laughable to suggest that SpaxeX is short on the "go" ratio. Where does that place the rest of the industry?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/14/2019 04:52 pm
Here is what I think is a less controversial way to say what Ed is getting at: Isn't it a shame resources have to be spent on show rather the go? SpaceX has a better handle on show/go ratio than I do. For me it is a little painful to see rare and precious developement bucks spent on showmanship.

See the video of Elon answering Asa Hutchinson's question.

Show is Go.

Successful exploitation of Space is a Technical and Economic problem.  Economics is a SOCIAL SCIENCE.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: matthewkantar on 01/14/2019 04:57 pm
Here is what I think is a less controversial way to say what Ed is getting at: Isn't it a shame resources have to be spent on show rather the go? SpaceX has a better handle on show/go ratio than I do. For me it is a little painful to see rare and precious developement bucks spent on showmanship.

It is laughable to suggest that SpaxeX is short on the "go" ratio. Where does that place the rest of the industry?

I didn't say they were short on "go," just that there is some potential go money being spent on show. I fullly understand that they know much better than I do, but I grew up watching commercial space ventures collapse, so I still worry.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: birdman on 01/14/2019 04:57 pm
Here is what I think is a less controversial way to say what Ed is getting at: Isn't it a shame resources have to be spent on show rather the go? SpaceX has a better handle on show/go ratio than I do. For me it is a little painful to see rare and precious developement bucks spent on showmanship.

Well SpaceX has already done a hell of a lot more than most other companies in the couple of years it's been around.

And I still don't see why the thing can't be both. Sure, it looks cool and good for PR, but I don't think they made any concessions in terms of practical use either. It's a cobbled together piece of crud (spacecraft-wise, at least) but as long as it can hop a couple of times and get some nice data to make sure they aren't going to crash their next iteration more expensive Starship, I don't see why it has to be anything more.

Also, for SpaceX right now, I don't think BFR development money is "rare and precious". Unlike NASA, which would probably still be around for better or for worse if SLS turns out to be a complete failure, the future of SpaceX is entirely dependent on the quality, the reusability, and the profitability of BFR/SS. It's the future of the company and what they NEED to be investing in right now. So that's exactly what they're doing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: mme on 01/14/2019 05:19 pm
Here is what I think is a less controversial way to say what Ed is getting at: Isn't it a shame resources have to be spent on show rather the go? SpaceX has a better handle on show/go ratio than I do. For me it is a little painful to see rare and precious developement bucks spent on showmanship.

See the video of Elon answering Asa Hutchinson's question.

Show is Go.

Successful exploitation of Space is a Technical and Economic problem.  Economics is a SOCIAL SCIENCE.
Agreed. As Hume said, "Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them."  The purpose of the "show" is to inspire people. The genius of the flying water tower is that it was probably dirt cheap to make it interesting and fun as well as useful.

Personally I wish we would do more because it's fun and interesting rather than try to justify everything as if there will always be a financial payback. But that's me.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/14/2019 06:04 pm
Here is what I think is a less controversial way to say what Ed is getting at: Isn't it a shame resources have to be spent on show rather the go? SpaceX has a better handle on show/go ratio than I do. For me it is a little painful to see rare and precious developement bucks spent on showmanship.

It is laughable to suggest that SpaxeX is short on the "go" ratio. Where does that place the rest of the industry?

I didn't say they were short on "go," just that there is some potential go money being spent on show. I fullly understand that they know much better than I do, but I grew up watching commercial space ventures collapse, so I still worry.

Ok, so they aren't short on "go". But Musk has always been a showman - but a showman that delivers (eventually). That's his thing. Do you really think they spent a significant portion of SpaceX resources to making this hopper look better?

How much should they be allowed to spend on "show"? Should it even matter as long as the provide sufficient "go"? And does it matter if us tax payers aren't paying for it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/14/2019 06:39 pm

With the way that shiny foil was spot welded on, there might be quite a "show" when it starts hopping and they start fluttering off in the breeze like Chinese rocket insulation.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RotoSequence on 01/14/2019 07:17 pm

With the way that shiny foil was spot welded on, there might be quite a "show" when it starts hopping and they start fluttering off in the breeze like Chinese rocket insulation.

SpaceX privately developed reusable, retropropulsive landing boosters, a space capsule, world class rocket engines, and other pioneering technologies, and you suddenly expect them to be complete incompetents with sheet steel?  ???
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RobLynn on 01/14/2019 07:31 pm
That’s just you wading into tinfoil hat territory.
With their 9m diameter 20m tall 'nut-job jumbo' SpaceX have set a whole new standard for high capacity tin foil millinery accoutrements.  Zeta Reticulans/NSA cabal are going to have to up the Jigawatts of their mind control rays significantly in response to this development.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lemurion on 01/14/2019 07:43 pm
I think that part of the reason some people have issues with recognizing the Hopper as a potential flight article is that they haven't come to terms with the fact that SpaceX appears to have transitioned from "rocket science" to "rocket engineering" or even "rocket mechanics."

It's a completely different worldview.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RonM on 01/14/2019 07:52 pm
I think that part of the reason some people have issues with recognizing the Hopper as a potential flight article is that they haven't come to terms with the fact that SpaceX appears to have transitioned from "rocket science" to "rocket engineering" or even "rocket mechanics."

It's a completely different worldview.

Hopper is being built in a "rocketshipyard" instead of a factory. That's probably why it's hard for some to take it seriously.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: freddo411 on 01/14/2019 07:53 pm

With the way that shiny foil was spot welded on, there might be quite a "show" when it starts hopping and they start fluttering off in the breeze like Chinese rocket insulation.

SpaceX privately developed reusable, retropropulsive landing boosters, a space capsule, world class rocket engines, and other pioneering technologies, and you suddenly expect them to be complete incompetents with sheet steel?  ???

One can't be too sure about construction sufficiency until you fly a bit....

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cinder on 01/14/2019 08:27 pm
Here is what I think is a less controversial way to say what Ed is getting at: Isn't it a shame resources have to be spent on show rather the go? SpaceX has a better handle on show/go ratio than I do. For me it is a little painful to see rare and precious developement bucks spent on showmanship.

It is laughable to suggest that SpaxeX is short on the "go" ratio. Where does that place the rest of the industry?

I didn't say they were short on "go," just that there is some potential go money being spent on show. I fullly understand that they know much better than I do, but I grew up watching commercial space ventures collapse, so I still worry.
Is the esthetic layer welded on and photo op done at the expense of the rest of the BFH's dev/mfg ?  Is it ruled out that those aren't contractors who ran out of things to do before SpaceX employees took over? 

It would seem a little more right for the secrecy of the rest of the SHSS project to take over again eventually.  The "water tower" public build was fun but it was pretty shallow.  We barely know what's behind the steel shell.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Star One on 01/14/2019 08:39 pm
I think that part of the reason some people have issues with recognizing the Hopper as a potential flight article is that they haven't come to terms with the fact that SpaceX appears to have transitioned from "rocket science" to "rocket engineering" or even "rocket mechanics."

It's a completely different worldview.

Hopper is being built in a "rocketshipyard" instead of a factory. That's probably why it's hard for some to take it seriously.

But the orbital test vehicle is being built in a factory.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: moreno7798 on 01/14/2019 08:43 pm
I think that part of the reason some people have issues with recognizing the Hopper as a potential flight article is that they haven't come to terms with the fact that SpaceX appears to have transitioned from "rocket science" to "rocket engineering" or even "rocket mechanics."

It's a completely different worldview.

Hopper is being built in a "rocketshipyard" instead of a factory. That's probably why it's hard for some to take it seriously.

Well said.

That picture of a rocket scientist in a white lab coat slowly pacing around a clean room completely contrasts what they're seeing now: A bunch of blue collar workers with Home Depot tools in hand putting together a rocket out in the open exposed to the elements.

More than anything, I think that's what people are having trouble coming to terms with.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RonM on 01/14/2019 08:44 pm
I think that part of the reason some people have issues with recognizing the Hopper as a potential flight article is that they haven't come to terms with the fact that SpaceX appears to have transitioned from "rocket science" to "rocket engineering" or even "rocket mechanics."

It's a completely different worldview.

Hopper is being built in a "rocketshipyard" instead of a factory. That's probably why it's hard for some to take it seriously.

But the orbital test vehicle is being built in a factory.

So what? We're talking about Hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/14/2019 08:44 pm
One large issue from the perspective of anything being build of the BFR scale away from Boca Chick is how does it get to the site. Nomadd, could you weigh in if the existing roadways from the Port of Brownsville could accommodate a 9m diameter object - possibly with some temporary power line removal, etc, or is it not realistic without the new roadway?


If not realistic then don't count on seeing a higher fidelity craft showing up before that roadway has been built...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rsdavis9 on 01/14/2019 08:45 pm
Or assembled from pieces on site.

Elon did say they are building components in san pedro.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/14/2019 08:45 pm
I think that part of the reason some people have issues with recognizing the Hopper as a potential flight article is that they haven't come to terms with the fact that SpaceX appears to have transitioned from "rocket science" to "rocket engineering" or even "rocket mechanics."

It's a completely different worldview.

Hopper is being built in a "rocketshipyard" instead of a factory. That's probably why it's hard for some to take it seriously.

But the orbital test vehicle is being built in a factory.
Since the factory hasn't any plans to materialize before June... sections of SS-OTV are being built in a dockside tent. (Ok a fabric sprung structure building)

Its a rather good democratization of rocket building.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/14/2019 08:59 pm
Or assembled from pieces on site.

Elon did say they are building components in san pedro.
True - but it's hard to imagine those pieces not also being 9m in diameter. I just can't imagine a longitudinal weld.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: rsdavis9 on 01/14/2019 09:02 pm
Or assembled from pieces on site.

Elon did say they are building components in san pedro.
True - but it's hard to imagine those pieces not also being 9m in diameter. I just can't imagine a longitudinal weld.

Well the shell is the big thing.
If you can assemble the shell in san pedro in a tent whats so different about boca chica in a tent?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: WindyCity on 01/14/2019 09:12 pm
I nominate "it's settled then" as the name of the first people carrying ship.
Musk would probably like that. It has an Ian M. Banks Culture ring to it, following in the wake of OCISLY and JRTI.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cinder on 01/14/2019 09:21 pm
Can someone rule out (will delete if this was already established):

"Outsourcing" the simpler parts of the BFH to the water tower company allowed cheaper mfg (they build water tower vs spaceships), faster mfg (no/little SpaceX staff req'd), altogether offering a sooner photo op (whether or not a coincidence with the layoffs bad press) as well as a bone to the public (e.g. Star Trek spaceship open air shipyard, done before the remaining secret sauce happens behind steel/tent/etc).
 
It fits with "unforeseen issues" and the unusual (?) fit issues we saw on stacking.  And with a team of SpaceX staff visiting the work.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/14/2019 09:23 pm
I nominate "it's settled then" as the name of the first people carrying ship.
Musk would probably like that. It has an Ian M. Banks Culture ring to it, following in the wake of OCISLY and JRTI.
Hello. "Heart of Gold".

https://www.space.com/34220-spacex-first-mars-ship-hitchhikers-guide-galaxy.html
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cinder on 01/14/2019 09:39 pm
It's already established that Musk has pet faves (H'sGttG, Culture ships) for spacecraft names.  It also doesn't belong in this thread.  Could the discussion happen in its own new thread?  Even if it's a short discussion.
Or in one of the previous threads.  Searched and only found these two:
https://forum.nasaspaceflight.com/index.php?topic=31497.msg1032572#msg1032572 (2014)
https://forum.nasaspaceflight.com/index.php?topic=43887.msg1729417#msg1729417 (2017)

Edit/Lar: Roger that. Ixnay on the Amingnay discussions...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: tenkendojo on 01/14/2019 10:00 pm
One large issue from the perspective of anything being build of the BFR scale away from Boca Chick is how does it get to the site. Nomadd, could you weigh in if the existing roadways from the Port of Brownsville could accommodate a 9m diameter object - possibly with some temporary power line removal, etc, or is it not realistic without the new roadway?


If not realistic then don't count on seeing a higher fidelity craft showing up before that roadway has been built...

The Orbital testing version of BFR/Starship will be launched from Cape Canaveral, and will most likely use the same method as transporting the Saturn V components, via sea barges.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RobLynn on 01/14/2019 10:04 pm
One large issue from the perspective of anything being build of the BFR scale away from Boca Chick is how does it get to the site. Nomadd, could you weigh in if the existing roadways from the Port of Brownsville could accommodate a 9m diameter object - possibly with some temporary power line removal, etc, or is it not realistic without the new roadway?


If not realistic then don't count on seeing a higher fidelity craft showing up before that roadway has been built...

SpaceX will need water access for big stuff at Boca Chica - they must have plans for a pier and possibly breakwater at coast of end of Boca Chica Blvd next to their facility.

In the meantime they can pull a flat bottomed barge in off sea and up beach using a heavy earthmover or winch?  Shift onto oversized trailer using a crane and pull to site (they need that trailer anyway to move hopper to launch site) and recover barge to sea using a tug.  The beach is only a few 10's of meters wide, and tidal range only ~0.34m

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: IntoTheVoid on 01/14/2019 10:06 pm
One large issue from the perspective of anything being build of the BFR scale away from Boca Chick is how does it get to the site. Nomadd, could you weigh in if the existing roadways from the Port of Brownsville could accommodate a 9m diameter object - possibly with some temporary power line removal, etc, or is it not realistic without the new roadway?


If not realistic then don't count on seeing a higher fidelity craft showing up before that roadway has been built...

The Orbital testing version of BFR/Starship will be launched from Cape Canaveral, and will most likely use the same method as transporting the Saturn V components, via sea barges.
Welcome, but...
That is your highly speculative opinion and should be labeled as such. Unless you're an insider, which has not been established.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/14/2019 10:32 pm
One large issue from the perspective of anything being build of the BFR scale away from Boca Chick is how does it get to the site. Nomadd, could you weigh in if the existing roadways from the Port of Brownsville could accommodate a 9m diameter object - possibly with some temporary power line removal, etc, or is it not realistic without the new roadway?


If not realistic then don't count on seeing a higher fidelity craft showing up before that roadway has been built...

The Orbital testing version of BFR/Starship will be launched from Cape Canaveral, and will most likely use the same method as transporting the Saturn V components, via sea barges.
Welcome, but...
That is your highly speculative opinion and should be labeled as such. Unless you're an insider, which has not been established.

That is where SpaceX has shown it launching from, in both 2016 and 2017 archeticture animations, and in the dearmoon presentation. The dearmoon flight plan graphic shows launch from Florida.

Any other launch site is highly speculative. The Cape is the only one we know for sure that SpaceX is thinking about using.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ThereIWas3 on 01/14/2019 10:38 pm
Seems to me that where orbital and #dearmoon launches happen need not be the same as where the high altitude and supersonic tests happen.  Elon has already said that the latter will be from Texas.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Zed_Noir on 01/14/2019 10:48 pm
I nominate "it's settled then" as the name of the first people carrying ship.
Musk would probably like that. It has an Ian M. Banks Culture ring to it, following in the wake of OCISLY and JRTI.
Hello. "Heart of Gold".

https://www.space.com/34220-spacex-first-mars-ship-hitchhikers-guide-galaxy.html

Sigh.  ???

The "Heart of Gold " will be the first crewed Starship to land on Mars. Musk will name the first crewed LEO bound development Starship something else.

Will remind folks we are using the Golden Rule for the naming of SpaceX vehicles.

The Golden Rule is "Those who have the most Gold makes the Rules".

In the case of SpaceX it is the one with the most voting shares. Which I reckon is the SX CTO. He gets to name the SpaceX vehicles as he pleases.

Of course you might be able to persuade the SX CTO in what to name the initial crewed Starship by underwriting a few test flights. Including the test vehicles.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: docmordrid on 01/14/2019 10:50 pm

SpaceX will need water access for big stuff at Boca Chica - they must have plans for a pier and possibly breakwater at coast of end of Boca Chica Blvd next to their facility.
>

Covered; a road is to be built between the harbor and Highway 4, which runs next to the SpaceX facilities.

Link... (https://www.portofbrownsville.com/officials-plan-to-break-ground-on-east-loop-project/)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/14/2019 11:01 pm

SpaceX will need water access for big stuff at Boca Chica - they must have plans for a pier and possibly breakwater at coast of end of Boca Chica Blvd next to their facility.
&gt;

Covered; a road is to be built between the harbor and Highway 4, which runs next to the SpaceX facilities.

Link... (https://www.portofbrownsville.com/officials-plan-to-break-ground-on-east-loop-project/)
Exactly -  but it needs to be built before large stuff can be moved from the port. And for those saying they can use a barge to shore, that isn’t realistic nor viable. A real transport plan with real logistics needs to be put into place before you will see real hardware show up at BC.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/14/2019 11:04 pm

SpaceX will need water access for big stuff at Boca Chica - they must have plans for a pier and possibly breakwater at coast of end of Boca Chica Blvd next to their facility.
>

Covered; a road is to be built between the harbor and Highway 4, which runs next to the SpaceX facilities.

Link... (https://www.portofbrownsville.com/officials-plan-to-break-ground-on-east-loop-project/)
Not by June.
 They might make it down 511. There are about 40 power lines crossing the road, but all low voltage. It would just take a little work on the corner lot to cut the corner onto Hwy 4.
 As with a lot of things, people tend to greatly underestimate what a pier would entail here.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RobLynn on 01/14/2019 11:44 pm
Not by June.
 They might make it down 511. There are about 40 power lines crossing the road, but all low voltage. It would just take a little work on the corner lot to cut the corner onto Hwy 4.
 As with a lot of things, people tend to greatly underestimate what a pier would entail here.

Paying for the lines to be under-grounded and any other road upgrades necessary is probably the cheapest option then
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: IntoTheVoid on 01/14/2019 11:45 pm
One large issue from the perspective of anything being build of the BFR scale away from Boca Chick is how does it get to the site. Nomadd, could you weigh in if the existing roadways from the Port of Brownsville could accommodate a 9m diameter object - possibly with some temporary power line removal, etc, or is it not realistic without the new roadway?


If not realistic then don't count on seeing a higher fidelity craft showing up before that roadway has been built...

The Orbital testing version of BFR/Starship will be launched from Cape Canaveral, and will most likely use the same method as transporting the Saturn V components, via sea barges.
Welcome, but...
That is your highly speculative opinion and should be labeled as such. Unless you're an insider, which has not been established.

That is where SpaceX has shown it launching from, in both 2016 and 2017 archeticture animations, and in the dearmoon presentation. The dearmoon flight plan graphic shows launch from Florida.

Any other launch site is highly speculative. The Cape is the only one we know for sure that SpaceX is thinking about using.
Actually, at about 1:19 in the DearMoon presentation he specifically says that they haven't decided on where the first orbital launches will be from. And the only specific mention he makes at that time is of a floating platform, without specifying where that platform might or might not be located.

 DearMoon (https://www.youtube.com/watch?v=zu7WJD8vpAQ)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/15/2019 12:00 am
Seems to me that where orbital and #dearmoon launches happen need not be the same as where the high altitude and supersonic tests happen.  Elon has already said that the latter will be from Texas.

Exactly. If supersonic hand high speed test will happen at Boca Chica, it won't be with the hopper. No, the next test article being constructed (the one they are aiming to complete by June in San Pedro) will ALSO be flown at Boca Chica.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/15/2019 12:14 am

SpaceX will need water access for big stuff at Boca Chica - they must have plans for a pier and possibly breakwater at coast of end of Boca Chica Blvd next to their facility.
>

Covered; a road is to be built between the harbor and Highway 4, which runs next to the SpaceX facilities.

Link... (https://www.portofbrownsville.com/officials-plan-to-break-ground-on-east-loop-project/)
Not by June.
 They might make it down 511. There are about 40 power lines crossing the road, but all low voltage. It would just take a little work on the corner lot to cut the corner onto Hwy 4.
 As with a lot of things, people tend to greatly underestimate what a pier would entail here.
Companies that move large infrastructure, construct temporary landings, and use barges and pontoons to ferry their fare. I was thinking they could transport a complete SS prototype assuming it was horizontal, on a barge and literally dry it out on the beach between tides. A temporary roadway of heavy timbers and steel sheet would be laid down used and removed between tides to drive an SPMT vehicle carrying the SS onto the road.
However this would be expensive.... but SX has the drone ships, with positioning thrusters.... Would EM  decide SX could do this themselves on the cheap? Even if the drone ships are not suitable, a barge must be easy to acquire. SX are familiar with tugs etc. 
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: dnavas on 01/15/2019 12:32 am
Companies that move large infrastructure, construct temporary landings, and use barges and pontoons to ferry their fare.

Why not just rent a hovercraft?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RonM on 01/15/2019 01:10 am

SpaceX will need water access for big stuff at Boca Chica - they must have plans for a pier and possibly breakwater at coast of end of Boca Chica Blvd next to their facility.
>

Covered; a road is to be built between the harbor and Highway 4, which runs next to the SpaceX facilities.

Link... (https://www.portofbrownsville.com/officials-plan-to-break-ground-on-east-loop-project/)
Not by June.
 They might make it down 511. There are about 40 power lines crossing the road, but all low voltage. It would just take a little work on the corner lot to cut the corner onto Hwy 4.
 As with a lot of things, people tend to greatly underestimate what a pier would entail here.
Companies that move large infrastructure, construct temporary landings, and use barges and pontoons to ferry their fare. I was thinking they could transport a complete SS prototype assuming it was horizontal, on a barge and literally dry it out on the beach between tides. A temporary roadway of heavy timbers and steel sheet would be laid down used and removed between tides to drive an SPMT vehicle carrying the SS onto the road.
However this would be expensive.... but SX has the drone ships, with positioning thrusters.... Would EM  decide SX could do this themselves on the cheap? Even if the drone ships are not suitable, a barge must be easy to acquire. SX are familiar with tugs etc.

I don't that is happening. It's a public beach. They would need an environmental impact study and approval before doing work on the beach. I don't think SpaceX wants to wait a few years before they can conduct an amphibious landing.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: docmordrid on 01/15/2019 01:10 am
I would think hovercraft and SeaBee style operations on the beach would require an amended EA, get the greenies upset and start a flood of court filings.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DistantTemple on 01/15/2019 01:14 am
Companies that move large infrastructure, construct temporary landings, and use barges and pontoons to ferry their fare.

Why not just rent a hovercraft?
Someone email Elon.... I bet there's and army surplus one around  somewhere!  Absolutely perfect idea!!!!!

Its not like they will be brining in barges and hovercraft every week or month - well not at first. And if this is theoretically temporary until the road gets built.... And isn't Brownsville gagging for the sort of lift SX has given McGregor?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Warby12 on 01/15/2019 02:37 am

SpaceX will need water access for big stuff at Boca Chica - they must have plans for a pier and possibly breakwater at coast of end of Boca Chica Blvd next to their facility.
>

Covered; a road is to be built between the harbor and Highway 4, which runs next to the SpaceX facilities.

Link... (https://www.portofbrownsville.com/officials-plan-to-break-ground-on-east-loop-project/)
Not by June.
 They might make it down 511. There are about 40 power lines crossing the road, but all low voltage. It would just take a little work on the corner lot to cut the corner onto Hwy 4.
 As with a lot of things, people tend to greatly underestimate what a pier would entail here.
Companies that move large infrastructure, construct temporary landings, and use barges and pontoons to ferry their fare. I was thinking they could transport a complete SS prototype assuming it was horizontal, on a barge and literally dry it out on the beach between tides. A temporary roadway of heavy timbers and steel sheet would be laid down used and removed between tides to drive an SPMT vehicle carrying the SS onto the road.
However this would be expensive.... but SX has the drone ships, with positioning thrusters.... Would EM  decide SX could do this themselves on the cheap? Even if the drone ships are not suitable, a barge must be easy to acquire. SX are familiar with tugs etc.

Possible  I bet, but I don't think I would want my beautiful spaceship nudged against the beach in hurricane season.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/15/2019 03:38 am
One large issue from the perspective of anything being build of the BFR scale away from Boca Chick is how does it get to the site. Nomadd, could you weigh in if the existing roadways from the Port of Brownsville could accommodate a 9m diameter object - possibly with some temporary power line removal, etc, or is it not realistic without the new roadway?


If not realistic then don't count on seeing a higher fidelity craft showing up before that roadway has been built...

The Orbital testing version of BFR/Starship will be launched from Cape Canaveral, and will most likely use the same method as transporting the Saturn V components, via sea barges.
Welcome, but...
That is your highly speculative opinion and should be labeled as such. Unless you're an insider, which has not been established.

That is where SpaceX has shown it launching from, in both 2016 and 2017 archeticture animations, and in the dearmoon presentation. The dearmoon flight plan graphic shows launch from Florida.

Any other launch site is highly speculative. The Cape is the only one we know for sure that SpaceX is thinking about using.
Actually, at about 1:19 in the DearMoon presentation he specifically says that they haven't decided on where the first orbital launches will be from. And the only specific mention he makes at that time is of a floating platform, without specifying where that platform might or might not be located.

 DearMoon (https://www.youtube.com/watch?v=zu7WJD8vpAQ)
Yes, that is consistent with what I said.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: IntoTheVoid on 01/15/2019 04:19 am
Any other launch site is highly speculative. The Cape is the only one we know for sure that SpaceX is thinking about using.
Actually, at about 1:19 in the DearMoon presentation he specifically says that they haven't decided on where the first orbital launches will be from. And the only specific mention he makes at that time is of a floating platform, without specifying where that platform might or might not be located.

 DearMoon (https://www.youtube.com/watch?v=zu7WJD8vpAQ)
Yes, that is consistent with what I said.
No, you presented the cape as non-speculative, which the video refutes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: ngkiwi on 01/15/2019 05:25 am
This is pure speculation:  The orbital BFH is assembled and launched at Vandenberg Air Force Base.  It deorbits and lands at Boca Chica.

I am picking transportation, logistics, desire, delta v, deorbiting over populated areas to name a few would rule it out, however, it could also be a first step in proving the SS as an intercity travel system
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/15/2019 05:52 am
Responding to a post in the update thread:

Looking later picture and Videos

I starting to have doubts about this Starhopper purpose

1. it's not build by SpaceX it self, but by a company that build Water-towers 
2. Starhopper is build right next to Mission control center at Boca Chica, too close for flight test
3. were is the launch-pad, fuel tanks and landing-pad for that thing ?
4. this thing stand dangerous close to town of Boca Chica for start and landing

Personal i think Starhopper is merely a water-tower with capacity of 1600 m^3 at Mission control
and Elon Musk is mess around with fandom...
Have you completely missed the launch and landing area? It was noted in the video above your post.

The hopper will be moved there before it flies. But it is waiting for the interior to be fitted out (tanks and engines), and for the pad to be done. Musk has said it should be ready in a month. Why is that so hard to believe?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: QuantumG on 01/15/2019 06:58 am
Pet peeve, people keep talking about "tanks" being "installed inside". That big shiny thing you see in front of you, that is the tanks. Those big dome things, they're bits that separate the propellants and stop them from falling out the bottom. I wouldn't be surprised if those engines we can see are what will get this monster off the ground, too.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/15/2019 07:03 am
Pet peeve, people keep talking about "tanks" being "installed inside". That big shiny thing you see in front of you, that is the tanks. Those big dome things, they're bits that separate the propellants and stop them from falling out the bottom. I wouldn't be surprised if those engines we can see are what will get this monster off the ground, too.

Good point about the "tanks".

But unless Elon is lying or mistaken, he has said it will get new/real engines. Also, see image... That engine will not be fired. You do not expose the nozzle cooling channel inlets to a dusty environment on an engine you plan to use. (see image)

https://twitter.com/elonmusk/status/1081572521105707009
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/15/2019 07:41 am
Pet peeve, people keep talking about "tanks" being "installed inside". That big shiny thing you see in front of you, that is the tanks. Those big dome things, they're bits that separate the propellants and stop them from falling out the bottom. I wouldn't be surprised if those engines we can see are what will get this monster off the ground, too.

Completely agree about the tanks.
I'm a lot less sure about the engines. With the hopper integrated and the crane gone, the only way to add the bulkhead is through the bottom. And that would mean that they have to remove everything that is currently installed there. And since Musk said that the flight engines will undergo testing in McGregor this month, I believe that the currently installed engines will be replaced with the real things over the next few weeks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Rei on 01/15/2019 03:03 pm
So, they're taking off the cosmetic panels that covered the seam between segments on the "photo" side now. Wouldn't be surprised if they separate the two portions today.  If so, we'll hopefully see bulkhead installation get started over the next several days.  Then the bottom portion will genuinely be "tanks"  ;)

At some point - personally - I expect them to install a dummy payload inside the upper portion.  Just so photographs can give the payload volume a sense of scale.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/15/2019 03:46 pm
Well if they install the tanks bulkheads before getting the new engines that will be illuminating.  Not sure how easy it will be to work on it while it's vertical, they are so used to horizontal work on F9s.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Cheapchips on 01/15/2019 04:01 pm
Well if they install the tanks bulkheads before getting the new engines that will be illuminating.  Not sure how easy it will be to work on it while it's vertical, they are so used to horizontal work on F9s.

I'm sure part of the hopper's purpose is to give them plenty of practical experience with vertical work.

As pointed out a while back, there's a wield heating line where the bottom bulkhead would be (now covered with tin foil).  It's possible they only need to install the top and tank dividers once they've lifted the hat off.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/15/2019 04:13 pm
I know it is not the best photo but I caught it being moved.
So they picked up a scissor lift and are moving it somewhere. Typically for external stuff they've used boom lifts, so it's a bit odd they are craning around a scissor lift. BocaChicaGal, did you see where they dropped it?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: acsawdey on 01/15/2019 04:18 pm
I know it is not the best photo but I caught it being moved.
So they picked up a scissor lift and are moving it somewhere. Typically for external stuff they've used boom lifts, so it's a bit odd they are craning around a scissor lift. BocaChicaGal, did you see where they dropped it?

Is this the scissors lift that we inferred was inside the hopper but haven't actually seen until now?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: bocachicagal on 01/15/2019 04:24 pm
I know it is not the best photo but I caught it being moved.
So they picked up a scissor lift and are moving it somewhere. Typically for external stuff they've used boom lifts, so it's a bit odd they are craning around a scissor lift. BocaChicaGal, did you see where they dropped it?
I did not see where they set it down as I was too far away. I can visually see one inside the concrete base. Looks like the Hopper is being separated.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: bocachicagal on 01/15/2019 05:00 pm
I know it is not the best photo but I caught it being moved.
So they picked up a scissor lift and are moving it somewhere. Typically for external stuff they've used boom lifts, so it's a bit odd they are craning around a scissor lift. BocaChicaGal, did you see where they dropped it?
I did not see where they set it down as I was too far away. I can visually see one inside the concrete base. Looks like the Hopper is being separated.
Nosecone and bottom section has been separated.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: OxCartMark on 01/15/2019 05:09 pm
Nosecone and bottom section has been separated.


That's normal.  My Estes model rockets all did that when they got to the top of their flights.  It lets the parachutes out.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/15/2019 05:26 pm
Once again it has been separated.
You cheated and drove there. Real photographers walk through the rain.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: philw1776 on 01/15/2019 05:50 pm
Pet peeve, people keep talking about "tanks" being "installed inside". That big shiny thing you see in front of you, that is the tanks. Those big dome things, they're bits that separate the propellants and stop them from falling out the bottom. I wouldn't be surprised if those engines we can see are what will get this monster off the ground, too.

Yah, I've talked about dropping in small tanks but I agree that it's more likely the tanks are there as you say.
Flight engine arrival & installation date TBD.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wargrim on 01/15/2019 06:04 pm
Looks like the border guard did tell the truth. Maybe they will lift the dome in today, put "hat" back on and start welding up the next dome the coming days.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/15/2019 07:25 pm
 It looks like the rain has shut things down for the day.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Chris Bergin on 01/15/2019 07:32 pm
I just got rained out. This is where they have been working since the separation.

Taking out the fake Raptors?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: kevinof on 01/15/2019 07:38 pm
... and fit the lower tank dome?

I just got rained out. This is where they have been working since the separation.

Taking out the fake Raptors?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: kdhilliard on 01/15/2019 07:52 pm
I just got rained out. This is where they have been working since the separation.
Was the crane in place to lift the Raptors out from above?  If so, that suggests the lowest bulkhead had not yet been installed.

Edit: Looking more closely, I see that they are lifting the Raptor from below with the bell resting on a pallet.  Strange, how high it was lifted,  if they are ultimately removing it from below.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: acsawdey on 01/15/2019 08:10 pm
I just got rained out. This is where they have been working since the separation.
Was the crane in place to lift the Raptors out from above?  If so, that suggests the lowest bulkhead had not yet been installed.

Edit: Looking more closely, I see that they are lifting the Raptor from below with the bell resting on a pallet.  Strange, how high it was lifted,  if they are ultimately removing it from below.

I wonder if it's not actually lifting that high. It could be that the fake sheet-metal nozzle extension is not attached to the real bell, but is just slid down over it. The pallet is lifted up to the point where the real bell is resting on it, and the fake extension just slides up. Then the thrust chamber above the real bell can be unbolted and the whole thing lowered down. We know from the photos through the leg hole that there is what appears to be a real nozzle with cooling fittings and thrust chamber above. For a fit check it would make sense for the top of the thrust chamber to bolt to the thrust vectoring system the same way a real raptor would.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Slarty1080 on 01/15/2019 08:34 pm
Given the all the current outside engineering work in all elements at Boca Chica, another use for the BFH might be testing out all weather engineering arrangements. There must be a lot to learn from this sort of novel build it outside approach. I note they had to use sand bags at one point probably to stop water ingress to the base of the BFH during construction.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: IntoTheVoid on 01/15/2019 08:56 pm
I just got rained out. This is where they have been working since the separation.
Was the crane in place to lift the Raptors out from above?  If so, that suggests the lowest bulkhead had not yet been installed.

Edit: Looking more closely, I see that they are lifting the Raptor from below with the bell resting on a pallet.  Strange, how high it was lifted,  if they are ultimately removing it from below.

I wonder if it's not actually lifting that high. It could be that the fake sheet-metal nozzle extension is not attached to the real bell, but is just slid down over it. The pallet is lifted up to the point where the real bell is resting on it, and the fake extension just slides up. Then the thrust chamber above the real bell can be unbolted and the whole thing lowered down. We know from the photos through the leg hole that there is what appears to be a real nozzle with cooling fittings and thrust chamber above. For a fit check it would make sense for the top of the thrust chamber to bolt to the thrust vectoring system the same way a real raptor would.

That certainly appears to be the case in bocachicagal's latest pic.

All three have been removed. Once on the ground they were quickly covered. Still raining here.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: _mit on 01/15/2019 10:09 pm
Pet peeve, people keep talking about "tanks" being "installed inside". That big shiny thing you see in front of you, that is the tanks. Those big dome things, they're bits that separate the propellants and stop them from falling out the bottom. I wouldn't be surprised if those engines we can see are what will get this monster off the ground, too.

Yah, I've talked about dropping in small tanks but I agree that it's more likely the tanks are there as you say.
Flight engine arrival & installation date TBD.

Could they go with say a methane tank inside an oxygen tank so that they'd only need one bulkhead - or is that too much surface area in common? I was picturing the full build-out scenario where there will be a landing fuel tank inside the outer tank and thought it could keep them from needing to extend up into the "foil" section of the hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: georgegassaway on 01/15/2019 11:15 pm
Given how relatively easily they removed the upper section from the lower section, that could indicate what they might do when it is time to move it to the pad.

Not as one complete vehicle, but move the two separately, then rejoin again at the pad.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/15/2019 11:47 pm
Given how relatively easily they removed the upper section from the lower section, that could indicate what they might do when it is time to move it to the pad.

Not as one complete vehicle, but move the two separately, then rejoin again at the pad.
That's my guess. Of course, even though the thing looks really tall when assembled, about 95% of the mass is in the bottom section so it wouldn't really be top heavy. And final assembly might be a lot more than a few bolts through tabs.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: QuantumG on 01/16/2019 12:14 am
Final weld together on the pad, ya think? Doing the first pressure test on the pad seems like a good idea.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RobLynn on 01/16/2019 12:32 am
SpaceX are going to need a big trailer of some sort to transport Hopper plus future 1st Starship and maybe Superheavy from delivery barges to and from launch pad.  So they will probably have it ready to use in a few weeks when they need to move the Hopper to the launchpad, without disassembly.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: QuantumG on 01/16/2019 12:43 am
Are ya thinking they'll take it down the existing road or are we waiting until that loooooooong access road is built?

I love this picture because you can just make out the Starhopper in the background, that's how far they have to move it.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: groknull on 01/16/2019 12:45 am
Pet peeve, people keep talking about "tanks" being "installed inside". That big shiny thing you see in front of you, that is the tanks. Those big dome things, they're bits that separate the propellants and stop them from falling out the bottom. I wouldn't be surprised if those engines we can see are what will get this monster off the ground, too.

Yah, I've talked about dropping in small tanks but I agree that it's more likely the tanks are there as you say.
Flight engine arrival & installation date TBD.

Could they go with say a methane tank inside an oxygen tank so that they'd only need one bulkhead - or is that too much surface area in common? I was picturing the full build-out scenario where there will be a landing fuel tank inside the outer tank and thought it could keep them from needing to extend up into the "foil" section of the hopper.

It is possible to make propellant tanks concentric, with a number of tradeoffs, structural mass usually being the biggest negative.  There are some interesting upsides, though, including the possibility of the inside tank acting as main and header tank for that propellant component.

LOX inside LCH4 might be a better arrangement.  LCH4 (tank) fully submerged in LOX (tank) runs the risk of freezing the methane, especially with subcooled LOX.  With concentric tanks, LCH4 in the outer tank would abut the entire side of the vehicle - convenient for methane heat shield cooling.

That said, the hopper doesn't need to have production or flight prototype style tanks to do basic testing on the engines and landing dynamics.  Many tank arrangements would be functional for a hopper.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Lars-J on 01/16/2019 01:21 am
Are ya thinking they'll take it down the existing road or are we waiting until that loooooooong access road is built?

I love this picture because you can just make out the Starhopper in the background, that's how far they have to move it.

Yep, it will have to come down that existing road. They are not building another road, although they will probably widen or improve it at some point. (The gray section in the pad area is not a replacement road, even though it looks like the start of one - unless they have really changed their plans)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/16/2019 01:39 am
Are ya thinking they'll take it down the existing road or are we waiting until that loooooooong access road is built?

I love this picture because you can just make out the Starhopper in the background, that's how far they have to move it.

The highway shoulders were reconstructed to bear weight, and the project ended exactly where that ramp hits the road, so I think the road has been the plan since it was going to be a Falcon site. The ramp is going the other way now, so they'll either have to make a sharp turn or back it up.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/16/2019 01:50 am
 To answer a few questions, they lifted the engines up about four feet with a reach forklift, one at a time, did some work and lowered them back down. They stayed in one piece, including the added on bell. They threw a cover on them within a few seconds of lowering them, and a good photo was hard to get since they weren't considerate enough to warn us first.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Oersted on 01/16/2019 05:40 am
Here's a manual focus ring for you, Nomadd. I'm sure you can fit it onto your camera somehow.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Joel193 on 01/16/2019 09:57 am
BFH? Do you mean a Falcon heavy with more boosters or a BFR with side boosters?

A MOAR BOOSTERS FH would have ridiculous LEO payload but would be pretty useless given the current fairing size.

A multi-core BFR would only reduce the number of refueling launches required for Mars journeys. The Mars payload wouldn't increase as that is dependent on the spaceship's Delta V.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jpo234 on 01/16/2019 10:17 am
BFH? Do you mean a Falcon heavy with more boosters or a BFR with side boosters?

A MOAR BOOSTERS FH would have ridiculous LEO payload but would be pretty useless given the current fairing size.

A multi-core BFR would only reduce the number of refueling launches required for Mars journeys. The Mars payload wouldn't increase as that is dependent on the spaceship's Delta V.

Hint: Read the Subject line of your very own post:

Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: IntoTheVoid on 01/16/2019 12:38 pm
To answer a few questions, they lifted the engines up about four feet with a reach forklift, one at a time, did some work and lowered them back down. They stayed in one piece, including the added on bell. They threw a cover on them within a few seconds of lowering them, and a good photo was hard to get since they weren't considerate enough to warn us first.
Could you help us better understand this crop of a recent bocachicagal pic where it appears that the lower portion of the bell is detached and raised relative to the thrust chamber and upper bell? Or are you considering that as stayed in one piece, or is that one 'engine' not representative of the other two? Thanks for all your reporting and insights.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DJPledger on 01/16/2019 12:47 pm
To answer a few questions, they lifted the engines up about four feet with a reach forklift, one at a time, did some work and lowered them back down. They stayed in one piece, including the added on bell. They threw a cover on them within a few seconds of lowering them, and a good photo was hard to get since they weren't considerate enough to warn us first.
Could you help us better understand this crop of a recent bocachicagal pic where it appears that the lower portion of the bell is detached and raised relative to the thrust chamber and upper bell? Or are you considering that as stayed in one piece, or is that one 'engine' not representative of the other two? Thanks for all your reporting and insights.
Boilerplate bell extension likely held only by gravity so as soon as the "engine" was lowered on to the pallet, the bell extension detached. They weren't really engines as they had no powerpacks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: IntoTheVoid on 01/16/2019 01:13 pm
To answer a few questions, they lifted the engines up about four feet with a reach forklift, one at a time, did some work and lowered them back down. They stayed in one piece, including the added on bell. They threw a cover on them within a few seconds of lowering them, and a good photo was hard to get since they weren't considerate enough to warn us first.
Could you help us better understand this crop of a recent bocachicagal pic where it appears that the lower portion of the bell is detached and raised relative to the thrust chamber and upper bell? Or are you considering that as stayed in one piece, or is that one 'engine' not representative of the other two? Thanks for all your reporting and insights.
Boilerplate bell extension likely held only by gravity so as soon as the "engine" was lowered on to the pallet, the bell extension detached. They weren't really engines as they had no powerpacks.
That is what I 'see' as well, which contradicts some of what Nomadd said about it staying in one piece, which was why I quoted him, and was looking for his insight.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/16/2019 01:40 pm
To answer a few questions, they lifted the engines up about four feet with a reach forklift, one at a time, did some work and lowered them back down. They stayed in one piece, including the added on bell. They threw a cover on them within a few seconds of lowering them, and a good photo was hard to get since they weren't considerate enough to warn us first.
Could you help us better understand this crop of a recent bocachicagal pic where it appears that the lower portion of the bell is detached and raised relative to the thrust chamber and upper bell? Or are you considering that as stayed in one piece, or is that one 'engine' not representative of the other two? Thanks for all your reporting and insights.

 It looks like I was wrong. The one I got coming out was fuzzy and through a fence in the rain. The cone in BCGs photo looks bigger than the revealed upper part in the installed photos. It must go further down into the extension than I thought.
 She got better pictures than me because she was patient enough to wait in a good spot in the rain instead of wandering around, looking for better angles like I did. We might have to start a supply service out to her so she can stay out there full time.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Tommyboy on 01/16/2019 02:22 pm
Final weld together on the pad, ya think? Doing the first pressure test on the pad seems like a good idea.
They can pressure test without the top on, all things that have to be pressurized are in the water tower section. The conical part seems to mainly be for aesthetic (and maybe aerodynamic) reasons, nor for structural reasons.

Delivery at the big dish area.
What would they need helium for at Boca Chica? I'd think helium is to expensive for pressure testing (just use air or N2), and considering that I remember Elon saying that the BFH would use autogenous pressurization just like the real deal that also can't be its purpose. Maybe they need an inert gas to purge some tanks/plumbing?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/16/2019 03:26 pm
Final weld together on the pad, ya think? Doing the first pressure test on the pad seems like a good idea.
They can pressure test without the top on, all things that have to be pressurized are in the water tower section. The conical part seems to mainly be for aesthetic (and maybe aerodynamic) reasons, nor for structural reasons.

Delivery at the big dish area.
What would they need helium for at Boca Chica? I'd think helium is to expensive for pressure testing (just use air or N2), and considering that I remember Elon saying that the BFH would use autogenous pressurization just like the real deal that also can't be its purpose. Maybe they need an inert gas to purge some tanks/plumbing?

They might use helium to press the tanks on the pad while hooked up to GSE before the engines are running.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: philw1776 on 01/16/2019 03:28 pm
Final weld together on the pad, ya think? Doing the first pressure test on the pad seems like a good idea.
They can pressure test without the top on, all things that have to be pressurized are in the water tower section. The conical part seems to mainly be for aesthetic (and maybe aerodynamic) reasons, nor for structural reasons.

Delivery at the big dish area.
What would they need helium for at Boca Chica? I'd think helium is to expensive for pressure testing (just use air or N2), and considering that I remember Elon saying that the BFH would use autogenous pressurization just like the real deal that also can't be its purpose. Maybe they need an inert gas to purge some tanks/plumbing?

Ignore map labels.  5 years old when planning for F9 launches.  No helium.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/16/2019 03:33 pm
Final weld together on the pad, ya think? Doing the first pressure test on the pad seems like a good idea.
They can pressure test without the top on, all things that have to be pressurized are in the water tower section. The conical part seems to mainly be for aesthetic (and maybe aerodynamic) reasons, nor for structural reasons.

Delivery at the big dish area.
What would they need helium for at Boca Chica? I'd think helium is to expensive for pressure testing (just use air or N2), and considering that I remember Elon saying that the BFH would use autogenous pressurization just like the real deal that also can't be its purpose. Maybe they need an inert gas to purge some tanks/plumbing?

Ignore map labels.  5 years old when planning for F9 launches.  No helium.

Reference to this:

Delivery at the big dish area.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Johnnyhinbos on 01/16/2019 03:55 pm
Final weld together on the pad, ya think? Doing the first pressure test on the pad seems like a good idea.
They can pressure test without the top on, all things that have to be pressurized are in the water tower section. The conical part seems to mainly be for aesthetic (and maybe aerodynamic) reasons, nor for structural reasons.

Delivery at the big dish area.
What would they need helium for at Boca Chica? I'd think helium is to expensive for pressure testing (just use air or N2), and considering that I remember Elon saying that the BFH would use autogenous pressurization just like the real deal that also can't be its purpose. Maybe they need an inert gas to purge some tanks/plumbing?

Ignore map labels.  5 years old when planning for F9 launches.  No helium.
Helium:


(photo credit to BocaChicaGal from photo thread this AM)

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wargrim on 01/16/2019 04:02 pm
What would they need helium for at Boca Chica? I'd think helium is to expensive for pressure testing (just use air or N2), and considering that I remember Elon saying that the BFH would use autogenous pressurization just like the real deal that also can't be its purpose. Maybe they need an inert gas to purge some tanks/plumbing?

Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/16/2019 04:11 pm
They might use helium to press the tanks on the pad while hooked up to GSE before the engines are running.

Isn't helium also often used as a shielding gas in stainless steel welding applications?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RonM on 01/16/2019 04:13 pm
Delivery at the big dish area.
What would they need helium for at Boca Chica? I'd think helium is to expensive for pressure testing (just use air or N2), and considering that I remember Elon saying that the BFH would use autogenous pressurization just like the real deal that also can't be its purpose. Maybe they need an inert gas to purge some tanks/plumbing?

Inert gas for purging tanks is reasonable. When did Elon say BFH would be autogenous? Nice to test early, but not really needed for test hopping.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/16/2019 04:18 pm
Inert gas for purging tanks is reasonable. When did Elon say BFH would be autogenous? Nice to test early, but not really needed for test hopping.

Yes but there are cheaper options (nitrogen) if they just needed an inert gas.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: acsawdey on 01/16/2019 04:40 pm
Inert gas for purging tanks is reasonable. When did Elon say BFH would be autogenous? Nice to test early, but not really needed for test hopping.

Yes but there are cheaper options (nitrogen) if they just needed an inert gas.

If you use nitrogen, don't you run the risk of condensing some of the pressurant into the LOX or LCH4? Thus if you are on the pad for a long time (as might be with a new hopper) you might have significant amounts of nitrogen mixed in with your propellants.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wargrim on 01/16/2019 04:45 pm
One of the smaller tanks stored at the big dish area was transported to the launch site area.

Things are starting to move. Nice. Pad and production Raptors seem to be the longer items on the ready-to-hop checklist.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RoboGoofers on 01/16/2019 05:03 pm
They might use helium to press the tanks on the pad while hooked up to GSE before the engines are running.

Isn't helium also often used as a shielding gas in stainless steel welding applications?

That would be a lot of welding.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: JonathanD on 01/16/2019 05:06 pm
That would be a lot of welding.

Well, if they decided to replace those spot welds on the hopper with seams...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MrHollifield on 01/16/2019 05:11 pm
Do the tracking antennas have waveguides that might be pressurized with helium? The delivery may have nothing to do with BFH.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jeffreycornish on 01/16/2019 05:22 pm
Do the tracking antennas have waveguides that might be pressurized with helium? The delivery may have nothing to do with BFH.

For radio astronomy some telescopes will cool components with cryogens to drop the amount of noise.

https://en.wikipedia.org/wiki/Beam_waveguide_antenna

However, 1) that is a LOT of Helium for two tracking/data dishes and 2) Helium would be a logical BFH tank pressurant leading up to autogenous tank pressurization.

SpaceX is doing things in steps, not leaps (beyond building a rocket outdoors, out of stainless steel, etc, etc, etc)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: burger on 01/16/2019 05:23 pm
What would they need helium for at Boca Chica? I'd think helium is to expensive for pressure testing (just use air or N2), and considering that I remember Elon saying that the BFH would use autogenous pressurization just like the real deal that also can't be its purpose. Maybe they need an inert gas to purge some tanks/plumbing?


Helium is also often used for leak testing. The small molecules mean it can find it's way through tiny cracks/leaks and it's easy to detect.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RonM on 01/16/2019 05:26 pm
Inert gas for purging tanks is reasonable. When did Elon say BFH would be autogenous? Nice to test early, but not really needed for test hopping.

Yes but there are cheaper options (nitrogen) if they just needed an inert gas.

If you use nitrogen, don't you run the risk of condensing some of the pressurant into the LOX or LCH4? Thus if you are on the pad for a long time (as might be with a new hopper) you might have significant amounts of nitrogen mixed in with your propellants.

I believe that's correct. There are reasons why the industry uses helium instead of nitrogen to pressurize propellant tanks. Any experts like to explain?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/16/2019 05:48 pm
Do the tracking antennas have waveguides that might be pressurized with helium? The delivery may have nothing to do with BFH.
They use to, but one has been converted and no longer uses waveguides. The other is still a decoration.
 And those tanks are about a hundred times as big as waveguide pressure tanks would be.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Nomadd on 01/16/2019 05:49 pm
One of the smaller tanks stored at the big dish area was transported to the launch site area.
It's vertical. I'm working on the pole camera for a day or two, so it's all yours.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: envy887 on 01/16/2019 05:50 pm
Inert gas for purging tanks is reasonable. When did Elon say BFH would be autogenous? Nice to test early, but not really needed for test hopping.

Yes but there are cheaper options (nitrogen) if they just needed an inert gas.

If you use nitrogen, don't you run the risk of condensing some of the pressurant into the LOX or LCH4? Thus if you are on the pad for a long time (as might be with a new hopper) you might have significant amounts of nitrogen mixed in with your propellants.

I believe that's correct. There are reasons why the industry uses helium instead of nitrogen to pressurize propellant tanks. Any experts like to explain?
More pressure per kg.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Bananas_on_Mars on 01/16/2019 06:01 pm
They might use helium to press the tanks on the pad while hooked up to GSE before the engines are running.

Isn't helium also often used as a shielding gas in stainless steel welding applications?
Helium is normally only used as a mix with Argon when welding aluminium (and even than only in some special cases), for stainless steel you normally use pure argon, sometimes with a few percent of hydrogen. Argon is far cheaper than helium.

My pet project ISRU would perhaps use a helium cooling loop for liquefying air on site... Don't know how the commercial air liquefying works, but a helium cooling loop is planned for skylon, so it should be able to build a pretty compact unit when using helium...
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MizaruSpaceXNut on 01/16/2019 06:37 pm
To answer a few questions, they lifted the engines up about four feet with a reach forklift, one at a time, did some work and lowered them back down. They stayed in one piece, including the added on bell. They threw a cover on them within a few seconds of lowering them, and a good photo was hard to get since they weren't considerate enough to warn us first.
Reckon why they were hurrying to cover the dummy engines? Perhaps they didn't want you to get pictures? I

had to sign a non-disclosure agreement where I worked! It forbade me to invent anything or go to work for a

competitor for a year after I retired! Some companies are secretive, sometimes.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: jeffreycornish on 01/16/2019 06:56 pm
They might use helium to press the tanks on the pad while hooked up to GSE before the engines are running.

Isn't helium also often used as a shielding gas in stainless steel welding applications?
Helium is normally only used as a mix with Argon when welding aluminium (and even than only in some special cases), for stainless steel you normally use pure argon, sometimes with a few percent of hydrogen. Argon is far cheaper than helium.

My pet project ISRU would perhaps use a helium cooling loop for liquefying air on site... Don't know how the commercial air liquefying works, but a helium cooling loop is planned for skylon, so it should be able to build a pretty compact unit when using helium...

A bit of a stretch here, as there doesn't appear to be the equipment to do it, but perhaps SpaceX could look into an IRSU setup: Liquify O2, and generate CH4 from CO2 and Water onsite.   However, I'd expect a lot more equipment to do so, or at least a couple weird trailers connected to solar arrays and dewers.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: enbandi on 01/16/2019 07:10 pm
According possible ISRU experiments in BC my opinion is that wont likelly happen (there).
Dont forget that BC is a far off/side location from core engineering/ management/ logistics perspective, each makes any kind of activity more difficult, while BC dont offer any advantages over LA or any other place.
Hopper tests and so hopper construction have to do there due to permits and so, but you can test a small ISRU plant maybe directly in Hawthorne/Seattle.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: archae86 on 01/16/2019 07:13 pm
The recently posted bulkhead photos from bocachicagal show a line of tightly spaced large holes all along the rim.  The combination of size and spacing surprises me.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: DJPledger on 01/16/2019 07:18 pm
To answer a few questions, they lifted the engines up about four feet with a reach forklift, one at a time, did some work and lowered them back down. They stayed in one piece, including the added on bell. They threw a cover on them within a few seconds of lowering them, and a good photo was hard to get since they weren't considerate enough to warn us first.
Reckon why they were hurrying to cover the dummy engines? Perhaps they didn't want you to get pictures? I

had to sign a non-disclosure agreement where I worked! It forbade me to invent anything or go to work for a

competitor for a year after I retired! Some companies are secretive, sometimes.
I think these were real test engines with the powerpacks removed so could be possibly covered by ITAR. Also test hardware may be on the sensitive side.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Bananas_on_Mars on 01/16/2019 07:27 pm
According possible ISRU experiments in BC my opinion is that wont likelly happen (there).
Dont forget that BC is a far off/side location from core engineering/ management/ logistics perspective, each makes any kind of activity more difficult, while BC dont offer any advantages over LA or any other place.
Hopper tests and so hopper construction have to do there due to permits and so, but you can test a small ISRU plant maybe directly in Hawthorne/Seattle.

In Boca Chica, they have a big solar field, storage tanks and a test hopper that might make good use of the propellant they produce. And not to many neighbours in case your ISRU equipment decides to undergo RUD.
ISRU equipment on Mars might have to run unsupervised for years, so they might as well do the main monitoring in Hawthorne.

"SpaceX is already developing high efficiency CO2 capture with H2O to form liquid CH4 (methane) & O2. Critical for propellant production at Mars Base Alpha." Elon Musk, June 2018 (https://twitter.com/elonmusk/status/1005874658015522816)

I guess they're ready to go a little bit bigger than what you can do in a lab.
The ISRU equipment sized for for Starship should fit into one or two shipping containers.

Of course this is a little bit offtopic here, but i just wanted to chime in and say the helium delivery isn't necessarily hopper related.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: matthewkantar on 01/16/2019 07:28 pm
All these perforations seem to be for rosette welds. This is a clear indication the tank will be pressurized. If they rivet the domes into place, my head will explode.

Matthew
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: RobLynn on 01/16/2019 07:33 pm
Reckon why they were hurrying to cover the dummy engines? Perhaps they didn't want you to get pictures?

Could be patenting some engine design features that would be revealed by photos.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wolfram66 on 01/16/2019 07:50 pm
All these perforations seem to be for rosette welds. This is a clear indication the tank will be pressurized. If they rivet the domes into place, my head will explode.

Matthew

probably just a bolted pressure vessel as seen in this mechanical engineering textbook question from chegg

https://www.chegg.com/homework-help/questions-and-answers/gas-storage-tank-fabricated-bolting-together-two-half-cylindrical-thin-shells-two-hemisphe-q16510177 (https://www.chegg.com/homework-help/questions-and-answers/gas-storage-tank-fabricated-bolting-together-two-half-cylindrical-thin-shells-two-hemisphe-q16510177)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Kaputnik on 01/16/2019 07:54 pm
Sorry if it's been mentioned, but do we think the bulkhead is also S/S?
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: gaballard on 01/16/2019 08:01 pm
To answer a few questions, they lifted the engines up about four feet with a reach forklift, one at a time, did some work and lowered them back down. They stayed in one piece, including the added on bell. They threw a cover on them within a few seconds of lowering them, and a good photo was hard to get since they weren't considerate enough to warn us first.
Reckon why they were hurrying to cover the dummy engines? Perhaps they didn't want you to get pictures? I

had to sign a non-disclosure agreement where I worked! It forbade me to invent anything or go to work for a

competitor for a year after I retired! Some companies are secretive, sometimes.

Sorry for being off-topic, but FWIW, non-compete clauses like that are essentially unenforceable and, depending on where you worked, illegal.

Source: https://www.hrexaminer.com/is-your-non-compete-agreement-enforceable/ (https://www.hrexaminer.com/is-your-non-compete-agreement-enforceable/)
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: WindyCity on 01/16/2019 08:10 pm
I don't recall any posts explaining why the BFH tests are being conducted at Boca Chica. Pardon me if that question has been explored earlier. For testing purposes, why wouldn't they have used existing facilities at McGregor? The F9 hopper tests climbed pretty high. I don't think they reached 5km in altitude, so perhaps that's the issue.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: philw1776 on 01/16/2019 08:15 pm
I don't recall any posts explaining why the BFH tests are being conducted at Boca Chica. Pardon me if that question has been explored earlier. For testing purposes, why wouldn't they have used existing facilities at McGregor? The F9 hopper tests climbed pretty high. I don't think they reached 5km in altitude, so perhaps that's the issue.

because MacGregor subsequently outlawed ANY & ALL flights
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: Wolfram66 on 01/16/2019 08:15 pm
All these perforations seem to be for rosette welds. This is a clear indication the tank will be pressurized. If they rivet the domes into place, my head will explode.

Matthew

I Flipped BCG's image around to see what is written on the dome... and enhanced for clarity w/ PhotoshopExpress

Adding edit of BCGs picture of other tank dome. Head #2 Section “A”
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: WindyCity on 01/16/2019 08:26 pm
I don't recall any posts explaining why the BFH tests are being conducted at Boca Chica. Pardon me if that question has been explored earlier. For testing purposes, why wouldn't they have used existing facilities at McGregor? The F9 hopper tests climbed pretty high. I don't think they reached 5km in altitude, so perhaps that's the issue.

because MacGregor subsequently outlawed ANY & ALL flights

Ah. Hadn't caught that. Bovine apoplexy? Rattled locals' brains. Thanks for the info.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: MikeAtkinson on 01/16/2019 08:42 pm
Sorry if it's been mentioned, but do we think the bulkhead is also S/S?

I think so, similar to the "water tower" sections, a different grade of stainless than the shiny cladding.,
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: QuantumG on 01/16/2019 08:51 pm
One typically does hydrostatic testing before loading propellants into a redneck rocket. Hydrostatic testing is done with water, thus the name, and doesn't involve helium. i.e., you pump water into the tank-under-test and look for leaks.
Title: Re: Developing the BFS - Phase 1 Big Falcon Hopper (BFH) Discussion - THREAD 2
Post by: AC in NC on 01/16/2019 08:58 pm
Sorry if it's been mentioned, but do we think the bulkhead is also S/S?

I think so, similar to the "water tower" sections, a different grade of stainless than the shiny cladding.,

If I'm not mistaken, the TFH sections also were similar grade of stainless with the shiny cladding.  It's just we never much got a chance to see TFH sections before the cladding was already on