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SpaceX Vehicles and Missions => SpaceX Mega Thread Archive Section => Topic started by: Chris Bergin on 02/17/2015 10:35 am

Title: General Falcon and Dragon discussion (Thread 12)
Post by: Chris Bergin on 02/17/2015 10:35 am
Thread 12 for general discussion on SpaceX's Falcon and Dragon vehicles. Thread 11 isn't locked for the interim, just relocated in the SpaceX "100,000 plus archive section." Allowing quotes from that thread to be posted into this new thread.

Previous threads (now over 3 million views for these 11 SpaceX threads alone):

Thread 1:
http://forum.nasaspaceflight.com/index.php?topic=19228.0

Thread 2:
http://forum.nasaspaceflight.com/index.php?topic=22769.0

Thread 3:
http://forum.nasaspaceflight.com/index.php?topic=24179.0

Thread 4:
http://forum.nasaspaceflight.com/index.php?topic=25597.0

Thread 5:
http://forum.nasaspaceflight.com/index.php?topic=28006.0

Thread 6:
http://forum.nasaspaceflight.com/index.php?topic=29476.0

Thread 7:
http://forum.nasaspaceflight.com/index.php?topic=30385.0

Thread 8:
http://forum.nasaspaceflight.com/index.php?topic=31402.0

Thread 9:
http://forum.nasaspaceflight.com/index.php?topic=32719.0

Thread 10:
http://forum.nasaspaceflight.com/index.php?topic=33598.0

Thread 11:
http://forum.nasaspaceflight.com/index.php?topic=35364.0


SpaceX news articles on this site:
Old: http://forum.nasaspaceflight.com/index.php?topic=21862.0 (links)

Then recent news articles, not linked above, as we moved to a tag group system:
All recent: http://www.nasaspaceflight.com/tag/spacex/


L2 SpaceX - Dedicated all-vehicle (Falcon to BFR/MCT) section:
http://forum.nasaspaceflight.com/index.php?board=60.0


NOTE: Posts that are uncivil (which is very rare for this forum), off topic (not so rare) or just pointless will be deleted without notice.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: SpacemanInSPACE on 02/17/2015 07:36 pm
Amazing how many developments they have coming up for the falcon/dragon system. 1st stage resuse efforts, dragon pad abort, falcon heavy demo.... Did I miss something??
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 02/18/2015 01:48 am
SFN is running with the LC-13 and SLC-4W landing pad leases

Link.... (http://spaceflightnow.com/2015/02/17/spacex-leases-property-for-landing-pads-at-cape-canaveral-vandenberg/)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deltaV on 02/18/2015 03:54 am
From the previous thread:

If the ISS is 180 degrees out of phase only some kind of magic propellantless propulsion is going to allow you to reach it in a few hours.

If you have about 1.6 km/s of delta-vee (or less depending on the latitude of launch site and inclination of target orbit) to waste on a worst-case plane change you can rendezvous with the ISS in one-quarter orbit (less than half an hour). There are two launch opportunities when the phasing is exactly right but the planes are a bit off; launch at the one with the smaller plane change requirement. Phasing isn't important enough to be worth investing that much delta-vee in, but if you wanted to you could do it by e.g. using Falcon Heavy instead of Falcon 9. No advanced preparation nor magic propulsion required. I'm not saying this is a good idea, just that your "magic" claim is wrong.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: oiorionsbelt on 02/25/2015 04:09 pm
Not sure if this picture has been posted elsewhere, so in case it hasn't ....
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dror on 02/25/2015 05:19 pm
This picture and the sight of the expanding flame during launches got me thinking, and I know nothing about it, what if the middle engine was replaced with a truncated spike?
Could it perform a bit like an aerospike engine?
Could it raise the overall ISP by even a nudge?
 :-\
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: RanulfC on 02/25/2015 05:45 pm
This picture and the sight of the expanding flame during launches got me thinking, and I know nothing about it, what if the middle engine was replaced with a truncated spike?
Could it perform a bit like an aerospike engine?
Could it raise the overall ISP by even a nudge?
 :-\

Not really helpful as you'd lose about 147,000lbs of thrust which you need on takeoff :)

It WOULD perform "like" an aerospike because that's what it would be and there'd be some ISP improvement in general but no where near enough to make up for the lost thrust :)

Randy
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Helodriver on 02/25/2015 05:54 pm
Not sure if this picture has been posted elsewhere, so in case it hasn't ....


I know it has because I'm the one who shot originally shot it.

Taken last year at the Dragon 2 reveal event.

Here it is full size.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: abaddon on 02/25/2015 05:55 pm
This picture and the sight of the expanding flame during launches got me thinking, and I know nothing about it, what if the middle engine was replaced with a truncated spike?
Could it perform a bit like an aerospike engine?
Could it raise the overall ISP by even a nudge?
 :-\

Not really helpful as you'd lose about 147,000lbs of thrust which you need on takeoff :)

It WOULD perform "like" an aerospike because that's what it would be and there'd be some ISP improvement in general but no where near enough to make up for the lost thrust :)

Randy

Not to mention, how are you going to land the thing?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 02/25/2015 05:57 pm
This picture and the sight of the expanding flame during launches got me thinking, and I know nothing about it, what if the middle engine was replaced with a truncated spike?
Could it perform a bit like an aerospike engine?
Could it raise the overall ISP by even a nudge?
 :-\

Not really helpful as you'd lose about 147,000lbs of thrust which you need on takeoff :)

It WOULD perform "like" an aerospike because that's what it would be and there'd be some ISP improvement in general but no where near enough to make up for the lost thrust :)

Randy

Not to mention, how are you going to land the thing?

Very carefully, balancing on the truncated spike. ;)

No, I don't think aerospike is worth it for a first stage, since most of its thrust expended deep in the atmosphere.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 02/25/2015 06:04 pm
Also, that spike would be very narrow and hence not much to "push" on
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: oiorionsbelt on 02/25/2015 06:17 pm
Thanks Helodriver.
 What is IPA? International Pale Ale? :)
It's between E9and E8
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: SpacemanInSPACE on 02/25/2015 08:21 pm
Next Dragon leaving Hawthorne according to Spacex twitter, likely CRS-6.

Bout time for a new mission thread Chris!  ;D

https://twitter.com/SpaceX/status/570673437770948608 (https://twitter.com/SpaceX/status/570673437770948608)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: kch on 02/25/2015 08:30 pm
Thanks Helodriver.
 What is IPA? International Pale Ale? :)
It's between E9and E8

Very close:

http://en.wikipedia.org/wiki/India_Pale_Ale (http://en.wikipedia.org/wiki/India_Pale_Ale)

 ;D
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: spacenut on 02/25/2015 08:39 pm
What if they used an aerospike engine on the second stage and it served double duty as a heat shield for second stage return?  Would that affect overall performance?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ISP on 02/25/2015 09:06 pm
What if they used an aerospike engine on the second stage and it served double duty as a heat shield for second stage return?  Would that affect overall performance?

There is no advantage in placing an aerospike engine on the second stage. A conventional bell nozzle does better.

Aerospike engines are meant to mitigate under/over expansion of the exhaust of a rocket in the atmosphere, since that (slightly) decreases performance. This happens because the air pressure decreases at altitude, and a nozzle can only work "efficiently" at either sea-level or vacuum. It's why, for every rocket engine, the Isp tends to be higher in a vacuum than at sea level.

A traditional bell nozzles does fine in a vacuum; an aerospike would quickly become inefficient.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: inventodoc on 02/25/2015 10:43 pm
This picture and the sight of the expanding flame during launches got me thinking, and I know nothing about it, what if the middle engine was replaced with a truncated spike?
Could it perform a bit like an aerospike engine?
Could it raise the overall ISP by even a nudge?
 :-\

I'd like to applaud the creative thinking of this post as well as the interesting assessment by others afterwards.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: spacenut on 02/25/2015 11:57 pm
I wasn't thinking of efficiency, but a method of returning the 2nd stage using the aerospike as a heat shield so the second stage could be reused. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 02/26/2015 06:29 am
Has anyone heard anything about NASA directing SpaceX to redesign Dragon to be able to carry water for the ISS?  This was the first I've seen about it:

http://spaceflightnow.com/2015/01/15/nasa-hopes-to-replace-cargo-lost-on-antares-failure-this-year/

Quote
Gerstenmaier said the Antares launch failure proved the value of having at least two suppliers capable of sending cargo to the space station. It also shows why NASA selected two companies — Boeing and SpaceX — to fly astronauts to the complex.

“You don’t put all your critical spares on one vehicle,” Gerstenmaier said. “If you can split between two vehicles or three vehicles, from a redundancy standpoint then you can effectively utilize your redundancy.”

He said NASA already directed SpaceX to redesign its Dragon cargo capsule to carry water to the space station, a capability that only Orbital’s Cygnus spacecraft was previously able to handle.

“We thought we had enough redundancy so we didn’t have to make design changes to carry water on both vehicles, but now, in hindsight, we need to make a design change,” Gerstenmaier said. “We accepted some non-redundancy items to keep costs down, now we know we need that redundancy.”

How does that work exactly?  Is NASA on the hook to pay for any vehicle changes they request?  It would be one thing if Elon said, "Hey, we're changing Dragon a bit so that it can freight water to the station."  But, if the article is to be believed, Gerstenmaier said NASA is ordering it.  Does the CRS contract allow them to do so?  Does it have a mechanism to deal with the costs of changing the vehicle to meet new customer requirements?

I think it's a good idea btw.

How does that need a redesign? It can transport all that other stuff. Couldn't they just put some containers in there?

The work (and the cost associated with it) is not for the water redesign per-se.

Its mostly for paperwork, to document and certify how the (probably bags of) water will be stowed, secured and moved in and out, and to ensure safety, mass-distribution, leak risk and handling etc.

When the mass of the paper > the mass of the water, they'll be good to go  :P

Does anyone have an estimate on a reasonable timeline for completion of the work so Dragon can do water deliveries to the ISS?  Could it be finished in time for the upcoming CRS-6?  It was mentioned in the pre-EVA briefing that they were targeting CRS-6 for mid to late April now.  Might that slip (from 4/8) be related to the time needed to finish the "design changes" (assuming that most of the work was study and documentation as opposed to physical changes).  SpaceX just tweeted out pics of the finished Dragon capsule ready for shipping to the Cape (see link below), so I don't imagine that a delayed capsule is the hold up.

http://forum.nasaspaceflight.com/index.php?topic=36892.msg1337723#msg1337723

 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dror on 02/26/2015 06:59 am
Can water be transported in a special container in the unpressurised trunk?
I believe that was the method in ATV.
Seems like a waste of much needed volume to put it in bags inside the small capsule.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Burninate on 02/26/2015 07:52 am
Can water be transported in a special container in the unpressurised trunk?
I believe that was the method in ATV.
Seems like a waste of much needed volume to put it in bags inside the small capsule.
Water weighs 1 ton per cubic meter.  It's a solid material rather than hollow cases & circuit board racks.  It's the heaviest thing per volume around.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 02/26/2015 07:55 am
Water weighs 1 ton per cubic meter.  It's a solid material rather than hollow cases & circuit board racks.  It's the heaviest thing per volume around.

I doubt that after packing the water to NASA standards this will still be true.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rpapo on 02/26/2015 10:20 am
Water weighs 1 ton per cubic meter.  It's a solid material rather than hollow cases & circuit board racks.  It's the heaviest thing per volume around.
It's the densest consumable the ISS needs in significant quantities.  It is -far- from the heaviest [per volume] thing around.  If it were, ships would never sink in it.

It has the advantage, however, of being highly recyclable, so the ISS only needs to replenish what gets wasted.  If the ISS didn't have extreme recycling going on, they would require far more supplies than they currently do.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: eischei on 02/28/2015 04:36 pm
The thought about the Aerospike came to me as well. I have in mind that the russian N1 experienced a certain performance gain, only because of the arangement of the engines (no source though).

Could Falcon 9 1.1 have a similar advantage?

Regards,

Sepp
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: TomH on 02/28/2015 04:40 pm
Water weighs 1 ton per cubic meter.  It's a solid material rather than hollow cases & circuit board racks.  It's the heaviest thing per volume around.
It's the densest consumable the ISS needs in significant quantities.  It is -far- from the heaviest thing around.  If it were, ships would never sink in it.

It has the advantage, however, of being highly recyclable, so the ISS only needs to replenish what gets wasted.  If the ISS didn't have extreme recycling going on, they would require far more supplies than they currently do.

He didn't say it was the heaviest thing around. He said, It's the heaviest thing around per volume. That's exactly what density is. I understood him to mean the same thing as you-the densest consumable in significant quantities.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dror on 02/28/2015 06:02 pm
Can water be transported in a special container in the unpressurised trunk?
I believe that was the method in ATV.
Seems like a waste of much needed volume to put it in bags inside the small capsule.
Water weighs 1 ton per cubic meter.  It's a solid material rather than hollow cases & circuit board racks.  It's the heaviest thing per volume around.

That's Irrelevant, it's still a wasted volume in the cabin and dragon is volume limited.
If they need to certify a water container, a barrel in the trunk seems like a good alternative.
The biggest disadvantage may be the crew time needed to unpack it with the robotic arm.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rpapo on 02/28/2015 06:14 pm
That's Irrelevant, it's still a wasted volume in the cabin and dragon is volume limited.
If they need to certify a water container, a barrel in the trunk seems like a good alternative.
The biggest disadvantage may be the crew time needed to unpack it with the robotic arm.
Yes, Dragon is volume limited.  Which means that if they can choose to load it up with denser stuff (like water) and still have an adequate payload weight margin.  What that would do to their margins for returning the first stage, I cannot say.

With regards to an external tank, does the ISS have an external connection for receiving water?  As far as I know, it does not.  Such an external tank would have to be carried over to the Quest airlock and brought in through there.  In other words, it would have to be small enough to fit through the door there.  The other airlock doors are smaller.

Schedule an EVA to receive can(s) of water?  I find that hard to imagine happening except in a dire emergency.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 02/28/2015 06:31 pm

That's Irrelevant, it's still a wasted volume in the cabin and dragon is volume limited.
If they need to certify a water container, a barrel in the trunk seems like a good alternative.
The biggest disadvantage may be the crew time needed to unpack it with the robotic arm.


What good is using the arm and "unpacking" it? It has no way of getting inside.  The ATV was plumbed for water transfer.  The Dragon is not, and that is a major mod.  So, containers on the inside is the simpler method.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 02/28/2015 06:45 pm
One could imagine water tanks outside the pressure vessel but inside the capsule envelope with a port inside the pressurized portion where water vessels could be filled up by astronauts. But this is a mod of Dragon and likely non-trivial.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: BobHk on 02/28/2015 10:52 pm
I've been looking for the total water capacity of ISS and ran across this:

http://www.water-technology.net/projects/iss_water_recovery/ (http://www.water-technology.net/projects/iss_water_recovery/)
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110012703.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110012703.pdf)

The WRS reduced total water launch needs by 6.8t per annum. 

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: the_other_Doug on 03/01/2015 03:30 am
Also please recall how the Shuttle would deliver water to the ISS.  Especially since at least some of the water the Shuttle delivered was being generated real-time by its fuel cells.

The Shuttle docking system was not plumbed to replenish the station's water tanks.  They used bags for water transfer.  Lots and lots and lots of bags.  (Or jugs, same difference, but mostly soft-sided bags.)  Some were pre-loaded on the ground before launch, others were filled from the fuel cell potable water system real-time.

So, it's not unprecedented in the slightest degree to pack a supply ship full of bags or jugs of water for transfer to the station.  It's not like it hasn't been done before.  (You just don't want to do a lot of maneuvering with a lot of half-full jugs of water on board.  Ever hear of fuel slosh?  It caused really significant controlability issues on the first two manned lunar landings...)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 03/02/2015 03:53 am
A tweet from Musk about F9 performance upgrades coming soon: (we already knew about the densification and M1D thrust upgrade, but the upper stage stretch(?) is new)

https://twitter.com/elonmusk/status/572257004938403840

Quote
Elon Musk ‏@elonmusk
Upgrades in the works to allow landing for geo missions: thrust +15%, deep cryo oxygen, upper stage tank vol +10%
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 03/02/2015 04:04 am
At what point does it graduate to v1.2?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cartman on 03/02/2015 04:12 am
So if S2 is ~14m, this is a ~1m stretch. How significant is this for GSE, can they support this by just lengthening some umbilicals for the payload, or do they have to do more?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 03/02/2015 04:14 am
So if S2 is ~14m, this is a ~1m stretch. How significant is this for GSE, can they support this by just lengthening some umbilicals for the payload, or do they have to do more?

1m is probably not a big deal. And the T/E is modular. I would assume that they want to put all of these modifications in use before FH flies. This might give even more benefit for FH.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 03/02/2015 04:15 am
At what point does it graduate to v1.2?
Actually, I don't think this is nearly the level of v1.0->v1.1 (which really should've been 1.5 or 2.0, now that we know the magnitude of the changes).

At first, I thought it was a stretch of the first stage tanks not the second. I think stretching the upper stage is less of a big deal because the upper stage is much smaller to begin with, though it should help the performance significantly (especially to high energy).

The propellant densification (i.e. deep cryo LOx) is an interesting upgrade.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Galactic Penguin SST on 03/02/2015 04:16 am
Actually, upper stage tank volume +10% does not necessarily mean the outer structure needs to be stretched. A good example is the good old Ariane 4 - its LH2 third stage was modified twice in history (first flight 1988, first modification in 1992 and the second in 1994) to allow for slight increases in the fuel capacity with just internal tank stretches of inches. Each stretch brought about 100-150 kg increase in GTO payload capacity.

(diagram found via capcomespace.net (http://www.capcomespace.net/dossiers/espace_europeen/ariane/ariane4/caracteristiques.htm)) 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 03/02/2015 04:43 am
At first, I thought it was a stretch of the first stage tanks not the second. I think stretching the upper stage is less of a big deal because the upper stage is much smaller to begin with, though it should help the performance significantly (especially to high energy).


Not sure.  This is on the tank that gets to orbit.  I think it represents a lot more dV compared with a first stage stretch.

It gets carried by the first stage, unused, until staging.  Then it gets carried by the second stage until it is "1 m from empty" - and then you have 10% of the second stage pushing a practically empty stage.

The stretch will also reduce the stage velocity by a tad (the other changes not withstanding of course)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 03/02/2015 04:52 am
A tweet from Musk about F9 performance upgrades coming soon: (we already knew about the densification and M1D thrust upgrade, but the upper stage stretch(?) is new)

https://twitter.com/elonmusk/status/572257004938403840

Quote
Elon Musk ‏@elonmusk
Upgrades in the works to allow landing for geo missions: thrust +15%, deep cryo oxygen, upper stage tank vol +10%

I just posted this as my congratulation comment on the live thread:
Quote
Here's to a year that's boring when it's supposed to be boring and still exciting when it's supposed to be exciting...

Well...  I got what I wished for... 

Changes like this probably also factor into the decision to hold off on FH.  When it finally flies, all these changes would have had to be qualified only once.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: TrevorMonty on 03/02/2015 05:30 am
Besides the extra 10% tankage also expect deep cryo oxygen of upper which may give closer to 20% increase in fuel. The extra performance in 1st stage shouldn't have any problems lifting it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: FutureSpaceTourist on 03/02/2015 07:34 am
Any insights on how these F9 changes may affect USAF certification, which I assume has been based on F9 v1.1? I don't see SpaceX operating two F9 variants?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cambrianera on 03/02/2015 09:26 am
A tweet from Musk about F9 performance upgrades coming soon: (we already knew about the densification and M1D thrust upgrade, but the upper stage stretch(?) is new)

https://twitter.com/elonmusk/status/572257004938403840

Quote
Elon Musk ‏@elonmusk
Upgrades in the works to allow landing for geo missions: thrust +15%, deep cryo oxygen, upper stage tank vol +10%

Well, it was a low hanging fruit.
http://forum.nasaspaceflight.com/index.php?topic=36045.msg1285819#msg1285819

a stretch is all you need to improve your GTO margins.
A two meter stretch would add 20000 kg of propellant to the second stage for a mere 300 kg of extra tankage (only 2m sidewalls added).
With 20% more propellant you get at least 1000 kg of extra payload.
This would have no influence on first stage T/W, and small influence on second stage T/W; most of this extra mass is masked by GTO payload reduction compared to LEO.


And +10% is more like 1 m stretch.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Dave G on 03/02/2015 09:43 am
It all makes sense.  First stage has already been stretched as far as it can.  Any longer and it wouldn't be road transportable. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: kevinof on 03/02/2015 09:46 am
The tweet from Musk didn't say anything about a stretch - wonder if they can do this by increasing the tank size while keeping the stage dimensions the same?



A tweet from Musk about F9 performance upgrades coming soon: (we already knew about the densification and M1D thrust upgrade, but the upper stage stretch(?) is new)

https://twitter.com/elonmusk/status/572257004938403840

Quote
Elon Musk ‏@elonmusk
Upgrades in the works to allow landing for geo missions: thrust +15%, deep cryo oxygen, upper stage tank vol +10%

Well, it was a low hanging fruit.
http://forum.nasaspaceflight.com/index.php?topic=36045.msg1285819#msg1285819

a stretch is all you need to improve your GTO margins.
A two meter stretch would add 20000 kg of propellant to the second stage for a mere 300 kg of extra tankage (only 2m sidewalls added).
With 20% more propellant you get at least 1000 kg of extra payload.
This would have no influence on first stage T/W, and small influence on second stage T/W; most of this extra mass is masked by GTO payload reduction compared to LEO.


And +10% is more like 1 m stretch.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ugordan on 03/02/2015 11:14 am
Any insights on how these F9 changes may affect USAF certification, which I assume has been based on F9 v1.1? I don't see SpaceX operating two F9 variants?

I'll throw in a question about NASA's own certification and how this will play into it? Can anyone in the know comment? Not interested in speculation for the sake of speculation.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cuddihy on 03/02/2015 11:43 am
It actually could be no stretch if the U/S really has been flying at less than 90% fuel load, which has been speculated before. Perhaps they designed it with subcooling in mind and the lower stage couldn't provide enough for the extra prop  to be loaded until subcooling increased the lower stage total impulse enough to make it work.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: kevinof on 03/02/2015 11:55 am
I think this is more realistic than stretching the 2nd stage. The latter would require re-tooling, aerodynamic analysis and more. Can't see this happening, at least in the short term.

If you're right and they are only now topping up the tanks then that possibly gives them the extra 10%. Add in better performance of the 1d+ which should increase power by 15-20% and you have the extra grunt to push the added fuel uphill.

then again, what do I know?

It actually could be no stretch if the U/S really has been flying at less than 90% fuel load, which has been speculated before. Perhaps they designed it with subcooling in mind and the lower stage couldn't provide enough for the extra prop  to be loaded until subcooling increased the lower stage total impulse enough to make it work.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: su27k on 03/02/2015 12:16 pm
It actually could be no stretch if the U/S really has been flying at less than 90% fuel load, which has been speculated before. Perhaps they designed it with subcooling in mind and the lower stage couldn't provide enough for the extra prop  to be loaded until subcooling increased the lower stage total impulse enough to make it work.

Or the Upper Stages have been flying had shorter tanks?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/02/2015 12:42 pm
It actually could be no stretch if the U/S really has been flying at less than 90% fuel load, which has been speculated before. Perhaps they designed it with subcooling in mind and the lower stage couldn't provide enough for the extra prop  to be loaded until subcooling increased the lower stage total impulse enough to make it work.

Read it again. He said tank volume +10%.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Norm38 on 03/02/2015 01:00 pm
A two meter stretch would add 20000 kg of propellant to the second stage for a mere 300 kg of extra tankage (only 2m sidewalls added).

And +10% is more like 1 m stretch.

We know that SpaceX likes to make incremental changes, and they treat each expendable like a flying experiment.  So I wouldn't be at all surprised if they first stretched 1m, evaluated performance, checked for vibrations etc, then later stretched another meter if it bought them more performance.  But first they may want to get hard numbers on the first stage upgrade performance.

They shouldn't have to retool, as first and second stages are built on the same tooling today.  Length is a free variable.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cambrianera on 03/02/2015 01:01 pm
I think this is more realistic than stretching the 2nd stage. The latter would require re-tooling, aerodynamic analysis and more. Can't see this happening, at least in the short term.
All speculations obviously, but re-tooling seems not needed for a simple stretch; ditto for aerodynamic analysis given 1m stretch on 60 m rocket.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 03/02/2015 02:15 pm
Any insights on how these F9 changes may affect USAF certification, which I assume has been based on F9 v1.1? I don't see SpaceX operating two F9 variants?

I'll throw in a question about NASA's own certification and how this will play into it? Can anyone in the know comment? Not interested in speculation for the sake of speculation.

Just speculation, but EM only mentioned it in the context of GEO missions, so the LEO configuration may be unaffected, and hence certification is unchanged.


But that would stick them with two different second stage models to have to manufacture in parallel, which doesn't seem to be their M.O.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/02/2015 02:21 pm
Also, once you do the S2 stretch, you get more margin for S1 engine-out performance, and more margin for  boostback burn to the Cape, so there's added incentive to fly all future missions with the stretch.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GWH on 03/02/2015 02:29 pm
With densified LOX they are only changing one variable, which leaves (3) scenarios for the rocket:
1.) All tank volumes stay the same, vary the combustion mixture so that the engines are now running on proportionally higher O2.
2. ) Marginally lengthen kerosene tanks while shortening LOX tanks to maintain same fuel/oxidizer ratios
3.) Shorten the overall first stage proportionally relative to the lower volume required by the denser LOX. Increase the length of the first stage by the same amount. 

Without looking at exact numbers of tank length vs. oxidizer density it seems entirely plausible that SpaceX can increase the total tank volume of the second stage by 10% without increasing the total rocket length through the use of densified LOX.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/02/2015 02:59 pm
it seems entirely plausible that SpaceX can increase the total tank volume of the second stage by 10% without increasing the total rocket length through the use of densified LOX.

Densified LOX does not change the volume of a tank. It changes the mass of LOX in a given volume.

Also, Elon mentioned the 10% increase in S2 tank volume right after mentioning the densified LOX. These are clearly not the same thing.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GWH on 03/02/2015 03:02 pm
Yes that's exactly what my post implies. You need less volume of lox to maintain same ratio.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/02/2015 03:22 pm
Yes that's exactly what my post implies. You need less volume of lox to maintain same ratio.

I don't see how it's possible to increase total tank volume 10% without stretching the stage length (assuming no change in diameter, which seems a safe assumption).

The following paper suggests a 9% increase in LOX mass is possible by supercooling. So maybe they keep the LOX tank volume as is, and increase the RP-1 tank volume 10% to maintain the ratio.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050203875.pdf

In any case, hard to see how you do that without stretching the stage slightly. As others have pointed out, changing S2 tank length slightly is not a big deal from a manufacturing POV, and probably not a big deal structurally or aerodynamically.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GWH on 03/02/2015 03:47 pm
The following paper suggests a 9% increase in LOX mass is possible by supercooling. So maybe they keep the LOX tank volume as is, and increase the RP-1 tank volume 10% to maintain the ratio.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050203875.pdf

In any case, hard to see how you do that without stretching the stage slightly. As others have pointed out, changing S2 tank length slightly is not a big deal from a manufacturing POV, and probably not a big deal structurally or aerodynamically.

Or, leave the first stage total mass of propellant/oxidizer the exact same.  Now that the 1st stage LOX is denser you don't need as long of a tank (volume) to maintain the same mass balance.  Take that additional length and add it to the second stage.  Gain your 10% total volume increase in the second stage without changing the overall length of rocket.  10% less volume on the 1st stage LOX is probably pretty close to 10% overall tanks volume of the second stage. 
 Launch pad and infrastructure and erector changes can also be less since again the overall length of the rocket isn't changing. 
Proportionally they will see much larger gains in performance by increasing the tank volume of the second stage 10% rather than the 1st stage by a couple %.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cambrianera on 03/02/2015 04:00 pm

Well, It's only 1 meter.  You'd have to lengthen the tank by only about 19 inches on each end to get 1 meter.  Perhaps within the current shell, they can reposition some equipment and wiring at either end to squeeze in a slightly bigger tank.
Hmm.. the tank is the shell.
If you stretch the tank, you stretch the stage.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: WindnWar on 03/02/2015 09:47 pm
Can someone run the numbers on what additional performance these upgrades would allow in expendable mode versus the current spec? More thrust, fuel densification and now a second stage stretch it would seem to be a nice increase. Should be a point or so increase in ISP as well from the increased chamber pressure. I know it is mostly to allow landing attempts on more launches but if it allows them to grab more expendable launches too I doubt they will mind.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/02/2015 09:56 pm
Can someone run the numbers on what additional performance these upgrades would allow in expendable mode versus the current spec? More thrust, fuel densification and now a second stage stretch it would seem to be a nice increase. Should be a point or so increase in ISP as well from the increased chamber pressure. I know it is mostly to allow landing attempts on more launches but if it allows them to grab more expendable launches too I doubt they will mind.

Edit: Lars-J says below that the "performance calculator" on the NASA NLS II website is outdated, so I've deleted that reference.

LouScheffer also made some educated guesses here on the performance improvement from the planned upgrades:

http://forum.nasaspaceflight.com/index.php?topic=34077.msg1340430#msg1340430
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 03/02/2015 10:29 pm
Can someone run the numbers on what additional performance these upgrades would allow in expendable mode versus the current spec? More thrust, fuel densification and now a second stage stretch it would seem to be a nice increase. Should be a point or so increase in ISP as well from the increased chamber pressure. I know it is mostly to allow landing attempts on more launches but if it allows them to grab more expendable launches too I doubt they will mind.

If the "performance calculator" on the NASA NLS II website is correct, upgraded F9 will be able to put about 4,750 kg into the GTO orbit that it just put about 4,150 kg in on the ABS/Eutelsat mission, ie a 600 kg increase in GTO capacity.

Don't use those numbers as gospel. They are several years old and outdated - and certainly don't try to use them to match these new enhancements. They may line up on occasion, but that is merely because SpaceX got to the same performance by different means.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Burninate on 03/02/2015 10:34 pm
Can someone run the numbers on what additional performance these upgrades would allow in expendable mode versus the current spec? More thrust, fuel densification and now a second stage stretch it would seem to be a nice increase. Should be a point or so increase in ISP as well from the increased chamber pressure. I know it is mostly to allow landing attempts on more launches but if it allows them to grab more expendable launches too I doubt they will mind.

If the "performance calculator" on the NASA NLS II website is correct, upgraded F9 will be able to put about 4,750 kg into the GTO orbit that it just put about 4,150 kg in on the ABS/Eutelsat mission, ie a 600 kg increase in GTO capacity.

Don't use those numbers as gospel. They are several years old and outdated - and certainly don't try to use them to match these new enhancements. They may line up on occasion, but that is merely because SpaceX got to the same performance by different means.
Is there some phase of the USAF certification process that would be publicly accessible where we could ascertain accurate, updated figures for Falcon stage mass?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/03/2015 12:06 am
Air Force may not be permitted to release any technical details to the public since it's likely all SpaceX proprietary information. That would all probably have to come directly from SpaceX.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Owlon on 03/03/2015 01:16 am
Specific figures for 1st and 2nd stage mass on F9 are very much not public information.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: edkyle99 on 03/03/2015 02:54 am
Is there a thread with a discussion about the key people at SpaceX, specifically about the designers and decision makers?  Who, for example, made the decisions to drop the original Merlin 1 in favor of Merlin 1C, then to go to 1D?  Who invented Octoweb?  Who created the landing legs and grid fins and, especially, the flight software to make recovery attempts?  Who decided that a hypersonic reentry burn might work?  Who decided that Falcon Heavy was the way to go, rather than, say, adding a high energy upper stage atop Falcon 9?  Who are the key designers, of hardware and of industrial processes?  Who runs the show at McGregor and at the launch pads?  Ect.

 - Ed Kyle
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Zed_Noir on 03/03/2015 03:07 am
Is there a thread with a discussion about the key people at SpaceX, specifically about the designers and decision makers?  Who, for example, made the decisions to drop the original Merlin 1 in favor of Merlin 1C, then to go to 1D?  Who invented Octoweb?  Who created the landing legs and grid fins and, especially, the flight software to make recovery attempts?  Who decided that a hypersonic reentry burn might work?  Who decided that Falcon Heavy was the way to go, rather than, say, adding a high energy upper stage atop Falcon 9?  Who are the key designers, of hardware and of industrial processes?  Who runs the show at McGregor and at the launch pads?  Ect.

 - Ed Kyle

Well we know who the CEO & the CTO is at SpaceX. Think the buck stops with him.


Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/03/2015 04:22 am
Is there a thread with a discussion about the key people at SpaceX, specifically about the designers and decision makers?  Who, for example, made the decisions to drop the original Merlin 1 in favor of Merlin 1C, then to go to 1D?  Who invented Octoweb?  Who created the landing legs and grid fins and, especially, the flight software to make recovery attempts?  Who decided that a hypersonic reentry burn might work?  Who decided that Falcon Heavy was the way to go, rather than, say, adding a high energy upper stage atop Falcon 9?  Who are the key designers, of hardware and of industrial processes?  Who runs the show at McGregor and at the launch pads?  Ect.

 - Ed Kyle

Sounds like this is a job for an author with inside access to SpaceX...a la Tracy Kidder's "Soul of a New Machine." But maybe already too late for that, unfortunately, unless someone is already on the case...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Zed_Noir on 03/03/2015 05:44 am


Sounds like this is a job for an author with inside access to SpaceX...a la Tracy Kidder's "Soul of a New Machine." But maybe already too late for that, unfortunately, unless someone is already on the case...

Sounds like Stewart Money and his Here Be Dragons (http://www.amazon.com/Here-Dragons-Rise-Spacex-Journey/dp/1926837339) book. Sort of.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 03/03/2015 07:14 am
Companies tend to keep exact information about employees secret to avoid having their good people poached by competitors. So I would be very surprised if SpaceX made the information you are looking for public.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: The Amazing Catstronaut on 03/03/2015 07:32 am
It all makes sense.  First stage has already been stretched as far as it can.  Any longer and it wouldn't be road transportable.

What's the legal road length limit (no idea what the correct term is - feel free to correct me), for road transportable cargo in the USA?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 03/03/2015 08:09 am
Is there a thread with a discussion about the key people at SpaceX, specifically about the designers and decision makers?  Who, for example, made the decisions to drop the original Merlin 1 in favor of Merlin 1C, then to go to 1D?  Who invented Octoweb?  Who created the landing legs and grid fins and, especially, the flight software to make recovery attempts?  Who decided that a hypersonic reentry burn might work?  Who decided that Falcon Heavy was the way to go, rather than, say, adding a high energy upper stage atop Falcon 9?  Who are the key designers, of hardware and of industrial processes?  Who runs the show at McGregor and at the launch pads?  Ect.

 - Ed Kyle
No such thread present and I don't think Chris would allow such a thread to exist. It would involve heavy speculation about the acts of individuals, and that doesn't line up with forum policy.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GalacticIntruder on 03/03/2015 08:21 am
It all makes sense.  First stage has already been stretched as far as it can.  Any longer and it wouldn't be road transportable.

What's the legal road length limit (no idea what the correct term is - feel free to correct me), for road transportable cargo in the USA?

Standard permitted US trucks with trailers, are usually, under 13 feet height, 65-75 ft length(some states allow 125ft), under 80,000 lbs weight. Special permits and routes, restrictions, and pilot cars, are needed for heavier, and larger stuff. Each US State has rules and permits. There is really is no max length when pilots cars are being used, and most of the constraints are for weight and height, (ie, under bridges and over bridges)

IIRC SpaceX and their F9 is set at 3.66m diameter so they could ship across the US without special permits and routes.

Ex.  http://wideloadshipping.com/texas-state-shipping-regulations/ (http://wideloadshipping.com/texas-state-shipping-regulations/)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: intrepidpursuit on 03/03/2015 10:42 am
I was always under the impression that the stage diameter was limited my shipping constraints but that the height was limited by bending loads on the stage during flight. Does anyone have a quote on the length limitation?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 03/03/2015 12:27 pm
It's not really a matter of legal statutes or permits. It's that pesky reality. Once you go over about 13 1/2 feet high or 120 feet long, the number of possible routes drops off a cliff.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/03/2015 03:28 pm


Sounds like this is a job for an author with inside access to SpaceX...a la Tracy Kidder's "Soul of a New Machine." But maybe already too late for that, unfortunately, unless someone is already on the case...

Sounds like Stewart Money and his Here Be Dragons (http://www.amazon.com/Here-Dragons-Rise-Spacex-Journey/dp/1926837339) book. Sort of.

Thanks for mentioning that book. I hadn't heard of it. Unfortunately it doesn't sound very well written or edited, and it's $32. For a paperback.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: arachnitect on 03/03/2015 09:14 pm
Is there a thread with a discussion about the key people at SpaceX, specifically about the designers and decision makers?  Who, for example, made the decisions to drop the original Merlin 1 in favor of Merlin 1C, then to go to 1D?  Who invented Octoweb?  Who created the landing legs and grid fins and, especially, the flight software to make recovery attempts?  Who decided that a hypersonic reentry burn might work?  Who decided that Falcon Heavy was the way to go, rather than, say, adding a high energy upper stage atop Falcon 9?  Who are the key designers, of hardware and of industrial processes?  Who runs the show at McGregor and at the launch pads?  Ect.

 - Ed Kyle

It's an interesting question.

I would much rather read the history of Spacex according to Tom rather than Elon.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: drzerg on 03/04/2015 03:51 am
Can someone answer is it possible to bring astronauts back to earth from ISS in cargo Dragon version in case of emergency?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: zodiacchris on 03/04/2015 04:07 am
Please go and look in the archive, this particular issue has been discussed to death! But in a nutshell, there are issues with cooling and seats, plus air supply/ scrubbing, and the Caro Dragon can't undock itself...
Cheers,
Chris
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: king1999 on 03/04/2015 04:12 am
Is there a thread with a discussion about the key people at SpaceX, specifically about the designers and decision makers?  Who, for example, made the decisions to drop the original Merlin 1 in favor of Merlin 1C, then to go to 1D?  Who invented Octoweb?  Who created the landing legs and grid fins and, especially, the flight software to make recovery attempts?  Who decided that a hypersonic reentry burn might work?  Who decided that Falcon Heavy was the way to go, rather than, say, adding a high energy upper stage atop Falcon 9?  Who are the key designers, of hardware and of industrial processes?  Who runs the show at McGregor and at the launch pads?  Ect.

 - Ed Kyle
I believe all these were conceived by Elon while he was taking showers. :)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 03/04/2015 04:17 am
<snip quote>
Target orbit:  407.59 x 63928 @ 24.83 degrees  -> Delta V to GEO = 1592.5 m/s
Achieved:      432       x 63401 @ 24.71 degrees  -> Delta V to GEO = 1591.7 m/s  (0.8 m/s better than target)
Achieved       400       x 63293 @ 24.86 degrees  -> Delta V to GEO = 1595.5 m/s  (probably the second stage)
Achieved       406       x 63066 @ 24.84 degrees  -> Delta V to GEO = 1595.8 m/s  (3.3 m/s worse than target)

I don't know what the spec on injection error was, but these seem like very typical numbers.  I can't imagine 3.3 m/s is more than 3 sigma out.

Lou posted this in the ABS/Eutelsat discussion thread.  Ignoring the accuracy issue, I was surprised to see that the orbits were closer to the 1500m/s-to-GTO than the 1800m/s-to-GTO range. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: su27k on 03/04/2015 04:32 am
Is there a thread with a discussion about the key people at SpaceX, specifically about the designers and decision makers?  Who, for example, made the decisions to drop the original Merlin 1 in favor of Merlin 1C, then to go to 1D?  Who invented Octoweb?  Who created the landing legs and grid fins and, especially, the flight software to make recovery attempts?  Who decided that a hypersonic reentry burn might work?  Who decided that Falcon Heavy was the way to go, rather than, say, adding a high energy upper stage atop Falcon 9?  Who are the key designers, of hardware and of industrial processes?  Who runs the show at McGregor and at the launch pads?  Ect.

 - Ed Kyle

Sounds like this is a job for an author with inside access to SpaceX...a la Tracy Kidder's "Soul of a New Machine." But maybe already too late for that, unfortunately, unless someone is already on the case...

The COTS part is documented at http://www.jsc.nasa.gov/history/oral_histories/c3po.htm
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: macpacheco on 03/04/2015 05:39 am
<snip quote>
Target orbit:  407.59 x 63928 @ 24.83 degrees  -> Delta V to GEO = 1592.5 m/s
Achieved:      432       x 63401 @ 24.71 degrees  -> Delta V to GEO = 1591.7 m/s  (0.8 m/s better than target)
Achieved       400       x 63293 @ 24.86 degrees  -> Delta V to GEO = 1595.5 m/s  (probably the second stage)
Achieved       406       x 63066 @ 24.84 degrees  -> Delta V to GEO = 1595.8 m/s  (3.3 m/s worse than target)

I don't know what the spec on injection error was, but these seem like very typical numbers.  I can't imagine 3.3 m/s is more than 3 sigma out.

Lou posted this in the ABS/Eutelsat discussion thread.  Ignoring the accuracy issue, I was surprised to see that the orbits were closer to the 1500m/s-to-GTO than the 1800m/s-to-GTO range.
What was the closest DeltaV to GEO any launch has achieved ?
How close could a FHR get a 6 ton payload to GEO, with RTLS+center booster barge landing ?
I predict FHR will get large payloads so close to GEO there will be little incentive not to go electric, like 1-2 months transit time.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 03/04/2015 01:06 pm
Please go and look in the archive, this particular issue has been discussed to death! But in a nutshell, there are issues with cooling and seats, plus air supply/ scrubbing, and the Caro Dragon can't undock itself...
Cheers,
Chris
That's a pretty bad nutshell. The issues are mostly minor for a fast track re-entry as long as it's not a major ISS systems failure requiring a total evacuation. One person isn't going to overheat the interior in a few hours and an SCBA could take care of air for that long. You're not talking about a regular thing. Lots of people in those discussions didn't seem to grasp the meaning of the term "emergency".  The Apollo 13 capsule would still be out there if some folks had been in charge of coming up with a solution.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JamesH on 03/04/2015 02:40 pm
Please go and look in the archive, this particular issue has been discussed to death! But in a nutshell, there are issues with cooling and seats, plus air supply/ scrubbing, and the Caro Dragon can't undock itself...
Cheers,
Chris
That's a pretty bad nutshell. The issues are mostly minor for a fast track re-entry as long as it's not a major ISS systems failure requiring a total evacuation. One person isn't going to overheat the interior in a few hours and an SCBA could take care of air for that long. You're not talking about a regular thing. Lots of people in those discussions didn't seem to grasp the meaning of the term "emergency".  The Apollo 13 capsule would still be out there if some folks had been in charge of coming up with a solution.

Indeed. If you are stuck on a disintegrating ISS and the options are a cargo Dragon or certain death, I think I know which I would go for.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Ben the Space Brit on 03/04/2015 03:13 pm
The one issue no-one seems to have addressed (or, instead, just hand-waved away as irrelevant) is how a Cargo Dragon could detach from the ISS if, assuming a serious emergency, the berthing bolt motors and the Candarm-2 were both depowered.

NOTE: Invoking 'explosive bolts' would require a large scale redesign of the Dragon's berthing mechanism and the hull around it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mongo62 on 03/04/2015 03:39 pm
The one issue no-one seems to have addressed (or, instead, just hand-waved away as irrelevant) is how a Cargo Dragon could detach from the ISS if, assuming a serious emergency, the berthing bolt motors and the Candarm-2 were both depowered.

NOTE: Invoking 'explosive bolts' would require a large scale redesign of the Dragon's berthing mechanism and the hull around it.

In that specific situation, I would think that they would be up the creek.

But if there still was internal power to the relevant bits of the ISS, could not the berthing mechanism and Canadarm be operated remotely from the ground, perhaps with a jury-rigged setup?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 03/04/2015 04:19 pm
The one issue no-one seems to have addressed (or, instead, just hand-waved away as irrelevant) is how a Cargo Dragon could detach from the ISS if, assuming a serious emergency, the berthing bolt motors and the Candarm-2 were both depowered.

NOTE: Invoking 'explosive bolts' would require a large scale redesign of the Dragon's berthing mechanism and the hull around it.
If they were serious about this, a battery powered inverter to back up the berthing bolt motors wouldn't be too hard. I'm not sure what other latches you'd have to manually disengage to release the ship. Would the Candarm really be needed for unberthing if you were willing to forgo procedure and use thrusters to back out?
 The main reason I could see for doing this is if a Soyuz became unaccessible or unusable for some reason during a total evacuation.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nlec on 03/04/2015 04:20 pm
The one issue no-one seems to have addressed (or, instead, just hand-waved away as irrelevant) is how a Cargo Dragon could detach from the ISS if, assuming a serious emergency, the berthing bolt motors and the Candarm-2 were both depowered.

NOTE: Invoking 'explosive bolts' would require a large scale redesign of the Dragon's berthing mechanism and the hull around it.

In that specific situation, I would think that they would be up the creek.

But if there still was internal power to the relevant bits of the ISS, could not the berthing mechanism and Canadarm be operated remotely from the ground, perhaps with a jury-rigged setup?

Robonaut?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: BobHk on 03/04/2015 04:54 pm
The one issue no-one seems to have addressed (or, instead, just hand-waved away as irrelevant) is how a Cargo Dragon could detach from the ISS if, assuming a serious emergency, the berthing bolt motors and the Candarm-2 were both depowered.

NOTE: Invoking 'explosive bolts' would require a large scale redesign of the Dragon's berthing mechanism and the hull around it.

How many pressure/space suits do they have on ISS? 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kansan52 on 03/04/2015 05:09 pm
Don't know about the bolts but the Candarm can be operated from Mission Control, if the comms, power, ect is available.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GalacticIntruder on 03/04/2015 11:07 pm
Musk will talk at the GPU conference March 17, with CEO of Nvidia.
I have no idea what he will talk about. I assume it is about Nvidia hardware, which SpaceX and Tesla use, and maybe the new Tegra K1.

http://www.gputechconf.com/ (http://www.gputechconf.com/)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: gongora on 03/05/2015 03:58 pm
Thought this was interesting in regards to AF visibility for the SpaceX launches:
Florida Today article on new AF launch support center http://www.floridatoday.com/story/tech/science/space/spacex/2015/03/04/th-space-wing-unveils-new-launch-support-center/24380797/ (http://www.floridatoday.com/story/tech/science/space/spacex/2015/03/04/th-space-wing-unveils-new-launch-support-center/24380797/)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: CJ on 03/05/2015 10:02 pm
Second stage reuse (sorry, couldn't find a specific thread for it, and it sort of fits here)

SpaceX nixed making the second stage reusable for cost-benefit reasons, but would their calculation change if somebody offered them, say, a billion dollar prize to make it work?  I'm not going wildly hypothetical here, BTW, because such a prize is part of some legislation currently before congress, the CATS act. what follows is a quote from the linked article; (Edit: I was wrong, it's not before congress yet, as it hasn't been sponsored or introduced.) 

Quote
Specifically, the bill offers $1 billion to the first fully reusable launch vehicle, capable of placing a payload of one metric ton (including two people) into orbit, which flies two missions in one week. A second $1-billion prize would go to the first RLV, with the same payload requirement, that flies ten times in ten weeks. Both milestones would also have $750-million second prizes.

http://www.thespacereview.com/article/2705/1

If that bill passes and the prize becomes official, I have two questions; #1 could they go for it, and #2, would they go for it?
My SWAG is that it's feasible if they can make the second stage reusable, AND do RTLS for both stages. That one-week turnaround is a very tight window.   

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: gongora on 03/05/2015 10:46 pm
Second stage reuse (sorry, couldn't find a specific thread for it, and it sort of fits here)

SpaceX nixed making the second stage reusable for cost-benefit reasons, but would their calculation change if somebody offered them, say, a billion dollar prize to make it work?  I'm not going wildly hypothetical here, BTW, because such a prize is part of some legislation currently before congress, the CATS act. what follows is a quote from the linked article;

Quote
Specifically, the bill offers $1 billion to the first fully reusable launch vehicle, capable of placing a payload of one metric ton (including two people) into orbit, which flies two missions in one week. A second $1-billion prize would go to the first RLV, with the same payload requirement, that flies ten times in ten weeks. Both milestones would also have $750-million second prizes.

http://www.thespacereview.com/article/2705/1

If that bill passes and the prize becomes official, I have two questions; #1 could they go for it, and #2, would they go for it?
My SWAG is that it's feasible if they can make the second stage reusable, AND do RTLS for both stages. That one-week turnaround is a very tight window.   

The article specifically says that the bill has NOT been introduced to Congress yet and doesn't have a sponsor.  If a bill like that ever did pass then for $1B of course they'd go for it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: CJ on 03/05/2015 11:27 pm
Second stage reuse (sorry, couldn't find a specific thread for it, and it sort of fits here)

SpaceX nixed making the second stage reusable for cost-benefit reasons, but would their calculation change if somebody offered them, say, a billion dollar prize to make it work?  I'm not going wildly hypothetical here, BTW, because such a prize is part of some legislation currently before congress, the CATS act. what follows is a quote from the linked article;

Quote
Specifically, the bill offers $1 billion to the first fully reusable launch vehicle, capable of placing a payload of one metric ton (including two people) into orbit, which flies two missions in one week. A second $1-billion prize would go to the first RLV, with the same payload requirement, that flies ten times in ten weeks. Both milestones would also have $750-million second prizes.

http://www.thespacereview.com/article/2705/1

If that bill passes and the prize becomes official, I have two questions; #1 could they go for it, and #2, would they go for it?
My SWAG is that it's feasible if they can make the second stage reusable, AND do RTLS for both stages. That one-week turnaround is a very tight window.   

The article specifically says that the bill has NOT been introduced to Congress yet and doesn't have a sponsor.  If a bill like that ever did pass then for $1B of course they'd go for it.

Mea culpa; my reading comprehension sucks today. I'll fix my post, thanks.

My guess, if they decided (for the prize, or any other reason) to make the 2nd stage reusable, is they'd deal with the stability-during-reentry issue by spinning the stage. I really don't see any other option, given its far-aft CG and the fact they'd need to put the TPS on the nose (or would they? An active RCS system to give stability during reentry would mass too much. Could the Nobium engine bell withstand reentry if they covered the rest of the stage base with TPS?) They'd have to land nose-first anyway, due to the size of that engine bell, plus the fact the Merlin would be worse than useless for landing.

My guess; TPS on the nose, extended slightly to form a protruding flange to protect the sides from direct plasma flow (the sides would need SPAM). A pair of Dracos for spin-up, and a single SuperDraco in the nose for landing. The landing legs would be Dragon 2 style, in the nose TPS. A pair of grid fins (smaller than the stage 1 ones) would be deploy from the stage base, and be used for control plus post-entry de-spin.   

The added mass to the second stage would mainly be the TPS, the tiny landing legs, 2 small grid fins, 1 super draco and 2 dracos, some structural changes to create the needed strong points, and the hydrazine tankage.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mongo62 on 03/06/2015 12:33 am
Quote
Specifically, the bill offers $1 billion to the first fully reusable launch vehicle, capable of placing a payload of one metric ton (including two people) into orbit, which flies two missions in one week. A second $1-billion prize would go to the first RLV, with the same payload requirement, that flies ten times in ten weeks. Both milestones would also have $750-million second prizes.

Could a Falcon Heavy be able to do this in the near future with modifications to the upper stage? A D2 with one tonne of payload and two human occupants might mass around six tonnes (just guessing here, I assume that it's close to the Cargo Dragon mass), so assuming the full 45 tonne performance to LEO, there might be around 39 tonnes for extra mass in the second stage, including propellant (both kerolox and hypergolic), tankage for the hypergolic propellant, and the SuperDracos to land it propulsively.

I know that the actual mass would be different, because the 'extra' mass would be contained in the US instead of being a separate payload on top of the US, but I don't know how to calculate the actual number.

Could a Falcon upper stage with that mass dedicated to landing perform a propulsive deceleration to a velocity that allows a first-stage style propulsive landing, with no more atmospheric heating than the first stage gets?

If a fully reusable FH in this configuration can indeed put a (partly loaded) D2 into LEO, would a full F9-sized payload to LEO also be achievable with a fully reusable FH? Would it be cheaper to place this size of payload into LEO using a partly reusable F9 with expended US, or the same sized payload into LEO with a fully reusable FH with returning US? (Obviously, if there's several billion dollars in prize money available, the profitability of the payload by itself would not matter, this is about regular non-contest payloads.)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 03/06/2015 01:42 am
http://www.wsj.com/articles/BL-DGB-40041

Quote
SpaceX’s Valuation Rockets to $12 Billion With Google Investment

SpaceX now ranks fourth on The Wall Street Journal’s list of billion-dollar private companies, securing a $12 billion valuation.
>

I'm not sure I would have taken up that deal if I were google.
12 billion is a hell of a lot. If they launch 10 times and launch a couple of dragons as well, they have a yearly revenue of a billion. This is already stretching their revenue expectations for this year. So their valuation is 12 times their revenue? How many companies outside of websites have such a valuation?
Airbus group (note they make a couple of planes, fighterjets, helicopters and missiles as well) has a valuation of only 50B.

SpaceX just got handed a shitload of money. Which of course is great, rather see Google wasting it on SpaceX than giving it to people that try to make an algorithm to present me the best personalized add on my screen.
Because the Constellation could make $12 billion profit in a single year, easy, if (IF! If, if, if!) it is deployed successfully to the scale Musk has talked about and SpaceX remains solvent long enough for them to build up the subscriber base (which seems likely as SpaceX is fairly diversified--well, more than Iridium was--and seems likely to dominate the commercial launch industry as well as being well-capitalized and starting up in an era of low interest rates).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mariusuiram on 03/06/2015 05:25 am
http://www.wsj.com/articles/BL-DGB-40041

Quote
SpaceX’s Valuation Rockets to $12 Billion With Google Investment

SpaceX now ranks fourth on The Wall Street Journal’s list of billion-dollar private companies, securing a $12 billion valuation.
>

I'm not sure I would have taken up that deal if I were google.
12 billion is a hell of a lot. If they launch 10 times and launch a couple of dragons as well, they have a yearly revenue of a billion. This is already stretching their revenue expectations for this year. So their valuation is 12 times their revenue? How many companies outside of websites have such a valuation?
Airbus group (note they make a couple of planes, fighterjets, helicopters and missiles as well) has a valuation of only 50B.

SpaceX just got handed a shitload of money. Which of course is great, rather see Google wasting it on SpaceX than giving it to people that try to make an algorithm to present me the best personalized add on my screen.
Because the Constellation could make $12 billion profit in a single year, easy, if (IF! If, if, if!) it is deployed successfully to the scale Musk has talked about and SpaceX remains solvent long enough for them to build up the subscriber base (which seems likely as SpaceX is fairly diversified--well, more than Iridium was--and seems likely to dominate the commercial launch industry as well as being well-capitalized and starting up in an era of low interest rates).

$12 billion in profit in a single year is a pretty big if (at least 1 more if than you listed :) ). But you dont need that really.

We've done this before, but SpaceX is aiming for more than 10 launches per year. Even conservatively in 2015-2018, with 3-4 pads but no "revolutions", they should be doing 15-20 launches per year and 6-8 dragons between Crew & Cargo (and DragonLab????).

That's a lot closer to US$2 billion in revenue (20*$80 = 1.6 billion, 6*$70 = 420 million). Operational margins (before investing in R&D, etc) might be 20% giving them US$400 million a year. Now all of that is getting dumped back into new projects and expansions, but a 30x valuation isnt unreasonable for a company that is growing exponentially.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cosmicvoid on 03/06/2015 06:29 am
Because the Constellation could make $12 billion profit in a single year...

The Constellation??  What?? :o
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cro-magnon gramps on 03/06/2015 06:40 am
Because the Constellation could make $12 billion profit in a single year...

The Constellation??  What?? :o

Didn't you get the message, Elon, Google and another co. are going to build satellites for a 4000 satellite LEO constellation for World Wide Internet... the On Topic Thread for it is here... http://forum.nasaspaceflight.com/index.php?topic=36552.0
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Ben the Space Brit on 03/06/2015 10:09 am
Don't know about the bolts but the Candarm can be operated from Mission Control, if the comms, power, ect is available.

Yeah, but that would require an emergency scenario with these criteria:

1) The US segment crew can't access the Soyuz crew vehicles;

2) There is power and sufficient systems integrity to allow mission control to operate the arm and berthing mechanism;

3) DESPITE 2, the interior of the USOS is unsafe for continued habitation;

4) It is not safer to remain attached to the station with the CBM hatch sealed than risk an urgent EDL in a non-crew vehicle.

I'm pretty sure that's a fairly unlikely confluence of criteria.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cosmicvoid on 03/07/2015 12:22 am
Didn't you get the message, Elon, Google and another co. are going to build satellites for a 4000 satellite LEO constellation ...

Ahh, yes, I'm aware of that "constellation".  The Capitalization confused me into thinking it was a reference to the cancelled rocket program.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Comga on 03/07/2015 05:51 am
I thought you were referring to the Starship Constellation. (http://en.memory-alpha.org/wiki/USS_Constellation_%28NCC-1017%29)
Oh. You were being serious?
The numbers didn't sound like it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 03/09/2015 11:47 am
I have a probably stupid question. After all the reading on this forum I do not recall if Falcon 9 second stages are acceptance testfired in McGregor like the first stages. Or are only the engines tested before installation? I know they would have to be tested without the vacuum extension.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 03/09/2015 12:22 pm
I have a probably stupid question. After all the reading on this forum I do not recall if Falcon 9 second stages are acceptance testfired in McGregor like the first stages. Or are only the engines tested before installation? I know they would have to be tested without the vacuum extension.
Yes, they are acceptance tested. Yes, the vaccuum nozzle extension is not mounted when they are fired, since the testing is at sea level.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: sheltonjr on 03/10/2015 09:14 pm
Is it attached to the second stage at any time when they fir the engine?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: S.Paulissen on 03/10/2015 09:20 pm
I'm 99% sure it's not.  If someone knows otherwise please correct me.

https://www.youtube.com/watch?v=wkdReoxGHG8
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 03/10/2015 09:59 pm
They do have an engine test stand where they fire them not attached to the stage. This test looks like not attached to the stage but there is better footage that shows firing the Merlin vac without vac extension more clearly.

My question was regarding testfiring the stage, not just the engine. And I believe the statement of cscott that they do testfire the stage.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MattMason on 03/13/2015 11:46 am
For your Friday the 13th yuk-yuks comes a series of Twitter messages from comedian and billionaire Elon Musk, regarding the existence of alien life, on Thursday 3/12.

- Seems like an opportune moment to bring up the Fermi Paradox, aka "where are the aliens?" Really odd that we see no sign of them.
- Btw, please don't mention the pyramids. Stacking stone blocks is not evidence of an advanced civilization.
- The rumor that I'm building a spaceship to get back to my home planet Mars is totally untrue
- The ancient Egyptians were amazing, but if aliens built the pyramids, they would've left behind a computer or something

Elon Musk: A man who goes there while he and his team are working to really go there.  :D

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

The start of his pontifications begin here: https://twitter.com/elonmusk/status/576139467632717825 (https://twitter.com/elonmusk/status/576139467632717825)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: grythumn on 03/13/2015 01:35 pm
Because the Constellation could make $12 billion profit in a single year...

The Constellation??  What?? :o

Wait. Elon's acquired a supercarrier (http://en.wikipedia.org/wiki/USS_Constellation_%28CV-64%29) and is using it to acquire $12b in profit in a year? Where's his white cat? At this point I think he's contractually obligated to have a fluffy white cat.

-Bob
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 03/13/2015 01:53 pm
I thought you were referring to the Starship Constellation. (http://en.memory-alpha.org/wiki/USS_Constellation_%28NCC-1017%29)
Oh. You were being serious?
The numbers didn't sound like it.
Numbers didn't sound like it? Perhaps you're either 1) unaware of just how much revenue these 2 industries (broadband and space satellite services) generate or 2) you're not grasping the scope of the announced project (which, if successful, would provide far more throughput and at far lower latency than all the world's satellites combined).

The satellite services industry (basically, telecomm) is over $100 billion per year revenue /currently/. Global internet service revenue is several times that. And those numbers will only grow in the coming decade as more and more of the world is connected (such a constellation would be a perfect backhaul solution to mobile, and with upgrades could serve mobile directly, though you'd still want local mobile sites in cities). So, trillions in revenue (~$4 trillion last year for global telecomm) is the market that the SpaceX constellation would be operating in, and would be able to service a huge portion of it.

And you think $12 billion per year isn't serious?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: vt_hokie on 03/13/2015 02:23 pm
While Musk was making his billions off of Paypal I was losing my shirt on Loral thanks to Globalstar.  I hope Musk's venture fares better, or at least doesn't drag down SpaceX if it fails to be profitable!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: starsilk on 03/13/2015 02:36 pm
Because the Constellation could make $12 billion profit in a single year...

The Constellation??  What?? :o

Wait. Elon's acquired a supercarrier (http://en.wikipedia.org/wiki/USS_Constellation_%28CV-64%29) and is using it to acquire $12b in profit in a year? Where's his white cat? At this point I think he's contractually obligated to have a fluffy white cat.

-Bob

too late.. https://twitter.com/elonmusk/status/192701084932907009
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: seanpg71 on 03/13/2015 06:38 pm
Don't know about the bolts but the Candarm can be operated from Mission Control, if the comms, power, ect is available.

Yeah, but that would require an emergency scenario with these criteria:

1) The US segment crew can't access the Soyuz crew vehicles;

2) There is power and sufficient systems integrity to allow mission control to operate the arm and berthing mechanism;

3) DESPITE 2, the interior of the USOS is unsafe for continued habitation;

4) It is not safer to remain attached to the station with the CBM hatch sealed than risk an urgent EDL in a non-crew vehicle.

I'm pretty sure that's a fairly unlikely confluence of criteria.

Yeah, but we people ask this question, they generally seem to be asking whether it would be survivable.  So from what I've gathered it's probably a bit like NASA shoving an astronaut in the trunk of a car when driving them around.  NASA's not going to do it, but the astronaut would probably be fine if the exact situation came up where that was called for.

As opposed to say, traveling in the wheel well of an airplane where there is a good chance of death.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: FutureSpaceTourist on 03/16/2015 10:19 pm
Any insights on how these F9 changes may affect USAF certification, which I assume has been based on F9 v1.1? I don't see SpaceX operating two F9 variants?

Gwynne Shotwell addressed this question in her remarks today:

Quote
Shotwell said about half of the certification issues being worked by the two U.S. government agencies [USAF & NASA] relate to the company’s specific practices in building its rockets, and not to any specific rocket design. Because of that, she said, the more-powerful Falcon 9 is unlikely to force a renewed certification process.

See more at: http://spacenews.com/spacex-falcon-9-upgrade-wont-require-new-certification (http://spacenews.com/spacex-falcon-9-upgrade-wont-require-new-certification)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: BobHk on 03/16/2015 10:43 pm
Any insights on how these F9 changes may affect USAF certification, which I assume has been based on F9 v1.1? I don't see SpaceX operating two F9 variants?

Gwynne Shotwell addressed this question in her remarks today:

Quote
Shotwell said about half of the certification issues being worked by the two U.S. government agencies [USAF & NASA] relate to the company’s specific practices in building its rockets, and not to any specific rocket design. Because of that, she said, the more-powerful Falcon 9 is unlikely to force a renewed certification process.

See more at: http://spacenews.com/spacex-falcon-9-upgrade-wont-require-new-certification (http://spacenews.com/spacex-falcon-9-upgrade-wont-require-new-certification)

That, if it ends up being true (AF doesn't go back and hem and haw about design changes later), is a HUGE boost/benefit to SpaceX.  Hooray!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: SpacemanInSPACE on 03/16/2015 10:50 pm
Gwynne Shotwell confirms Dragon reuses components for CRS missions. First news I've heard of this.

https://twitter.com/AvWeekParis/status/577532588417372160 (https://twitter.com/AvWeekParis/status/577532588417372160)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Zed_Noir on 03/16/2015 11:58 pm
Gwynne Shotwell confirms Dragon reuses components for CRS missions. First news I've heard of this.

https://twitter.com/AvWeekParis/status/577532588417372160 (https://twitter.com/AvWeekParis/status/577532588417372160)

My guess is the robot arm grapple target is being re-installed on the new cargo Dragons. Along with other components.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Coastal Ron on 03/17/2015 12:52 am
Gwynne Shotwell confirms Dragon reuses components for CRS missions. First news I've heard of this.

https://twitter.com/AvWeekParis/status/577532588417372160 (https://twitter.com/AvWeekParis/status/577532588417372160)

My guess is the robot arm grapple target is being re-installed on the new cargo Dragons. Along with other components.

Things that don't accumulate much wear makes sense.  I wonder if computer units (or pairs) would be reused?  Hatches?  ECLSS?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: catdlr on 03/17/2015 04:02 am
Fight between SpaceX and industry heavyweights heads to Capitol Hill

http://www.washingtonpost.com/business/economy/fight-between-spacex-and-industry-heavyweights-heads-to-capitol-hill/2015/03/16/ebfee9b4-c99e-11e4-a199-6cb5e63819d2_story.html (http://www.washingtonpost.com/business/economy/fight-between-spacex-and-industry-heavyweights-heads-to-capitol-hill/2015/03/16/ebfee9b4-c99e-11e4-a199-6cb5e63819d2_story.html)[/size]

Quote
In a recent interview, Gwynne Shotwell, SpaceX’s president, accused ULA of being a slow-moving monopolist that is dependent on government handouts and resistant to change.

“It’s not in the ULA genetics to be an innovative company,” she said. “But innovation is key to survive in this marketplace.”
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: FutureSpaceTourist on 03/17/2015 06:49 am
That, if it ends up being true (AF doesn't go back and hem and haw about design changes later), is a HUGE boost/benefit to SpaceX.  Hooray!

Well at least is seems they will only focus on the design deltas and not look any more at company processes.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 03/17/2015 07:00 am
Gwynne Shotwell confirms Dragon reuses components for CRS missions. First news I've heard of this.

https://twitter.com/AvWeekParis/status/577532588417372160 (https://twitter.com/AvWeekParis/status/577532588417372160)

My guess is the robot arm grapple target is being re-installed on the new cargo Dragons. Along with other components.

Things that don't accumulate much wear makes sense.  I wonder if computer units (or pairs) would be reused?  Hatches?  ECLSS?
Except for the heat shield, does anything accumulate appreciable wear?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 03/17/2015 11:54 am
This answers the oft-posed question: where are all the used dragons, and why aren't they donated to museums or something?  The answer seems to be that used dragons are taken apart for parts.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: jak Kennedy on 03/17/2015 12:15 pm
Quote
Shotwell said about half of the certification issues being worked by the two U.S. government agencies [USAF & NASA] relate to the company’s specific practices in building its rockets, and not to any specific rocket design. Because of that, she said, the more-powerful Falcon 9 is unlikely to force a renewed certification process.

Quote

That, if it ends up being true (AF doesn't go back and hem and haw about design changes later), is a HUGE boost/benefit to SpaceX.  Hooray!

And a boost/benefit for the AF because otherwise they will never benifit from reduced costs if they can't certify quicker than the upgrades.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dror on 03/17/2015 12:37 pm
This answers the oft-posed question: where are all the used dragons, and why aren't they donated to museums or something?  The answer seems to be that used dragons are taken apart for parts.
There was a picture here, that came out during a spacex broadcast, of a room full of dragons.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: OnWithTheShow on 03/17/2015 01:46 pm
Seems likely it is internal components that are being reused and maybe the draco arrays. Heatshield, aeroshell, and pressure vessel most likely not.

From this thread: http://forum.nasaspaceflight.com/index.php?topic=34749.msg1199517#msg1199517 (http://forum.nasaspaceflight.com/index.php?topic=34749.msg1199517#msg1199517)

This photo:


[Mod Edit: Attach photos please!]
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Graham on 03/17/2015 11:13 pm
I saw this article on Aviation Weekly regarding an upgraded Falcon 9 debuting this summer. I hadn't heard anything previous about this and some quick searches didn't reveal anything either. Anyways according to Shotwell this will allow ASDS landings on GTO missions. Thoughts?
Article: http://aviationweek.com/blog/spacexs-new-spin-falcon-9
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 03/17/2015 11:35 pm
I saw this article on Aviation Weekly regarding an upgraded Falcon 9 debuting this summer. I hadn't heard anything previous about this and some quick searches didn't reveal anything either. Anyways according to Shotwell this will allow ASDS landings on GTO missions. Thoughts?
Article: http://aviationweek.com/blog/spacexs-new-spin-falcon-9

This was discussed here: http://forum.nasaspaceflight.com/index.php?topic=36815.msg1340178#msg1340178 (general SpaceX/Falcon thread)

... And also here - the mission thread for the first flight using some of these upgrades: http://forum.nasaspaceflight.com/index.php?topic=34077.msg1340181#msg1340181

And no, it won't be called a v1.2. This upgrade is much smaller than v1.0 -> v1.1.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: AnalogMan on 03/17/2015 11:41 pm
I saw this article on Aviation Weekly regarding an upgraded Falcon 9 debuting this summer. I hadn't heard anything previous about this and some quick searches didn't reveal anything either. Anyways according to Shotwell this will allow ASDS landings on GTO missions. Thoughts?
Article: http://aviationweek.com/blog/spacexs-new-spin-falcon-9 (http://aviationweek.com/blog/spacexs-new-spin-falcon-9)

And no, it won't be called a v1.2. This upgrade is much smaller than v1.0 -> v1.1.

Quote from Gwynne Shotwell: "I don't know what we're going to call it. Enhanced Falcon 9, Falcon 9 v1.2, Full-Performance Falcon 9."

So v1.2 is a possibility according to SpaceX.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Graham on 03/17/2015 11:45 pm
I saw this article on Aviation Weekly regarding an upgraded Falcon 9 debuting this summer. I hadn't heard anything previous about this and some quick searches didn't reveal anything either. Anyways according to Shotwell this will allow ASDS landings on GTO missions. Thoughts?
Article: http://aviationweek.com/blog/spacexs-new-spin-falcon-9

This was discussed here: http://forum.nasaspaceflight.com/index.php?topic=36815.msg1340178#msg1340178 (general SpaceX/Falcon thread)

... And also here - the mission thread for the first flight using some of these upgrades: http://forum.nasaspaceflight.com/index.php?topic=34077.msg1340181#msg1340181

And no, it won't be called a v1.2. This upgrade is much smaller than v1.0 -> v1.1.
I didn't see those posts when I searched the site, but it's interesting. It's great that these upgrades are occurring so that core landings can take place on GTO missions given that a large chunk of the commercial market is for com sats going to geostationary.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 03/17/2015 11:58 pm
https://twitter.com/AvWeekParis/status/577873951365287937
Shotwell: We have 4 Falcon 9 launches by summer, then doing "minor spin" on the rocket. "That will be the vehicle moving forward" #satshow

https://twitter.com/pbdes/status/577879010262188033
SpaceX's Shotwell: More-powerful Falcon 9 debuts this summer adds ~30% performance to V1.1, enables recovery of 1st stage for GEO. #satshow

https://twitter.com/jeff_foust/status/577878260949864448
Shotwell: Falcon Heavy side booster will be the same as the enhanced F9 v1.1 to be introduced later this year. #satshow

https://twitter.com/AvWeekParis/status/577878756368367616
Shotwell: #SpaceX is doing two Falcon 9 cores - upgraded rocket to be center core of new Falcon Heavy, current v1.1 to be boosters. #satshow



Based on the timing of those last two tweets, it seems like they both come from the same statement but one of the authors misheard/misunderstood Ms. Shotwell's quote. 

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Graham on 03/18/2015 12:05 am
https://twitter.com/AvWeekParis/status/577873951365287937
Shotwell: We have 4 Falcon 9 launches by summer, then doing "minor spin" on the rocket. "That will be the vehicle moving forward" #satshow

https://twitter.com/pbdes/status/577879010262188033
SpaceX's Shotwell: More-powerful Falcon 9 debuts this summer adds ~30% performance to V1.1, enables recovery of 1st stage for GEO. #satshow

https://twitter.com/jeff_foust/status/577878260949864448
Shotwell: Falcon Heavy side booster will be the same as the enhanced F9 v1.1 to be introduced later this year. #satshow

https://twitter.com/AvWeekParis/status/577878756368367616
Shotwell: #SpaceX is doing two Falcon 9 cores - upgraded rocket to be center core of new Falcon Heavy, current v1.1 to be boosters. #satshow



Based on the timing of those last two tweets, it seems like they both come from the same statement but one of the authors misheard/misunderstood Ms. Shotwell's quote.
But which one is correct? Without any real evidence my first guess is that the Heavy's core booster will be the upgraded Falcon 9 and the side boosters will be the v1.1's. I figure this because, at least last I heard, Heavy would be without crossfeed so it would make more sense to have the booster that will burn longer as the core booster. But I could be completely wrong
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Karlman on 03/18/2015 12:20 am
Hmm.. My first thought on reading the linked article..

Falcon v1.2 with the upgrades Gwynne Shotwell talks about is the new first stage for Falcon 9, and the center of the Falcon heavy.

She specifically says she wants only to produce 2 cores.. and goes on to say the following:
Quote
I want to be building only two versions, or two cores in my factory, more than that would not be great from a customer perspective. So Falcon Heavy is two different cores, the inner core and then the two side boosters, and the new single stick Falcon 9 will be a Falcon Heavy with side boosters.

So my take would be:
- one core production line that makes cores that are topped by the interstage, and then second stage. Will accept physical connections from the side boosters
- a second core production line that makes side boosters.. have all the connectors and feeds and anything else to connect to the center core (the folding connector thing from the latest F Heavy video) and has the rounded fairing/cap instead of the interstage connection. Whether it's just a cap bolted on for aerodynamics, or actually a shaped extension of the stage possibly allowing fuel tank stretch can be debated.

Karlman
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jdeshetler on 03/18/2015 12:31 am
Almost as high as SLS Block 1 with extended payload fairing for a fraction of costs....  :o
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Graham on 03/18/2015 12:35 am
Almost as high as SLS Block 1 with extended payload fairing for a fraction of costs....  :o
Wow, I never seem to realize how tall the Falcon is. I guess now all I need is someone smarter than me to figure out what it's payload to LEO/GTO is
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lee Jay on 03/18/2015 12:44 am
It all makes sense.  First stage has already been stretched as far as it can.  Any longer and it wouldn't be road transportable. 

Why not?  As I understand it, it's only about 37m long on the road, which is far shorter than is done routinely.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 03/18/2015 01:06 am
I wonder what the motivation is to keep the v1.1 configuration for the side cores.  Is it cheaper to make compared with v1.2?  Because using her logic, it's better to build only one type of core.

You can always fly 3 x v1.2, and not fully utilize their performance (e.g. partial fuel load, etc), but why keep making "older models"

I'd understand if the FH side cores were built with lighter walls (since they see less compressive load) and the center core was built with heavier walls (since it sees 2-3x the compressive load) but that's clearly not what's happening here.

---

Also, the barge is clearly here to stay.  I would love to see fly-back too - that would be a a slam dunk  :)



Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nadreck on 03/18/2015 01:13 am
I wonder what the motivation is to keep the v1.1 configuration for the side cores.  Is it cheaper to make compared with v1.2?  Because using her logic, it's better to build only one type of core.



One possibility, M1D has more cycles than M1D+, Centre core going to barge has shorter lifespan (higher odds of being eliminated before its operational life span is up), M1D side cores are going back to launch site and a higher rate of them will be able to outlive their cycle rating.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 03/18/2015 01:17 am
I wonder what the motivation is to keep the v1.1 configuration for the side cores.  Is it cheaper to make compared with v1.2?  Because using her logic, it's better to build only one type of core.



One possibility, M1D has more cycles than M1D+, Centre core going to barge has shorter lifespan (higher odds of being eliminated before its operational life span is up), M1D side cores are going back to launch site and a higher rate of them will be able to outlive their cycle rating.
Or more likely:
Shotwell's statement was misinterpreted.

The boosters will be different from the core for some fairly obvious reasons (for one, the load paths are different).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 03/18/2015 01:25 am
I wonder what the motivation is to keep the v1.1 configuration for the side cores.  Is it cheaper to make compared with v1.2?  Because using her logic, it's better to build only one type of core.



One possibility, M1D has more cycles than M1D+, Centre core going to barge has shorter lifespan (higher odds of being eliminated before its operational life span is up), M1D side cores are going back to launch site and a higher rate of them will be able to outlive their cycle rating.
Or more likely:
Shotwell's statement was misinterpreted.

The boosters will be different from the core for some fairly obvious reasons (for one, the load paths are different).

The load on the center core may not be THAT different from 1-stick F9, since the second stage weighs the same.  It's just that in an FH, staging occurs later, so the US generates less dV.

But the load on the side cores is very definitely smaller - it is transferred through the side (which btw requires the thrust structure to be different, and subjects the body to a bending moment) - so they should be different beasts.

 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 03/18/2015 02:09 am

1. But the load on the side cores is very definitely smaller -

2.  it is transferred through the side (which btw requires the thrust structure to be different,

3.  and subjects the body to a bending moment) - so they should be different beasts.



1.  A minor amount

2.  Not really, since the structure is over built and was already designed for it.  Just need attach fittings.

3.   There is no bending moment.  The outboard boosters would cant their engines so that they point through the CG and which also negates bending moment.

The design is not hard.  The existing Atlas V core is the exact same core that would be used in a Heavy version. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 03/18/2015 02:22 am

1. But the load on the side cores is very definitely smaller -

2.  it is transferred through the side (which btw requires the thrust structure to be different,

3.  and subjects the body to a bending moment) - so they should be different beasts.



1.  A minor amount

2.  Not really, since the structure is over built and was already designed for it.  Just need attach fittings.

3.   There is no bending moment.  The outboard boosters would cant their engines so that they point through the CG and which also negates bending moment.

The design is not hard.  The existing Atlas V core is the exact same core that would be used in a Heavy version.

3.  I was wondering whether they'll do that.  But if you cant the thrust vector, while you eliminate the moment, you add a "squishing" load on the boosters, especially on the center one.  Cylinders are very good at carrying axial loads, but are very poor at carrying one-directional sideways loads (to be differentiated from symmetrical radial loads) - they easily deform into ellipses-like cross-sections.  And even if the sideways component is small, we're talking about a fraction of the entire thrust - not a trivial amount.

I agree it's been done before, just not so sure you can handwave the differences between the center core and side core loads away like that.

2. "Overbuilt and already designed for it" means mass.  So the trade-off is between having exact-same cores, or optimization. Especially with reusable cores, I am not sure that commonality wins, since each core flies multiple times and so for a one-time saving at manufacturing (maybe), you lose every time you fly something too heavy.

But, if I were SpaceX, I'd start with "same" since FH can over-perform anyway, and then switch to two core types in the next revision.

1.  Tiny amount?  Anything above the common bulkhead on a side core sees almost no load.  On a center core, it sees a fully fueled second stage and payload - that's a huge difference.

Anyhoo.  To stay on-topic - what's really odd is the 1.1 / 1.2 combo, but as RB said, it might just be incorrect information.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 03/18/2015 02:35 am

2. "Overbuilt and already designed for it" means mass.  So the trade-off is between having exact-same cores, or optimization. Especially with reusable cores, I am not sure that commonality wins, since each core flies multiple times and so for a one-time saving at manufacturing (maybe), you lose every time you fly something too heavy.


Optimization?  Spacex's MO is anything but optimization, more like producibility, commonality, simplicity, etc.  That is how Spacex is lowering costs now.  The whole reuse thing ignores optimization.    There is extra mass all over the vehicle.  They don't need the extra TV cameras, comm systems, etc.

Like I have said, even if they return stages, the resuse part has yet to be seen.  So, just concentrating on a cheap ELV may be all that is possible.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 03/18/2015 02:40 am

3.  I was wondering whether they'll do that.  But if you cant the thrust vector, while you eliminate the moment, you add a "squishing" load on the boosters, especially on the center one.  Cylinders are very good at carrying axial loads, but are very poor at carrying one-directional sideways loads (to be differentiated from symmetrical radial loads) - they easily deform into ellipses-like cross-sections.  And even if the sideways component is small, we're talking about a fraction of the entire thrust - not a trivial amount.

1.  Tiny amount?  Anything above the common bulkhead on a side core sees almost no load.  On a center core, it sees a fully fueled second stage and payload - that's a huge difference.


3.  Tanks don't enter the picture, it is all on the thrust section.  The upper side attach points are on the interstage and also react against each other.

1.  not enough difference to make it worth changing the tank skin gage; and to engineer and maintain another configuration to go with it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 03/18/2015 02:45 am

2. "Overbuilt and already designed for it" means mass.  So the trade-off is between having exact-same cores, or optimization. Especially with reusable cores, I am not sure that commonality wins, since each core flies multiple times and so for a one-time saving at manufacturing (maybe), you lose every time you fly something too heavy.


Optimization?  Spacex's MO is anything but optimization, more like producibility, commonality, simplicity, etc.  That is how Spacex is lowering costs now.  The whole reuse thing ignores optimization.    There is extra mass all over the vehicle.  They don't need the extra TV cameras, comm systems, etc.

Like I have said, even if they return stages, the resuse part has yet to be seen.  So, just concentrating on a cheap ELV may be all that is possible.

I honestly don't think you're getting how SpaceX thinks.

And sure, keep the doubt going.  IF they return stages, IF they reuse them.  IF it makes you happy.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 03/18/2015 02:49 am

I honestly don't think you're getting how SpaceX thinks.


I know their mantra is that if they can't reuse, then they have failed.    There is want and then there is reality.   Some times the two are not the same.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 03/18/2015 02:56 am

I honestly don't think you're getting how SpaceX thinks.


I know their mantra is that if they can't reuse, then they have failed.    There is want and then there is reality.   Some times the two are not the same.

SpaceX would just try again, like they did when parachute recovery failed them.
SpaceX now is a huge player in commercial launch, perhaps soon will be dominant. They don't have to pay dividends because their private shareholders expect them to reinvest their profits so the company can grow, and this includes reuse.

But I expect they will be successful, at very least mildly successful, at reusing F9.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 03/18/2015 02:59 am

I honestly don't think you're getting how SpaceX thinks.


I know their mantra is that if they can't reuse, then they have failed.    There is want and then there is reality.   Some times the two are not the same.
No, that's not what I was aiming for.  Their only demonstrated mantra to date has been that they have no mantra.

They are not extreme in any direction, they are just practical.

Take the trade off we're taking about.  The side cores and center cores see different loads.  There's performance to be gained by making them different.  There's also value in making them the same.  So they'll have to choose.

My point was that with reusable boosters, the "win" due to commonality only happens once, but the win due to differentiation happens on every flight.  So with reusability, there's more motivation to differentiate.

What they'll actually do is unknown.  My guess was that they'll start out with commonality, and later on differentiate.

Shotwell's comment didn't help, since brining v1.1 into this just confused things.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 03/18/2015 03:07 am

Take the trade off we're taking about.  The side cores and center cores see different loads.  There's performance to be gained by making them different. 

The performance gained is minor and overwhelmed by the commonality factor.  The difference is only a few hundred pounds due to skin gage thickness, which since it on the first stage (9 or 10 to 1 ratio) translates to few tens of pounds of payload performance
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 03/18/2015 03:08 am

I wonder what the motivation is to keep the v1.1 configuration for the side cores.  Is it cheaper to make compared with v1.2?  Because using her logic, it's better to build only one type of core.



One possibility, M1D has more cycles than M1D+, Centre core going to barge has shorter lifespan (higher odds of being eliminated before its operational life span is up), M1D side cores are going back to launch site and a higher rate of them will be able to outlive their cycle rating.
Or more likely:
Shotwell's statement was misinterpreted.

The boosters will be different from the core for some fairly obvious reasons (for one, the load paths are different).

Exactly. Some people are just overthinking this instead of seeing the obvious.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: S.Paulissen on 03/18/2015 04:52 am
I, for the first time in a long time, am firmly in Jim's camp on this one, excepting the pessimism on first stage recovery. 

The economic reuse of the core remains to be seen.  It's not a forgone conclusion yet.

Gwynne's words are highly interpretable.  I read them and took it to mean the exact opposite what many in this thread did, I believe it meant all cores were going to be upgraded thrust, subcooled "1.2" variants.

You can't argue for optimization and recovery at the same time.  Throwing engineering margin at a rocket to enable reuse is in direct opposition to the type of optimization being spoken about in this thread. 

It's an untenable argument to say SpaceX doesn't have a mantra.  That's silly.  You don't make a a single engine and shoehorn a way oversized vacuum version of it onto a second stage that's made with identical tooling to  your first stage (when you could lighten it by using other tooling) if you're not driven by producibility/commonality over performance.  You don't use a kerolox upper stage that gets neither long coasts of hypergols nor the performance of hydrolox unless you're not driven by optimization.  The mantra is three fold and clear as day: lower cost, lower cost and lower cost. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 03/18/2015 05:54 am
Of course SpaceX has a mantra(s). And the most central one is "optimize for cost". Which is in stark contrast to other competitors that tend to optimize for performance/efficiency.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: QuantumG on 03/18/2015 08:13 am
Of course SpaceX has a mantra(s). And the most central one is "optimize for cost". Which is in stark contrast to other competitors that tend to optimize for performance/efficiency.

I thought it was "optimize for Mars".
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 03/18/2015 09:09 am
Of course SpaceX has a mantra(s). And the most central one is "optimize for cost". Which is in stark contrast to other competitors that tend to optimize for performance/efficiency.
Was "Stark contrast" a pun?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Graham on 03/18/2015 11:08 am
I, for the first time in a long time, am firmly in Jim's camp on this one, excepting the pessimism on first stage recovery. 

The economic reuse of the core remains to be seen.  It's not a forgone conclusion yet.

Gwynne's words are highly interpretable.  I read them and took it to mean the exact opposite what many in this thread did, I believe it meant all cores were going to be upgraded thrust, subcooled "1.2" variants.

You can't argue for optimization and recovery at the same time.  Throwing engineering margin at a rocket to enable reuse is in direct opposition to the type of optimization being spoken about in this thread. 

It's an untenable argument to say SpaceX doesn't have a mantra.  That's silly.  You don't make a a single engine and shoehorn a way oversized vacuum version of it onto a second stage that's made with identical tooling to  your first stage (when you could lighten it by using other tooling) if you're not driven by producibility/commonality over performance.  You don't use a kerolox upper stage that gets neither long coasts of hypergols nor the performance of hydrolox unless you're not driven by optimization.  The mantra is three fold and clear as day: lower cost, lower cost and lower cost.
I think it will be interesting how economic core return will be. I have trouble believing some of the numbers I've seen like $5-$10 million, but I also find it hard to believe that core returns, especially once they get into the cadence of it, will not significantly lower costs. There are 9 engines on the first stage as well as avionics and control systems. Those are some of the most expensive parts of rockets so I find it hard to believe that reusing it will not lower costs. My only fear is that the post flight examination process on a returned core will be so long and strenuous that it will end up raising costs, like what we saw with the Shuttle.   
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 03/18/2015 11:35 am
$5-10 million is several times too low for an F9R flight. Even WITH full reuse, it'd require a launch rate of about 100 per year.

However, as you say, more modest numbers are certainly possible. Maybe not a halving of the cost, but enough to allow SpaceX to compete with, say, Vega, when all is said and done.

And reuse for Falcon heavy should make a bigger difference in its cost since proportionally more of the vehicle is reused (and because core manufacturing cost surely makes up a larger share of the Falcon heavy expendable launch cost).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mader Levap on 03/18/2015 11:46 am
Shouldn't it be actually v2.1?

SpaceX itself said that name "v1.1" was pretty much for marketing reason, not reflecting actual progress that would deserve "v2.0".
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Graham on 03/18/2015 11:49 am
If SpaceX can get the F9 down to the cost of Vega that would give them a huge edge. The F9 has about 10000kg more to LEO so that's a heckuva good deal. Especially when you consider that the F9 can take 2+ sats to orbit and with the advent of SEP the F9 is a far better deal.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Graham on 03/18/2015 11:50 am
Shouldn't it be actually v2.1?

SpaceX itself said that name "v1.1" was pretty much for marketing reason, not reflecting actual progress that would deserve "v2.0".
Maybe, but this upgrade is a lot smaller than the 1.0 to 1.1 so it might not make sense
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Ben the Space Brit on 03/18/2015 11:59 am
I think that SpaceX needs to be very careful about what it calls things. Any implication that the full-throttle Merlin version is different in any way to v.1.1 will inspire their political enemies (who are manifold) to demand that they start the qualification process (NASA as well as USAF) all over again.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mader Levap on 03/18/2015 12:37 pm
Shouldn't it be actually v2.1?

SpaceX itself said that name "v1.1" was pretty much for marketing reason, not reflecting actual progress that would deserve "v2.0".
Maybe, but this upgrade is a lot smaller than the 1.0 to 1.1 so it might not make sense
I mean version of F9 currenty named "v1.1" should be actually named "v2.0". Then calling version with cooled/densifed/more thrust/whatever "v2.1" would make sense and everything would be in right ballpark change-wise.

I think that SpaceX needs to be very careful about what it calls things. Any implication that the full-throttle Merlin version is different in any way to v.1.1 will inspire their political enemies (who are manifold) to demand that they start the qualification process (NASA as well as USAF) all over again.
So there is no chance it will be named "v1.2". That would indeed imply there is as much changes as with 1.0->1.1 transition. This is how determining versions for marketing purposes (and not according to actual changes) bites back. Now only way they can salvage it while still using version numbers is with something like "v1.1.1". Too unwieldy.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: spacenut on 03/18/2015 12:39 pm
At least SpaceX is incrementally doing upgrades and making slow but steady progress.  Delta IV hasn't changed since the development of Delta IV heavy.  Atlas hasn't changed since they started Atlas V.  They should have at least developed their common upper stage by now, and a domestic kerolox engine.  SpaceX has incrementally doubled the Merlin engine's thrust output.  They have lengthened their booster for extra fuel, and are trying to develop first stage reuse. 

I can see where this can pay off.  First use a new Falcon 9 v1.2 or whatever they are going to call it, to launch humans into orbit.  Then reuse the first stage to launch cheap fuel to either a fuel depot, or to fuel up the Mars transport.  That way if it fails, there is no large cost loss.  Same rocket could be reused say 5-10 times and then inspect it.  Just use the new ones for humans and critical payloads, like military payloads.  Having cheaply supplied fuel depots can bring about a robust in space infrastructure. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: abaddon on 03/18/2015 12:41 pm
I think that SpaceX needs to be very careful about what it calls things. Any implication that the full-throttle Merlin version is different in any way to v.1.1 will inspire their political enemies (who are manifold) to demand that they start the qualification process (NASA as well as USAF) all over again.

This exact question was raised yesterday in House Armed Services Committee hearing - Assuring Assured Access to Space.  Quoting from summary in Space Policy section:
Quote
In the second panel it was asked whether SpaceX's continued improvements to the Falcon 9 represents a moving target and it was stated that it does not as there is a process in the contract that covers this and the same thing happens on ULA launches as each launch often represents the first flight of some item on each rocket. [General Hyten, Cmdr AFSPC] did not see this as an issue for either provider.

That doesn't cover NASA, but I would imagine the same applies there as well.

I think it is clear that any certification issues with either NASA or USAF will be a part of the internal process, not due to FUD from an external source.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: abaddon on 03/18/2015 12:44 pm
Delta IV hasn't changed since the development of Delta IV heavy.  Atlas hasn't changed since they started Atlas V.

According to the USAF, that is incorrect.  And I am sure there are plenty of publicly known examples of this type of thing, e.g. RS-68a for one.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 03/18/2015 01:00 pm
Delta IV hasn't changed since the development of Delta IV heavy.  Atlas hasn't changed since they started Atlas V.

According to the USAF, that is incorrect.  And I am sure there are plenty of publicly known examples of this type of thing, e.g. RS-68a for one.

Common avionics, common upper stage engine, common practices, common payload adapters, etc.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: newpylong on 03/18/2015 01:36 pm
Almost as high as SLS Block 1 with extended payload fairing for a fraction of costs....  :o

Where did you come up with that made up height and extended fairing?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 03/18/2015 02:47 pm
Delta IV hasn't changed since the development of Delta IV heavy.  Atlas hasn't changed since they started Atlas V.

According to the USAF, that is incorrect.  And I am sure there are plenty of publicly known examples of this type of thing, e.g. RS-68a for one.

Common avionics, common upper stage engine, common practices, common payload adapters, etc.
There are 2 Delta IV upper stages (different volumes, same basic engine). Are you aware of whether they each separately had to go through a rigorous qualification?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 03/18/2015 02:54 pm
Shouldn't it be actually v2.1?

SpaceX itself said that name "v1.1" was pretty much for marketing reason, not reflecting actual progress that would deserve "v2.0".

Stop trying to come up with your own names. This is just small incremental upgrades, and SpaceX will likely just call it "enhanced F9" or "higher thrust F9". And when it becomes the standard core later this year, just "F9". And it when it lands, "F9R".
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/18/2015 03:05 pm
Don't know why SpaceX doesn't simply follow the model for aircraft designation that has worked fine for over a hundred years: F9A, F9B, F9C, etc.

This v1.0, v1.1, v1.2 stuff is annoying and even SpaceX apparently doesn't know what the next upgrade will be called, so now we have entire threads dedicated to (wasted on?) discussing what it should be called.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Oberon_Command on 03/18/2015 03:21 pm
Don't know why SpaceX doesn't simply follow the model for aircraft designation that has worked fine for over a hundred years: F9A, F9B, F9C, etc.

This v1.0, v1.1, v1.2 stuff is annoying and even SpaceX apparently doesn't know what the next upgrade will be called, so now we have entire threads dedicated to (wasted on?) discussing what the next generation will be called.

<Major>.<minor>.<build number> is an extremely common way of tracking software versions. Given Musk's background in software, it makes perfect sense that he'd go with a similar nomenclature. I could see this sort of thing being useful when tracking individual vehicles once reusability gets going. You might have a vehicle numbered "F9S1 1.2.0007", for instance, which would be the seventh v1.2 first stage, and would be referred to such in mission planning documents. Although, in my experience the build number usually doesn't reset across versions, so it might actually be something like "F9S1 1.2.0019", with the 0019 indicating that this is the 19th F9 core stage produced of any version.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 03/18/2015 03:27 pm
Falcon v1.2 with the upgrades Gwynne Shotwell talks about is the new first stage for Falcon 9, and the center of the Falcon heavy.

She specifically says she wants only to produce 2 cores.. and goes on to say the following:
Quote
I want to be building only two versions, or two cores in my factory, more than that would not be great from a customer perspective. So Falcon Heavy is two different cores, the inner core and then the two side boosters, and the new single stick Falcon 9 will be a Falcon Heavy with side boosters.

Either you got the quote wrong, or the article has been edited since you read/wrote the above.

Gwynne's quote in that article is now:
Quote
What we're also doing is modifying the structure a little bit.  I want to be building only two versions, or two cores in my factory, any more than that would not be great from a customer perspective. So Falcon Heavy is two different cores, the inner core and then the two side boosters, and the new single stick Falcon 9 will basically be a Falcon Heavy side booster.

This implies (to me) that the new uprated & stretched F9 v1.2 is the FH side booster and the single-stick F9 (used for the SES launch, etc).  The inner core of the heavy is a different configuration.  I don't know if that means it's an unstretched, lower-thrust v1.1, or else a redesigned core with "modified structure" or what.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 03/18/2015 03:36 pm
There has never been mention of first stage stretching. Only of second stage stretching.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/18/2015 03:39 pm
Don't know why SpaceX doesn't simply follow the model for aircraft designation that has worked fine for over a hundred years: F9A, F9B, F9C, etc.

This v1.0, v1.1, v1.2 stuff is annoying and even SpaceX apparently doesn't know what the next upgrade will be called, so now we have entire threads dedicated to (wasted on?) discussing what the next generation will be called.

<Major>.<minor>.<build number> is an extremely common way of tracking software versions. Given Musk's background in software, it makes perfect sense that he'd go with a similar nomenclature. I could see this sort of thing being useful when tracking individual vehicles once reusability gets going. You might have a vehicle numbered "F9S1 1.2.0007", for instance, which would be the seventh v1.2 first stage, and would be referred to such in mission planning documents. Although, in my experience the build number usually doesn't reset across versions, so it might actually be something like "F9S1 1.2.0019", with the 0019 indicating that this is the 19th F9 core stage produced of any version.

Yes, I know how software revision numbers work. Unfortunately that revision system makes for unwieldy rocket names. Aircraft manufacturers have no trouble doing complex configuration management while assigning simple model letters (A,B,C, etc) to upgraded versions.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GreenShrike on 03/18/2015 06:19 pm
There has never been mention of first stage stretching. Only of second stage stretching.

No, but something has to be done to maintain F9's oxidizer/fuel ratio.

Subchilling LOX gets you around 10% more mass per volume, but doing the same to RP-1 only gets you around 5% -- and that's only if RP-1 is getting chilled as well, which may be doubtful since I believe Elon only mentioned chilling LOX.

So, assuming the O/F ratio will remain the same and the additional LOX isn't simply shoved into the Merlins' combustion chambers, they'll need to cram more RP-1 into the stage to main the current ratio.

Will SpaceX move the common bulkhead to shrink the LOX tank and give more volume to the RP-1 tank? Or will they stretch the stage slightly and get more RP-1 volume that way?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 03/18/2015 06:45 pm
They have probably planned for this from the beginning. The needed stretch of the RP-1 tank is really very small. They may have included it in the design already.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: gongora on 03/18/2015 06:52 pm
Falcon v1.2 with the upgrades Gwynne Shotwell talks about is the new first stage for Falcon 9, and the center of the Falcon heavy.

She specifically says she wants only to produce 2 cores.. and goes on to say the following:
Quote
I want to be building only two versions, or two cores in my factory, more than that would not be great from a customer perspective. So Falcon Heavy is two different cores, the inner core and then the two side boosters, and the new single stick Falcon 9 will be a Falcon Heavy with side boosters.

Either you got the quote wrong, or the article has been edited since you read/wrote the above.

Gwynne's quote in that article is now:
Quote

What we're also doing is modifying the structure a little bit.  I want to be building only two versions, or two cores in my factory, any more than that would not be great from a customer perspective. So Falcon Heavy is two different cores, the inner core and then the two side boosters, and the new single stick Falcon 9 will basically be a Falcon Heavy side booster.

This implies (to me) that the new uprated & stretched F9 v1.2 is the FH side booster and the single-stick F9 (used for the SES launch, etc).  The inner core of the heavy is a different configuration.  I don't know if that means it's an unstretched, lower-thrust v1.1, or else a redesigned core with "modified structure" or what.

Pretty sure the article did get edited, makes more sense now.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GreenShrike on 03/18/2015 07:24 pm
They have probably planned for this from the beginning.

Which would imply that F9 wasn't flying with a full fuel load, wouldn't it? Wasn't there a rumour to that effect?

The needed stretch of the RP-1 tank is really very small. They may have included it in the design already.

The first stage is around 42m tall. Subtract some for the engines to leave only tankage, of which better than half for LOX.  So, say very roughly around a 25m/15m split for LOX/RP-1. So 10% additional RP-1 volume would need something on the order of a 1m stretch.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 03/18/2015 07:35 pm

There has never been mention of first stage stretching. Only of second stage stretching.

No, but something has to be done to maintain F9's oxidizer/fuel ratio.

Subchilling LOX gets you around 10% more mass per volume, but doing the same to RP-1 only gets you around 5% -- and that's only if RP-1 is getting chilled as well, which may be doubtful since I believe Elon only mentioned chilling LOX.

So, assuming the O/F ratio will remain the same and the additional LOX isn't simply shoved into the Merlins' combustion chambers, they'll need to cram more RP-1 into the stage to main the current ratio.

Will SpaceX move the common bulkhead to shrink the LOX tank and give more volume to the RP-1 tank? Or will they stretch the stage slightly and get more RP-1 volume that way?

That's how much volume CAN be gained by sub-cooling, but they could simply cool LOX less to maintain the same fuel/oxidizer ratio.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 03/18/2015 07:59 pm
The first stage is around 42m tall. Subtract some for the engines to leave only tankage, of which better than half for LOX.  So, say very roughly around a 25m/15m split for LOX/RP-1. So 10% additional RP-1 volume would need something on the order of a 1m stretch.

I am sure the ratio is higher. More than 2/1 for LOX. Also LOX is less dense. Also RP-1 will be cooled, just not enough to keep the ratio. If they have reserved 30cm of tank length for RP-1 increase it should be enough to have the needed ratio.

I am not sure but they may have the tank full already and run more fuel rich than needed.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Coastal Ron on 03/18/2015 08:38 pm
So my take would be:
- one core production line that makes cores that are topped by the interstage, and then second stage. Will accept physical connections from the side boosters
- a second core production line that makes side boosters.. have all the connectors and feeds and anything else to connect to the center core (the folding connector thing from the latest F Heavy video) and has the rounded fairing/cap instead of the interstage connection. Whether it's just a cap bolted on for aerodynamics, or actually a shaped extension of the stage possibly allowing fuel tank stretch can be debated.

They use the same production line to make both the 1st and 2nd stages.  The way the stages are designed for manufacturing the main difference would just be the length of the tanks.

What Shotwell was likely referencing was that for the 1st stage they would only have two basic models, with the main difference being the length.

Having been a factory scheduling manager I know I'd be happy that they designed the new version so that the Falcon Heavy core was the exception, meaning that I'd only have to plan to build one for the occasional Falcon Heavy customer.  And it means that I wouldn't have to worry about where the boosters were coming from, since they could be new build or previously used Falcon 9 boosters that were recovered.  Lots of flexibility.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: S.Paulissen on 03/18/2015 11:21 pm
You just move the bulkhead guys.  Mass is mass, it doesn't matter what tank ratio which propellant component gets or what ratio density increases relative to the other, you nudge the bulkhead to even up the propellant volume ratios and you're done.

The engines' O/F ratio will have to be modestly retuned to achieve the same molar ratio as the original design or they'll simply run it as is since it was fuel rich as it is now and now have a little more cooling capacity from the chilled RP-1 circulating through the nozzle.  I can't tell you what they'll do.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Burninate on 03/18/2015 11:33 pm
I've heard some comments to the effect that solid rocket boosters are an implicitly high-vibration mode of propulsion due to how the chunks of propellant break off, vaporize, and burn, and thus, goes the logic, steady liquid-fueled rocket propulsion is more compatible with fragile payloads.

Would we expect densified propellant, for which mixing occurs later in the combustion pipeline, to cause higher vibration levels for the payload than fully liquid propellant?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: clongton on 03/18/2015 11:56 pm
All this talk about what everybody thinks SpaceX should be naming their incremental upgrades is annoying. They will do what they want to do. Like Jim said most Delta-IV flights carry at least one new thing or upgrade. Yet it is still just "Delta-IV".
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 03/19/2015 12:14 am
I've heard some comments to the effect that solid rocket boosters are an implicitly high-vibration mode of propulsion due to how the chunks of propellant break off, vaporize, and burn, and thus, goes the logic, steady liquid-fueled rocket propulsion is more compatible with fragile payloads.

Would we expect densified propellant, for which mixing occurs later in the combustion pipeline, to cause higher vibration levels for the payload than fully liquid propellant?

no, not the same analogy
a.  The SRM is a pipe unlike a engine and has other acoustical properties.

b  propellant is preheated in cooling the thrust chamber and nozzle
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GreenShrike on 03/19/2015 02:26 am
You just move the bulkhead guys.  Mass is mass, it doesn't matter what tank ratio which propellant component gets or what ratio density increases relative to the other, you nudge the bulkhead to even up the propellant volume ratios and you're done.

You see, that's pretty much what I was expecting, too. Sure moving the bulkhead would likely require some additional analysis due to the structural change, but I wouldn't think it'd be that big a deal.

Then Elon mentions stretching S2, so they're apparently open to minor core stretches, and now the F9 S1 cores are supposed to be the same as the FH's side boosters, which supposedly longer than the center core. This, I think, leaves open at least the vague possibility that S1 will grow to the boosters' size rather than having the FH boosters shrink, and also deals with the nagging question of how the O/F ratio will be maintained.

And when the SpaceX could use every extra bit of oomph in the F9 they can get to enable consistent recovery for 4+ tonne GEO comsats, suddenly I'm wondering if their "enhanced F9" might grow just a little bit taller than v1.1.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Karlman on 03/19/2015 02:41 am
(snip)
Either you got the quote wrong, or the article has been edited since you read/wrote the above.

Gwynne's quote in that article is now:
Quote
What we're also doing is modifying the structure a little bit.  I want to be building only two versions, or two cores in my factory, any more than that would not be great from a customer perspective. So Falcon Heavy is two different cores, the inner core and then the two side boosters, and the new single stick Falcon 9 will basically be a Falcon Heavy side booster.

I'm pretty certain I copy pasted her quote and the used the quote button on the reply page, so I think the source was updated after my quote.
Either way the current statement is more clear, thanks for pointing that out, and saving pages of more post on the poor NSF servers :)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 03/19/2015 02:53 am
Of course SpaceX has a mantra(s). And the most central one is "optimize for cost". Which is in stark contrast to other competitors that tend to optimize for performance/efficiency.

Well it is a very vague mantra, so can be used to justify almost any decision...  Cost is tricky number - remember the debates about how much Shuttle flights are per kg? 

SpaceX does no blindly pursue higher ISP (for example).  That's for sure.  But they invest money in long term goals, which increases cost in the near term.  They make some decisions that only make sense for a market that's much larger than today's market, and this also raises costs until that market emerges.

The one characteristic I see over all is that they take a holistic look at the problem, and go back to first principles to find their preferred solution.  None of the "this is how it's done" attitude, and no departmental tunnel-vision.

It's not a mantra, it's a way of running a company.

When you try to distill from that various "mantras", you fall back into the trap that other aerospace companies found themselves in.  They follow the mantra even when it stops making sense in the global scheme of things.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 03/19/2015 03:01 am
(snip)
Either you got the quote wrong, or the article has been edited since you read/wrote the above.

Gwynne's quote in that article is now:
Quote
What we're also doing is modifying the structure a little bit.  I want to be building only two versions, or two cores in my factory, any more than that would not be great from a customer perspective. So Falcon Heavy is two different cores, the inner core and then the two side boosters, and the new single stick Falcon 9 will basically be a Falcon Heavy side booster.

I'm pretty certain I copy pasted her quote and the used the quote button on the reply page, so I think the source was updated after my quote.
Either way the current statement is more clear, thanks for pointing that out, and saving pages of more post on the poor NSF servers :)

Either way she's saying the FH will have two types of cores, except now I understand the quote to suggest that the side cores are like a standard F9, and the center core is beefier.

I like that better than the first version, because I'd be surprised if the F9 can carry 3x the load, and I believe that for various reasons you can't lighten it up economically to form the side cores.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 03/19/2015 03:25 am
There has never been mention of first stage stretching. Only of second stage stretching.

No, but something has to be done to maintain F9's oxidizer/fuel ratio.

Subchilling LOX gets you around 10% more mass per volume, but doing the same to RP-1 only gets you around 5% -- and that's only if RP-1 is getting chilled as well, which may be doubtful since I believe Elon only mentioned chilling LOX.


Here's Ms. Shotwell's comment on RP-1 chilling:

https://twitter.com/AvWeekParis/status/577534249420468224
Quote
Shotwell on Falcon 9 Merlin engine upgrade: We're doing slightly chilled RP, mostly chilled oxidizer. "Hey, if Russia can do it..." #satshow

I'm not 100% sure how to read that statement.  There's a couple of possibilities:
     A.  They aren't chilling the RP-1 as far as is possible and therefore, for whatever reason, they aren't maximizing the possible fuel density gains. 
     B.  That the RP-1 will be maximally chilled but, due to their properties, RP-1 can't be chilled as much as LOX.  i.e. RP-1 freezes at around -37oC, while max demonstrated density gains to LOX were achieved at around -205oC.
     C.  Some other interpretation I haven't thought of yet.

Whichever it is, there's no doubt at all that they are in fact chilling the RP-1.  Unless someone wants to argue that Ms. Shotwell was mistaken.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GreenShrike on 03/19/2015 07:44 pm

Here's Ms. Shotwell's comment on RP-1 chilling:

https://twitter.com/AvWeekParis/status/577534249420468224
Quote
Shotwell on Falcon 9 Merlin engine upgrade: We're doing slightly chilled RP, mostly chilled oxidizer. "Hey, if Russia can do it..." #satshow

I'm not 100% sure how to read that statement.  There's a couple of possibilities:
     A.  They aren't chilling the RP-1 as far as is possible and therefore, for whatever reason, they aren't maximizing the possible fuel density gains. 
     B.  That the RP-1 will be maximally chilled but, due to their properties, RP-1 can't be chilled as much as LOX.  i.e. RP-1 freezes at around -37oC, while max demonstrated density gains to LOX were achieved at around -205oC.
     C.  Some other interpretation I haven't thought of yet.

Cheers, I hadn't seen that.

I'd suspect "A" myself, for two reasons: first, heavy hydrocarbons can become viscous at low temperatures, so kerosene at -30oC may behave more like tar than gasoline; and second, if they only chill the RP-1 to 1-3oC, they'd avoid having the logo on the rocket frost over. *


* What? It's a valid concern. I'm personally waiting for SpaceX to put a superhydrophobic coating down a strip of F9 S1, so the SpaceX logo can take up the entire side without be obscured by ice or frost, like they show in all their videos. ;-)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: okan170 on 03/20/2015 04:46 am
I did some public renders of some SpaceX scenes and thought I'd post them here for you guys!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: The Amazing Catstronaut on 03/20/2015 07:41 am
Beautiful. Masterfully done.  :D
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: baldusi on 03/20/2015 12:53 pm
Thanks Okan! You keep mesmerizing us with your amazing renders. I loved the dual Dragon v2, could you do two v1 + 2 v2 for extreme SpaceX fans?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: arachnitect on 03/20/2015 06:20 pm
Thanks Okan! You keep mesmerizing us with your amazing renders. I loved the dual Dragon v2, could you do two v1 + 2 v2 for extreme SpaceX fans?

Can't be done, breaks the forum [/sarcasm]

Just to be a joyless pedant, let me point out that 4x Dragon at station is almost certainly never going to happen. Even 3x Dragon would be really unlikely (1 cargo Dragon, and doing a direct crew handover with both missions flying Spacex).

1 crew + 1 cargo dragon will be pretty common though.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Sesquipedalian on 03/20/2015 08:41 pm
I was looking at the recent (http://i.imgur.com/ZJfbZzz.jpg) images (http://i.imgur.com/wzy8ooH.jpg) of the wind tunnel test of Falcon Heavy and noticed they had what appeared to be LOX feedlines running down the outside of the stage.  I was wondering why this was the case, as it had been previously established that the LOX feed runs down the center of the kerosene tank, with the tank making a torus shape around it.

But then I realized that by moving the LOX feed to the outside of the rocket, they gain a significant amount of volume on the inside.  This could be a way to accomplish their stated goals of increasing tank capacity without requiring a tank stretch and the cascade of changes that would entail.


EDIT: Reposted (http://forum.nasaspaceflight.com/index.php?topic=36806.msg1348689#msg1348689) on the Falcon Heavy thread since the model is a Falcon Heavy, but given the stage commonality, they are probably planning the same thing for the single stick.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MP99 on 03/21/2015 09:50 am
Shouldn't it be actually v2.1?

SpaceX itself said that name "v1.1" was pretty much for marketing reason, not reflecting actual progress that would deserve "v2.0".

Stop trying to come up with your own names. This is just small incremental upgrades, and SpaceX will likely just call it "enhanced F9" or "higher thrust F9". And when it becomes the standard core later this year, just "F9". And it when it lands, "F9R".

V1.1.1 seems appropriate... :-)

Cheers, Martin
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MP99 on 03/21/2015 09:52 am


There has never been mention of first stage stretching. Only of second stage stretching.

No, but something has to be done to maintain F9's oxidizer/fuel ratio.

Subchilling LOX gets you around 10% more mass per volume, but doing the same to RP-1 only gets you around 5% -- and that's only if RP-1 is getting chilled as well, which may be doubtful since I believe Elon only mentioned chilling LOX.

So, assuming the O/F ratio will remain the same and the additional LOX isn't simply shoved into the Merlins' combustion chambers, they'll need to cram more RP-1 into the stage to main the current ratio.

Gwynne recently said that the MR will change.

Cheers, Martin
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 03/21/2015 10:26 am
Shouldn't it be actually v2.1?

SpaceX itself said that name "v1.1" was pretty much for marketing reason, not reflecting actual progress that would deserve "v2.0".

Stop trying to come up with your own names. This is just small incremental upgrades, and SpaceX will likely just call it "enhanced F9" or "higher thrust F9". And when it becomes the standard core later this year, just "F9". And it when it lands, "F9R".

V1.1.1 seems appropriate... :-)

Cheers, Martin

I think keeping the digit count where it is would be less confusing/tongue tying.

Call it v1.2
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 03/21/2015 02:58 pm

I was looking at the recent (http://i.imgur.com/ZJfbZzz.jpg) images (http://i.imgur.com/wzy8ooH.jpg) of the wind tunnel test of Falcon Heavy and noticed they had what appeared to be LOX feedlines running down the outside of the stage.  I was wondering why this was the case, as it had been previously established that the LOX feed runs down the center of the kerosene tank, with the tank making a torus shape around it.

But then I realized that by moving the LOX feed to the outside of the rocket, they gain a significant amount of volume on the inside.  This could be a way to accomplish their stated goals of increasing tank capacity without requiring a tank stretch and the cascade of changes that would entail.


EDIT: Reposted (http://forum.nasaspaceflight.com/index.php?topic=36806.msg1348689#msg1348689) on the Falcon Heavy thread since the model is a Falcon Heavy, but given the stage commonality, they are probably planning the same thing for the single stick.

I responded on that thread. (Short version: This is not a LOX feed, and it has existed on all F9 v1.1, you just haven't noticed)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rcoppola on 03/21/2015 08:51 pm
Thanks Lars-J for clearing that up.

Now, and I have lost track which of the many threads this question could potentially go in:

This enhanced F9 v1.2 (or whatever it will be called), will this fall under the current USAF certification program? to be completed in a couple months?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 03/21/2015 10:51 pm
Doesn't sound like the upgrade will cause a problem...

http://spacenews.com/spacex-aims-to-debut-new-version-of-falcon-9-this-summer/

Quote
Shotwell said the new-version Falcon 9 will not force the company to begin a lengthy new process of certifying the vehicle with NASA and the U.S. Defense Department to carry those agencies’ high-value payloads.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: BobHk on 03/21/2015 10:54 pm
Thanks Lars-J for clearing that up.

Now, and I have lost track which of the many threads this question could potentially go in:

This enhanced F9 v1.2 (or whatever it will be called), will this fall under the current USAF certification program? to be completed in a couple months?

http://spacenews.com/spacex-aims-to-debut-new-version-of-falcon-9-this-summer/ (http://spacenews.com/spacex-aims-to-debut-new-version-of-falcon-9-this-summer/)

Quote
“There will be iterations that go on from there, but they will be certified as changes. It won’t be certified as an entirely new rocket,” Shotwell said.

“Nearly half of the activity for certification is certifying SpaceX as a company — our manufacturing processes, our quality control, our launch sites and our launch processes,” she said. “In fact this has taken a majority of the time, to understand how we do business. That doesn’t change with the rocket, and in fact that doesn’t change when we go from a Falcon 9 single stick to a Falcon Heavy.

“So certification, while it might be an iterative process, becomes quicker and quicker to certify vehicle changes.”

I'm glad FH doesn't require major hurdles in cert/recert.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Krevsin on 03/22/2015 05:10 pm
I have a question, does it make sense to test the Dragon V2 trunk on a Dragon V1 flight?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Ben the Space Brit on 03/22/2015 05:34 pm
I have a question, does it make sense to test the Dragon V2 trunk on a Dragon V1 flight?

I'm not sure that there is sufficient commonality between the spacecraft to make that possible (umbilical locations, reliance of solar power, etc.).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 03/22/2015 05:42 pm
I have a question, does it make sense to test the Dragon V2 trunk on a Dragon V1 flight?

One problem is that the DV1 and DV2 interfaces are vastly different.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 03/22/2015 05:55 pm
I am not sure where to put that question so I put it here.

There was a lot of talk about certification recently. I am wondering what would it take to certify a rocket, any rocket, or specifically Falcon 9/FH for nuclear payloads like plutonium batteries?

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 03/24/2015 07:53 am
As far as the general USAF Falcon 9 progress goes,

AF releases results of Space Launch Process review... (http://www.af.mil/News/ArticleDisplay/tabid/223/Article/581248/af-releases-results-of-space-launch-process-review.aspx)

Quote
WASHINGTON (AFNS) --
>
>
 A relatively small amount of work remains, primarily focused on second stage engine and fairing qualification and contamination control. By implementing these changes to the certification process and assuming work progresses as predicted, both parties continue to remain on course to provide certification by June 2015.
>
>

EDIT: fixed embedded USAF website  link. Here's the raw one,

http://www.af.mil/News/ArticleDisplay/tabid/223/Article/581248/af-releases-results-of-space-launch-process-review.aspx
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 03/24/2015 12:22 pm
Quote
A relatively small amount of work remains, primarily focused on second stage engine and fairing qualification and contamination control. By implementing these changes to the certification process and assuming work progresses as predicted, both parties continue to remain on course to provide certification by June 2015.

"Implementing these changes to the certification process"?  I think perhaps "implementing these changes to the certified process"?  That is, SpaceX agrees to tweak the way they qualify the second stage engine and fairing and the way they handle contamination control to add the extra paperwork the AF requires?

Or have I misunderstood what's being negotiated?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 03/24/2015 12:27 pm
It's quite possible that changes need to be made to the certification process itself so it's relevant for how SpaceX processes their vehicles. Remember, the certification process itself is not simply a set of universal principles, but itself evolved along with and responding to the practices of the aerospace primes for which they were developed.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 03/24/2015 12:36 pm
It's quite possible that changes need to be made to the certification process itself so it's relevant for how SpaceX processes their vehicles. Remember, the certification process itself is not simply a set of universal principles, but itself evolved along with and responding to the practices of the aerospace primes for which they were developed.

I guess the wording in the article is signficant, then -- indicating which party is moving in this negotiation.  With my wording, it was SpaceX who needed to conform to the AF's process; with the wording in the article (and your interpretation) it's the AF's process which needs to change to suit SpaceX.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/24/2015 12:36 pm
Quote
A relatively small amount of work remains, primarily focused on second stage engine and fairing qualification and contamination control. By implementing these changes to the certification process and assuming work progresses as predicted, both parties continue to remain on course to provide certification by June 2015.

"Implementing these changes to the certification process"?  I think perhaps "implementing these changes to the certified process"?  That is, SpaceX agrees to tweak the way they qualify the second stage engine and fairing and the way they handle contamination control to add the extra paperwork the AF requires?

Or have I misunderstood what's being negotiated?

That para is poorly written. There should have been a pragraph break between the sentence about second stage/fairing qual and the "certification process."

What they meant was, assuming that the Air Force implements the recommended changes to their own certification process, and also assuming SpaceX stays on track with closing their open items, they should be certified by June.

Overall, yes, it was definitely the Air Force certification process that was the focus of the review panel. The Air Force messed up by somehow moving the goalposts so that the expected certification date changed from end of last year to mid-2015, and the review panel was convened to find out what went wrong and recommend changes to the Air Force certification process so that kind of hiccup wouldn't happen again.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rcoppola on 03/24/2015 04:57 pm
With the added capabilities of F9V1.2, I wonder if the next phase of their certification will be for re-use flights. Not necessarily to re-use any cores, at least not anytime soon but rather to allow legs, grids, etc on their EELV flights.

I'm thinking there must have been some initial discussions around that for the future.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 03/24/2015 05:01 pm
With the added capabilities of F9V1.2, I wonder if the next phase of their certification will be for re-use flights. Not necessarily to re-use any cores, at least not anytime soon but rather to allow legs, grids, etc on their EELV flights.

I'm thinking there must have been some initial discussions around that for the future.

If it lowers costs and has been proven on many flights, I don't think the DoD will complain too much.

Remember that the AF/DoD keep funding studies for reusable first stages - so they are not philosophically against the idea. And not they might get that capability (a reusable first stage) for basically 'free'.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 03/24/2015 11:51 pm
As far as the general USAF Falcon 9 progress goes,
AF releases results of Space Launch Process review... (http://www.af.mil/News/ArticleDisplay/tabid/223/Article/581248/af-releases-results-of-space-launch-process-review.aspx)
Quote
WASHINGTON (AFNS) --
A relatively small amount of work remains, primarily focused on second stage engine and fairing qualification and contamination control. By implementing these changes to the certification process and assuming work progresses as predicted, both parties continue to remain on course to provide certification by June 2015.

Seems to debunk the contention that a demonstrable ability to vertically integrate payloads has been the hold-up to certification.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: BobHk on 03/25/2015 01:34 am
As far as the general USAF Falcon 9 progress goes,
AF releases results of Space Launch Process review... (http://www.af.mil/News/ArticleDisplay/tabid/223/Article/581248/af-releases-results-of-space-launch-process-review.aspx)
Quote
WASHINGTON (AFNS) --
A relatively small amount of work remains, primarily focused on second stage engine and fairing qualification and contamination control. By implementing these changes to the certification process and assuming work progresses as predicted, both parties continue to remain on course to provide certification by June 2015.

Seems to debunk the contention that a demonstrable ability to vertically integrate payloads has been the hold-up to certification.

Well you can believe what you want but...

http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/ (http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/)
Quote
In a 2013 report, the U.S. Government Accountability Office, Congress’ watchdog agency, said certification has been complicated by Air Force changes to the technical requirements for integrating satellites with their launch vehicles. - See more at: http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/#sthash.gzk4z6dx.dpuf

oh yeah:

EDIT:  page 16 is the money shot, look at that slide...
http://www.gao.gov/assets/660/652037.pdf (http://www.gao.gov/assets/660/652037.pdf)

Quote
New entrants will be required to integrate payloads with the launch vehicle upright, or
vertical, and the payload attached to the vehicle from above, as
NSS payloads are currently designed to be vertically integrated.
  •Though not mentioned in the NECG, Air Force officials confirmed that new
entrants will be required to vertically integrate payloads, even if the new entrant’s
launch vehicle was designed to horizontally integrate payloads.
  •Senior Air Force officials indicated that even if a payload could be retrofitted to be
horizontally mated to the launch vehicle and significant cost savings could be
realized by allowing horizontal integration, the requirement for vertical payload
integration would stand, as NSS payloads a re designed to be vertically mated to
the launch vehicle.

What is the NECG? 
 New Entrant Certification Guide (NECG)
https://www.fbo.gov/index?s=opportunity&mode=form&id=6159d0e6915a8463867ae7053f90a2c7&tab=core&_cview=0 (https://www.fbo.gov/index?s=opportunity&mode=form&id=6159d0e6915a8463867ae7053f90a2c7&tab=core&_cview=0)

...which doesn't mention Vertical integration.

Quote
The event will kick-off the morning of Thursday, 1 December 2011. We will hold group general sessions from 8:30 AM to 12:00 PM to present overview information about the NECG.

But it does mention its a risk based guide for certification for ... NSS missions....blah blah blah
https://www.fbo.gov/utils/view?id=57db20315ff156689cac2b312fa6b4ff (https://www.fbo.gov/utils/view?id=57db20315ff156689cac2b312fa6b4ff)

And SpaceX was duly concerned:
http://www.spacex.com/press/2012/12/19/gao-report-raises-serious-concerns-over-ula-block-buy (http://www.spacex.com/press/2012/12/19/gao-report-raises-serious-concerns-over-ula-block-buy)

SpaceX saw the monopoly coming and tried to kill it in its crib but...

SpaceX sues Lock-Mart and Boeing
October 24, 2005 by Braddock Gaskill
http://www.nasaspaceflight.com/2005/10/spacex-sues-lock-mart-and-boeing/ (http://www.nasaspaceflight.com/2005/10/spacex-sues-lock-mart-and-boeing/)
Quote
"The new Air Force procurement rules approved in March fundamentally changed the model of the EELV program from a series of competitive fixed-price launch contracts for specific satellites to a non-competitive cost-reimbursement capability contract. This model treats the EELV launch services more as an on-going US Government subsidized industry than a competitive marketplace for launch contracts."

I really love the slide on page ten about 'ULA...realizing savings..."
from here
http://www.gao.gov/assets/660/652037.pdf (http://www.gao.gov/assets/660/652037.pdf)

And we still have Boeing execs integrated directly in the AF like burrowed tics:
http://spacenews.com/42243former-boeing-exec-named-to-new-usaf-launch-post/ (http://spacenews.com/42243former-boeing-exec-named-to-new-usaf-launch-post/)
http://query.nytimes.com/gst/fullpage.html?res=9B04EEDB1339F936A35752C0A9639C8B63 (http://query.nytimes.com/gst/fullpage.html?res=9B04EEDB1339F936A35752C0A9639C8B63)
http://www.wsj.com/articles/SB106968087463716900 (http://www.wsj.com/articles/SB106968087463716900)
http://www.washingtonpost.com/wp-dyn/articles/A51778-2004Nov15.html (http://www.washingtonpost.com/wp-dyn/articles/A51778-2004Nov15.html)
http://nlpc.org/stories/2014/05/18/space-launch-deal-puts-spotlight-revolving-door (http://nlpc.org/stories/2014/05/18/space-launch-deal-puts-spotlight-revolving-door)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/25/2015 02:24 am
As far as the general USAF Falcon 9 progress goes,
AF releases results of Space Launch Process review... (http://www.af.mil/News/ArticleDisplay/tabid/223/Article/581248/af-releases-results-of-space-launch-process-review.aspx)
Quote
WASHINGTON (AFNS) --
A relatively small amount of work remains, primarily focused on second stage engine and fairing qualification and contamination control. By implementing these changes to the certification process and assuming work progresses as predicted, both parties continue to remain on course to provide certification by June 2015.

Seems to debunk the contention that a demonstrable ability to vertically integrate payloads has been the hold-up to certification.

Well you can believe what you want but...

http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/ (http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/)
Quote
In a 2013 report, the U.S. Government Accountability Office, Congress’ watchdog agency, said certification has been complicated by Air Force changes to the technical requirements for integrating satellites with their launch vehicles.

Nevertheless, the Air Force was saying right up until the end of last year that they hoped to certify SpaceX in time for NROL-79, by end of December, well before SpaceX would have been able to demonstrate vertical integration. And now they're expecting certification by June, again well before SpaceX will have demonstrated vertical integration.

Yes, changing integration requirements have reportedly been a problem in the process. But deruch's conclusion is still correct. Certification was, and apparently still is, going to happen before SpaceX demonstrates vertical integration.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: BobHk on 03/25/2015 02:33 am
As far as the general USAF Falcon 9 progress goes,
AF releases results of Space Launch Process review... (http://www.af.mil/News/ArticleDisplay/tabid/223/Article/581248/af-releases-results-of-space-launch-process-review.aspx)
Quote
WASHINGTON (AFNS) --
A relatively small amount of work remains, primarily focused on second stage engine and fairing qualification and contamination control. By implementing these changes to the certification process and assuming work progresses as predicted, both parties continue to remain on course to provide certification by June 2015.

Seems to debunk the contention that a demonstrable ability to vertically integrate payloads has been the hold-up to certification.

Well you can believe what you want but...

http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/ (http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/)
Quote
In a 2013 report, the U.S. Government Accountability Office, Congress’ watchdog agency, said certification has been complicated by Air Force changes to the technical requirements for integrating satellites with their launch vehicles.

Nevertheless, the Air Force was saying right up until the end of last year that they hoped to certify SpaceX in time for NROL-79, by end of December, well before SpaceX would have been able to demonstrate vertical integration. And now they're expecting certification by June, again well before SpaceX will have demonstrated vertical integration.

Yes, changing integration requirements have reportedly been a problem in the process. But deruch's conclusion is still correct. Certification was, and apparently still is, going to happen before SpaceX demonstrates vertical integration.

Which is meaningless because Vertical Integration wasn't part of the NECG requirements for NSS launches.  Call a spade a spade. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 03/25/2015 02:56 am
I'm not sure what you're trying to say.

Deruch simply observed that the article said nothing about vertical integration being the main sticking point in certification, contrary to speculation from some members here in past months who opined that perhaps certification was being held up until SpaceX demonstrated vertical integration.

If you're saying something different, please clarify.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 03/25/2015 04:02 am
As far as the general USAF Falcon 9 progress goes,
AF releases results of Space Launch Process review... (http://www.af.mil/News/ArticleDisplay/tabid/223/Article/581248/af-releases-results-of-space-launch-process-review.aspx)
Quote
WASHINGTON (AFNS) --
A relatively small amount of work remains, primarily focused on second stage engine and fairing qualification and contamination control. By implementing these changes to the certification process and assuming work progresses as predicted, both parties continue to remain on course to provide certification by June 2015.

Seems to debunk the contention that a demonstrable ability to vertically integrate payloads has been the hold-up to certification.

Well you can believe what you want but...

http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/ (http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/)
Quote
In a 2013 report, the U.S. Government Accountability Office, Congress’ watchdog agency, said certification has been complicated by Air Force changes to the technical requirements for integrating satellites with their launch vehicles. - See more at: http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/#sthash.gzk4z6dx.dpuf
<snip>

Bob, I think you've misinterpreted my comment. 

Firstly, Vertical Integration (VI) is required to launch DoD payloads.  SpaceX has known this for a very long time.  Whether it was a specified requirement from the beginning of the certification process or not is moot.  It certainly became an explicit part of the NECG when the USAF updated the System Performance Requirements Document (SPRD) and the Standard Interface Specification (SIS) (https://www.fbo.gov/index?s=opportunity&mode=form&id=5bac634da67cf98e097c969111769e08&tab=core&_cview=0) to reflect that VI was a requirement at least in 2013 if not stated elsewhere earlier.  I'm not at all interested in rehashing the discussions on the "nefariosities" of various actors and organizations either directly or tangentially involved in certification (my tinfoil hat is currently on vacation with my indignant outrage hat), especially as that would belong in other threads. 

Secondly, the point my comment was relating to, which had been debated/discussed on here and in other threads, is whether or not SpaceX needs more than an "approved plan" on how to achieve VI to get certification.  i.e. Is demonstrating actual, current VI capability (hardware built, processes vetted and verified, etc.) a hard requirement for certification? or Is having a USAF approved, detailed plan and schedule for how to meet these requirements prior to the launch date of the first won contract enough to get certified.  In other words, do they have to actually build the infrastructure to support VI before they can get certified? 

My position has always been that an approved plan to eventually meet the VI requirements in a timely manner was enough (or at least should have been enough) and therefore SpaceX's lack of current VI capability WAS NOT the barrier to certification of the F9 in December when they missed the USAF's recent planned deadline.  Others, mainly Jim (only poster I can remember by name but IIRC there were others as well), argued that SpaceX's lack of VI infrastructure was the main hold up.  I still don't see how that position is consistent with the various statements coming out of the AF that they expected certification to be completed last December.  There was no credible reason to expect SpaceX to have an established VI capability by that deadline and therefore no reason to announce December as an expected completion date if demonstrable VI capability was integral to certification. 

Now, we have a new statement from the AF that still doesn't mention VI as an open issue.  Besides Pad 39A work, SpaceX hasn't done much publicly visible to advance them towards VI capability since the end of December.  So, I'm wondering if any of the members that were arguing VI capability was the hold up are reading this new AF statement differently from myself.  Do they still maintain that VI was the prime hold up?  etc.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MP99 on 03/25/2015 08:49 am


As far as the general USAF Falcon 9 progress goes,
AF releases results of Space Launch Process review... (http://www.af.mil/News/ArticleDisplay/tabid/223/Article/581248/af-releases-results-of-space-launch-process-review.aspx)
Quote
WASHINGTON (AFNS) --
A relatively small amount of work remains, primarily focused on second stage engine and fairing qualification and contamination control. By implementing these changes to the certification process and assuming work progresses as predicted, both parties continue to remain on course to provide certification by June 2015.

Seems to debunk the contention that a demonstrable ability to vertically integrate payloads has been the hold-up to certification.

Well you can believe what you want but...

http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/ (http://spacenews.com/spacex-close-to-launch-certification-as-air-force-re-examines-process/)
Quote
In a 2013 report, the U.S. Government Accountability Office, Congress’ watchdog agency, said certification has been complicated by Air Force changes to the technical requirements for integrating satellites with their launch vehicles.

Nevertheless, the Air Force was saying right up until the end of last year that they hoped to certify SpaceX in time for NROL-79, by end of December, well before SpaceX would have been able to demonstrate vertical integration. And now they're expecting certification by June, again well before SpaceX will have demonstrated vertical integration.

I wonder how much of a coincidence it is that this is in the ballpark of when the upgraded F9 will fly?

Basically, that the certification is for the vehicle with upgraded Merlin and densification. After all, those will be standard when AF payloads fly.

Cheers, Martin
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 03/25/2015 10:27 am
I said VI may have been one of the reasons for the hold up.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 03/25/2015 12:31 pm
I wonder how much of a coincidence it is that this is in the ballpark of when the upgraded F9 will fly?

Basically, that the certification is for the vehicle with upgraded Merlin and densification. After all, those will be standard when AF payloads fly.

Cheers, Martin

IMHO, purely coincidental.  Gwynne has said that these upgrades/changes wouldn't trigger a full scale recertification but rather be treated as modifications.  If they were being treated as part of this first certification effort, why talk about getting modifications approved?  Why not just say, "They're already included"?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: okan170 on 04/03/2015 01:43 am
Thanks Okan! You keep mesmerizing us with your amazing renders. I loved the dual Dragon v2, could you do two v1 + 2 v2 for extreme SpaceX fans?

While its likely never to happen, here you go.  All the Dragons!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dglow on 04/03/2015 08:53 am
While its likely never to happen, here you go.  All the Here be Dragons!

T,FTFY

Another lovely render – thank you.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: baldusi on 04/05/2015 10:21 pm
Thanks Okan! You keep mesmerizing us with your amazing renders. I loved the dual Dragon v2, could you do two v1 + 2 v2 for extreme SpaceX fans?

While its likely never to happen, here you go.  All the Dragons!
You've just became the Michelangelo for SpaceX fans! Thaaaaanks.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DatUser14 on 04/06/2015 03:03 pm
I was doing some thinking over the last week, had an idea on increasing GTO performance for F9 1.1. Couldnt one use the SHERPA to do much of the orbit raising or use it to go from a low LEO to GTO, leaving enough margin for the (eventual) second stage return. this is just speculation with no numbers, feel free to poke holes in it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GreenShrike on 04/06/2015 04:10 pm
I was doing some thinking over the last week, had an idea on increasing GTO performance for F9 1.1. Couldnt one use the SHERPA to do much of the orbit raising or use it to go from a low LEO to GTO, leaving enough margin for the (eventual) second stage return. this is just speculation with no numbers, feel free to poke holes in it.

The board has speculated a number of times that adding a third or kick stage to F9 would increase GTO performance. Usually these are imagined as being either Kestrel or Draco based, and the additional margin could be used to add reuse hardware to S2.

While you can do a search to find the exact discussions, I believe the general consensus was that it would be rather a lot of engineering work for not a lot of gain, and that SpaceX's drive for full reusability would bias them against designing yet another expendable stage.

I personally think they'll wait until the Falcon Heavy is flying regularly to determine actual numbers on stage recovery and refurbishment costs, and then re-evaluate whether it'd be worth the time implement a reusable S2 for FH. While with the current economics SpaceX obviously doesn't believe it worth the time and engineering investment for a reusable S2, in several years massive LEO constellations could easily be enough to tip the decision the other way.

If reuse is easy and cheap enough, I could see the FH being employed as a fully reusable medium+ launcher, rather than a semi-expendable heavy, and having a fully reusable F9 relegated to light lift duties only.

Of course, that's also far enough out that SpaceX might by then be getting annoyed with kerosene and implement a methane-powered mini-BFR for all non-super heavy work, so who knows? It's certainly going to be fun to watch (and argue over ;-) ).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dror on 04/06/2015 05:55 pm
I was doing some thinking over the last week, had an idea on increasing GTO performance for F9 1.1. Couldnt one use the SHERPA to do much of the orbit raising or use it to go from a low LEO to GTO, leaving enough margin for the (eventual) second stage return. this is just speculation with no numbers, feel free to poke holes in it.

The board has speculated a number of times that adding a third or kick stage to F9 would increase GTO performance. Usually these are imagined as being either Kestrel or Draco based, and the additional margin could be used to add reuse hardware to S2.

While you can do a search to find the exact discussions, I believe the general consensus was that it would be rather a lot of engineering work for not a lot of gain, and that SpaceX's drive for full reusability would bias them against designing yet another expendable stage.

A jupiter reusable tug, or a SpaceX equivalent, can turn the general consensus on it's face.
Buying, building or leasing one of those will enable falcon 9 to become a full RLV with a common seconed stage for LEO and GTO with a fair capability.

Quote
Of course, that's also far enough out that SpaceX might by then be getting annoyed with kerosene and implement a methane-powered mini-BFR for all non-super heavy work, so who knows? It's certainly going to be fun to watch (and argue over ;-) ).
That's even better, but will still benefit from a reusable tug.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: spacenut on 04/06/2015 08:43 pm
Would the tug have ion propulsion?  Or hypergolic? 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 04/06/2015 08:59 pm
New images tweeted by SpaceX: https://twitter.com/SpaceX/status/585182828943560704

Quote
SpaceX ‏@SpaceX
Continued progress on Pad 39A and its hangar that will house Falcon 9 and Falcon Heavy at @NASAKennedy
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GreenShrike on 04/07/2015 04:07 am
A jupiter reusable tug, or a SpaceX equivalent, can turn the general consensus on it's face.
Buying, building or leasing one of those will enable falcon 9 to become a full RLV with a common seconed stage for LEO and GTO with a fair capability.

The problem with that is Falcon 9 is about to be joined by Falcon Heavy.

The Jupiter is a great way for hauling dumb but cheap cargo canisters around, and could be of use to satellites if a rocket's GTO and beyond performance is anemic. With the FH flying, and especially with a potential mini-BFR, they'll have sufficient performance to lift practically any non-SLS payload built anywhere it wants to go. SpaceX can simply do without the added complexity of a tug -- they have quite enough on their plate as it is.

Consider: what would a reusable tug require? Coordinating a rendezvous with the incoming S2, then an on-orbit square dance where the payload is passed from one partner to the next. The tug would need to be refueled, so S2 would need to transfer propellant over to it. This could be done either by pumping prop from S2 into the tug, or by hauling a separate jerry can up along with the payload (so an S2::jerry can::payload stack). In the latter case, S2 would transfer the can and payload stack to the tug, the tug would boost the payload to the appropriate orbit, release the payload, then haul the jerry can back down to LEO for release and disposal. A jerry can would be cheap, but still a cost to be borne.

Or you could forget the complexity and risk of orbital ballet, skip a hell of a lot of engineering design and development work, and just use a bigger rocket from the start, with an S2 of sufficient capacity to carry the payload to the target orbit, and possibly get back down to LEO, and then land back on Earth.

Tell me, which sounds more like the company that didn't bother developing a large engine for their medium+ rocket and just bolted 9 of their in-hand small engines together; that didn't bother making a "real" in-space engine, welded a big nozzle onto one of their booster engines and just lumped the resultant mass and ISP penalty; that uses the same giant 5m fairing regardless of how tiny the payload is; and that for a heavy launcher, didn't bother with a dial-a-rocket SRB system, just glued three basically identical cores together, and will fly the result regardless of whether 6 tonnes need lifting or 20?


In any event, if the SpaceX S2 is reusable, remember that hiring a tug needs to cost less than expending an S2. That puts a serious constraint on a tug's pricing.

For typical com sat missions, the tug would also need to be cheaper than the price difference between a fully reusable F9 (which is presumably too light for the job, so a tug is needed), and a fully reusable FH (because any sort of expendable FH can send the largest com sats to GTO). To SpaceX, the cost difference between fully reusable F9s and FHs is the cost to integrate the side boosters, and the boosters' fuel and refurbishment costs.

I don't know if the total cost difference is less than building an S2, but I believe that SpaceX is certainly hoping it is -- which means that the price difference between F9 and FH -- currently, what, ~$30M? -- might shrink to a lot less. That's not a lot of range for a tug to play in.

And if a reusable FH can't lift it, well, that's what the BFR is for. :-)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GreenShrike on 04/07/2015 04:14 am
Would the tug have ion propulsion?  Or hypergolic?

Inefficient but high-thrust chemical engines would get the job done and the tug back to LEO for another run soonest, which means more jobs and more money for the tug's operator. Ion propulsion would severely limit the number of jobs the tug could do per year, and expose the tug to long periods of high radiation.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dror on 04/07/2015 09:30 am
A jupiter reusable tug, or a SpaceX equivalent, can turn the general consensus on it's face.
Buying, building or leasing one of those will enable falcon 9 to become a full RLV with a common seconed stage for LEO and GTO with a fair capability.

The problem with that is Falcon 9 is about to be joined by Falcon Heavy.

The Jupiter is a great way for hauling dumb but cheap cargo canisters around, and could be of use to satellites if a rocket's GTO and beyond performance is anemic. With the FH flying, and especially with a potential mini-BFR, they'll have sufficient performance to lift practically any non-SLS payload built anywhere it wants to go. SpaceX can simply do without the added complexity of a tug -- they have quite enough on their plate as it is.


Well, if you're comparing complexities, you should consider Jupiter in oppose to reusability of s2 from a gso orbit, and of using such a robust s2 for all of the missions.
The other way makes the s2 lighter and saves fuel on reuse from leo always, counting on a proven (to be) hardware and procedure.
I'm assuming full success of Jupiter , of course ...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Rebel44 on 04/07/2015 11:05 am
IMO, with FH capabilities, it makes more sense for satelite operators to "simply" launch satelites with significantly more fuel, instead of paying for design, launch and operating costs of a tug.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JBF on 04/07/2015 12:50 pm
IMO, with FH capabilities, it makes more sense for satelite operators to "simply" launch satelites with significantly more fuel, instead of paying for design, launch and operating costs of a tug.

That is true right now, but what if there was already a tug in orbit? This is a standard infrastructure problem, do we invest in it now or not.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: AncientU on 04/07/2015 01:23 pm
Bigelow is hiring someone to make the tugs he needs to position/land the inflatables (BA-330 specifically).  Could be Jupiter, but the Bigelow art suggests a form similar to F9 second stage.  Wonder who will get this contract?  Fuel choice will also be interesting -- not kerlox, maybe methlox or hypers, unlikely hydrolox (too expensive and boil-off is a challenge).  Are there other choices?

The day of tugs is coming...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: saliva_sweet on 04/07/2015 01:29 pm
Quote from: Stephen Clark ‏@StephenClark1
Clarke: Closely watching Falcon 9 production schedule at SpaceX, was cause of Jason 3 launch slip from March to July.

Looks like the SpaceX production bottleneck has not been resolved yet.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 04/07/2015 03:12 pm
Quote from: Stephen Clark ‏@StephenClark1
Clarke: Closely watching Falcon 9 production schedule at SpaceX, was cause of Jason 3 launch slip from March to July.

Looks like the SpaceX production bottleneck has not been resolved yet.

And that is in direct contradiction to this tweet:
https://twitter.com/StephenClark1/status/585418874012598272 (https://twitter.com/StephenClark1/status/585418874012598272)

Quote from: Stephen Clark ‏@StephenClark1
Steven Clarke of NASA’s joint agency satellite division: Continue working Falcon 9 certification for Jason 3 launch from VAFB on July 22.

How can production at SpaceX be the driver of a delay when in fact the certification process is the driver of the delay? Nicely contradictory information being provided by Clark & Clarke there....
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: baldusi on 04/07/2015 03:18 pm
Quote from: Stephen Clark ‏@StephenClark1
Clarke: Closely watching Falcon 9 production schedule at SpaceX, was cause of Jason 3 launch slip from March to July.

Looks like the SpaceX production bottleneck has not been resolved yet.
That production schedule was the reason for the slip, doesn't necessarily means that it is the current bottleneck. The Jason-3 craft might have enhancements or customizations that required a certification process before manufacturing, or the the process was not certified and needed some changes to comply, or they might have had even some discarded manufactured items that simply weren't built or failed to test to the new stringent standards. I'm not saying that manufacturing is not the bottleneck, I'm just stating that one thing doesn't imply the other.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: saliva_sweet on 04/07/2015 04:11 pm
How can production at SpaceX be the driver of a delay when in fact the certification process is the driver of the delay? Nicely contradictory information being provided by Clark & Clarke there....

I recall there was information that an eumetsat bigwig had stated that F9 cert had been done a while ago. There was a public post which I can't find now, but it's still in L2. Also I recall Jim was implying in the Jason-3 thread that the reasons NASA had given for the delay (SpX-6 being moved forward, range availability and certification) were not the whole story (to say the least).

My speculation is that the certification is done, but NASA is keeping a back door open and won't put the stamp on the papers until the last launch before Jason-3 is deemed a success, which is prudent I guess. Had SpaceX had a core for Jason-3 in march they probably would have gotten the cert then.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GreenShrike on 04/07/2015 09:19 pm
Well, if you're comparing complexities, you should consider Jupiter in oppose to reusability of s2 from a gso orbit, and of using such a robust s2 for all of the missions.

Why would SES, Inmarsat, et al give a fig if S2 reuse causes SpaceX complications?

They just care about launch costs, which is something you didn't address in my post.

Hiring a tug will cost money. So you need to ask yourself how will hiring a tug will, overall, result in launch cost savings.

With Exoliner, a tug works because rather than launching expensive autonomous spacecraft like Cygnus, the Exoliner will be very little more than a pressurized tin can. Bigelow modules could certainly use a tug so they didn't need fuel tanks and a main propulsion system capable of hauling their massive bulk around.

But GEO comsats still need fuel and small thrusters for stationkeeping and EOL maneuvers, and they still need avionics for the same reason, so unlike Exoliner, a tug won't save a comsat any hardware. It won't save them propellant, either, as whether the sat or the tug uses prop to get the sat through GTO and into GEO, prop will be required.

So where does a tug save a comsat money?

Quote
The other way makes the s2 lighter and saves fuel on reuse from leo always, counting on a proven (to be) hardware and procedure.

Doesn't matter if tug ops are "proven" -- a non-zero chance of failure will, if you roll the dice often enough, bite you.

Introducing a bundle of mission-critical events into the launch timeline is something that SES et al would care very much about. Direct injection into GTO by the S2 is simpler, which means less things to go wrong, which means greater chance of mission success.

The best way to win (i.e. gain an functional comsat in GEO) for SES et al is to roll the dice as infrequently as possible. That is, unless there's some sort of gain -- financial, operations, or other -- to offset the increased risk.

Which means we're back to: how does a tug save comsat operators money?

Because I'm thinking it's going to be simpler and cheaper to just step up to a FH if the F9 can't do the job.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GreenShrike on 04/07/2015 09:20 pm
IMO, with FH capabilities, it makes more sense for satelite operators to "simply" launch satelites with significantly more fuel, instead of paying for design, launch and operating costs of a tug.

That is true right now, but what if there was already a tug in orbit? This is a standard infrastructure problem, do we invest in it now or not.

Okay, let's play: so what if there was a tug in orbit?

I could see a tug being hired to refuel comsats. Maybe repair them. Maybe deliver upgrade modules. Maybe deorbit them or move them to a graveyard orbit.

None of these are initial launch problems, and none of these would have any effect on a decision as to whether a tug should be used to haul a sat up to GEO.

How do you think things would be different?


I think have Jupiters on-orbit would be a very cool addition to our space infrastructure. Unfortunately, being being cool cuts no ice with accounting departments or shareholders.

I don't think SpaceX will bother with tugs; if a Falcon 9 can't lift a load, they'd rather just sell the client a Falcon Heavy. And if they're reusable, I don't think they'll be significantly more money. The price of hiring a tug would need to be less that the difference between an F9 and FH launch -- and then some, to offset the additional risk.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nadreck on 04/07/2015 09:59 pm

I don't think SpaceX will bother with tugs; if a Falcon 9 can't lift a load, they'd rather just sell the client a Falcon Heavy. And if they're reusable, I don't think they'll be significantly more money. The price of hiring a tug would need to be less that the difference between an F9 and FH launch -- and then some, to offset the additional risk.

I think that their 4000 satellite constellation could use something like the Jupiter electric as tenders. And I think those tenders will be needed, and in fact should end up being mandated or some other means mandated to dispose of LEO and MEO satellites that go dark.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rcoppola on 04/07/2015 10:13 pm
Quote from: Stephen Clark ‏@StephenClark1
Clarke: Closely watching Falcon 9 production schedule at SpaceX, was cause of Jason 3 launch slip from March to July.

Looks like the SpaceX production bottleneck has not been resolved yet.
Seems reasonable that all of this has something to do with 2 primary drivers and their impacts to both production/operations and overall certification:

-The imminent transitions to Falcon 9v1.2 (or 2.0)
-A more difficult and infrastructure intensive return profile.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Burninate on 04/08/2015 06:43 pm
I was doing some thinking over the last week, had an idea on increasing GTO performance for F9 1.1. Couldnt one use the SHERPA to do much of the orbit raising or use it to go from a low LEO to GTO, leaving enough margin for the (eventual) second stage return. this is just speculation with no numbers, feel free to poke holes in it.

The board has speculated a number of times that adding a third or kick stage to F9 would increase GTO performance. Usually these are imagined as being either Kestrel or Draco based, and the additional margin could be used to add reuse hardware to S2.

While you can do a search to find the exact discussions, I believe the general consensus was that it would be rather a lot of engineering work for not a lot of gain, and that SpaceX's drive for full reusability would bias them against designing yet another expendable stage.

I personally think they'll wait until the Falcon Heavy is flying regularly to determine actual numbers on stage recovery and refurbishment costs, and then re-evaluate whether it'd be worth the time implement a reusable S2 for FH. While with the current economics SpaceX obviously doesn't believe it worth the time and engineering investment for a reusable S2, in several years massive LEO constellations could easily be enough to tip the decision the other way.

If reuse is easy and cheap enough, I could see the FH being employed as a fully reusable medium+ launcher, rather than a semi-expendable heavy, and having a fully reusable F9 relegated to light lift duties only.

Of course, that's also far enough out that SpaceX might by then be getting annoyed with kerosene and implement a methane-powered mini-BFR for all non-super heavy work, so who knows? It's certainly going to be fun to watch (and argue over ;-) ).
Linky to my bullet points:
http://forum.nasaspaceflight.com/index.php?topic=36719.0

Making a reusable Merlin 1D-Vac stage is certainly difficult, but it would be a lot easier if A) The dry mass penalties you incur there weren't directly subtracted from the payload figure, and B) You could count on separation of the M1D-Vac stage at a reliable altitude in LEO for all launches instead of LEO / GTO / Supersynchronous Orbit.  The expectation is that something the size of Merlin 1D-Vac is much, much more expensive than something the size of Draco.

Alternately: You just raise F9E's GTO payload by something like ~40-50% apples to apples, and on higher dV missions, you increase payload by a factor of several (ex: C3=0 and SEL point payloads go up by ~+150%, TMI & GSO even farther)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 04/09/2015 08:16 pm
SpaceX has released a launch compilation video in 4K (3840 x 2160) resolution: (lots of F9 launches plus Grasshopper)

https://www.youtube.com/watch?v=gmJgW-yMAIg

If your computer is man/woman enough to handle it (and you have a monitor with sufficient resolution), crank it up to 4K and enjoy. :)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Rebel44 on 04/09/2015 09:24 pm
It looks really great on my 32" 4K monitor :)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: go4mars on 04/10/2015 01:12 am
At first I didn't like the music.  Then I very much did when it went to video game mode.  Seemed fitting.


That will be mandatory viewing for some kids I know.  ;)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cartman on 04/12/2015 10:56 pm
Hans today (rephrased slightly): "We are taking the next step on Dragon reusability on the long run, so we are able to reuse Dragons. The water landing is the hardest part, sea water corrosion. NASA guy said that they are already reusing some parts, reusability is acceptable when the hardware performs, once we see it we wont have any objections to go down that path"
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 04/13/2015 08:10 am

My speculation is that the certification is done, but NASA is keeping a back door open and won't put the stamp on the papers until the last launch before Jason-3 is deemed a success, which is prudent I guess. Had SpaceX had a core for Jason-3 in march they probably would have gotten the cert then.

Emphasis mine.
You said it: speculation. NASA not stamping the papers until after the mission means that certification is NOT done. There is even a NASA guy (Steven Clarke) being quoted as saying that certification is still being worked. Meaning that certification is not done (yet).
The whole premiss was that SpaceX needed to be certified before the mission could be flown.
I don't buy the story that Jason-3 was delayed because there was no booster available. It doesn't match up with public statements by NASA.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 04/13/2015 09:03 am
Also from the CRS-6 pre-mission briefing, confirmation that Dragon is now able to transport water to the station (though none on this mission).  The "redesign" work that had to be done was actually on the NASA side in that they had to resize the water bags to be able to fit them in the tighter areas of Dragon without taking away from the cold racks area desired to transport science.  Then I'm sure everyone had to do a study to show that that would work ok.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: matthewkantar on 04/15/2015 02:34 am
Hans from Spacex was asked about the dimensions of the Falcon 9 first stage at the CRS-6 post flight briefing. I think he said the stage weighs between 60 and 70 thousand pounds. He did seem to agonize for a second, possibly caught between the desire to be honest and need to keep secrets secret. Or maybe he was converting from Metric in his head or wasn't sure of the number in the first place.

In any case, this number seems high. I would have guessed more like a third of that weight.

Matthew
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: sanman on 04/15/2015 03:30 am
After 1st-stage recovery/reusability is achieved for F9, then what is the next big mountain to climb? What is the next big new goal to chase?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: puhnitor on 04/15/2015 03:39 am
After 1st-stage recovery/reusability is achieved for F9, then what is the next big mountain to climb? What is the next big new goal to chase?

Do the same thing 3 times for Falcon Heavy. Propulsively land Dragon. The build, fly, and recover MCT. Actually get MCT to Mars with colonists. Still lots of work to do.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: sanman on 04/15/2015 04:28 am
Do the same thing 3 times for Falcon Heavy. Propulsively land Dragon. The build, fly, and recover MCT. Actually get MCT to Mars with colonists. Still lots of work to do.

Okay, so it seems like FH will fly on its expected timetable, and its landing recoveries can happen on their own timetable without holding anything else up.

When is Dragon v2 expected to fly? When will it attempt propulsive landing?

MCT sounds like it will be a long time after these things.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mader Levap on 04/15/2015 09:36 am
Okay, so it seems like FH will fly on its expected timetable
Not so fast. FH already slipped by two years and right now there is not much to heard about it half of year before it is supposed to fly. I will be very surprised if they manage to fly FH in 2015.

When is Dragon v2 expected to fly?
You mean crewed Dragonrider? Somewhere around 2017.

MCT sounds like it will be a long time after these things.
Yep, their Mars plans are way, way far out. I don't think Elon can retire on Mars. He was born too early. He can became giant whom's shoulders are used by next generation to actually land on Mars, however.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: sanman on 04/16/2015 12:31 am
Not so fast. FH already slipped by two years and right now there is not much to heard about it half of year before it is supposed to fly. I will be very surprised if they manage to fly FH in 2015.

So FH helps in getting heavier launch customers, but how does FH figure in the Mars plan?

Quote
You mean crewed Dragonrider? Somewhere around 2017.

Well, surely it won't be crewed on the initial flights - when will the first unmanned flight of Dragon v2.0 be?
Any estimates on how long before crews are routinely returning via powered landings?


Quote
Yep, their Mars plans are way, way far out. I don't think Elon can retire on Mars. He was born too early. He can became giant whom's shoulders are used by next generation to actually land on Mars, however.

Still, it's hard to imagine Musk sitting still after FH's and Dragons are achieving powered landings.
Provided some new business venture idea doesn't steal his attention for too long, he's probably going to push for some kind of progress on a crewed Mars vehicle.

Does anybody foreesee any possible zigzags or deviations from the current plan in SpaceX's future?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 04/16/2015 06:22 am
Not so fast. FH already slipped by two years and right now there is not much to heard about it half of year before it is supposed to fly. I will be very surprised if they manage to fly FH in 2015.

So FH helps in getting heavier launch customers, but how does FH figure in the Mars plan?

Precursor missions like placing com and gps sats into Mars orbit. Land a rover or rovers on Mars using Red Dragon to make sure they can get water and survey a landing site for MCT.
Not for landing infrastructure or launching fuel. That's for MCT.

Quote
Yep, their Mars plans are way, way far out. I don't think Elon can retire on Mars. He was born too early. He can became giant whom's shoulders are used by next generation to actually land on Mars, however.

Still, it's hard to imagine Musk sitting still after FH's and Dragons are achieving powered landings.
Provided some new business venture idea doesn't steal his attention for too long, he's probably going to push for some kind of progress on a crewed Mars vehicle.

Does anybody foreesee any possible zigzags or deviations from the current plan in SpaceX's future?

No zigzags. Mars is his aim and he has a good chance of achieving it. Present schedule has the first launch of the big booster in 2019/2020. The first unmanned MCT mission is well doable by 2024, followed by a manned mission 2026.

For being more cautious expect slips and the first manned mission will occur 2030. Elon Musk, not getting younger may launch as early - or late for his age - at 2034 as the latest.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: sanman on 04/16/2015 06:51 am
Wow, this is going to be a long wait. I hope there are enough further interesting breakthroughs in between to keep our attention.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dglow on 04/16/2015 07:08 am
Wow, this is going to be a long wait. I hope there are enough further interesting breakthroughs in between to keep our attention.

Oh, I think there might be. Besides, the journey is the reward.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 04/16/2015 04:55 pm
Wow, this is going to be a long wait. I hope there are enough further interesting breakthroughs in between to keep our attention.


Depends on your attention span, I guess.  I'm seeing breakthroughs all over the place.  Of course, I'm looking at more than just SpaceX and Mars.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mader Levap on 04/16/2015 09:22 pm
Wow, this is going to be a long wait. I hope there are enough further interesting breakthroughs in between to keep our attention.
I am sure SpaceX will make us entertained for decades. There is always another thing to do, another achievement to done, another mountain to climb on.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: sanman on 04/16/2015 10:02 pm
Well, hopefully they'll do other stuff in the meantime along the way, like land Dragon on the Moon, etc. The Moon may not have as much long term potential as Mars, but its near-term potential is much greater due to its closer proximity, lower gravity, simpler EDL, etc. I was thinking that we may see multiple SpaceX missions to the Moon - including manned ones - before a manned Mars mission happens.

Would a fully-fueled Dragon v2 be able to go from the lunar surface to orbit, like the Apollo lunar modules did?
Would they need to use something other than SuperDracos for this different application?


Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 04/16/2015 10:48 pm

Would a fully-fueled Dragon v2 be able to go from the lunar surface to orbit, like the Apollo lunar modules did?


It can't even land on the moon
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dglow on 04/17/2015 12:06 am

Would a fully-fueled Dragon v2 be able to go from the lunar surface to orbit, like the Apollo lunar modules did?


It can't even land on the moon

Okay, but why not?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 04/17/2015 12:09 am

Would a fully-fueled Dragon v2 be able to go from the lunar surface to orbit, like the Apollo lunar modules did?


It can't even land on the moon

Okay, but why not?

Because it doesn't have enough propellant. Not even close.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: sanman on 04/17/2015 12:22 am
Hmm, could it potentially be modified and fitted with something other than SuperDracos to land on the Moon?
Or would this be so difficult as to make it more worthwhile to design a purpose-built lander from scratch?

It just seems like the Moon would easier for SpaceX to take paying customers to, even if SpaceX prefers Mars.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jdeshetler on 04/17/2015 12:53 am
Hmm, could it potentially be modified and fitted with something other than SuperDracos to land on the Moon?
Or would this be so difficult as to make it more worthwhile to design a purpose-built lander from scratch?

It just seems like the Moon would easier for SpaceX to take paying customers to, even if SpaceX prefers Mars.

It is almost like have Apollo landing on Moon even with attached SuperDraco thrown in. Very different mission criteria so that's what LM (Lunar Module) is for.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: spacenut on 04/17/2015 01:43 am
The Dragon capsule is heavy with the heat shield.  A separate lunar lander would be better like the Apollo LEM.  The Dragon slows down during reentry with the atmosphere, then it can use the Dracos to land.  The moon would require almost continuous burn to slow down and land.  Even if it could land, it wouldn't have the fuel to take off. 

L1 would be a better staging point.  Launch a Dragon to L1, dock with a lander, then come back to dock with the Dragon.  The Dragon would still need a powered service module to get back home. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 04/17/2015 02:01 am
Hmm, could it potentially be modified and fitted with something other than SuperDracos to land on the Moon?
Or would this be so difficult as to make it more worthwhile to design a purpose-built lander from scratch?

It just seems like the Moon would easier for SpaceX to take paying customers to, even if SpaceX prefers Mars.

For space tourism, a "fly around the moon" is a much more alluring ticket, and requires a lot less development.

Specifically for your questions, Dragon would not need different engines, it would need larger fuel tanks.  Much larger.  But since the landing gear is in the heat shield, you can't use a service module, you'll need to stretch it.  If the entire stretched volume is dedicated to propellant, I am not sure, but it might not be a giant stretch.

But, I don't think that's in anyone's plans.  It's a detour.  Also, landing is just step 0.  Now you need to survive on the moon, EVA on the moon, etc.  It's a giant detour.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dglow on 04/17/2015 02:06 am

Would a fully-fueled Dragon v2 be able to go from the lunar surface to orbit, like the Apollo lunar modules did?


It can't even land on the moon

Okay, but why not?

Because it doesn't have enough propellant. Not even close.

Hang on – Jim said "It can't even land on the moon".
The SDs are designed to propulsively land on Terra Firma but can't do Luna? Why? Please explain.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: acsawdey on 04/17/2015 02:17 am
No air.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 04/17/2015 02:20 am

No air.

Eh.... No. SDs work just fine in vacuum (other than losing some efficiency) - but lack of sufficient propellant is the big deal breaker.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mme on 04/17/2015 02:34 am

No air.

Eh.... No. SDs work just fine in vacuum (other than losing some efficiency) - but lack of sufficient propellant is the big deal breaker.
Which I assume is do to the lack of atmosphere to use for braking. Is that right?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 04/17/2015 03:01 am
Right, I think "No air" refers to the fact that most of the deceleration for an Earth landing comes from the atmosphere.  You don't have this convenience on the Moon.  Although the initial velocity is lower, and acceleration with respect to the surface greater, it's still not sufficient to get you down in one piece.


My question is, launched from a Falcon Heavy, is there even sufficient propellant to enter lunar orbit and then escape it again for the trip home?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mlindner on 04/17/2015 03:12 am
So why is no one talking about the final video that's been released that shows the landing from the barge?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: FutureSpaceTourist on 04/17/2015 04:34 am
So why is no one talking about the final video that's been released that shows the landing from the barge?

Because there are other threads doing just that.

Edit:

For example: http://forum.nasaspaceflight.com/index.php?topic=36892.0 (http://forum.nasaspaceflight.com/index.php?topic=36892.0) & http://forum.nasaspaceflight.com/index.php?topic=36527.0 (http://forum.nasaspaceflight.com/index.php?topic=36527.0)

Please let's not start another parallel discussion!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 04/17/2015 04:59 am
Right, I think "No air" refers to the fact that most of the deceleration for an Earth landing comes from the atmosphere.  You don't have this convenience on the Moon.  Although the initial velocity is lower, and acceleration with respect to the surface greater, it's still not sufficient to get you down in one piece.


My question is, launched from a Falcon Heavy, is there even sufficient propellant to enter lunar orbit and then escape it again for the trip home?

If you're not landing, it is in principle possible to store more propellant in the trunk area, since you don't need the landing gear before you come back to Earth and discard the trunk.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 04/17/2015 05:36 am
My question is, launched from a Falcon Heavy, is there even sufficient propellant to enter lunar orbit and then escape it again for the trip home?

We do not know what the delta-v capability of Dragon 2 is. There was a major increase of fuel storage mentioned at the time of the CCtCap, so it is increased. Entering and then leaving a highly elliptic moon orbit should be possible but probably not LMO.

I think landing a Dragon 2 on the moon should be possible, when the earth departure stage is still live and able to fire near the moon. Use that as a crasher stage and let Dragon 2 do only a small part of the whole deceleration. But it is still a bad idea and it could never launch from the surface.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: TrevorMonty on 04/17/2015 06:14 am

Would a fully-fueled Dragon v2 be able to go from the lunar surface to orbit, like the Apollo lunar modules did?


It can't even land on the moon

Okay, but why not?

Because it doesn't have enough propellant. Not even close.

Hang on – Jim said "It can't even land on the moon".
The SDs are designed to propulsively land on Terra Firma but can't do Luna? Why? Please explain.
Here is delta V calculator. Lunar orbit to surface is about 2km/s. Isp for Supadraco try 300( just a guess). Try 6t for Dragon dry mass.

http://www.strout.net/info/science/delta-v/
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MP99 on 04/17/2015 07:56 am
Specifically for your questions, Dragon would not need different engines, it would need larger fuel tanks.  Much larger.

No disagreement on the need for more prop, but ISTM they could do with an engine with lower thrust and vacuum optimised.

Cheers, Martin
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dglow on 04/17/2015 12:07 pm
Here is delta V calculator. Lunar orbit to surface is about 2km/s. Isp for Supadraco try 300( just a guess). Try 6t for Dragon dry mass.

http://www.strout.net/info/science/delta-v/

Thanks. I see lunar orbit to surface quoted at 1.6 km/s. What we're missing is delta-v remaining to be killed on Earth EDL assuming no parachutes. Show me a calculator for that.   :o  :)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: e of pi on 04/17/2015 12:41 pm
Thanks. I see lunar orbit to surface quoted at 1.6 km/s. What we're missing is delta-v remaining to be killed on Earth EDL assuming no parachutes. Show me a calculator for that.   :o  :)
Assuming the capsule has a chance to reach terminal velocity (drag=weight):

Mass=~6800 kg, thus weight (W) is ~66.7 kN
Dragon diameter is 3.67m^2, thus reference area (Sref) is ~10.6m^2
Assuming a coefficient of drag (Cd) of ~1.5 and air density (rho) of 1.22 kg/m^3:

W=D=0.5*rho*v^2 * Sref * Cd

Solve for v:

v=sqrt( W / (0.5*rho*Sref*Cd) )
v=sqrt( 66700 / (0.5*1.22*10.6*1.5) )
v=sqrt(6877 m^2/s^2) = 83 m/s.

Even if Dragon's traveling two or three times its terminal velocity when it lights the thrusters to land, I doubt it has more than a few hundred m/s of landing prop capacity--certainly nothing like 1.6 km/s.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: jak Kennedy on 04/17/2015 01:11 pm

Would a fully-fueled Dragon v2 be able to go from the lunar surface to orbit, like the Apollo lunar modules did?


It can't even land on the moon

Okay, but why not?

Because it doesn't have enough propellant. Not even close.

Hang on – Jim said "It can't even land on the moon".
The SDs are designed to propulsively land on Terra Firma but can't do Luna? Why? Please explain.
Here is delta V calculator. Lunar orbit to surface is about 2km/s. Isp for Supadraco try 300( just a guess). Try 6t for Dragon dry mass.

http://www.strout.net/info/science/delta-v/

So it would need a descent stage, problem fixed. Just like the LM.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 04/17/2015 03:14 pm
Specifically for your questions, Dragon would not need different engines, it would need larger fuel tanks.  Much larger.

No disagreement on the need for more prop, but ISTM they could do with an engine with lower thrust and vacuum optimised.

Cheers, Martin
Yup, without a doubt.

But they are not landing on the moon IMO, do this is highly hypothetical.

I think lunar fly arounds will be popular tourism tickets, but I don't know if SpaceX will do it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dglow on 04/17/2015 03:33 pm
Even if Dragon's traveling two or three times its terminal velocity when it lights the thrusters to land, I doubt it has more than a few hundred m/s of landing prop capacity--certainly nothing like 1.6 km/s.

Thank you, sir.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JasonAW3 on 04/17/2015 04:41 pm

Would a fully-fueled Dragon v2 be able to go from the lunar surface to orbit, like the Apollo lunar modules did?


It can't even land on the moon

I take it that's because of its need to decellerate in Earth's atmosphere sufficently before it could make a powered descent?

With the 1/6th gravity of the moon, would it be possible, in theory, to add sufficent tankage, say to a trunk style landing stage, to use the Super Draco engines to land on the moon?  Again, the thrusters would be dealing with 1/6th the weight, but the full actual mass for inertia purposes.

     I estimate, with a trunk about 3/4 full of fuel tankage, the Dragon V2 should have about enough fuel to land, take off into orbit, but I don't think it would have quite enough to make a TEI burn, course correction or proper retro thrust for an Earth splashdown.

Does that sound about right to you?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 04/17/2015 10:24 pm
For myself, if I was going to land any craft on the Moon, it would have longer legs and higher ground clearance than the Dragon V2 appears to have anyway.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dglow on 04/17/2015 10:44 pm
Nah, just put a couple of rovers on the surface with little zen garden rakes.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Herb Schaltegger on 04/18/2015 02:43 pm
I've done a forum search but as we all know, quite often NSF is like trying to take a sip from a firehose. Just too many false hits to be relevant -

Now that said, does anyone recall where the landing radar transceiver(s?) are located on the F9v1.1 stage? I SEEM to recall an annotated image somewhere showing a small dome, perhaps mounted on or near a folded leg. If anyone can point me to that image or another source, I'd appreciate it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: edkyle99 on 04/18/2015 02:57 pm
Re:  Talk about Dragon on the lunar surface.  Consider the Lunar Module Ascent Stage.  It weighed about half as much as a Dragon.  It took a Saturn V to get it on the Moon.  So, widely handwaving, you need two Saturn V's worth of rocket to get Dragon there.   That's maybe seven or eight or more Falcon Heavies (assuming expendable no crossfeed). 

Bottom line is that Dragon is not a good spacecraft for a landing mission.  There is no reason to cart a heat shield down to the lunar surface.  (It would be interesting to see what SpaceX came up with if asked to design a lunar landing spacecraft.)

 - Ed Kyle
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mvpel on 04/18/2015 03:02 pm
Here is delta V calculator. Lunar orbit to surface is about 2km/s. Isp for Supadraco try 300( just a guess). Try 6t for Dragon dry mass.

http://www.strout.net/info/science/delta-v/

I recall reading somewhere that the Superdraco Isp is actually 235 seconds.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: joek on 04/18/2015 07:27 pm
A bit dated but contains some info for F9 v1.1 and FH that has been speculated about in various threads; a search did not find this previously posted: Final Supplemental Environmental Assessment to the November 2007 Environmental Assessment for the Operation and Launch of the Falcon 1 and Falcon 9 Space Vehicles (http://www.nasa.gov/sites/default/files/files/Final_Falcon_Launch_EA.pdf), August 2013 (also attached).

F9 v1.1 propellant (pg. 2-3)
F9 v1.1    gal[1]  kg[2]
S1-RP1    38,500  119,100
S1-LOX    64,000  276,568
S2-RP1    9,000  27,841
S2-LOX    15,000  64,821

Acoustic analysis for launches at Texas site (Appendix B).  Plots for FH shown in attachments below.

[1] Given.
[2] Calculated from conversion numbers given in EA.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 04/18/2015 10:08 pm
...does anyone recall where the landing radar transceiver(s?) are located on the F9v1.1 stage? I SEEM to recall an annotated image somewhere showing a small dome, perhaps mounted on or near a folded leg. If anyone can point me to that image or another source, I'd appreciate it.

Not sure that we know for a fact. But it might be under this white square cover:

http://forum.nasaspaceflight.com/index.php?topic=37136.msg1350749#msg1350749
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Karloss12 on 04/19/2015 01:20 pm
During the CRS-6 post launch Media Conference a journalist made the coment that the rocket appeared to lift off slower than on previous flights and asked Hans if this was the case and if any modifications had been made to cause this.  Hans essentially said no changes had been made and everything was normal.

A second journalist asked how much fuel was left after landing.  Hans said about 2-3 seconds.

From these two questions, I got thinking that the F9R was possibly being pushed to its reusable capacity.  The landing barge was located as close as possible to the launch site.  I wonder if that was the limit and they couldn't have made it closer.

There was a launch recently where the barge was positioned many hundreds of miles out to sea.  From recollection this was because the payload needed the propellant, preventing the barge from being closer.

If all this is true then is it possible to now estimate a maximum payload to LEO for getting the 1st stage to boost back all the way to the launch pad.  Could the payload be 2000kg or maybe 7000kg.

Or will SpaceX be reducing the performance of the F9 to conceal its capacity from the competition.  Can they choose to only partially fill the propellant tanks?  Or run the engines at a low efficiency thrust etc etc...

I'm thinking the F9R might be considered as being in the low-med lift class.  In 15 years time, the BFR will be the  medium-heavy or larger work horse of SpaceX.  What status will the F9R have?  Will the F9R have a place at the low class end of the market or become redundant and we will look back on it as a worthy stepping stone to establishing reusibility but ultimately not commercially viable in the long term?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: BigDustyman on 04/19/2015 01:37 pm
there is alredy an upgrade on its way in the form of upgraded motor and I believe tankage which will give them more flexability
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Karloss12 on 04/19/2015 02:01 pm
there is alredy an upgrade on its way in the form of upgraded motor and I believe tankage which will give them more flexability

I'm aware of them cranking up the thrust of the Merlin 1D's but not making substantial upgrades to them.  In any case this will only make a small increase in lift capacity if any.

However, I haven't heard of them stretching the tanks from the current v1.1 configuration.  If they are able to do this, than getting a 10000kg payload into LEO and also landing the stage back at the launch site will result in the F9R as certainly being viable for many years as a medium launcher.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: jak Kennedy on 04/19/2015 02:25 pm
Re:  Talk about Dragon on the lunar surface.  Consider the Lunar Module Ascent Stage.  It weighed about half as much as a Dragon.  It took a Saturn V to get it on the Moon.  So, widely handwaving, you need two Saturn V's worth of rocket to get Dragon there.   That's maybe seven or eight or more Falcon Heavies (assuming expendable no crossfeed). 

Bottom line is that Dragon is not a good spacecraft for a landing mission.  There is no reason to cart a heat shield down to the lunar surface.  (It would be interesting to see what SpaceX came up with if asked to design a lunar landing spacecraft.)

 - Ed Kyle

The Apollo program lofted a return capsule which wouldn't be needed if a single Dragon was used for both lunar descent and reentry. That would save some weight.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 04/19/2015 03:38 pm

The Apollo program lofted a return capsule which wouldn't be needed if a single Dragon was used for both lunar descent and reentry. That would save some weight.

Not true, see LOR vs direct mission.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: TrevorMonty on 04/19/2015 03:58 pm
Here is delta V calculator. Lunar orbit to surface is about 2km/s. Isp for Supadraco try 300( just a guess). Try 6t for Dragon dry mass.

http://www.strout.net/info/science/delta-v/

I recall reading somewhere that the Superdraco Isp is actually 235 seconds.
Your a probably right I did say a guess. Here some rough figures for fuel required to land a 6t Dragon on moon and return to LLO..
ISP 300 6t fuel one way, 18t return.
ISP 235 8.5t, 29t.

As comparison a dedicated lander eg Masten Zeus using RL10
ISP450 3.5, 9t

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: macpacheco on 04/19/2015 07:21 pm
A second journalist asked how much fuel was left after landing.  Hans said about 2-3 seconds.
Jim explained many times over that fuel reserves go to the 2nd stage.
SpaceX wants S1 to have as little fuel left as safely possible after landing.
Its also a good idea not having a lot of fuel, should the stage blow up like in the last attempt.
3 seconds sound like too little fuel to most, but if this is SpaceX planning, then that's the way it is.
In essence staging point is selected such that projected fuel after landing is 3 seconds worth.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Owlon on 04/19/2015 07:32 pm
During the CRS-6 post launch Media Conference a journalist made the coment that the rocket appeared to lift off slower than on previous flights and asked Hans if this was the case and if any modifications had been made to cause this.  Hans essentially said no changes had been made and everything was normal.

A second journalist asked how much fuel was left after landing.  Hans said about 2-3 seconds.
...

I'll note that well after reusability tests started, SpaceX management have said the payload numbers (13,150 kg to LEO, 4,850 kg to GTO) on their website refer to performance with return to launch site. Fully expendable performance is probably somewhere more like 16,000-17,000 kg to LEO and in the 5000s to GTO. This flight may have had lots of margin in the 2nd stage, done an excessively long/cautious reentry burn, etc.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: spacenut on 04/19/2015 07:55 pm
Yes, since the Saturn IB could launch about 20 tons and the first stage had 1.5million lbs thrust.  Falcon 9 has 1.4 and 1.5 in a vacuum.  So the 13,150 seems a little low.  Just thinking. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ugordan on 04/19/2015 08:07 pm
Saturn Ib had a high energy upper stage which, unlike EELV, was powered by a correspondingly high thrust engine.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Owlon on 04/19/2015 08:23 pm
Saturn Ib had a high energy upper stage which, unlike EELV, was powered by a correspondingly high thrust engine.

But the Falcon 9 has much lighter stages. I expect Falcon 9 to have very similar mass and payload capacity to the Saturn IB after the new upgrades are implemented (higher thrust, subcooled LOX, 2nd stage stretch)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: spacenut on 04/19/2015 09:21 pm
Also, doesn't the Falcon 9 stage higher?

Looked it up, Saturn IB 150 seconds on first stage and 480 on second.  (Second was 200k lbs thrust)

Falcon 9 - 180 seconds on first stage and 375 on second, about 75 seconds shorter.  (Falcon 9 upper is also 200k lbs in vacuum. 

So a few seconds shorter and you get a few tons lighter payload.  So Falcon 9 stated payloads are probably right for booster return. 

So if they wanted to take off the landing legs and go for ELV, it is almost a match for Saturn IB, especially if maximum thrust on Merlins is used. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 04/20/2015 04:56 am
During the CRS-6 post launch Media Conference a journalist made the coment that the rocket appeared to lift off slower than on previous flights and asked Hans if this was the case and if any modifications had been made to cause this.  Hans essentially said no changes had been made and everything was normal.

A second journalist asked how much fuel was left after landing.  Hans said about 2-3 seconds.

From these two questions, I got thinking that the F9R was possibly being pushed to its reusable capacity.  The landing barge was located as close as possible to the launch site.  I wonder if that was the limit and they couldn't have made it closer.

There was a launch recently where the barge was positioned many hundreds of miles out to sea.  From recollection this was because the payload needed the propellant, preventing the barge from being closer.

If all this is true then is it possible to now estimate a maximum payload to LEO for getting the 1st stage to boost back all the way to the launch pad.  Could the payload be 2000kg or maybe 7000kg.

Or will SpaceX be reducing the performance of the F9 to conceal its capacity from the competition.  Can they choose to only partially fill the propellant tanks?  Or run the engines at a low efficiency thrust etc etc...

I'm thinking the F9R might be considered as being in the low-med lift class.  In 15 years time, the BFR will be the  medium-heavy or larger work horse of SpaceX.  What status will the F9R have?  Will the F9R have a place at the low class end of the market or become redundant and we will look back on it as a worthy stepping stone to establishing reusibility but ultimately not commercially viable in the long term?

Bad starting assumption.  They were not performance limited.  Gwynne Shotwell was quoted on April 15th as feeling that they had sufficiently shown that they can hit the mark and hoping that the Range might allow them to do a full RTLS and land landing on CRS-7 (http://www.defensenews.com/story/defense/air-space/space/2015/04/15/spacex-ground-attempt-reusable-landing-sea/25827625).  If they are unable to do so based on performance limits, why press for it?  Especially as CRS-7 will have the IDA in the trunk and will therefore likely weigh more than CRS-6 whose trunk was empty.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jcc on 04/20/2015 07:13 pm
I would not put too much faith in that Defense News article. I think they misinterpreted what Gwynn said. The article leads with the statement that SpaceX hopes the "next" attempt will be on land, but doesn't quote her saying that, and no mention of CRS7, which will be the next attempt. I think she only said that in the future they will land on land.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Karloss12 on 04/20/2015 09:39 pm
During the CRS-6 post launch Media Conference a journalist made the coment that the rocket appeared to lift off slower than on previous flights and asked Hans if this was the case and if any modifications had been made to cause this.  Hans essentially said no changes had been made and everything was normal.

A second journalist asked how much fuel was left after landing.  Hans said about 2-3 seconds.
...

I'll note that well after reusability tests started, SpaceX management have said the payload numbers (13,150 kg to LEO, 4,850 kg to GTO) on their website refer to performance with return to launch site. Fully expendable performance is probably somewhere more like 16,000-17,000 kg to LEO and in the 5000s to GTO. This flight may have had lots of margin in the 2nd stage, done an excessively long/cautious reentry burn, etc.

It seems like SpaceX has been making these sorts of statements since the planning stages of F9 V1.0.  Are these numbers for the existing F9v1.1 or for the next major update of the F9 (with a further stretched tank???).

I would imagine if there is a next major update then they will be getting pretty close to the final optimum F9 vehicle (of course there will always be minor technology upgrades).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 04/21/2015 01:51 am
I would not put too much faith in that Defense News article. I think they misinterpreted what Gwynn said. The article leads with the statement that SpaceX hopes the "next" attempt will be on land, but doesn't quote her saying that, and no mention of CRS7, which will be the next attempt. I think she only said that in the future they will land on land.

Okay.  Good point.   But SpaceX, in the form of both Elon and Gwynne, have, on multiple occasions, said that they felt they could do RTLS already but were working to get range approval.  I think the issue is kind of moot anyways because I don't think the landing pad is ready yet and I'm somewhat doubtful they could have it ready in time for CRS-7.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Graham on 04/22/2015 07:27 pm
Anyone know how long it takes for the Dragon's solar array covers to de-orbit?  Seems a little wasteful to create more space junk when they could have hinged them instead of blowing them off Liberty Bell 7 style.

https://vine.co/v/ea10ZjP3zQ5
The CRS 5 panel covers decayed after 2 days ( http://www.n2yo.com/satellite/?s=40372 )
EDIT: I mistakenly wrote that the covers decayed after 12 days, not 2
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Comga on 04/22/2015 07:53 pm
Anyone know how long it takes for the Dragon's solar array covers to de-orbit?  Seems a little wasteful to create more space junk when they could have hinged them instead of blowing them off Liberty Bell 7 style.

https://vine.co/v/ea10ZjP3zQ5
The CRS 5 panel covers decayed after 12 days ( http://www.n2yo.com/satellite/?s=40372 )
Cool link
It may have the second stage confused with one of the covers, as two objects, the first and third have similar orbits (144 by 168 km and 149 by 186 km) as opposed to the second (165 by 205 km).
Even at 200 km these are already out of the way of almost any operational satellites and won't be up there much longer.

OBJECT B
NORAD ID: 40589
Int'l Code: 2015-021B
Perigee: 144.1 km
Apogee: 168.2 km
Inclination: 51.6 °
Period: 87.6 minutes
Semi major axis: 6534 km
Launch date: April 14, 2015
Source: United States (US)

DRAGON CRS-6 DEB
NORAD ID: 40590
Int'l Code: 2015-021C
Perigee: 165.2 km
Apogee: 205.7 km
Inclination: 51.6 °
Period: 88.2 minutes
Semi major axis: 6563 km
Launch date: April 14, 2015
Source: United States (US)
 
DRAGON CRS-6 DEB
NORAD ID: 40591
Int'l Code: 2015-021D
Perigee: 148.7 km
Apogee: 185.6 km
Inclination: 51.7 °
Period: 87.8 minutes
Semi major axis: 6545 km
Launch date: April 14, 2015
Source: United States (US)
Note: This is SATELLITE DEBRIS
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: baldusi on 04/22/2015 08:55 pm
Anyone know how long it takes for the Dragon's solar array covers to de-orbit?  Seems a little wasteful to create more space junk when they could have hinged them instead of blowing them off Liberty Bell 7 style.

https://vine.co/v/ea10ZjP3zQ5
They are light and have a very high drag factor. SpaceX designed them in such a way that solar panels deploy on cover separation. That means less failure modes. Thus, it was deemed riskier and the debris risk is very low.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: okan170 on 04/26/2015 11:08 pm
Falcon 9R with Dragon 2.  Remarkable how similar, yet different its turned out from how it all started in those animations years ago...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 04/27/2015 03:36 am
OK, that's a new desktop wallpaper if ever I saw one.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Endeavour_01 on 04/27/2015 04:19 am
Falcon 9R with Dragon 2.  Remarkable how similar, yet different its turned out from how it all started in those animations years ago...

All I can say is wow. Another great render okan.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Ben the Space Brit on 04/27/2015 11:58 am
So, SpaceX are going to launch to GTO whilst they have a Dragon at ISS. Do they have multiple MCC rooms at Hawthorne? Or do they have a different way to monitor two vehicles simultaneously?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 04/27/2015 02:06 pm
Launch vehicles are controlled and monitored from the LCC at the Cape.   The MCC just monitors the launch
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: TomH on 04/27/2015 09:53 pm
Quote from: okan170
Falcon 9R with Dragon 2.  Remarkable how similar, yet different its turned out from how it all started in those animations years ago...

Mmmmmm, slurp, slurp. Eye candy!!!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: jabe on 04/27/2015 10:08 pm
just had a thought while watching clouds roll in for today's launch..why not launch a reused F9 core during thick cloud cover like today and see what happens :)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: abaddon on 04/27/2015 10:30 pm
just had a thought while watching clouds roll in for today's launch..why not launch a reused F9 core during thick cloud cover like today and see what happens :)

The weather rules in place now have been refined over hundreds of launches over many decades.  The F9 is not particularly special when it comes to weather (winds, lightning, etc).  There is no need to waste a reused F9 core, whenever they manage to get one.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: jabe on 04/27/2015 10:48 pm
The weather rules in place now have been refined over hundreds of launches over many decades.  The F9 is not particularly special when it comes to weather (winds, lightning, etc).  There is no need to waste a reused F9 core, whenever they manage to get one.
tell that too the Russians :)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: abaddon on 04/27/2015 10:55 pm
tell that too the Russians :)

I'll be happy to do so, when they launch from the CCAFS.  Until then, not relevant.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: jabe on 04/27/2015 10:57 pm
tell that too the Russians :)

I'll be happy to do so, when they launch from the CCAFS.  Until then, not relevant.
is lightning the main concern? (ala apollo lightning strike) seeing some of the weather Russia launches from I always wonder if cape is too cautious at times...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: craigcocca on 04/28/2015 03:02 am
SpaceX must be shipping a new F9 from Hawthorne at least once a month to keep up with this launch cadence. Does anyone know when they ship and what route they take?  I can certainly see them getting on I-105 eastbound, but can't really imagine how they negotiate some of the interchanges on the way to I-10 to Texas.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 04/28/2015 06:35 am
I do understand the anvil cloud rule as it indicates very turbulent airflows and lightning risk.

I would like to know what the rationale behind thick cloud rules is. It can't be visibility because tracking does not depend on visibility.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: LucR on 04/28/2015 09:56 am
AFAIK the issue with thick clouds is sound reflection, causing it to propagate much further away from the pad and with higher levels.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: king1999 on 04/29/2015 08:55 pm
When Elon Musk founded SpaceX, I don't think in his wildest dream he would foresee that Falcon and Dragon at one point would become almost the sole supply line for the International Space Station (barring the infrequent Japanese supply ship). Just saying...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 04/29/2015 08:59 pm
When Elon Musk founded SpaceX, I don't think in his wildest dream he would foresee that Falcon and Dragon at one point would become almost the sole supply line for the International Space Station (barring the infrequent Japanese supply ship). Just saying...

It isn't close to "almost".   Progress and Cygnus can still be launched
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 04/29/2015 09:26 pm
When Elon Musk founded SpaceX, I don't think in his wildest dream he would foresee that Falcon and Dragon at one point would become almost the sole supply line for the International Space Station (barring the infrequent Japanese supply ship). Just saying...

I'm not clairvoyant, but it's pretty clear that Musk's dreams are a tad larger than having other providers fall short on the way to ISS...

In not too many years, this "whole ISS thing" will be just a phase in SpaceX's past.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: whitelancer64 on 04/29/2015 09:32 pm
tell that too the Russians :)

I'll be happy to do so, when they launch from the CCAFS.  Until then, not relevant.
is lightning the main concern? (ala apollo lightning strike) seeing some of the weather Russia launches from I always wonder if cape is too cautious at times...

I have been under the impression that the Russian's weather rules for launch are pretty similar to NASA's, at least in terms of cloud cover and wind rules. I've never found a full set of Russian launch rules though, so I don't know for sure.

However, they have significantly fewer thunderstorms due to their inland launch locations, compared to Florida, which is on a large flat landmass next to an ocean. Storms roll over and by Florida far more frequently, and so they get more weather-related launch scrubs. Yes, lightning strikes are the main concern, those are more likely near thunderstorms and when going through thick clouds, though high-level winds are dangerous also.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: starsilk on 04/29/2015 09:36 pm
When Elon Musk founded SpaceX, I don't think in his wildest dream he would foresee that Falcon and Dragon at one point would become almost the sole supply line for the International Space Station (barring the infrequent Japanese supply ship). Just saying...

let's not jinx things. nobody is immune to screwups, rocketry and space at the moment is still difficult enough that it is a matter of when, not if.

and at the moment, that would be exceptionally bad for the ISS.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 04/29/2015 09:50 pm

is lightning the main concern? (ala apollo lightning strike) seeing some of the weather Russia launches from I always wonder if cape is too cautious at times...

It has nothing do with the "cape".  There is no comparison.  Russian rockets have different design constraints.   Other than the lightning related constraints (which have a good basis), the launch vehicle contractor sets the weather rules. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Joffan on 04/29/2015 09:55 pm

let's not jinx things. nobody is immune to screwups, rocketry and space at the moment is still difficult enough that it is a matter of when, not if.

and at the moment, that would be exceptionally bad for the ISS.

Well, let's also not be scared of describing the situation as we see it; "jinx" is just superstition. There's no special reason to think that Dragon will be the sole ISS supply ship at any point - future Progress missions have not been grounded that we've been told about, HTV will be visiting this summer - and equally I don't expect the ever-improving SpaceX team to suddenly get significantly worse at getting their launches away safely.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mme on 04/29/2015 10:16 pm

let's not jinx things. nobody is immune to screwups, rocketry and space at the moment is still difficult enough that it is a matter of when, not if.

and at the moment, that would be exceptionally bad for the ISS.

Well, let's also not be scared of describing the situation as we see it; "jinx" is just superstition. There's no special reason to think that Dragon will be the sole ISS supply ship at any point - future Progress missions have not been grounded that we've been told about, HTV will be visiting this summer - and equally I don't expect the ever-improving SpaceX team to suddenly get significantly worse at getting their launches away safely.

I agree that "jinxing" is not a thing.  But even though I am a huge SpaceX fan, I think it's a bad idea to assume that SpaceX is immune to failure.  I think they'll take these incidents to heart and stay vigilant, but Space Is Hard (tm) and fecal matter occurs.  So for me it's not a matter of jinxing anything, but avoiding hubris.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: starsilk on 04/29/2015 10:27 pm

let's not jinx things. nobody is immune to screwups, rocketry and space at the moment is still difficult enough that it is a matter of when, not if.

and at the moment, that would be exceptionally bad for the ISS.

Well, let's also not be scared of describing the situation as we see it; "jinx" is just superstition. There's no special reason to think that Dragon will be the sole ISS supply ship at any point - future Progress missions have not been grounded that we've been told about, HTV will be visiting this summer - and equally I don't expect the ever-improving SpaceX team to suddenly get significantly worse at getting their launches away safely.

as we all know, superstition has nothing at all to do with space flight...

http://www.thespacereview.com/article/1137/1

(and to add to that list, SpaceX is certainly not immune, with their four leaf clover on every mission patch).

to be serious, the real issue is increased pressure to perform. adding stress to an already difficult endeavor is not usually a way to improve the odds of success.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 04/29/2015 10:33 pm
My dad used to say that he's heard superstition helps even those that do not believe in it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: kch on 04/29/2015 10:43 pm
My dad used to say that he's heard superstition helps even those that do not believe in it.

It seems to work a lot better than that plain ol' ordinary stition ... ;)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: LouScheffer on 04/30/2015 01:19 am
just had a thought while watching clouds roll in for today's launch..why not launch a reused F9 core during thick cloud cover like today and see what happens :)
If the worry is lightning, and it's an on-going problem, perhaps you could address it experimentally.  At T-1 minute, launch 6 or so sounding rockets in a 1km radius ring around the pad.  These could be the kind that leave behind an ionized trail, or trail a copper wire, all designed to trigger lightning if possible.  If none of them get hit by lightning, then you are probably good to go.  You'd also get an excellent measurement of the wind conditions the rocket would encounter on the way up, and all in time to stop the count if something looks unsafe.

The rockets traditionally used to trigger lightning do not appear to be particularly large or expensive.  University research labs can launch several during a single thunderstorm.  http://www.aerospacelab-journal.org/sites/www.aerospacelab-journal.org/files/AL05-05_0.pdf  And since Florida is a hotbed of lightning research, the needed expertise is already local.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 04/30/2015 01:41 am
They did in fact do a lot of experimental work after AC-67 which led them to write the current weather criteria.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 04/30/2015 05:18 am

If the worry is lightning, and it's an on-going problem, perhaps you could address it experimentally.  At T-1 minute, launch 6 or so sounding rockets in a 1km radius ring around the pad.  These could be the kind that leave behind an ionized trail, or trail a copper wire, all designed to trigger lightning if possible.  If none of them get hit by lightning, then you are probably good to go.  You'd also get an excellent measurement of the wind conditions the rocket would encounter on the way up, and all in time to stop the count if something looks unsafe.

The rockets traditionally used to trigger lightning do not appear to be particularly large or expensive.  University research labs can launch several during a single thunderstorm.  http://www.aerospacelab-journal.org/sites/www.aerospacelab-journal.org/files/AL05-05_0.pdf  And since Florida is a hotbed of lightning research, the needed expertise is already local.


And fry the spacecraft from EMP and induced voltages.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 04/30/2015 05:41 am
And fry the spacecraft from EMP and induced voltages.

Oh! I did not know that rockets get damaged on the pad when thunderstorms pass.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: LouScheffer on 04/30/2015 11:40 am

If the worry is lightning, and it's an on-going problem, perhaps you could address it experimentally.  At T-1 minute, launch 6 or so sounding rockets in a 1km radius ring around the pad. [...]  If none of them get hit by lightning, then you are probably good to go.

And fry the spacecraft from EMP and induced voltages.
Clearly a concern, but not a show-stopper.  Any induced strikes are much further away than the existing lightning protection towers, so any EMP and induced voltages should be much less than the rocket already has to withstand.

Also, the shuttle on mission STS-127 was on the pad when lightning struck 11 times within a half km.  No problems were observed (  http://www.space.com/6954-nasa-delays-shuttle-launch-investigate-lightning-damage.html ).  On the other hand they did spend an extra day double-checking.  I don't know if this is because they don't have good enough sensors to estimate the magnitude of the induced EMP/voltage, or because they were super-cautious since it was a crewed launch.  If the sensors are not present. it might eventually make sense to add them, if launching from a place where nearby lightning strikes are common.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: abaddon on 04/30/2015 01:17 pm
At current launch tempos none of this is necessary.  It's easily sufficient to simply wait for a window that is clear.

Maybe in the future if/when launching (far) more frequently it might be something that is more valuable to explore.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 04/30/2015 01:35 pm

Clearly a concern, but not a show-stopper.  Any induced strikes are much further away than the existing lightning protection towers, so any EMP and induced voltages should be much less than the rocket already has to withstand.


Just hand wave it away.  Should have expected that was going to be the response. 

A.  Not true.  The towers are not 100% insurance. 
b.  And they are not going to install sensors on the spacecraft
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: LouScheffer on 04/30/2015 07:22 pm

Clearly a concern, but not a show-stopper.  Any induced strikes are much further away than the existing lightning protection towers, so any EMP and induced voltages should be much less than the rocket already has to withstand.


Just hand wave it away.  Should have expected that was going to be the response. 
You are completely correct.  A handwaving response is far too serious a reply to a one-sentence, arm-waving, unsubstantiated assertion of a problem, but it's perfectly normal for NSF.
Quote
A.  Not true.  The towers are not 100% insurance. 
True, but from google maps it looks like the towers are about 150 meters from the pad.  Here we are talking at least a kilometer away, a factor of 6 further.   Any effects will be reduced by at least this factor, and more like a factor of 36 for radiated effects.

In terms of experience rather than analysis, do you know of any cases where a strike at least a kilometer away caused damage to a spacecraft due to induced voltage/EMP?

Quote
b.  And they are not going to install sensors on the spacecraft
Agreed.  The sensors would go on the pad, to measure how the rocket/payload might be affected.  If the disturbance, as measured at the rocket, is within the design specs, it should be safe to proceed.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 04/30/2015 07:25 pm
There are lasers to induce lightning. No rocket needed.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 04/30/2015 11:48 pm

Clearly a concern, but not a show-stopper.  Any induced strikes are much further away than the existing lightning protection towers, so any EMP and induced voltages should be much less than the rocket already has to withstand.


Just hand wave it away.  Should have expected that was going to be the response. 
You are completely correct.  A handwaving response is far too serious a reply to a one-sentence, arm-waving, unsubstantiated assertion of a problem, but it's perfectly normal for NSF.
Quote
A.  Not true.  The towers are not 100% insurance. 
True, but from google maps it looks like the towers are about 150 meters from the pad.  Here we are talking at least a kilometer away, a factor of 6 further.   Any effects will be reduced by at least this factor, and more like a factor of 36 for radiated effects.

In terms of experience rather than analysis, do you know of any cases where a strike at least a kilometer away caused damage to a spacecraft due to induced voltage/EMP?

Quote
b.  And they are not going to install sensors on the spacecraft
Agreed.  The sensors would go on the pad, to measure how the rocket/payload might be affected.  If the disturbance, as measured at the rocket, is within the design specs, it should be safe to proceed.

What "hand waving"?. It is a problem. 
 It is a topic for every mission and there is a different solution for each one.  It's funny that you think that you can find the solutions and not the people working the launches.  Seems to be a recurring theme. 



Pad sensors do no good.  Satellites don't have design specs.  The potential damage is unquantifable. 

There has been damage in the past from near by hits
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 05/01/2015 01:00 am
I wouldn't take it for granted that the current lightning mitigation strategy is optimal. Certainly not to the point where any suggestion is considered to be "hand-waving".

And especially since there was damage incurred from lightning using current methods.

The laser-triggered lightning idea is a lot more than a testing method.  It can actively discharge clouds.  I've heard of it before, but don't know the exact details.

Still, the pilot rocket idea better simulates the real rocket launch (but cannot be used continuously)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 05/01/2015 06:01 am
I wouldn't take it for granted that the current lightning mitigation strategy is optimal. Certainly not to the point where any suggestion is considered to be "hand-waving".

And especially since there was damage incurred from lightning using current methods.

The laser-triggered lightning idea is a lot more than a testing method.  It can actively discharge clouds.  I've heard of it before, but don't know the exact details.

Still, the pilot rocket idea better simulates the real rocket launch (but cannot be used continuously)

I think Jim's point is that "active remediation" is unnecessary.  Just wait/scrub and launch when there's no/less lightning danger.  Sure, triggering the lightning may reduce the risk to a launch in those conditions but at the cost of potential damage while it's still on the pad.  Better to just call it a day and try again without the risks.  If you want to argue otherwise, bring numbers.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: LouScheffer on 05/01/2015 12:53 pm
I wouldn't take it for granted that the current lightning mitigation strategy is optimal. [...]

And especially since there was damage incurred from lightning using current methods.

The laser-triggered lightning idea is a lot more than a testing method.  It can actively discharge clouds.  I've heard of it before, but don't know the exact details.

Still, the pilot rocket idea better simulates the real rocket launch (but cannot be used continuously)

I think Jim's point is that "active remediation" is unnecessary.  Just wait/scrub and launch when there's no/less lightning danger.  Sure, triggering the lightning may reduce the risk to a launch in those conditions but at the cost of potential damage while it's still on the pad.  Better to just call it a day and try again without the risks.  If you want to argue otherwise, bring numbers.
But even this strategy of standing down has risks.  As Jim himself noted
A.  The towers are not 100% insurance. 
So if active triggering could keep lightning strikes further away from the pad, it might be worthwhile, even if you don't use it to try to launch in otherwise iffy circumstances.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 05/01/2015 01:02 pm
My thought was more like fire the lasers if the weather conditions are not clearcut. If they trigger lightning, then don't launch.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: abaddon on 05/01/2015 02:44 pm
Since this has nothing to do with SpaceX in particular (and we have absolutely no indication that SpaceX has any intent to do anything like this), maybe this belongs somewhere else, like Advanced Concepts?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Galactic Penguin SST on 05/02/2015 05:54 pm
One question that I never got an answer: since according to Jim Falcon 9 does not use TDRS for telemetry when flying out of ground stations, what ground stations are used in Africa for GTO and other BLEO flights from the Cape? Some of the ones also used by Ariane? (like Libreville, Gabon and Malindi, Kenya)

Or do SpaceX use TDRS after all?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 05/19/2015 11:55 pm
I wouldn't take it for granted that the current lightning mitigation strategy is optimal. [...]

And especially since there was damage incurred from lightning using current methods.

The laser-triggered lightning idea is a lot more than a testing method.  It can actively discharge clouds.  I've heard of it before, but don't know the exact details.

Still, the pilot rocket idea better simulates the real rocket launch (but cannot be used continuously)

I think Jim's point is that "active remediation" is unnecessary.  Just wait/scrub and launch when there's no/less lightning danger.  Sure, triggering the lightning may reduce the risk to a launch in those conditions but at the cost of potential damage while it's still on the pad.  Better to just call it a day and try again without the risks.  If you want to argue otherwise, bring numbers.
But even this strategy of standing down has risks.  As Jim himself noted
A.  The towers are not 100% insurance. 
So if active triggering could keep lightning strikes further away from the pad, it might be worthwhile, even if you don't use it to try to launch in otherwise iffy circumstances.

http://www.pbs.org/wnet/savageplanet/03deadlyskies/02lresearch/indexmid.html
Quote
Another alternative is to induce lightning from passing thunderclouds. The most effective technique for triggering lightning involves launching a small rocket trailing a thin grounded wire toward a charged cloud overhead. The rockets used at Camp Blanding are about three feet long, and are fitted with a special spool carrying Kevlar-reinforced copper wire. This wire, connected to a designated strike point on the ground, extends down as the rocket rises towards the thundercloud. "This is equivalent to erecting a tall thin structure," Dr. Rakov explains. "The wire distorts the electrical field under the cloud, and if the conditions are right, there will be a lightning discharge."

"It is a dangerous operation," says Dr. Rakov. "Sometimes lightning does not behave well. Sometimes it deflects from the path as defined by the wire, and strikes elsewhere." No one is allowed outside during the tests, and all work is conducted from a special metallic trailer that is fully grounded and designed to protect the scientists from "anomalous discharges." No metallic wires enter the trailer, only pneumatic tubes and fiber optic cables to link the scientists with their rockets and testing instruments. "Why? Because lightning can travel along metallic wires, and get to you inside the shelter."

What it looks like: https://i.imgur.com/Wq8Ayh1.gifv

Doesn't sound quite like the fail-safe it's been thought to be by some on this forum.  That said, any real discussion of it by actual operators has to be based on weighing the positive against the negative.  Which, I think, is all anyone has suggested here.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 05/26/2015 09:25 pm
@Gruss_SN Mike Gruss Space News
BREAKING: The Air Force has certified SpaceX's Falcon 9 rocket to launch national security satellites.
https://twitter.com/Gruss_SN/status/603308428145074176
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nadreck on 05/26/2015 09:40 pm
@Gruss_SN Mike Gruss Space News
BREAKING: The Air Force has certified SpaceX's Falcon 9 rocket to launch national security satellites.
https://twitter.com/Gruss_SN/status/603308428145074176

Bloomberg's got it: http://www.bloomberg.com/news/articles/2015-05-26/spacex-gets-u-s-approval-to-enter-70-billion-military-market (http://www.bloomberg.com/news/articles/2015-05-26/spacex-gets-u-s-approval-to-enter-70-billion-military-market)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: FutureSpaceTourist on 05/26/2015 10:29 pm
Here's the USAF press release: http://www.af.mil/News/ArticleDisplay/tabid/223/Article/589724/air-forces-space-and-missiles-system-center-certifies-spacex-for-national-secur.aspx (http://www.af.mil/News/ArticleDisplay/tabid/223/Article/589724/air-forces-space-and-missiles-system-center-certifies-spacex-for-national-secur.aspx)

Quote
Air Force's Space and Missiles System Center Certifies SpaceX for National Security Space Missions

By Secretary of the Air Force Public Affairs, / Published May 26, 2015

LOS ANGELES AIR FORCE BASE, El Segundo, Calif. (AFNS) -- Lieutenant General Samuel Greaves, Commander of the Air Force Space and Missile Systems Center (SMC) and Air Force Program Executive Officer for Space, has announced the certification of Space Exploration Technologies Corporation’s (SpaceX) Falcon 9 Launch System for national security space missions.

SpaceX is now eligible for award of qualified national security space launch missions as one of two currently certified launch providers. The first upcoming opportunity for SpaceX to compete to provide launch services is projected to be in June when the Air Force releases a Request for Proposal for GPS III launch services.

“This is a very important milestone for the Air Force and the Department of Defense,” said Secretary of the Air Force Deborah Lee James. “SpaceX’s emergence as a viable commercial launch provider provides the opportunity to compete launch services for the first time in almost a decade. Ultimately, leveraging of the commercial space market drives down cost to the American taxpayer and improves our military’s resiliency.”

This milestone is the culmination of a significant two-year effort on the part of the Air Force and SpaceX to execute the certification process and reintroduce competition into the Evolved Expendable Launch Vehicle (EELV) program. The Air Force invested more than $60 million and 150 people in the certification effort which encompassed 125 certification criteria, including more than 2,800 discreet tasks, 3 certification flight demonstrations, verifying 160 payload interface requirements, 21 major subsystem reviews and 700 audits in order to establish the technical baseline from which the Air Force will make future flight worthiness determinations for launch.

“The SpaceX and SMC teams have worked hard to achieve certification, said Greaves. “And we’re also maintaining our spaceflight worthiness process supporting the National Security Space missions. Our intent is to promote the viability of multiple EELV-class launch providers as soon as feasible.”

Elon Musk, SpaceX CEO and Lead Designer, stated, “This is an important step toward bringing competition to National Security Space launch. We thank the Air Force for its confidence in us and look forward to serving it well.”

The certification process provides a path for launch-service providers to demonstrate the capability to design, produce, qualify, and deliver a new launch system and provide the mission assurance support required to deliver national security space satellites to orbit. This gives the Air Force confidence that the national security satellites being delivered to orbit will safely achieve the intended orbits with full mission capability.

The SMC, located at Los Angeles Air Force Base, Calif., is the U.S. Air Force's center for acquiring and developing military space systems. Its portfolio includes GPS, military satellite communications, defense meteorological satellites, space launch and range systems, satellite control networks, space based infrared systems and space situational awareness capabilities.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Joffan on 05/26/2015 11:01 pm
Here's the USAF press release: http://www.af.mil/News/ArticleDisplay/tabid/223/Article/589724/air-forces-space-and-missiles-system-center-certifies-spacex-for-national-secur.aspx (http://www.af.mil/News/ArticleDisplay/tabid/223/Article/589724/air-forces-space-and-missiles-system-center-certifies-spacex-for-national-secur.aspx)


And just a note to point out the new thread specifically for discussion of USAF certification (http://forum.nasaspaceflight.com/index.php?topic=37678.0)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GalacticIntruder on 06/04/2015 04:21 am
http://www.issconference.org/#papers (http://www.issconference.org/#papers)

Musk chat. July 7, 2015 at 08:45-10:00 am ET.

No idea what he will talk about. No idea who the interviewer is. However, I see Rachel Crane will be there, so it could be her, which would not be surprising.

Hopefully we get something new. We know about his past and his goals. And I don't want to hear about what he thinks about Vance's Musk Biography.

It would be a great time to show off the long awaited SpaceX spacesuit, even some Dragon 2 stuff.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DJPledger on 06/04/2015 06:59 am
http://www.issconference.org/#papers (http://www.issconference.org/#papers)

Musk chat. July 7, 2015 at 08:45-10:00 ET.

No idea what he will talk about. No idea who the interviewer is. However, I see Rachel Crane will be there, so it could be her, which would not be surprising.

Hopefully we get something new. We know about his past and his goals. And I don't won't to hear about what he thinks about Vance's Musk Biography.

It would be a great time to show off the long awaited SpaceX spacesuit, even some Dragon 2 stuff.
Lets also hope he will give us some new info. on the Raptor as well.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: okan170 on 06/09/2015 12:08 am
Dragon 2 approaching the space station, her first port of call.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Paul_G on 06/09/2015 12:09 pm
Okan,

Great image :) Can I ask what the white inflatable(? ) structure is on top of the Dragon capsule?

Thanks

Paul
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jimmy Murdok on 06/09/2015 12:19 pm
Okan,

Great image :) Can I ask what the white inflatable(? ) structure is on top of the Dragon capsule?

Thanks

Paul
No inflatable, just the shiny nose co
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Paul_G on 06/09/2015 12:52 pm
No inflatable, just the shiny nose co

And now I see it - thanks.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: symbios on 06/25/2015 12:48 am
While looking on Instagram on the nice new picture of ASDS I found this image that seems new.

https://instagram.com/spacex (https://instagram.com/spacex)

The date seems to be 2015-06-21. Are they testing the new legs?

Have anyone seen this picture before and is it new?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Zed_Noir on 06/25/2015 01:50 am
... Are they testing the new legs? ...

Maybe testing a different leg deployment time, like earlier.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: OnWithTheShow on 06/25/2015 01:56 am
Heavy central core?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 06/25/2015 02:30 am
Is that a "top down" or "bottom up" view of the legs?  I can't seem to figure it out.  Based on the tunnel and the expected conditions the legs face when extended, I'm currently assuming it's "bottom up". 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 06/25/2015 02:54 am
Is that a "top down" or "bottom up" view of the legs?  I can't seem to figure it out.  Based on the tunnel and the expected conditions the legs face when extended, I'm currently assuming it's "bottom up".

I was wondering the same thing.  It's hard to tell from the model, because the legs seem to be semi-transparent.  You can definitely see the pistons.

The flow, however, is definitely tail-to-head.  The only reason to test reverse flow is if they were planning to take off while on the legs, and there are many reasons why that's not likely.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: NovaSilisko on 06/25/2015 02:56 am
I think we're looking into the interstage, if you ask me.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 06/25/2015 03:01 am
I think we're looking into the interstage, if you ask me.

Looking at pictures on the web, I think the dark area is the inlet, and the fans are behind the camera, all as expected.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 06/25/2015 03:02 am
There it is.

Almost 100% conclusive....  :)

(link (http://velonews.competitor.com/2011/12/news/a-day-at-the-san-diego-low-speed-wind-tunnel-with-felt-and-project-1t4i_200101))
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 06/25/2015 03:08 am
Is that a "top down" or "bottom up" view of the legs?  I can't seem to figure it out.  Based on the tunnel and the expected conditions the legs face when extended, I'm currently assuming it's "bottom up".

I was wondering the same thing.  It's hard to tell from the model, because the legs seem to be semi-transparent.  You can definitely see the pistons.

The flow, however, is definitely tail-to-head.  The only reason to test reverse flow is if they were planning to take off while on the legs, and there are many reasons why that's not likely.

It might have been testing "reversed flow" for the F9R-dev1 vehicle (not likely, though).  But based on the pic with the biker, I now believe that it is a "top down" view.  I had originally thought the wind originated from behind the camera.  Your pic indicates that's not the case.  Thanks.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 06/25/2015 04:04 am
Is that a "top down" or "bottom up" view of the legs?  I can't seem to figure it out.  Based on the tunnel and the expected conditions the legs face when extended, I'm currently assuming it's "bottom up".

I was wondering the same thing.  It's hard to tell from the model, because the legs seem to be semi-transparent.  You can definitely see the pistons.

The flow, however, is definitely tail-to-head.  The only reason to test reverse flow is if they were planning to take off while on the legs, and there are many reasons why that's not likely.

It might have been testing "reversed flow" for the F9R-dev1 vehicle (not likely, though).  But based on the pic with the biker, I now believe that it is a "top down" view.  I had originally thought the wind originated from behind the camera.  Your pic indicates that's not the case.  Thanks.

Yup - the F9R-dev1 indeed took off with extended legs - I forgot about that - but it was moving oh-slow-slowly, so as you say, unlikely.

I wonder if this model had active deployable legs.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: TripD on 06/25/2015 04:35 am
Wait a minute.... you're all assuming what they are testing for on the bicyclist.  >.<
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deruch on 06/25/2015 07:21 am
Wait a minute.... you're all assuming what they are testing for on the bicyclist.  >.<

Not that much use for determining aerodynamic flows of a bicyclist with a tail wind.  So, yeah, we're assuming the biker is facing a headwind in that picture. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Chris Bergin on 06/26/2015 03:51 pm
A pretty long "political statement" from SpaceX, that you all may find interesting as it's about the rockets/engines - so cross posting:
http://forum.nasaspaceflight.com/index.php?topic=37873.msg1394509#msg1394509
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: sghill on 06/26/2015 03:55 pm
Those legs they are testing look bigger to me from looking at this image.  The ratio of their length in comparison to the diameter of the booster model appears higher.

And no grid fins....
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: obi-wan on 06/26/2015 05:51 pm
I was at NASA's "Mars Day on the Hill" yesterday at the Rayburh House Office Building, and had a chance to get up close and personal with a SuperDraco thruster in the Commercial Crew display. It's a monster! Got to pick it up and get a good close look at it - probably 20 pounds at least, and an incredibly small nozzle area ratio (2:1?) Clearly designed for sea-level use in pad abort situations, also probably with a comparatively low chamber pressure. Nice features in the 3D Inconel printing process, though (including a logo). (Note: I wouldn't be shocked if it turned out this is an older-generation SuperDraco and not representative of what's on the spacecraft now, but I don't have any evidence one way or the other.)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JBF on 06/26/2015 06:06 pm
I was at NASA's "Mars Day on the Hill" yesterday at the Rayburh House Office Building, and had a chance to get up close and personal with a SuperDraco thruster in the Commercial Crew display. It's a monster! Got to pick it up and get a good close look at it - probably 20 pounds at least, and an incredibly small nozzle area ratio (2:1?) Clearly designed for sea-level use in pad abort situations, also probably with a comparatively low chamber pressure. Nice features in the 3D Inconel printing process, though (including a logo). (Note: I wouldn't be shocked if it turned out this is an older-generation SuperDraco and not representative of what's on the spacecraft now, but I don't have any evidence one way or the other.)

Probably an older version, remember the new ones are designed to be mounted in pairs.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: matthewkantar on 06/26/2015 07:20 pm
If I saw those fractalish gussets when I was in school in the early 80's, I would have guessed they were alien artifacts. I know it is kind of old hat now, but I am amazed by how far 3D printing has come.

Matthew
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: catdlr on 06/27/2015 02:39 am
Elon Musk’s SpaceX is on a roll, but here’s why the pressure is really on

http://www.washingtonpost.com/business/economy/elon-musks-spacex-is-on-a-roll-but-heres-why-the-pressure-is-now-on/2015/06/26/4d2baf30-1687-11e5-9518-f9e0a8959f32_story.html

Quote
Elon Musk’s SpaceX is preparing to resupply the orbiting laboratory on Sunday. And with the failures of the Orbital ATK Antares rocket and Russia’s Progress 59 spacecraft, the pressure is on. Not just for the billionaire’s upstart space company, and its streak of seven straight successful launches to the station, but the future of the private space industry that SpaceX’s improbable success has helped spawn.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ClaytonBirchenough on 06/27/2015 12:40 pm
It seems the pressure is certainly on!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Ben the Space Brit on 06/27/2015 05:47 pm
Don't ask me why but something about the use of the term 'improbable success' raises my hackles a little.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dglow on 06/27/2015 06:56 pm
Don't ask me why but something about the use of the term 'improbable success' raises my hackles a little.

Consider the source, follow the money.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 06/27/2015 07:04 pm
Don't ask me why but something about the use of the term 'improbable success' raises my hackles a little.
Just a reference to the ratio of how many have tried to how many have succeeded. Back in 2003, when SpaceX was one of many startups, I don't think a lot of people would have bet even money on being where they are now.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: gongora on 06/27/2015 08:15 pm
Don't ask me why but something about the use of the term 'improbable success' raises my hackles a little.

Consider the source, follow the money.

Washington Post coverage of SpaceX is generally favorable.  I don't think the owner has ordered anyone to skew the tone of their writing.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dcporter on 06/27/2015 09:19 pm
Don't ask me why but something about the use of the term 'improbable success' raises my hackles a little.

Consider the source, follow the money.

Washington Post coverage of SpaceX is generally favorable.  I don't think the owner has ordered anyone to skew the tone of their writing.

Also the tone of "improbable success" was not necessarily negative, and not how I read it. Musk likes to call success unlikely for basically everything he's tried and succeeded at.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mader Levap on 06/27/2015 09:41 pm
Well, entire challenge is to make success probable.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: GalacticIntruder on 06/27/2015 10:10 pm
I could say any company that survives after its start up capital is exhausted is improbable. Most fail.

The Falcon 1 finally succeeded, so the odds of the company surviving went way up (regardless of NASA). Not to be confused with thriving an accelerating, though.

Given our hindsight, Musk had a better chance of success than some other random person trying the exact same things.

Another disjointed space article, this time with the WaPo. I know they need their word count, and filler, and casual readers but it is really annoying.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 06/27/2015 10:58 pm
Don't ask me why but something about the use of the term 'improbable success' raises my hackles a little.

Consider the source, follow the money.

Washington Post coverage of SpaceX is generally favorable.  I don't think the owner has ordered anyone to skew the tone of their writing.

Just for the record; the Washington Post is owned by Jeff Bezos, who also owns Blue Origin. IMO their snark factor wrt SpaceX has amped up a tad since the takeover.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 06/27/2015 11:04 pm
Another disjointed space article, this time with the WaPo. I know they need their word count, and filler, and casual readers but it is really annoying.

Because it's not a space article. It's a business article in the business section about a business whose business happens to be the space business, by an author who is not a science writer. Which happens to describe most of the people writing about SpaceX, unfortunately.




Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: gongora on 06/28/2015 12:05 am
Don't ask me why but something about the use of the term 'improbable success' raises my hackles a little.

Consider the source, follow the money.

Washington Post coverage of SpaceX is generally favorable.  I don't think the owner has ordered anyone to skew the tone of their writing.

Just for the record; the Washington Post is owned by Jeff Bezos, who also owns Blue Origin. IMO their snark factor wrt SpaceX has amped up a tad since the takeover.

I think everyone in this conversation already understood who the owner is, and I really haven't noticed snark in the WaPo articles about SpaceX.  They are better written than the articles at a lot of other newspapers.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 06/29/2015 11:47 pm
So here's an observation regarding faults...

Remember way back when, SpaceX was about to transition from F9.0/M1C to F9.1/M1D, (and there was a lot of uproar here on the forum about that) and then just before the transition, when there was only a single 9.0 in the line, there was the engine that had the cooling jacket rupture and blew a corner of the skirt off...

k, so there were all these questions - what are they going to do now?  and I was thinking - "Thank god it happened on the last (or second-to-last) flight of the 9.0 and not on the first flight of the 9.1....

Well, a couple of years later, and here we are again.  I believe there's only a single 9.1 in the barrel, and this time the  ante is a lot higher...

So I'll start with this:

I'd rather see the failure here, than I would on the first 9.2 flight.  At least it doesn't make it look as though SpaceX had an accident "because they were moving too fast".  There's already enough people who are going with "this was because they make their staff work too hard"

F9 had a great run, too bad it wasn't from here to posterity, but I still see it as a contender for leading rocket out there, especially as I watched the first stage continue to fly straight through the trauma of losing the payload and having the second stage come apart on it...

Cheers!

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 06/29/2015 11:49 pm
So here's an observation regarding faults...

Remember way back when, SpaceX was about to transition from F9.0/M1C to F9.1/M1D, (and there was a lot of uproar here on the forum about that) and then just before the transition, when there was only a single 9.0 in the line, there was the engine that had the cooling jacket rupture and blew a corner of the skirt off...

k, so there were all these questions - what are they going to do now?  and I was thinking - "Thank god it happened on the last (or second-to-last) flight of the 9.0 and not on the first flight of the 9.1....

Well, a couple of years later, and here we are again.  I believe there's only a single 9.1 in the barrel, and this time the  ante is a lot higher...

So I'll start with this:

I'd rather see the failure here, than I would on the first 9.2 flight.  At least it doesn't make it look as though SpaceX had an accident "because they were moving too fast".  There's already enough people who are going with "this was because they make their staff work too hard"

F9 had a great run, too bad it wasn't from here to posterity, but I still see it as a contender for leading rocket out there, especially as I watched the first stage continue to fly straight through the trauma of losing the payload and having the second stage come apart on it...

Cheers!



Still the same upperstage.  So the 9.2 change isn't a get out jail free card.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 06/30/2015 12:19 am
So here's an observation regarding faults...

Remember way back when, SpaceX was about to transition from F9.0/M1C to F9.1/M1D, (and there was a lot of uproar here on the forum about that) and then just before the transition, when there was only a single 9.0 in the line, there was the engine that had the cooling jacket rupture and blew a corner of the skirt off...

k, so there were all these questions - what are they going to do now?  and I was thinking - "Thank god it happened on the last (or second-to-last) flight of the 9.0 and not on the first flight of the 9.1....

Well, a couple of years later, and here we are again.  I believe there's only a single 9.1 in the barrel, and this time the  ante is a lot higher...

So I'll start with this:

I'd rather see the failure here, than I would on the first 9.2 flight.  At least it doesn't make it look as though SpaceX had an accident "because they were moving too fast".  There's already enough people who are going with "this was because they make their staff work too hard"

F9 had a great run, too bad it wasn't from here to posterity, but I still see it as a contender for leading rocket out there, especially as I watched the first stage continue to fly straight through the trauma of losing the payload and having the second stage come apart on it...

Cheers!



Still the same upperstage.  So the 9.2 change isn't a get out jail free card.

Who. Ever. Said. Anything. About. GetOutOfJailFreeCard ?!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 06/30/2015 12:39 am
So here's an observation regarding faults...

Remember way back when, SpaceX was about to transition from F9.0/M1C to F9.1/M1D, (and there was a lot of uproar here on the forum about that) and then just before the transition, when there was only a single 9.0 in the line, there was the engine that had the cooling jacket rupture and blew a corner of the skirt off...

k, so there were all these questions - what are they going to do now?  and I was thinking - "Thank god it happened on the last (or second-to-last) flight of the 9.0 and not on the first flight of the 9.1....

Well, a couple of years later, and here we are again.  I believe there's only a single 9.1 in the barrel, and this time the  ante is a lot higher...

So I'll start with this:

I'd rather see the failure here, than I would on the first 9.2 flight.  At least it doesn't make it look as though SpaceX had an accident "because they were moving too fast".  There's already enough people who are going with "this was because they make their staff work too hard"

F9 had a great run, too bad it wasn't from here to posterity, but I still see it as a contender for leading rocket out there, especially as I watched the first stage continue to fly straight through the trauma of losing the payload and having the second stage come apart on it...

Cheers!



Still the same upperstage.  So the 9.2 change isn't a get out jail free card.
Wasn't the Delta III upper stage pretty much identical to the Delta IV upper stage? Boeing/ULA certainly seems to treat it as a get out of jail free card, although I definitely agree with you that it's not (not for Delta III/IV nor for v1.1/1.2).

(Also, the v1.2 upper stage will be stretched, which means it isn't identical.)


And I will say that resetting the reliability statistic to zero isn't even in SpaceX's interests, as a new launch vehicle generally has much lower expected reliability than F9's 95%.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 06/30/2015 12:41 am
Still the same upperstage.  So the 9.2 change isn't a get out jail free card.

That's interesting.  So the second-stage doesn't get the uprated Merlin or subcooled propellant?  I guess the conventional wisdom was that the F9 upper stage was already overpowered, but I'd think they might be able to use the extra performance on FH, and that F9 and FH share a common upperstage.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 06/30/2015 12:51 am
Still the same upperstage.  So the 9.2 change isn't a get out jail free card.

That's interesting.  So the second-stage doesn't get the uprated Merlin or subcooled propellant?  I guess the conventional wisdom was that the F9 upper stage was already overpowered, but I'd think they might be able to use the extra performance on FH, and that F9 and FH share a common upperstage.

Jim may have been using "same" a bit loosely. We do know there will be some changes.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 06/30/2015 03:16 am
Still the same upperstage.  So the 9.2 change isn't a get out jail free card.

That's interesting.  So the second-stage doesn't get the uprated Merlin or subcooled propellant?  I guess the conventional wisdom was that the F9 upper stage was already overpowered, but I'd think they might be able to use the extra performance on FH, and that F9 and FH share a common upperstage.

Jim may have been using "same" a bit loosely. We do know there will be some changes.

a change in tank length or propellant temp doesn't really change manufacturing processes, handling and launch site operations of the hardware.  The vehicle's mechanical, propulsion and avionics/electrical architecture is basically the same.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: intrepidpursuit on 06/30/2015 03:33 pm
Still the same upperstage.  So the 9.2 change isn't a get out jail free card.

That's interesting.  So the second-stage doesn't get the uprated Merlin or subcooled propellant?  I guess the conventional wisdom was that the F9 upper stage was already overpowered, but I'd think they might be able to use the extra performance on FH, and that F9 and FH share a common upperstage.

Jim may have been using "same" a bit loosely. We do know there will be some changes.

a change in tank length or propellant temp doesn't really change manufacturing processes, handling and launch site operations of the hardware.  The vehicle's mechanical, propulsion and avionics/electrical architecture is basically the same.

Okay, so the upper stage will have an uprated engine, larger tanks in a different aspect ratio, presumably uprated pressure system for the higher density lox. For the upper stage this is at least as big a change as 1.0 to 1.1. It is certainly not a get out of jail free card, but there is a good chance that whatever system failed here is significantly updated in the new upper stage, so they may only have to make changes to a single upper stage if the problem does not exist in the 1.2 design. That is the point.

I suppose the 2 engine centuar is the "same" as the previous one as well.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 06/30/2015 03:40 pm

I suppose the 2 engine centuar is the "same" as the previous one as well.

Even more so since Centaur was originally two engines
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 06/30/2015 03:52 pm

1.  Okay, so the upper stage will have an uprated engine,

2.   larger tanks in a different aspect ratio,

3.  presumably uprated pressure system for the higher density lox.

4.  For the upper stage this is at least as big a change as 1.0 to 1.1. It is certainly not a get out of jail free card,

5.  but there is a good chance that whatever system failed here is significantly updated in the new upper stage,


1.  what says the upper stage engine is changing?  It doesn't need more thrust the way it is.  And anyways, even if it is a new one, the interfaces are the same and the thrust level will be kept the same (it is throttled).

2.  Meh. Tank lengths are always changed.  A few inches isn't going to matter especially when it comes to aspect ratio

3.  Why?  The viscosity is not changing.  Anyways, pressurant bottles are added and removed and pressure settings changed as needed for mission requirements and as vehicle designs mature even without block changes.

4.  Nonsense.  It is a tweak.  1.0 to 1.1 was a wholesale structural redesign of the aft end of the vehicle, which also necessitated launch pad mods.

5.  Not true.  As shown, the changes are minimal.  It is not an update.  So the same problem is likely there
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: intrepidpursuit on 06/30/2015 04:14 pm

1.  Okay, so the upper stage will have an uprated engine,

2.   larger tanks in a different aspect ratio,

3.  presumably uprated pressure system for the higher density lox.

4.  For the upper stage this is at least as big a change as 1.0 to 1.1. It is certainly not a get out of jail free card,

5.  but there is a good chance that whatever system failed here is significantly updated in the new upper stage,


1.  what says the upper stage engine is changing?  It doesn't need more thrust the way it is.  And anyways, even if it is a new one, the interfaces are the same and the thrust level will be kept the same (it is throttled).

2.  Meh. Tank lengths are always changed.  A few inches isn't going to matter especially when it comes to aspect ratio

3.  Why?  The viscosity is not changing.  Anyways, pressurant bottles are added and removed and pressure settings changed as needed for mission requirements and as vehicle designs mature even without block changes.

4.  Nonsense.  It is a tweak.  1.0 to 1.1 was a wholesale structural redesign of the aft end of the vehicle, which also necessitated launch pad mods.

5.  Not true.  As shown, the changes are minimal.  It is not an update.  So the same problem is likely there

I love that you pull no punches Jim.

1. We know the engine change is minor, referred to only as turning it up to 11 so to speak. But why would that not continue to make the upper stage engine match the lower stage engine? It would be silly NOT to uprate it.

4. I'm referring to the upper stage only here, so there was no structural redesign that I'm aware of, that was on the first stage.

5. We will just have to see how things progress. There are definitely being changes made to the upper stage in the design update, so at very least they can roll whatever changes they need to make into that design.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: 3jt on 07/01/2015 04:06 pm
As data loss increases with the breakup of the rocket, the ability of the software to translate raw telemetry into meaningful numbers decreases (because data is being lost).  A human can often "fill in the spaces" if they can see the raw hex dump and pull more information out of the data.  This used to be common in software debugging, but has become less so as debugging tools have improved, but I can still see its utility in the case like this, and am glad someone thought to dig out the hex editor.

Can someone explain why rockets don't have black boxes? Seems to me it couldn't be that hard to design a glorified SD card that can survive an explosion, float, etc.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 04:10 pm

Can someone explain why rockets don't have black boxes? Seems to me it couldn't be that hard to design a glorified SD card that can survive an explosion, float, etc.

Because unless you can find it, it is useless.  We still can't find airliners that have gone down. Many issues happen on orbit, how is the card retrieved? What data should be recorded and for how long?  Anyways, how would a black box help in this situation?

realtime telemetry is still the way to go
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rpapo on 07/01/2015 04:13 pm

Can someone explain why rockets don't have black boxes? Seems to me it couldn't be that hard to design a glorified SD card that can survive an explosion, float, etc.

Because unless you can find it, it is useless.  We still can't find airliners that have gone down. Many issues happen on orbit, how is the card retrieved?  A
Not only that, but rockets transmit everything that would be recorded in a black box, and a lot more, in real time to receivers that are focused intently on them, and them only.  Airliners aren't being tracked every millisecond of their way, and fail only rarely.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Req on 07/01/2015 04:13 pm

Can someone explain why rockets don't have black boxes? Seems to me it couldn't be that hard to design a glorified SD card that can survive an explosion, float, etc.

Because unless you can find it, it is useless.  We still can't find airliners that have gone down. Many issues happen on orbit, how is the card retrieved?  A

It's worth noting that airliners don't have dedicated range assets tracking them with high precision or pre-calculated debris corridors.  Also, Elon Musk has asked for designs for a blackbox for a Falcon.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: RonM on 07/01/2015 04:23 pm

Can someone explain why rockets don't have black boxes? Seems to me it couldn't be that hard to design a glorified SD card that can survive an explosion, float, etc.

Because unless you can find it, it is useless.  We still can't find airliners that have gone down. Many issues happen on orbit, how is the card retrieved?  A

Then why do they have black boxes on airlines? Because they can be recovered most of the time.

In this case and the Orbital failure a black box could be recovered.

Of course, once a rocket gets too far down range or reaches orbit, a black box could not be recovered.

There is a delay in transmitting telemetry. In situations such as this it would help to have a little more data. Also, what if telemetry is lost, but the system is still recording? Once again you get a little more data.

Considering how many millions of dollars a launch costs and the expense of delay in return to launch, black box systems would be a cheap investment.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: intrepidpursuit on 07/01/2015 04:32 pm

Can someone explain why rockets don't have black boxes? Seems to me it couldn't be that hard to design a glorified SD card that can survive an explosion, float, etc.

Because unless you can find it, it is useless.  We still can't find airliners that have gone down. Many issues happen on orbit, how is the card retrieved?  A

Then why do they have black boxes on airlines? Because they can be recovered most of the time.

In this case and the Orbital failure a black box could be recovered.

Of course, once a rocket gets too far down range or reaches orbit, a black box could not be recovered.

There is a delay in transmitting telemetry. In situations such as this it would help to have a little more data. Also, what if telemetry is lost, but the system is still recording? Once again you get a little more data.

Considering how many millions of dollars a launch costs and the expense of delay in return to launch, black box systems would be a cheap investment.

There is no more delay in a transponder then there would be writing to an SD card. The last bit of data received from telemetry would be the last bit written to the SD card. Plus, building a rocket black box that could survive hypersonic vehicle breakup and reentry would not be an easy task, and it would be a very heavy box.

After MH370 there have been discussions about giving airplanes rocket-like live telemetry feeds. The reason they don't have that is because there would have to be a satellite network servicing them and that is expensive. For rockets the launch site just builds the required radio assets to communicate with the rocket on ascent. Radio telemetry is better.

The first stage might need one to help when it is flying back, as it will be out of range of the range assets.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: 3jt on 07/01/2015 04:33 pm
There is a delay in transmitting telemetry. In situations such as this it would help to have a little more data. Also, what if telemetry is lost, but the system is still recording? Once again you get a little more data.

Considering how many millions of dollars a launch costs and the expense of delay in return to launch, black box systems would be a cheap investment.

My thoughts exactly. Also, keep in mind airliner black boxes are designed to survive a crash, not explosive disintegration. An airline black box is designed to go down with the debris and be picked up by sonar ping. If I were designing a rocket black box I'd make it float, detect impact with the ground/water, wait a few minutes for debris to stop falling, then inflate a great big orange airbag that's an antenna and/or a radar reflector.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 07/01/2015 04:45 pm
As data loss increases with the breakup of the rocket, the ability of the software to translate raw telemetry into meaningful numbers decreases (because data is being lost).  A human can often "fill in the spaces" if they can see the raw hex dump and pull more information out of the data.  This used to be common in software debugging, but has become less so as debugging tools have improved, but I can still see its utility in the case like this, and am glad someone thought to dig out the hex editor.

Can someone explain why rockets don't have black boxes? Seems to me it couldn't be that hard to design a glorified SD card that can survive an explosion, float, etc.

Yup - especially since the first thing that seems to go is the antenna, or antenna pointing.  "Couldn't get signal because the spacecraft lost orientation", etc. 

You could make it survive, and you could make it float, too, at least with very high likelihood.  Then it's just a matter of time before it's found.

You could also have a lot more information stored in it - no need to switch between video feeds, and sometimes a holistic view is worth 100 sensors.



Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: 3jt on 07/01/2015 04:53 pm

Can someone explain why rockets don't have black boxes? Seems to me it couldn't be that hard to design a glorified SD card that can survive an explosion, float, etc.

Because unless you can find it, it is useless.  We still can't find airliners that have gone down. Many issues happen on orbit, how is the card retrieved?  A

Then why do they have black boxes on airlines? Because they can be recovered most of the time.

In this case and the Orbital failure a black box could be recovered.

Of course, once a rocket gets too far down range or reaches orbit, a black box could not be recovered.

There is a delay in transmitting telemetry. In situations such as this it would help to have a little more data. Also, what if telemetry is lost, but the system is still recording? Once again you get a little more data.

Considering how many millions of dollars a launch costs and the expense of delay in return to launch, black box systems would be a cheap investment.
There is no more delay in a transponder then there would be writing to an SD card. The last bit of data received from telemetry would be the last bit written to the SD card. Plus, building a rocket black box that could survive hypersonic vehicle breakup and reentry would not be an easy task, and it would be a very heavy box.

Depends on the data rate and the size of your buffers... have to think about that one.

Building something that can survive breakup and reentry doesn't have to be big or heavy. CORONA satellites used to eject film canisters from orbit which were captured over the ocean by aircraft as they parachuted down. These days, shock isn't the issue with solid state devices, only heat, so use an ablative shield.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 04:56 pm

Can someone explain why rockets don't have black boxes? Seems to me it couldn't be that hard to design a glorified SD card that can survive an explosion, float, etc.

Because unless you can find it, it is useless.  We still can't find airliners that have gone down. Many issues happen on orbit, how is the card retrieved?  A

It's worth noting that airliners don't have dedicated range assets tracking them with high precision or pre-calculated debris corridors.  Also, Elon Musk has asked for designs for a blackbox for a Falcon.
Because airliners don't have the same accident rate.
Again, a black box wouldn't help in this situation. The same events that prevented telemetry from being sent would prevent the data from being recorded.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 05:01 pm

Building something that can survive breakup and reentry doesn't have to be big or heavy. CORONA satellites used to eject film canisters from orbit which were captured over the ocean by aircraft as they parachuted down. These days, shock isn't the issue with solid state devices, only heat, so use an ablative shield.

That was hundreds of pounds.   Also, again nominal data is useless.  Want is wanted is data from anomalies and many don't happen during ascent.  Even so, are recovery forces going to be staged along the whole launch trajectory in case there is an issue to retrieve the capsule?  Or what is done when the upper stage shuts down early during a GTO burn?  How is the capsule going to come down?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 05:05 pm
Black boxes are not a solution.  They can't cover all the situations, they don't provide any additional coverage and they add weight.  A black box would have not provided any more data later than what was received for CRS-7

Edit: added later
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 05:08 pm

In this case and the Orbital failure a black box could be recovered.


And wouldn't provide any additional data.  It doesn't matter wether the data is going into a storage device or transmitter, it would have ended at the same time.

Aircraft black boxes mostly focus on aircraft attitude and flight path and control surface inputs and positions.  There is some data on engine status but overall less 100 parameters are required by law.

Flight trajectory and attitude are a small part of a launch vehicle data stream.The vehicle's health is determined by hundreds/thousands of transducers.   When a vehicle blows up, the power to the transducers and data acquisition is cut off so there is no data for a black box to record after the event.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: wolfpack on 07/01/2015 05:20 pm

Because airliners don't have the same accident rate.
Again, a black box wouldn't help in this situation. The same events that prevented telemetry from being sent would prevent the data from being recorded.

Airliners would prefer telemetry if they knew how to handle the data (1000's flights/day). It is better than black box.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: R7 on 07/01/2015 05:31 pm
A blackbox storing bandwidth could be at least couple orders of magnitude higher than radiolink (1.8Mbps in F9). CRS-7 thread has great post (http://forum.nasaspaceflight.com/index.php?topic=37476.msg1398608#msg1398608) describing how telemetry messages can be prioritized and if bandwidth becomes conngested the lower priority messages are dropped. Also do they currently get down all the camera feeds or only some of them? Blackbox could store them all, also enable high speed cameras.

Not saying it would have definitely helped in this case but if it could be packaged to, say, less than one kg it wouldn't hurt.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 05:36 pm
Again, a black box would have not helped with the Cassiope restart failure.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 07/01/2015 05:52 pm

Airliners would prefer telemetry if they knew how to handle the data (1000's flights/day). It is better than black box.

That's a good point, but nobody suggested getting rid of telemetry.  The black box would be additional, for extra data and for data that may have been lost in transmission.

Airlines are very different than rockets.  They are not tracked, so just looking for a downed airline can take months...  Rockets are very well located.  Also, the accident rates are not the same.  Airlines are also thinking about telemetry for predictive failure prevention, and for real-time analysis and debugging.  With rockets, it's mostly to recover some information from catastrophic failure.

It's basically a "can't hurt" measure.  Such a unit would be very lightweight, practically harmless, and can come in handy, sometimes.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: NWade on 07/01/2015 06:18 pm
OK folks...  If you won't believe Jim - as a person with professional experience in Rocketry, then perhaps you'll believe a pilot who has extensive experience in Aviation - like myself?
 
Black boxes are heavy, failure-prone, and limited in what they record. They were invented and put to use long before we had modern satellite comm systems or high-speed real-time telemetry links. If real-time telemetry was an option at the time, then aircraft would have used that instead of black boxes. They are not a panacea, they don't work as well as you think ("the CSI effect"), and it would be a huge exercise to even attempt to develop a "black box" that could survive the kinds of temperature, pressure, and velocity changes that a rocket goes through (many orders of magnitude larger than what the fastest and highest jets deal with).
 
If you think that the vehicle can't send telemetry "fast enough" (i.e. there's a delay), then the problem is in the way the telemetry relay was designed; not the choice of solution. There's no reason that all the systems can't spit that data out to a radio-transmitter just as fast as they can be written to an SD card. Sure, you may need to run several channels in parallel to achieve the equivalent bandwidth of a modern SD card; but that is a lot less-challenging and costly than designing, manufacturing, installing, and then retrieving a whole second recording system!
 
And if you think that the telemetry is always going to be second-best because of antenna/pointing issues then again the problem is not telemetry as a method for gathering data, but rather the design of the system. All you have to do to address that concern is install redundant antennas and/or use omnidirectional antennae (as my SPOT or DeLorme InReach device does to send text communications up to a satellite, for relay).  Once more, this is a lot less-challenging and costly than designing, manufacturing, installing, and then retrieving a whole second recording system!
 
Its natural for us fans to want answers to the loss of the vehicle. Believe me, us pilots have the same reaction (perhaps even more-strongly than the general public) whenever an aviation accident is reported! But throwing out "solutions" and "improvements" without putting any research or critical thought into your idea simply lowers the signal-to-noise ratio on the forum. You don't have to be an expert in order to have a good idea - but you should take a moment to deduce whether your idea has merit before posting it and/or defending it.
 
--Noel
 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: chuck34 on 07/01/2015 06:22 pm
Anyways, how would a black box help in this situation?

realtime telemetry is still the way to go

If the telemetry antena failed, got knocked off, or misalligned, but the sensors were all still working and sending data to the black box?

Realtime telemetry is very nice, and should not go away.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: spacejulien on 07/01/2015 06:31 pm
A technology demonstrator of "a spaceflight equivalent" of a black box was flown with ATV-5:

http://www.esa.int/Our_Activities/Space_Engineering_Technology/ATV_s_internal_camera_delivered_data_but_not_images

It didn't fully transmit its collected data, development hiccups, I presume.

However, this is to collect data during the disintegration of a vehicle and during radio-blackout. It is not connected to the telemetry (which fails due to breakup). Thus, in the context of CRS-7, the unit would have downlinked images/films of wherever it would be installed, nothing more.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 06:51 pm

If the telemetry antena failed, got knocked off, or misalligned, but the sensors were all still working and sending data to the black box?

Realtime telemetry is very nice, and should not go away.

there are multiple antennas.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: chuck34 on 07/01/2015 07:43 pm

If the telemetry antena failed, got knocked off, or misalligned, but the sensors were all still working and sending data to the black box?

Realtime telemetry is very nice, and should not go away.

there are multiple antennas.

Good to know.  Are they in multiple locations, or simply multiple directions?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 07:53 pm
  Are they in multiple locations, or simply multiple directions?

They have hemispherical coverage and 180 degrees apart
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: chuck34 on 07/01/2015 08:09 pm
  Are they in multiple locations, or simply multiple directions?

They have hemispherical coverage and 180 degrees apart

Ok so my point still stands.  Something could knock out the antena, but not nesicarily the whole telemetry system/black box.  Granted this is a very unlikely scenario, but the question was "how would a black box help".  This is one (however unlikely) case.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 08:36 pm

Ok so my point still stands.  Something could knock out the antena, but not nesicarily the whole telemetry system/black box.  Granted this is a very unlikely scenario, but the question was "how would a black box help".  This is one (however unlikely) case.

The limited case is overshadowed by the other Blackbox limitations.  The case for taking out antennas is also applicable to the connection to the black box.  SO there is no advantage.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: philw1776 on 07/01/2015 08:38 pm
OK folks...  If you won't believe Jim - as a person with professional experience in Rocketry, then perhaps you'll believe a pilot who has extensive experience in Aviation - like myself?
 
Black boxes are heavy, failure-prone, and limited in what they record. They were invented and put to use long before we had modern satellite comm systems or high-speed real-time telemetry links. If real-time telemetry was an option at the time, then aircraft would have used that instead of black boxes. They are not a panacea, they don't work as well as you think ("the CSI effect"), and it would be a huge exercise to even attempt to develop a "black box" that could survive the kinds of temperature, pressure, and velocity changes that a rocket goes through (many orders of magnitude larger than what the fastest and highest jets deal with).
 
If you think that the vehicle can't send telemetry "fast enough" (i.e. there's a delay), then the problem is in the way the telemetry relay was designed; not the choice of solution. There's no reason that all the systems can't spit that data out to a radio-transmitter just as fast as they can be written to an SD card. Sure, you may need to run several channels in parallel to achieve the equivalent bandwidth of a modern SD card; but that is a lot less-challenging and costly than designing, manufacturing, installing, and then retrieving a whole second recording system!
 
And if you think that the telemetry is always going to be second-best because of antenna/pointing issues then again the problem is not telemetry as a method for gathering data, but rather the design of the system. All you have to do to address that concern is install redundant antennas and/or use omnidirectional antennae (as my SPOT or DeLorme InReach device does to send text communications up to a satellite, for relay).  Once more, this is a lot less-challenging and costly than designing, manufacturing, installing, and then retrieving a whole second recording system!
 
Its natural for us fans to want answers to the loss of the vehicle. Believe me, us pilots have the same reaction (perhaps even more-strongly than the general public) whenever an aviation accident is reported! But throwing out "solutions" and "improvements" without putting any research or critical thought into your idea simply lowers the signal-to-noise ratio on the forum. You don't have to be an expert in order to have a good idea - but you should take a moment to deduce whether your idea has merit before posting it and/or defending it.
 
--Noel
 

Informative post.
I'm OK with folks tossing out ideas that aren't fully thought out as many lack the background to answer their own "Why doesn't SpaceX just do THIS..."  There are many here, Jim et. al. who give cogent replies.  OK, OK sometimes with a bit of snark.

What is irksome is folks being SO married to their ideas that instead of reading and internalizing the replies, they defend their pet ideas ad nauseum despite having received quality replies explaining why the idea lacks merit, viability, whatever.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: 3jt on 07/01/2015 09:02 pm

Because airliners don't have the same accident rate.
Again, a black box wouldn't help in this situation. The same events that prevented telemetry from being sent would prevent the data from being recorded.

Airliners would prefer telemetry if they knew how to handle the data (1000's flights/day). It is better than black box.

A black box makes much more sense for a reusable first stage than a second stage that's never coming back.

I maintain you'd have a much better chance of getting a clear picture of the last millisecond on storage than you would over the air. In that last *millisecond* you could write ~5Mb of data to a $100 SSD, you can easily do 10-100x better than that. I don't know what their downlink rate (EDIT: 1.8Mbps = 1800 bits in that same amount of time) is but it's not that fast!

Instead of recording sensor data every millisecond you could be recording every microsecond.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: 3jt on 07/01/2015 09:11 pm
... you should take a moment to deduce whether your idea has merit before posting it and/or defending it.

Technology has changed in the past 30 years. We don't use tape recorders anymore.

Also, digital radio is just a touch more complicated than changing antenna or adding channels.

Sure, when the power goes out, you're going to lose your sensors. Your radio will stop transmitting and you'll lose whatever's in the buffer. If you're only taking measurements every second it's no big deal. If you're taking measurements every microsecond it's a different story. The power doesn't have to go out all at once, if you distribute your batteries.

A black box with a small capacitor won't lose whatever is in the buffer. And the bandwidth is orders of magnitude greater, which means you can record data much more frequently, right up to the last microsecond before the power goes out.

In other words, you can watch systems go offline individually. I don't know, that might make it easier to work out what went wrong. But what do I know?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: RonM on 07/01/2015 09:31 pm

Informative post.
I'm OK with folks tossing out ideas that aren't fully thought out as many lack the background to answer their own "Why doesn't SpaceX just do THIS..."  There are many here, Jim et. al. who give cogent replies.  OK, OK sometimes with a bit of snark.

What is irksome is folks being SO married to their ideas that instead of reading and internalizing the replies, they defend their pet ideas ad nauseum despite having received quality replies explaining why the idea lacks merit, viability, whatever.

If the reply is a snarky response without an explanation, it is worthless because it does not make a point. It doesn't matter if you're an industry insider if you don't support your position with some sort of argument.

Even just one simple sentence that actually says why something is wrong will work. That's all it takes.

And people who do get reasonable responses should pay attention. Typing it over and over again does not make an idea correct.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 07/01/2015 10:39 pm
 Using airline black boxes as an argument against data storage is nonsense. Those monstrosities are the best example of technological insanity I've ever seen. Any high school shop could come up with a solid state storage device with 100 times the capacity and speed of those idiotic airline boxes, and package it so it would withstand an explosion and 1,000 Gs easily. Packaging the EPIRB or whatever homing/ pinging device it would need would be the hard part of the project.
 They wouldn't replace telemetry but could be a valuable resource for stated reasons.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 10:47 pm
1.  if you distribute your batteries.

2.  A black box with a small capacitor won't lose whatever is in the buffer. And the bandwidth is orders of magnitude greater, which means you can record data much more frequently, right up to the last microsecond before the power goes out.


1. why complicated the electrical system?

2.  So can a transmitter.

Black box still can't come down from orbit.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 10:48 pm

A black box makes much more sense for a reusable first stage than a second stage that's never coming back.


Wrong, if the stage comes back, the black box is not needed.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/01/2015 10:52 pm
I maintain you'd have a much better chance of getting a clear picture of the last millisecond on storage than you would over the air. In that last *millisecond* you could write ~5Mb of data to a $100 SSD, .

Based on what?
Not true.  It isn't a file being transferred. 
And the last millisecond isn't always that important.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: RonM on 07/02/2015 02:54 am
Thanks guys for the interesting points about realtime telemetry. Looks like it is the best system.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: QuantumG on 07/02/2015 04:13 am
OK folks...  If you won't believe Jim - as a person with professional experience in Rocketry, then perhaps you'll believe a pilot who has extensive experience in Aviation - like myself?
 

Informative post.
I'm OK with folks tossing out ideas that aren't fully thought out as many lack the background to answer their own "Why doesn't SpaceX just do THIS..."  There are many here, Jim et. al. who give cogent replies.  OK, OK sometimes with a bit of snark.

What is irksome is folks being SO married to their ideas that instead of reading and internalizing the replies, they defend their pet ideas ad nauseum despite having received quality replies explaining why the idea lacks merit, viability, whatever.

Nah.. the problem is right there in the first line of NWade's post. We're not here to "believe" anyone. We're here to talk. If you don't like people talking, there's other places you can go to believe.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: 3jt on 07/02/2015 05:50 pm
I maintain you'd have a much better chance of getting a clear picture of the last millisecond on storage than you would over the air. In that last *millisecond* you could write ~5Mb of data to a $100 SSD, .

Based on what?
Not true.  It isn't a file being transferred. 
And the last millisecond isn't always that important.

Based on timing. Any time you transfer data, either over the wire or over the air, there's buffering before transmission. Also, encapsulating the data takes time, as does compression, encryption, modulation, amplification etc. Lag between measurement and transmission could easily be tens of milliseconds. That's ignoring the possibility of loss of signal, data corruption, etc. over the air.

By comparison, you could dump the entire contents of the flight computer's memory to a flash based black box on loss of bus power. Or all of the flight computers. But why stop at a memory dump? How about being able to play back all of the raw data from the entire flight for each of the flight computers? Not just the distilled version from telemetry. As well as the incoming/outgoing radio traffic, multiple uncompressed video streams (no artifacts), etc.

For the record, I'm not saying get rid of telemetry. I'm saying a black box with 10000x the bandwidth could do things telemetry can't, by storing more data AND recording data at a higher frequency. The last millisecond of data might not be necessary to work out the root cause, but it could let you watch the system's response unfold. Knowing an O2 tank ruptured isn't as useful as knowing how fast the pressure dropped, or watching strain sensors on the structure register plastic deformation before a crack appears, how fast the crack propagates, etc.

Also, 2-3 battery packs in parallel on a power bus isn't much more complicated than one battery pack. Could be handy for distributing weight.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/02/2015 06:36 pm

1.  Based on timing. Any time you transfer data, either over the wire or over the air, there's buffering before transmission. Also, encapsulating the data takes time, as does compression, encryption, modulation, amplification etc. Lag between measurement and transmission could easily be tens of milliseconds. That's ignoring the possibility of loss of signal, data corruption, etc. over the air.

2.  By comparison, you could dump the entire contents of the flight computer's memory to a flash based black box on loss of bus power. Or all of the flight computers. But why stop at a memory dump? How about being able to play back all of the raw data from the entire flight for each of the flight computers? Not just the distilled version from telemetry. As well as the incoming/outgoing radio traffic, multiple uncompressed video streams (no artifacts), etc.

For the record, I'm not saying get rid of telemetry. I'm saying a black box with 10000x the bandwidth could do things telemetry can't, by storing more data AND recording data at a higher frequency. The last millisecond of data might not be necessary to work out the root cause, but it could let you watch the system's response unfold.

 Knowing an O2 tank ruptured isn't as useful as knowing how fast the pressure dropped, or watching strain sensors on the structure register plastic deformation before a crack appears, how fast the crack propagates, etc.



The black box is useless for most of the flight.  It can't come down from orbit.
Also, A black box is useless if if can't be found, most failures are not near the launch site.

Telemetry doesn't go through  the flight computers.

Telemetry already provides the data such as how fast the pressure dropped and what the strain gages are doing
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: CuddlyRocket on 07/02/2015 06:58 pm
Black boxes will be incorporated into rockets eventually as it will be cheaper than arguing the point in court.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: D_Dom on 07/02/2015 07:53 pm
Maybe, if the reusability of boosters becomes commonplace. Expendable boosters court arguments have been decided for years based on telemetry.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: clongton on 07/02/2015 08:10 pm
All multistage rockets to date have the guidance computer located in the upper stage avionics ring and it commands whatever lower stage is propelling the vehicle. On the Falcon there is something new in that S1 obviously has a guidance computer of its own to execute turn-over, retro fire and re-entry and to guide the stage to the ASDS barge landing. So what is the relationship between the avionics of the 2 stages? Does S2 guide the launch with S1 slaved to it until separation? How does that work? And does that avionics package have FTS execution capability to guard against an off course descent?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/02/2015 08:35 pm
Black boxes will be incorporated into rockets eventually as it will be cheaper than arguing the point in court.

How can it be cheaper when there is no box to get data from?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/02/2015 08:38 pm
1.  Does S2 guide the launch with S1 slaved to it until separation?

2.How does that work?

3.   And does that avionics package have FTS execution capability to guard against an off course descent?

1.  yes,
2.  No different than the old way.  Commands are just interpreted by a different box
3.  Avionics and FTS are completely separate.  The only thing they share is that they are on the same rocket
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/02/2015 08:40 pm
Maybe, if the reusability of boosters becomes commonplace. Expendable boosters court arguments have been decided for years based on telemetry.

How so?  Data from a successful flight is really useless.  On a mishap, the rocket isn't coming back.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: clongton on 07/02/2015 08:42 pm
1.  Does S2 guide the launch with S1 slaved to it until separation?

2.  How does that work?

3.  And does that avionics package have FTS execution capability to guard against an off course descent?

1.  yes,
2.  No different than the old way.  Commands are just interpreted by a different box
3.  Avionics and FTS are completely separate.  The only thing they share is that they are on the same rocket


Thank you Jim
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Okie_Steve on 07/03/2015 02:35 am
I'm *GUESSING* that a leading contender for the F9 S2 failure will be something related to the Helium system.
Anyone have a guesstimate how much of a payload hit switching to liquid nitrogen would cause if it were possible.
Not saying it's feasible, just pondering. It's not nearly as cold or difficult to work with so putting N2 tanks inside the LOX tanks might not be needed.

Boiling temperature
Gas        Celsius    Fahrenheit
Oxygen   -183°   -297°
Nitrogen   -196°   -320°
Hydrogen   -253°   -423°
Helium   -270°   -452°
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/03/2015 12:03 pm
I'm *GUESSING* that a leading contender for the F9 S2 failure will be something related to the Helium system.
Anyone have a guesstimate how much of a payload hit switching to liquid nitrogen would cause if it were possible.
Not saying it's feasible, just pondering. It's not nearly as cold or difficult to work with so putting N2 tanks inside the LOX tanks might not be needed.

Boiling temperature
Gas        Celsius    Fahrenheit
Oxygen   -183°   -297°
Nitrogen   -196°   -320°
Hydrogen   -253°   -423°
Helium   -270°   -452°

Nitrogen is too close to Oxygen temps
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cuddihy on 07/03/2015 02:38 pm
So, 100% then 😀
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 07/03/2015 06:28 pm
I was going to suggest putting nitrogen bottles in the rp-1 tanks, but that doesn't really solve the problem when they switch to methane fuel.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/03/2015 06:29 pm
I was going to suggest putting nitrogen bottles in the rp-1 tanks, but that doesn't really solve the problem when they switch to methane fuel.

There are some in there already
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 07/03/2015 06:33 pm
Right, so the question is could more of them be moved in there, and could they in a practical sense replace the helium bottles.  Or would they share the same kinds of risks in addition to being heavier?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: TrevorMonty on 07/03/2015 08:15 pm
I was going to suggest putting nitrogen bottles in the rp-1 tanks, but that doesn't really solve the problem when they switch to methane fuel.
One of the advantages of methane is being able to do autogenous. Turn the liquid fuels into gases and use that to pressurize the tanks. This eliminates the need for He.
This is the plan for Firefly's LVs and both stages of ULA's Vulcan. One of the reasons BE4 is better choice than AR-1.

A question for forum rocket experts.
 Is there any reason why LOX tank of a RP1 LV couldn't be pressurized with oxygen gas ?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cambrianera on 07/03/2015 08:38 pm
I was trying to imagine a stage pressurization system without helium.
This is obviously easy with cryo propellants (both, fuel and oxidizer), less easy and not common with RP-1.
Obvious advantage of He is low mass; second (partial) advantage is chemical inertia.
I was considering LCH4 for pressurization of RP-1.
Molar mass of LCH4 is 4times that of He.
But storing high pressure He has an important mass impact; also regulating his flow from high pressure vessels isn’t free, mass wise.
LCH4 on the other side can be stored in same tank of RP-1, in the upper part of the tank, adding a minimal auxiliary bulkhead to the tank (red line in the sketch).
Pressure equalization system with RP-1 tank can be  as simple as a pipe going from flat bulkhead to the space above LCH4.
An heating system should be foreseen, to increase evaporation during engine burn; same (or similar) heating system should be foreseen for autogenous LOX pressurization.

High pressure gas for pneumatic actuators and turbopump start (in flight) should be separated.
Two (or three) small COPV vessels, equipped with heating system, could be filled with LCH4.
Heating system should transform LCH4 in high pressure GCH4.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: TrevorMonty on 07/03/2015 09:27 pm
You could place the pressurization LCH4 tanks in LOX tank as they are almost the same temperature.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Galactic Penguin SST on 07/04/2015 01:18 pm
Just a quick question.   Are 2nd stages hot-fire tested anywhere in their life-cycle?

They have a separate hot fire stand for second stages at McGregor.  My understanding is that all stages are tested there, but there is a dearth of news about that process.

 - Ed Kyle

I thought they only test fire the second stage engines, but not the whole second stage?

Does anyone know the answer to this?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MechE31 on 07/05/2015 01:25 am
Just a quick question.   Are 2nd stages hot-fire tested anywhere in their life-cycle?

They have a separate hot fire stand for second stages at McGregor.  My understanding is that all stages are tested there, but there is a dearth of news about that process.

 - Ed Kyle

I thought they only test fire the second stage engines, but not the whole second stage?

Does anyone know the answer to this?

Engines are testing prior to integration with the stage and then the stage is test fired after integration.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: CuddlyRocket on 07/06/2015 09:14 pm
Black boxes will be incorporated into rockets eventually as it will be cheaper than arguing the point in court.

How can it be cheaper when there is no box to get data from?

The fact that there is no box when one could be straightforwardly added will eventually be a point of contention in court proceedings - 'what are they hiding?' etc. There may be other arguments; lawyers are imaginative. And persuasive; and it's lay jurors they need to persuade (in the US, anyway). Cost of black boxes versus cost of legal fees or worse, damages.

Maybe, if the reusability of boosters becomes commonplace. Expendable boosters court arguments have been decided for years based on telemetry.

Because they had no option; because even if there had been a black box you wouldn't get it back. But if reusability is commonplace, then you would and people (well, lawyers) will ask why you haven't enabled that opportunity.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: intrepidpursuit on 07/06/2015 09:35 pm
Black boxes will be incorporated into rockets eventually as it will be cheaper than arguing the point in court.

How can it be cheaper when there is no box to get data from?

The fact that there is no box when one could be straightforwardly added will eventually be a point of contention in court proceedings - 'what are they hiding?' etc. There may be other arguments; lawyers are imaginative. And persuasive; and it's lay jurors they need to persuade (in the US, anyway). Cost of black boxes versus cost of legal fees or worse, damages.

Maybe, if the reusability of boosters becomes commonplace. Expendable boosters court arguments have been decided for years based on telemetry.

Because they had no option; because even if there had been a black box you wouldn't get it back. But if reusability is commonplace, then you would and people (well, lawyers) will ask why you haven't enabled that opportunity.

I'm sure they'll also say stupid things like "safety is the first priority" and "as soon as possible" but the rocket engineers will design the rocket not the lawyers. They should have put a parachute on the IDA so it could be recovered. They should have programmed the dragon to arm the chutes in the case of failure and land in the middle of the ocean and put ships out there just in case.

Generally lawyers are going to listen to experts who know more than they do. Until they get elected anyway.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/06/2015 09:54 pm

The fact that there is no box when one could be straightforwardly added will eventually be a point of contention in court proceedings - 'what are they hiding?' etc. There may be other arguments; lawyers are imaginative. And persuasive; and it's lay jurors they need to persuade (in the US, anyway). Cost of black boxes versus cost of legal fees or worse, damages.


Wrong, because it is not straight forward.  A black box on orbit is useless.   And what contention or hiding what?  The telemetry is available and provides more information.  A black box would help CRS-7 investigation


Because they had no option; because even if there had been a black box you wouldn't get it back. But if reusability is commonplace, then you would and people (well, lawyers) will ask why you haven't enabled that opportunity.


Because reusability and need for black box are mutually exclusive.  There is no need for a black box on a returned stage.  The "need" arises when an incidence causes a stage not to return.  Since no returning stage, no black box. 

Any incident that happens to a booster stage is going to be in line of sight of the launch site and hence telemetry will cover it.   Upperstages is the real issue, incidences happen a hemisphere away or on orbit which makes a black box useless.  It is can be fixed by using relay satellites or down range tracking sites.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 07/07/2015 05:06 am
I don't see why the resistance.  It is not replacing telemetry.  It is on top of telemetry.  You're no longer bandwidth limited so can save more data, and can continue to function even when the telemetry signal is lost.

How many times telemetry was lost because of uncontrolled rotation and loss of telemetry signal?  How about just damage to the antenna?  How many mishaps occurred outside of ground telemetry ground stations?

Jetliner blackboxes today look like they did when they used physical closed-loop magnetic tape systems in them.  Except now the innards are now (gasp!) hard disks.  They are large and heavy.  They also assume the plane's exact position is unknown.

A 21st-century designed-from-scratch black box can contain a single memory chip, a beacon, a battery and can actually be made to float.  It can be attached practically outside the rocket, so that it will break free in case of immersion. Unlike jetliners, rockets are tracked.

I honestly don't see the downside.  Worst case, it'll have a copy of the data already received by telemetry, plus extra data that wouldn't fit in the telemetry channel.  Best case, it will make all the difference in the investigation since telemetry was lost.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JamesH on 07/07/2015 09:09 am
Because reusability and need for black box are mutually exclusive.  There is no need for a black box on a returned stage.  The "need" arises when an incidence causes a stage not to return.  Since no returning stage, no black box. 

Weird how airliners have them then.....as far as I know they are reusable. Why don't they just use telemetry?

Telemetry is bandwidth limited, black boxes are not. As devices get more and more channels of data, only some of which can fit down the pipe (I'm thinking video as a prime example), black boxes would appear to be a valid approach.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: kevinof on 07/07/2015 09:56 am
Because reusability and need for black box are mutually exclusive.  There is no need for a black box on a returned stage.  The "need" arises when an incidence causes a stage not to return.  Since no returning stage, no black box. 

Weird how airliners have them then.....as far as I know they are reusable. Why don't they just use telemetry?

Telemetry is bandwidth limited, black boxes are not. As devices get more and more channels of data, only some of which can fit down the pipe (I'm thinking video as a prime example), black boxes would appear to be a valid approach.

Aircraft are designed to depart and arrive in one piece so routing all the sensor cables/data to the box in the tail is simple engineering.

If you want to re-use  a black box on a Falcon then it has to be in a piece of the spacecraft that will return. This rules out Stage 2 so now the black box has to be in S1 or the Dragon. Now you have the added complexity of routing sensor data from stage to stage just so it can be fed into a black box. Seems like an overly complex arrangement to me.


Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rpapo on 07/07/2015 10:18 am
Telemetry is bandwidth limited, black boxes are not. As devices get more and more channels of data, only some of which can fit down the pipe (I'm thinking video as a prime example), black boxes would appear to be a valid approach.
From what I've seen in my own work, data can generally be transmitted faster than it can be stored to any sort of semi-permanent media, even SDRAM or solid-state drives, let alone tape or hard drives.  You can store data faster to RAM, but that data is lost when power is lost.

Amongst other reasons, airlines prefer black boxes because (1) they don't require constant monitoring and the associated costs of doing that, and (2) they already have them, however old they are, and are in no hurry to spend money replacing them.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/07/2015 11:28 am
A black box would not have helped the Progress problem.    The black box would have been stuck on orbit.  TDRSS could have helped the situation.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 07/07/2015 01:49 pm

From what I've seen in my own work, data can generally be transmitted faster than it can be stored to any sort of semi-permanent media, even SDRAM or solid-state drives, let alone tape or hard drives.  You can store data faster to RAM, but that data is lost when power is lost.

Amongst other reasons, airlines prefer black boxes because (1) they don't require constant monitoring and the associated costs of doing that, and (2) they already have them, however old they are, and are in no hurry to spend money replacing them.

We know the telemetry link is limited to ~1Mbs.  That's a tiny tiny stream.

Video is compressed and limited, and with 3000 data channels, their frequency can't be high. 

So in that respect, a black box will capture more data.

As for stages, F9 avionics are completely independent (per stage), so you'd have one black box per stage, IMO.

There is talk about adding telemtry to jetliners, and some maintenance systems already use it.  But there's no talk of eliminating the black boxes.

It's not a bad idea to add them. Whether it'll get done is a different issue of course, many more factors at play.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/07/2015 03:15 pm

1.  Weird how airliners have them then.....as far as I know they are reusable. Why don't they just use telemetry?

2.  Telemetry is bandwidth limited, black boxes are not. As devices get more and more channels of data, only some of which can fit down the pipe (I'm thinking video as a prime example), black boxes would appear to be a valid approach.

Wrong analogy.

1.  It has nothing to do with being reusable.  It has to do with flight altitude.  Telemetry is line of sight and early airliners were not even in voice contact with ground sites for most of their flights.  Rockets have used telemetry since they are in sight of ground stations during launch.  Aircraft are now going towards telemetry with the event of relay spacecraft just as launch vehicles are doing.

2.  More channels of data is useless if the box is not recovered.

Black box is really helping out MH370. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JamesH on 07/07/2015 03:51 pm

1.  Weird how airliners have them then.....as far as I know they are reusable. Why don't they just use telemetry?

2.  Telemetry is bandwidth limited, black boxes are not. As devices get more and more channels of data, only some of which can fit down the pipe (I'm thinking video as a prime example), black boxes would appear to be a valid approach.

Wrong analogy.

1.  It has nothing to do with being reusable.  It has to do with flight altitude.  Telemetry is line of sight and early airliners were not even in voice contact with ground sites for most of their flights.  Rockets have used telemetry since they are in sight of ground stations during launch.  Aircraft are now going towards telemetry with the event of relay spacecraft just as launch vehicles are doing.

2.  More channels of data is useless if the box is not recovered.

Black box is really helping out MH370.

Hmm. Did however help with the 4U 9525. And ValuJet Flight 592, and many others.

With regard to black boxes left in orbit, why is that a problem? New Horizons 'black box' is going to take a year to send back all its data after the Pluto flypast. Are you saying sending black box data back from orbit is more difficult?

Remember, this isn't an alternative to telemetry, far from it, merely an adjunct to it. A means of storing a lot more information for later transmission that is not possible over the bandwidth limited radio channels. I suspect its already done with some of the video stuff.

This is interesting, where they talk about streaming data from planes, but comment that the bandwidth is a problem. http://www.sciencetimes.com/articles/4865/20150326/germanwings-plane-crash-why-do-we-still-use-black-boxes.htm





Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/07/2015 04:12 pm

With regard to black boxes left in orbit, why is that a problem? New Horizons 'black box' is going to take a year to send back all its data after the Pluto flypast. Are you saying sending black box data back from orbit is more difficult?


This is not a discussion about recording science data for later playback.    Black boxes are for accident investigations.   Again, data from normal mission is basically meaningless.  Recording vehicle health data onboard for later playback is useless when the vehicle no longer exists or operating.   That is the reason for real time telemetry to transmitted, so that the data is available vs being destroyed with the vehicle or stuck onboard the vehicle.

NASA past practices on spacecraft were to store and forward engineering data that happened during critical events (not science passes).  This bit them in the arse three times before a agency requirement was made that all critical events shall be covered by telemetry.  The three times were Mars Observer (telemetry transmitter was shutdown before MOI burn).  CONTOUR performed an SRM burn outside of ground station coverage.  Mars Polar Lander didn't bother to transmit engineering data during EDL.  The NASA requirement extends to launch vehicle powered flight (all burns).

I am not against recording vehicle engineering data onboard for later playback.  It happens all the time.  But it is not analogous to an aircraft box, it is not designed to survive accidents and it does not replace real time telemetry.  The recorded data is mostly consists of payload interface and environments. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DigitalMan on 07/07/2015 04:59 pm

With regard to black boxes left in orbit, why is that a problem? New Horizons 'black box' is going to take a year to send back all its data after the Pluto flypast. Are you saying sending black box data back from orbit is more difficult?


This is not a discussion about recording science data for later playback.    Black boxes are for accident investigations.   Again, data from normal mission is basically meaningless.  Recording vehicle health data onboard for later playback is useless when the vehicle no longer exists or operating.   That is the reason for real time telemetry to transmitted, so that the data is available vs being destroyed with the vehicle or stuck onboard the vehicle.

NASA past practices on spacecraft were to store and forward engineering data that happened during critical events (not science passes).  This bit them in the arse three times before a agency requirement was made that all critical events shall be covered by telemetry.  The three times were Mars Observer (telemetry transmitter was shutdown before MOI burn).  CONTOUR performed an SRM burn outside of ground station coverage.  Mars Polar Lander didn't bother to transmit engineering data during EDL.  The NASA requirement extends to launch vehicle powered flight (all burns).

I am not against recording vehicle engineering data onboard for later playback.  It happens all the time.  But it is not analogous to an aircraft box, it is not designed to survive accidents and it does not replace real time telemetry.  The recorded data is mostly consists of payload interface and environments. 

It seems inevitable to me as we become a more connected world black boxes will become irrelevant.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 07/07/2015 05:22 pm
It seems inevitable to me as we become a more connected world black boxes will become irrelevant.

They will, <facetious> once the downlink will become more reliable than on-the-spot recording while an anomaly is going on. </facetious> 

"trust in the cloud" is good when everything is nominal and 99% is good enough, but less so when the building is on fire and by definition you're operating within the 1%.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DigitalMan on 07/07/2015 05:26 pm
It seems inevitable to me as we become a more connected world black boxes will become irrelevant.

They will, <facetious> once the downlink will become more reliable than on-the-spot recording while an anomaly is going on. </facetious> 

"trust in the cloud" is good when everything is nominal and 99% is good enough, but less so when the building is on fire and by definition you're operating within the 1%.

It is far more likely you will never get the reliable on the spot recording you speak of.  How are you going to guarantee you can get access to it?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JamesH on 07/08/2015 09:08 am
It seems inevitable to me as we become a more connected world black boxes will become irrelevant.

They will, <facetious> once the downlink will become more reliable than on-the-spot recording while an anomaly is going on. </facetious> 

"trust in the cloud" is good when everything is nominal and 99% is good enough, but less so when the building is on fire and by definition you're operating within the 1%.

It is far more likely you will never get the reliable on the spot recording you speak of.  How are you going to guarantee you can get access to it?

I think you have that the wrong way round. Which is more reliable, recording to a black box type device on the spot, or sending the data to a low bandwidth radio system in the hope it makes it to the other end of the transmission? Of course both might be unreliable in a RUD, which is why you really need immediate telemetry for critical stuff. But for other stuff like video.....It's all down to bandwidth. Radio has a limited bandwidth. There is no way you can send video from more than a few cameras in real time. If you have a device with a load of cameras in the only way to get that video to the ground is to store it and send later. Or recover the storage somehow.

A picture says a thousand words (2 thousand bytes), I wonder if fully video instrumented stages would be easier to diagnose when they fail?

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/08/2015 11:14 am

I think you have that the wrong way round. Which is more reliable, recording to a black box type device on the spot, or sending the data to a low bandwidth radio system in the hope it makes it to the other end of the transmission?


There is no debate. Telemetry is.   There is no "hope", it always makes it.  1000's of rocket launches have proven that.  Telemetry is working before launch.  Don't know if box is recording, if recording is not corrupted or again, if the box is not coming back.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/08/2015 11:16 am

A picture says a thousand words (2 thousand bytes), I wonder if fully video instrumented stages would be easier to diagnose when they fail?


Video can't see most of the problems.*  How much mass is left for payload after all the additional wiring, sensors, recorders etc?.  And again, doesn't do any good when the box doesn't come back.

* wouldn't see a piece of FOD or bad bearing on ORB-3.
wouldn't a failed open valve on Atlas V NRO mission
Wouldn't see improperly installed IMU's on Proton
Wouldn't see prop feedline cavitation on first Delta IV heavy flight
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JamesH on 07/08/2015 11:56 am

I think you have that the wrong way round. Which is more reliable, recording to a black box type device on the spot, or sending the data to a low bandwidth radio system in the hope it makes it to the other end of the transmission?


There is no debate. Telemetry is.   There is no "hope", it always makes it.  1000's of rocket launches have proven that.  Telemetry is working before launch.  Don't know if box is recording, if recording is not corrupted or again, if the box is not coming back.

Well, I do agree that telemetry is vital, what I am not convinced about is that a black box type devices doesn't have some additional benefits.  You can store a lot more information, more than can be transmitted by traditional means. And you might be able to recover it, or you could equip it with a post RUD transmitter to dump data after an event. Additional wiring and HW weight would be fairly minimal I suspect. Ethernet would do the job, or something like CANBus as used in cars to reduce their wiring load. Worthwhile? Dunno, depends if there is current more telemetry type information than available bandwidth and the systems currently pick and chose what to send down. One can presumably envisage many more sensors on a launcher than are current used, as technology to make cheaper and smaller sensors becomes commonplace (including video). One can also envisage that as rockets becomes reusable, the need for even fuller sensor sets to monitor areas previously unmonitored might be useful. Data can be dumped from black boxes on return to analyse areas of the rocket that prior to re usability would not need to be monitored. I would assume that SpaceX probably do something liek that already - cameras in the fairings for example were recovered from a beach. They are effectively doing 'black box' type work.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 07/08/2015 02:08 pm
This argument is going nowhere, and it's pointless: we already know that Elon is interested in developing a black box recorder for the Falcon rockets.  So the answer is "both".  You're both right.  Congratulations.  Telemetry for all the reasons Jim has said, and a black box, just in case it can be recovered, for all of the reasons the others have mentioned.

Can we let it rest now?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 07/08/2015 02:27 pm
It seems inevitable to me as we become a more connected world black boxes will become irrelevant.

They will, <facetious> once the downlink will become more reliable than on-the-spot recording while an anomaly is going on. </facetious> 

"trust in the cloud" is good when everything is nominal and 99% is good enough, but less so when the building is on fire and by definition you're operating within the 1%.

It is far more likely you will never get the reliable on the spot recording you speak of.  How are you going to guarantee you can get access to it?
Who needs a guarantee?  This is on top of telemetry, not instead.

It can't hurt.  It won't sneak into your data center in the middle of the night and destroy your telemetry data.

Instead, it will likely come in a day or two later, with more data, more (and higher rez, higher frame rate) video streams.

Again, often sensor data is more telling than video, but sometimes one holistic view tells the story that all your sensors missed.  This is on top, not instead.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/08/2015 02:41 pm
Last post on the matter

Telemetry is the "black box" and prime for accident resolution.

Onboard recorders are for maintenance and glitch resolution
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ClaytonBirchenough on 07/08/2015 02:46 pm
I don't understand the talk of black boxes wrt rockets.

It seems that a black box would only be needed in a failure. I can't imagine the effort that would be needed to find and recover the black box after your RUD and/or FTS activation. Keep in mind, we still don't know where Malaysian Airlines flight MH370 is. AND IT'S A WHOLE AIRPLANE.

Also, it's not like you don't know what's going on with your rocket via telemetry. If you don't, isn't the FTS activated? Telemetry is a constant flow I thought. No black box has been needed on rockets, and it would only be logical that it would be needed even less in the future with the advances in technology.

EDIT: What Jim said^^^
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 07/08/2015 02:53 pm
I don't understand the talk of black boxes wrt rockets.

It seems that a black box would only be needed in a failure. I can't imagine the effort that would be needed to find and recover the black box after your RUD and/or FTS activation. Keep in mind, we still don't know where Malaysian Airlines flight MH370 is. AND IT'S A WHOLE AIRPLANE.

Also, it's not like you don't know what's going on with your rocket via telemetry. If you don't, isn't the FTS activated? Telemetry is a constant flow I thought. No black box has been needed on rockets, and it would only be logical that it would be needed even less in the future with the advances in technology.

EDIT: What Jim said^^^

I'll join the movement.  Last post on this as well:

MH 370 is irrelevant.  It flew for hours without being tracked.  I also sank.

In contrast, you know where rocket debris are to within miles, and finding something that floats, and actively transmits is straight forward, even if it is physically small.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: philw1776 on 07/23/2015 01:58 am
I wonder if this is on the horizon as a Dragon enhancement?

http://www.nasa.gov/mission_pages/tdm/green/gpim_overview.html#.VbBJMBNVikp

"AF-M315E also is expected to improve overall vehicle performance. It boasts a higher density than hydrazine, meaning more of it can be stored in containers of the same volume. In addition, it delivers a higher specific impulse, or thrust delivered per given quantity of fuel, and has a lower freezing point, requiring less spacecraft power to maintain its temperature."

Easier handling also reduces costs, a high priority SpaceX objective.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rcoppola on 07/23/2015 02:22 am
They mention needing new tanks, valves and thrusters as well. So it doesn't appear to be something you could just use with current Dragon designs. If a commercial entity decided to use this, once proven, would they need to license the technology or would they need to purchase the tanks, thrusters and valves from Ball and/or AR, or does it just become an open source, new standard anyone can design and build to?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: TrevorMonty on 07/23/2015 03:08 am
IMHO it will find its way into Dragon but not anytime soon. SpaceX would have to develop a new set of thrusters, SuperDraco included. Low toxicity has a lot benefits especially for reusable vehicles.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rcoppola on 07/29/2015 01:10 am
http://forum.nasaspaceflight.com/index.php?topic=32983.msg1410807#msg1410807

In the slides posted in the above link, it shows a "Center Pusher" under the Mvac during stage sep.
I don't recall ever seeing that. I wonder if that was needed because of the new thrust profile and/or 2nd stage stretch. Was the bell extended along with the interstage requiring an additional guide or is it because the pushers along the interstage are no longer able to push the stretched 2nd stage without additional help. Or all of the above.

Has that ever been done before...this center line, internal pusher?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ugordan on 07/29/2015 12:43 pm
A central pusher sounds like a kludge to me.

Anyway, any idea what provider Gerst had in mind here?
Quote
Gerst: One commercial crew provider wanted to load propellant with crew on-board rocket. We’re not comfortable, we'll have to work that out.

source: https://twitter.com/StephenClark1/status/626103867697008640

SpaceX and their LOX densification consequences?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: clongton on 07/29/2015 01:57 pm
So does anyone have information on this center pusher?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 07/29/2015 02:12 pm
A central pusher sounds like a kludge to me.

Anyway, any idea what provider Gerst had in mind here?
Quote
Gerst: One commercial crew provider wanted to load propellant with crew on-board rocket. We’re not comfortable, we'll have to work that out.

source: https://twitter.com/StephenClark1/status/626103867697008640

SpaceX and their LOX densification consequences?
As I understand it, all US crewed rockets to date have loaded propellant with the crew on-board. (EDIT: see below.)  This ensures that the pad abort system can lift them clear in case of any problem.  The alternative is to have the crew approach what is in effect a loaded bomb.  There is a period during which they are ingressing and it unsafe to use pad abort.

I don't know why NASA has suddenly become uncomfortable with the status quo ante, but it seems to have surprised SpaceX as well.  They are apparently in negotiations, it's not clear which side will prevail (they both presumably have solid safety-related reasons for doing things their way, although I can't argue the NASA side).

EDIT: I'm wrong about the status quo ante; Jim corrects me below.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/29/2015 02:17 pm

As I understand it, all US crewed rockets to date have loaded propellant with the crew on-board.  This ensures that the pad abort system can lift them clear in case of any problem.  The alternative is to have the crew approach what is in effect a loaded bomb.  There is a period during which they are ingressing and it unsafe to use pad abort.

I don't know why NASA has suddenly become uncomfortable with the status quo ante, but it seems to have surprised SpaceX as well.  They are apparently in negotiations, it's not clear which side will prevail (they both presumably have solid safety-related reasons for doing things their way, although I can't argue the NASA side).

No, all US crewed rockets (at least, Shuttle, Saturn, Redstone and Titan) have loaded propellants before the crew was onboard.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/29/2015 02:24 pm
I don't want to argue with Jim, but
http://quest.nasa.gov/qna/questions/FAQ_Shuttle_Launch.htm#How_long_before_liftoff indicates the ET is fueled after crew ingress.

That is blatantly wrong.  The ET is in stable replenish before the crew boards. 
Edit:

https://en.wikipedia.org/wiki/Space_shuttle_launch_countdown#T-3_hours_and_holding
http://www.nasa.gov/mission_pages/shuttle/launch/countdown101.html

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 07/29/2015 02:31 pm
Well, arguing with Jim is always a great way to learn something!

I confirmed that Saturn V (at least) also fueled before ingress (http://history.nasa.gov/ap11fj/01launch.htm).  So I'm wrong about "how it's always been done".  I swore I read that somewhere on this fine site, but I guess I misremembered.

*Anyway*, I think the reasoning is still that pad abort can take you away during any fueling problem.  The argument against is just that the astronauts don't like to sit in the cabin for so long?  (Although I think the SpaceX plan is to greatly speed up the fueling process as well, part of their quick-turnaround goals.). Jim can probably elaborate on the case for late ingress better than I can.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 07/29/2015 02:38 pm
Any issues with prop load would be resolved before the crew gets onboard.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rcoppola on 07/29/2015 03:44 pm
A central pusher sounds like a kludge to me.

Anyway, any idea what provider Gerst had in mind here?
Quote
Gerst: One commercial crew provider wanted to load propellant with crew on-board rocket. We’re not comfortable, we'll have to work that out.

source: https://twitter.com/StephenClark1/status/626103867697008640

SpaceX and their LOX densification consequences?
That's the first thing I thought as well. 

How long, once filled, can the tanks, chillers, pumps, valves, etc. maintain the desired fuel density? Is there enough Pad LOX - RP1 to deal with an additional couple hours(?) for crew ingress to be complete?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JasonAW3 on 07/29/2015 03:47 pm
Any issues with prop load would be resolved before the crew gets onboard.

Jim, correct me if I'm wrong here, but to my memory, NASA has never loaded any crews on any rockets for launches while they were unfueled.  I think that there may have been some unfueled practice runs, but never any unfueled for an actual launch.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: chipguy on 07/29/2015 04:35 pm
I wonder if this is on the horizon as a Dragon enhancement?

http://www.nasa.gov/mission_pages/tdm/green/gpim_overview.html#.VbBJMBNVikp

Easier handling also reduces costs, a high priority SpaceX objective.

This appears to be a green monopropellant substitute for hydrazine used as a monopropellant.

Either would represent a noticeable drop in ISP from current hypergolic bipropellants SpaceX uses although it would simplify plumbing and tankage.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cambrianera on 07/29/2015 05:02 pm
So does anyone have information on this center pusher?
They tried it on CRS-7; didn‘t worked well...
Also done on the wrong stage.
;)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: philw1776 on 07/29/2015 05:43 pm
I wonder if this is on the horizon as a Dragon enhancement?

http://www.nasa.gov/mission_pages/tdm/green/gpim_overview.html#.VbBJMBNVikp

Easier handling also reduces costs, a high priority SpaceX objective.

This appears to be a green monopropellant substitute for hydrazine used as a monopropellant.

Either would represent a noticeable drop in ISP from current hypergolic bipropellants SpaceX uses although it would simplify plumbing and tankage.

Per the article I cited...

"AF-M315E also is expected to improve overall vehicle performance. It boasts a higher density than hydrazine, meaning more of it can be stored in containers of the same volume. In addition, it delivers a higher specific impulse, or thrust delivered per given quantity of fuel"
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 07/29/2015 06:15 pm
I wonder if this is on the horizon as a Dragon enhancement?

http://www.nasa.gov/mission_pages/tdm/green/gpim_overview.html#.VbBJMBNVikp

Easier handling also reduces costs, a high priority SpaceX objective.

This appears to be a green monopropellant substitute for hydrazine used as a monopropellant.

Either would represent a noticeable drop in ISP from current hypergolic bipropellants SpaceX uses although it would simplify plumbing and tankage.

Per the article I cited...

"AF-M315E also is expected to improve overall vehicle performance. It boasts a higher density than hydrazine, meaning more of it can be stored in containers of the same volume. In addition, it delivers a higher specific impulse, or thrust delivered per given quantity of fuel"


I wonder what that means though. Do they compare to hydrazin which is relatively low energy or with modern hydrazin derivates like UDMH?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: darkenfast on 07/30/2015 09:02 am
The fuel after loading thing was brought up on the Pad 39A thread.  Someone on a tour wrote that SpaceX said that NASA wanted to fuel after loading the crew.  One or another got reversed here. Curious.

Edit.  Here's the post: http://forum.nasaspaceflight.com/index.php?topic=36100.msg1391389#msg1391389
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: acsawdey on 07/30/2015 03:06 pm
I wonder if this is on the horizon as a Dragon enhancement?

http://www.nasa.gov/mission_pages/tdm/green/gpim_overview.html#.VbBJMBNVikp

Easier handling also reduces costs, a high priority SpaceX objective.

This appears to be a green monopropellant substitute for hydrazine used as a monopropellant.

Either would represent a noticeable drop in ISP from current hypergolic bipropellants SpaceX uses although it would simplify plumbing and tankage.

Per the article I cited...

"AF-M315E also is expected to improve overall vehicle performance. It boasts a higher density than hydrazine, meaning more of it can be stored in containers of the same volume. In addition, it delivers a higher specific impulse, or thrust delivered per given quantity of fuel"


I wonder what that means though. Do they compare to hydrazin which is relatively low energy or with modern hydrazin derivates like UDMH?

The Isp of this stuff as a monopropellant is apparently around 261:

https://technology.grc.nasa.gov/sbir-competencies/han-monopropellant-propulsion.shtm (https://technology.grc.nasa.gov/sbir-competencies/han-monopropellant-propulsion.shtm)

That's getting pretty close to UDMH+N2O4 which is around 280 (ideally). SuperDraco Isp is given as 235, probably due to low chamber pressure and relatively low expansion. So it seems like a system based on this could be designed to replace SuperDraco. It might require higher chamber pressure to get to the same Isp.

The issue I have with the stuff is that it's essentially an explosive. While there is less toxicity hazard than UDMH/N2O4, there might be more danger of runaway decomposition or detonation if there are contaminants in the propellant system.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mhlas7 on 07/30/2015 03:26 pm
Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 07/30/2015 03:31 pm
Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?

Would it be a good idea to have different launch procedures? I really don't know.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mhlas7 on 07/30/2015 03:38 pm
Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?

Would it be a good idea to have different launch procedures? I really don't know.

The procedures for a crewed launch are going to be much different than an un-crewed launch anyway. Or would this be to much of a change in procedure?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rpapo on 07/30/2015 06:22 pm
Just how long does fuel remain densified (i.e. really cold) once it is pumped into the tanks?  Those tanks are typically not very well insulated.  Is there a way to keep the fuel really cold for hours on the pad?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ClaytonBirchenough on 07/30/2015 06:41 pm
Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?

I think Dragon V2 crewed flights might require a different ascent profile that might possibly include throttling to limit g forces... more gravity losses(?). Also, a crewed Dragon V2 masses more IIRC.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MP99 on 07/31/2015 02:29 pm
Just how long does fuel remain densified (i.e. really cold) once it is pumped into the tanks?  Those tanks are typically not very well insulated.  Is there a way to keep the fuel really cold for hours on the pad?

Today, we're used to vehicles venting GOX on the pad (and this is replenished by fill at the bottom of the tank).

In future, I suspect that there will be a higher rate of top-up at the base of the tank, with warmer liquid extracted from the top of the tank. As long as the liquid remains stratified, that will remove the warmest liquid (which may still be well below boiling point).

cheers, Martin
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: AnalogMan on 07/31/2015 10:13 pm
So does anyone have information on this center pusher?

Not really any more information, but better images of the center pusher and interstage pusher images from the slides posted in http://forum.nasaspaceflight.com/index.php?topic=32983.msg1410807#msg1410807 (http://forum.nasaspaceflight.com/index.php?topic=32983.msg1410807#msg1410807)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: philw1776 on 07/31/2015 11:29 pm
I wonder if this is on the horizon as a Dragon enhancement?

http://www.nasa.gov/mission_pages/tdm/green/gpim_overview.html#.VbBJMBNVikp

Easier handling also reduces costs, a high priority SpaceX objective.

This appears to be a green monopropellant substitute for hydrazine used as a monopropellant.

Either would represent a noticeable drop in ISP from current hypergolic bipropellants SpaceX uses although it would simplify plumbing and tankage.

Per the article I cited...

"AF-M315E also is expected to improve overall vehicle performance. It boasts a higher density than hydrazine, meaning more of it can be stored in containers of the same volume. In addition, it delivers a higher specific impulse, or thrust delivered per given quantity of fuel"


I wonder what that means though. Do they compare to hydrazin which is relatively low energy or with modern hydrazin derivates like UDMH?

This source lists hydrazine and UDMH

http://www.braeunig.us/space/propel.htm

Hydrazine has slightly higher ISP and higher energy density.  Hydrazine is widely used today.

So the NASA green propellant initiatiave being an improvement on hydrazine is a real plus.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Comga on 08/02/2015 06:37 pm
I wonder if this is on the horizon as a Dragon enhancement?
http://www.nasa.gov/mission_pages/tdm/green/gpim_overview.html#.VbBJMBNVikp (http://www.nasa.gov/mission_pages/tdm/green/gpim_overview.html#.VbBJMBNVikp)

Easier handling also reduces costs, a high priority SpaceX objective.

This appears to be a green monopropellant substitute for hydrazine used as a monopropellant.

Either would represent a noticeable drop in ISP from current hypergolic bipropellants SpaceX uses although it would simplify plumbing and tankage.

Per the article I cited...

"AF-M315E also is expected to improve overall vehicle performance. It boasts a higher density than hydrazine, meaning more of it can be stored in containers of the same volume. In addition, it delivers a higher specific impulse, or thrust delivered per given quantity of fuel"


I wonder what that means though. Do they compare to hydrazin which is relatively low energy or with modern hydrazin derivates like UDMH?

This source lists hydrazine and UDMH

http://www.braeunig.us/space/propel.htm (http://www.braeunig.us/space/propel.htm)

Hydrazine has slightly higher ISP and higher energy density.  Hydrazine is widely used today.

So the NASA green propellant initiative being an improvement on hydrazine is a real plus.

This is the propellant for the Green Propellant Infusion Mission (https://en.wikipedia.org/wiki/Green_Propellant_Infusion_Mission).  There are reasons for SpaceX NOT to incorporate it into Dragon.  It is not yet proven, and the hardware is experiencing difficulties.  It could be just a matter of time and effort, but it is not yet ready.

One could have said similar things about ISP's NoFBX, which looked real good, even getting manifested for a launch to the ISS, but has since faded due to technical difficulties.   
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: kch on 08/02/2015 06:53 pm

The Isp of this stuff as a monopropellant is apparently around 261:

https://technology.grc.nasa.gov/sbir-competencies/han-monopropellant-propulsion.shtm (https://technology.grc.nasa.gov/sbir-competencies/han-monopropellant-propulsion.shtm)

That's getting pretty close to UDMH+N2O4 which is around 280 (ideally). SuperDraco Isp is given as 235, probably due to low chamber pressure and relatively low expansion. So it seems like a system based on this could be designed to replace SuperDraco. It might require higher chamber pressure to get to the same Isp.

The issue I have with the stuff is that it's essentially an explosive. While there is less toxicity hazard than UDMH/N2O4, there might be more danger of runaway decomposition or detonation if there are contaminants in the propellant system.

That could be "mildly off-putting", I suppose.  ;D
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Roy_H on 08/12/2015 07:15 am
...
https://technology.grc.nasa.gov/sbir-competencies/han-monopropellant-propulsion.shtm (https://technology.grc.nasa.gov/sbir-competencies/han-monopropellant-propulsion.shtm)

...

The issue I have with the stuff is that it's essentially an explosive. While there is less toxicity hazard than UDMH/N2O4, there might be more danger of runaway decomposition or detonation if there are contaminants in the propellant system.

From the article:
"... However, HAN-based monopropellants require higher chamber temperatures (2,083 K vs. 883 K) to combust. Current hydrazine-based combustion chamber technology (Inconel® or niobium C103 and silicide coating) and catalyst (Shell 405) are inadequate. "

Says requires higher temperatures to combust, but you claim it can combust with contaminants or via decomposition. Is there any article to support this? How do you know that? I do agree that handling would have to insure there would be no spark generated by static electricity.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: acsawdey on 08/12/2015 03:12 pm
From the article:
"... However, HAN-based monopropellants require higher chamber temperatures (2,083 K vs. 883 K) to combust. Current hydrazine-based combustion chamber technology (Inconel® or niobium C103 and silicide coating) and catalyst (Shell 405) are inadequate. "

Says requires higher temperatures to combust, but you claim it can combust with contaminants or via decomposition. Is there any article to support this? How do you know that? I do agree that handling would have to insure there would be no spark generated by static electricity.

Here's a report on HAN stability from a while back:

http://www.dtic.mil/dtic/tr/fulltext/u2/a212896.pdf

It appears that iron and copper ions are a major contributor to slow decomposition, which evolves NO and NO2.  You don't want to have to vent gasses from the tank on orbit, nor do you want to discover that your thruster fuel has turned into unreactive sludge. Nor do you want to discover that some decomposition reaction produces some kind of insoluble nitrate compound whose crystals are likely to detonate.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: SVBarnard on 08/30/2015 06:49 am
So let me get this straight here. The Dragon V2 is complete now, I mean its been constructed, they tested it's launch escape system and it worked. Their rocket is already complete too. As far I understand  Boeing's capsule is already complete and its launch escape system has been tested too. What I am trying to say is these vehicles are all complete now, like 99% done.

So why all this bickering about CCDev being underfunded!!! Spacex could literally launch people to the ISS on their Dragon V1 but all it needs is a launch escape system which they've built and tested successfully. For Christ's sakes its a fully completed and fully functioning spaceship ready for manned flight, its ready to go!

The CCDev program was given 696 million dollars for just two companies (SpaceX and Boeing) for 2014, and this year they've been given a whopping 805 million dollars (and they'll certainly get more than 805 million next year)! And that's not enough money (even though their fricking capsules are complete)?

Wasn't the Falcon 9 rocket designed and built on just 300 million dollars? I mean isn't that what makes Elon Musk so special his ability to get things done for a fraction of the cost?

Now please I just stuck my neck out here and feel free to roast me but Im pretty sure I've made a valid point here?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 08/30/2015 07:01 am
Now please I just stuck my neck out here and feel free to roast me but Im pretty sure I've made a valid point here?

It is somewhat more complicated than that. A lot of requirements need to be satisfied before anything can fly with crew. The designs that flew were more like prototypes with limited fidelity to the final project, not the completed designs.

But let me join you and get roasted with you. What takes a lot of time and money is the deep reaching oversight and control by NASA under the chosen type of contract. Let NASA step aside and pull the stops out things could move faster. But still components like the ECLSS, the spacesuit, the software, the control panels need to be developed to flight readyness, then integrated in the capsule and flown in tests. It does take time.

Edit: and money.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 08/30/2015 12:05 pm
So let me get this straight here. The Dragon V2 is complete now,
snip
Boeing's capsule is already complete and its launch escape system has been tested too.

What I am trying to say is these vehicles are all complete now, like 99% done.



No, no and no.  They still have a lot of work to do.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 08/30/2015 04:06 pm
So let me get this straight here. The Dragon V2 is complete now,
snip
Boeing's capsule is already complete and its launch escape system has been tested too.

What I am trying to say is these vehicles are all complete now, like 99% done.



No, no and no.  They still have a lot of work to do.
Lots of hardware to be done, but I think it's hard for most to grasp the magnitude of non hardware work. Analysis, software, qualification, paperwork and a dozen other things Jim could list in a minute. A NASA accepted manned platform is a whole different ballgame than a cargo capsule. Being qualified to dock instead of being berthed alone must be huge bit of work.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nadreck on 08/30/2015 05:13 pm
So let me get this straight here. The Dragon V2 is complete now,
snip
Boeing's capsule is already complete and its launch escape system has been tested too.

What I am trying to say is these vehicles are all complete now, like 99% done.



No, no and no.  They still have a lot of work to do.
Lots of hardware to be done, but I think it's hard for most to grasp the magnitude of non hardware work. Analysis, software, qualification, paperwork and a dozen other things Jim could list in a minute. A NASA accepted manned platform is a whole different ballgame than a cargo capsule. Being qualified to dock instead of being berthed alone must be huge bit of work.

The hard part to grasp is which non hardware work must be completed before some hardware work that has gating items that can't be completed until that non hardware work can be done. In other words could they physically build something that works and have it ready to fly far sooner and just have the paper work to do? The answer is that if they did it would take longer, and cost even more, because many non-hardware items, when completed would cause changes to the hardware if they just went ahead and 'did' the hardware while waiting for the paperwork to 'catch up'.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rcoppola on 08/30/2015 05:21 pm
SVBarnard... In all reality, as of today, neither CST or Dragon are anywhere near 99% done. In fact, technically speaking, neither vehicle actually exists in anything approaching a fully integrated, Human Flight Worthy vehicle. Also true for their current HSF capable pad infrastructures.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: SVBarnard on 08/31/2015 04:01 am
Ok let me get this straight. What do you need in order to send people to space? You need a rocket, check (spacex has one), then you need some sort of spacecraft, check (spacex also already has one). I will say it again the Dragon has routinely gone and docked with the ISS many times, Elon says they could put someone in it and they'd survive just fine but it needs a launch escape system for which they've already designed, built, and certified. The hardware is 99% complete if you ask me. All the Dragon V2 is is a Dragon with boosters as it's LAS, and they already know they can dock it with the ISS no problem.

Plus the Falcon 9 was designed and built for 300 million and which do you think costs more a rocket or a space capsule? So if the Falcon 9 only cost them a 300 million then how much do they need just to build a simple space capsule? Apparently the hundreds of millions of dollars they have already received and the hundreds of million of dollars they'll continue to get just isn't enough.

I guess it takes not millions but billions of dollars just to man rate a capsule? Seems ludicrous to me.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 08/31/2015 06:11 am
I guess it takes not millions but billions of dollars just to man rate a capsule? Seems ludicrous to me.

It is ludicrous. However that happens when NASA is in the drivers seat. In their own estimate they calculated a NASA development program costs 5 to 10 times as much. And with the amount of oversight that the contracts require it is mostly a NASA style development. Good for SpaceX though as it is a great learning exercise paid for by Congress. If they fund it. :(

You do underestimate the time needed though IMO. It is a complex development. Unless you are in a desaster movie scenario and cut corners in the extreme taking some risks. A timeframe till some time 2017 is realistic.

Edit: fixed typo
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: douglas100 on 08/31/2015 08:22 am

Ok let me get this straight. What do you need in order to send people to space? You need a rocket, check...

Which won't be flying again until the cause of the failure is fixed. There's your first delay. And that the F9 was apparently brought down by an extremely unlikely failure should give you pause. Seemingly tiny details can kill you in this game. You've got to pay attention to them and that costs time and money.

Quote
I will say it again the Dragon has routinely gone and docked with the ISS many times...

No it hasn't, not once. It has berthed. Dragon 2 will use a completely different docking system. How do you know it is ready? The adaptors are not even on the ISS yet.

Quote
The hardware is 99% complete if you ask me...

You don't know that. Nor do you know the state of hardware and software testing. A small pointer: the Dragon which did the abort test was a modified Dragon 1. It wasn't an operational vehicle.

Guckyfan got it right:

Quote
You do underestimate the time needed though IMO. It is a complex development. Unless you are in a disaster movie scenario and cut corners in the extreme taking some risks. A timeframe till some time 2017 is realistic.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Chris Bergin on 08/31/2015 11:08 am
We've left this thread as-is because it's clear a member is being educated on a topic, which is good and totally allowed. I concur this member should have done a bit of reading before jumping in feet first, but it's beneficial for people who may be reading this, and are brand new to the subject, to see the answers and not make the same mistake.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 08/31/2015 12:16 pm
, then you need some sort of spacecraft, check (spacex also already has one). I will say it again the Dragon has routinely gone and docked with the ISS many times, Elon says they could put someone in it and they'd survive just fine but it needs a launch escape system for which they've already designed, built, and certified. The hardware is 99% complete if you ask me. All the Dragon V2 is is a Dragon with boosters as it's LAS, and they already know they can dock it with the ISS no problem.

Dragon 2 is not a Dragon with LAS. 
A. It has a different outer moldline
B.  It has a life support system
C. It has crew displays and controls.
D.  It has crew accommodations
E. It has an LAS.
F. It has landing gear
G.  It has a different parachute system
H. It has a docking system

So no, it is far from"99% composer's. And it is a wrong characterization that NASA processes are slowing it down and adding cost.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 08/31/2015 01:42 pm
, then you need some sort of spacecraft, check (spacex also already has one). I will say it again the Dragon has routinely gone and docked with the ISS many times, Elon says they could put someone in it and they'd survive just fine but it needs a launch escape system for which they've already designed, built, and certified. The hardware is 99% complete if you ask me. All the Dragon V2 is is a Dragon with boosters as it's LAS, and they already know they can dock it with the ISS no problem.

Dragon 2 is not a Dragon with LAS. 
A. It has a different outer moldline
B.  It has a life support system
C. It has crew displays and controls.
D.  It has crew accommodations
E. It has an LAS.
F. It has landing gear
G.  It has a different parachute system
H. It has a docking system

So no, it is far from"99% composer's. And it is a wrong characterization that NASA processes are slowing it down and adding cost.

To expend on Jim's answer:
A. The aeroshape is different and has required lot's and lot's of additional computational modeling and windtunnel testing.

B. Dragon 1 (the cargo Dragon) has no life support system. The ECLSS for Dragon 2 is all new and still in development

C. Dragon 1 does not have crew displays and controls. Both are still in development for Dragon 2, very much software related. Much work (testing and ironing out the bugs) still to do.

D. Dragon 1 does not have crew accommodations such as seats, restraints, pressure suits and personal hygiene facilities. Most of those are still in development and testing for Dragon 2.

E. Dragon 1 had no LAS. The LAS for Dragon 2 has flown once, successfully, but requires another flight test (ascent abort test) to be fully certified. Modifications will be made to the LAS, based on the results of the pad-abort LAS test. And those mods will require another round of test-firing of the SuperDracos at McGregor.

F. Dragon 1 has no landing gear. Dragon 2 is designed to have one, but the design is, as of yet, not final. It will require multiple DragonFly tests at McGregor to validate and complete the design.

G. Like Dragon 1, the Dragon 2 has a parachute system. But the system on Dragon 2 is different. That has already resulted in an additional test to verify the proper functioning of the parachute system of Dragon 2. That particular test took place even before the pad-abort test.

H. Dragon 1 does not dock. It flies up to the ISS and closes to about 10 meters distance. It is then grabbed by the ISS robotic arm which then berths the Dragon 1 to a CBM berthing port (not docking port). Dragon 2, on the other hand, will fly autonomously (no help required from the ISS robotic arm) to a docking port and make the connenction all by itself. This requires a docking port on the spacecraft, as well as a whole suit of sensors and software that are not present on Dragon 1.
It also requires a suitable docking port on the ISS. And that is currently also lacking. So, even if Dragon 2 was good to go to ISS right now, it still could not dock.

I. This one Jim didn't comment about: Dragon 2 has a different trunk then Dragon 1.

J. The launchpad for Dragon 2 becomes ready for crewed operations only in 2016.

K. Most of the procedures to be applied to operating a manned spacecraft are still in draft. More paperwork and simulations for SpaceX yet to be finished.


Also, one of the most important steps on the road to certification for human flight, of Dragon 2, is yet to be passed by SpaceX: the Dragon 2 Critical Design Review.

In short: the design of Dragon 2 - and all of it's associated aspects -  is not yet fixed and still in flux. As such, there is no such thing as a spacecraft that is 99% ready. Far from it.
A similar situation applies to the Boeing CST-100.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Callezetter on 08/31/2015 01:59 pm
AIAA Space 2015 Livestream starting in an hour (8am PDT) with Shotwell in the first panel
named "Crystal Ball - Executive Vision Discussion"

http://livestream.com/AIAAvideo/SPACE2015
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: edkyle99 on 08/31/2015 02:05 pm
Ok let me get this straight. What do you need in order to send people to space? You need a rocket, check (spacex has one) ....
Sorry if someone has already mentioned this, but SpaceX has not yet flown the Falcon 9 variant that is expected to launch Dragon 2.  This rocket, which is usually unofficially called "Falcon 9 v1.2", will use a stretched second stage and a first stage powered by "full thrust" Merlin engines.  It has to fly repeatedly and successfully before it will be allowed to carry human cargo.  The first one may launch this year, but that remains to be seen given the typical duration of launch vehicle failure investigations. 

About that failure, it really did happen, on June 28 of this year.  Falcon 9 has been successful and has a chance to prove reliable in the long run, but right now it is not ready to carry humans.

 - Ed Kyle
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: savuporo on 08/31/2015 03:09 pm
About that failure, it really did happen, on June 28 of this year.  Falcon 9 has been successful and has a chance to prove reliable in the long run, but right now it is not ready to carry humans.

 - Ed Kyle
I wonder how long of a run this will have to become. In this century, will anyone put people on top of the rocket with a lucky streak of about 10 launches ?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 08/31/2015 03:44 pm
About that failure, it really did happen, on June 28 of this year.  Falcon 9 has been successful and has a chance to prove reliable in the long run, but right now it is not ready to carry humans.

 - Ed Kyle
I wonder how long of a run this will have to become. In this century, will anyone put people on top of the rocket with a lucky streak of about 10 launches ?
NASA is planning to put people on a rocket that will have lanched less than half a dozen times.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Danny Dot on 08/31/2015 04:13 pm
Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?

I think Dragon V2 crewed flights might require a different ascent profile that might possibly include throttling to limit g forces... more gravity losses(?). Also, a crewed Dragon V2 masses more IIRC.

NASA Standard 3000 says the crew can take 14 G's on ascent.  I don't know why people think the crew can't take this.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Herb Schaltegger on 08/31/2015 05:37 pm
NASA Standard 3000 says the crew can take 14 G's on ascent.  I don't know why people think the crew can't take this.

NASA-STD-3000 is probably superseded here by specific requirements set forth in the commercial crew requirements and contracts.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Raj2014 on 08/31/2015 05:39 pm
Any news on when SpaceX CRS-8 will launch?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: AncientU on 08/31/2015 05:57 pm
About that failure, it really did happen, on June 28 of this year.  Falcon 9 has been successful and has a chance to prove reliable in the long run, but right now it is not ready to carry humans.

 - Ed Kyle
I wonder how long of a run this will have to become. In this century, will anyone put people on top of the rocket with a lucky streak of about 10 launches ?
NASA is planning to put people on a rocket that will have lanched less than half a dozen times.

Much less...
The original plan was one 'lucky' launch. 
Maybe two or three tops now.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ggr on 08/31/2015 06:06 pm
About that failure, it really did happen, on June 28 of this year.  Falcon 9 has been successful and has a chance to prove reliable in the long run, but right now it is not ready to carry humans.

 - Ed Kyle
I wonder how long of a run this will have to become. In this century, will anyone put people on top of the rocket with a lucky streak of about 10 launches ?
NASA is planning to put people on a rocket that will have lanched less than half a dozen times.

By comparison, the Saturn 5 launched a total of 13 times, only the first two were not crewed.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nadreck on 08/31/2015 06:06 pm
About that failure, it really did happen, on June 28 of this year.  Falcon 9 has been successful and has a chance to prove reliable in the long run, but right now it is not ready to carry humans.

 - Ed Kyle
I wonder how long of a run this will have to become. In this century, will anyone put people on top of the rocket with a lucky streak of about 10 launches ?
NASA is planning to put people on a rocket that will have lanched less than half a dozen times.

Much less...
The original plan was one 'lucky' launch. 
Maybe two or three tops now.
How much commonality will there be between each vehicle that flies up to and including the launch?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rsnellen4 on 08/31/2015 06:15 pm

By comparison, the Saturn 5 launched a total of 13 times, only the first two were not crewed.
And the last one... (Skylab)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Vultur on 09/01/2015 01:01 am
NASA is planning to put people on a rocket that will have lanched less than half a dozen times.

SLS will have one flight before EM-2, right? Or is there something else planned between EM-1 and EM-2?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 09/01/2015 06:59 am
NASA is planning to put people on a rocket that will have lanched less than half a dozen times.

SLS will have one flight before EM-2, right? Or is there something else planned between EM-1 and EM-2?

Just noting that one or two is also "less than half a dozen".....

Watercooler-talk has it that NASA is looking at launching at least one cargo mission in between EM-1 and the first manned SLS-Orion mission. Particularly ASAP and the astronaut office are not keen on flying the first manned SLS-Orion mission on an unproven new upperstage (EUS). This because EM-1 flies with a modified DCSS stage (known as iCPS) and the first manned SLS-Orion mission is tentavily slated for EUS.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: darkenfast on 09/01/2015 07:06 am
Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?

I think Dragon V2 crewed flights might require a different ascent profile that might possibly include throttling to limit g forces... more gravity losses(?). Also, a crewed Dragon V2 masses more IIRC.

NASA Standard 3000 says the crew can take 14 G's on ascent.  I don't know why people think the crew can't take this.
Are you sure that isn't referring to abort system loads?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JamesH on 09/01/2015 09:16 am
Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?

I think Dragon V2 crewed flights might require a different ascent profile that might possibly include throttling to limit g forces... more gravity losses(?). Also, a crewed Dragon V2 masses more IIRC.

NASA Standard 3000 says the crew can take 14 G's on ascent.  I don't know why people think the crew can't take this.


Modern fighter pilots with G suits can take about 9g before passing out. 14G is a LOT more than a human can sustainably ensure. 15g for a minute could easily kill you.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 09/01/2015 12:02 pm
Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?

I think Dragon V2 crewed flights might require a different ascent profile that might possibly include throttling to limit g forces... more gravity losses(?). Also, a crewed Dragon V2 masses more IIRC.

NASA Standard 3000 says the crew can take 14 G's on ascent.  I don't know why people think the crew can't take this.


Modern fighter pilots with G suits can take about 9g before passing out. 14G is a LOT more than a human can sustainably ensure. 15g for a minute could easily kill you.

The 14G number is for ascent abort scenario's lasting a very short time (mere seconds). I fully agree with you that sustained high G-levels will cause major injuries and possibly death.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nadreck on 09/01/2015 03:54 pm



Modern fighter pilots with G suits can take about 9g before passing out. 14G is a LOT more than a human can sustainably ensure. 15g for a minute could easily kill you.

The 14G number is for ascent abort scenario's lasting a very short time (mere seconds). I fully agree with you that sustained high G-levels will cause major injuries and possibly death.
The fighter pilot will lose consciousness at 9G because his orientation is such that the blood pools lower in his body and circulates "uphill" poorly. Lying on your back with slightly flexed legs works the best and has been tested with sustained accelerations over 15g by test pilots in the late 50's and early 60's.  Notice that all manned launches have the crew experiencing the acceleration in a supine position not sitting upright like a fighter pilot.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JamesH on 09/02/2015 10:54 am



Modern fighter pilots with G suits can take about 9g before passing out. 14G is a LOT more than a human can sustainably ensure. 15g for a minute could easily kill you.

The 14G number is for ascent abort scenario's lasting a very short time (mere seconds). I fully agree with you that sustained high G-levels will cause major injuries and possibly death.
The fighter pilot will lose consciousness at 9G because his orientation is such that the blood pools lower in his body and circulates "uphill" poorly. Lying on your back with slightly flexed legs works the best and has been tested with sustained accelerations over 15g by test pilots in the late 50's and early 60's.  Notice that all manned launches have the crew experiencing the acceleration in a supine position not sitting upright like a fighter pilot.

How long is 'sustained' in this case. Seconds? Minutes? Done in a centrifuge I pressume?

That notwithstanding, 15G for any length of time is going to leave the human involved incapacitated for some time, if not borderline dead.

EDIT: Some Wikipedia data https://en.wikipedia.org/wiki/G-force#Horizontal_axis_g-force
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 09/02/2015 01:03 pm



Modern fighter pilots with G suits can take about 9g before passing out. 14G is a LOT more than a human can sustainably ensure. 15g for a minute could easily kill you.

The 14G number is for ascent abort scenario's lasting a very short time (mere seconds). I fully agree with you that sustained high G-levels will cause major injuries and possibly death.
The fighter pilot will lose consciousness at 9G because his orientation is such that the blood pools lower in his body and circulates "uphill" poorly. Lying on your back with slightly flexed legs works the best and has been tested with sustained accelerations over 15g by test pilots in the late 50's and early 60's.  Notice that all manned launches have the crew experiencing the acceleration in a supine position not sitting upright like a fighter pilot.

How long is 'sustained' in this case. Seconds? Minutes? Done in a centrifuge I pressume?

That notwithstanding, 15G for any length of time is going to leave the human involved incapacitated for some time, if not borderline dead.

EDIT: Some Wikipedia data https://en.wikipedia.org/wiki/G-force#Horizontal_axis_g-force

"Sustained" as quoted by nadreck can't be over any longer than seconds. Exposure to 15G, even in a supine position, for any longer than 10 to 20 seconds causes major blood-vessel and organ trauma (rupture). The resulting internal bleeding will kill the exposed subject.
The 14G figure quoted in the NASA document is for very short periodes of exposure: up to 5 seconds at most. We're talking abort scenario's here, not sustained G-loading on a nominal launch.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nadreck on 09/02/2015 01:54 pm



Modern fighter pilots with G suits can take about 9g before passing out. 14G is a LOT more than a human can sustainably ensure. 15g for a minute could easily kill you.

The 14G number is for ascent abort scenario's lasting a very short time (mere seconds). I fully agree with you that sustained high G-levels will cause major injuries and possibly death.
The fighter pilot will lose consciousness at 9G because his orientation is such that the blood pools lower in his body and circulates "uphill" poorly. Lying on your back with slightly flexed legs works the best and has been tested with sustained accelerations over 15g by test pilots in the late 50's and early 60's.  Notice that all manned launches have the crew experiencing the acceleration in a supine position not sitting upright like a fighter pilot.

How long is 'sustained' in this case. Seconds? Minutes? Done in a centrifuge I pressume?

That notwithstanding, 15G for any length of time is going to leave the human involved incapacitated for some time, if not borderline dead.

EDIT: Some Wikipedia data https://en.wikipedia.org/wiki/G-force#Horizontal_axis_g-force

"Sustained" as quoted by nadreck can't be over any longer than seconds. Exposure to 15G, even in a supine position, for any longer than 10 to 20 seconds causes major blood-vessel and organ trauma (rupture). The resulting internal bleeding will kill the exposed subject.
The 14G figure quoted in the NASA document is for very short periodes of exposure: up to 5 seconds at most. We're talking abort scenario's here, not sustained G-loading on a nominal launch.

From what JamesH quoted:

https://en.wikipedia.org/wiki/G-force#Horizontal_axis_g-force (https://en.wikipedia.org/wiki/G-force#Horizontal_axis_g-force)

Quote
Early experiments showed that untrained humans were able to tolerate a range of accelerations depending on the time of exposure. This ranged from as much as 20 g for less than 10 seconds, to 10 g for 1 minute, and 6 g for 10 minutes for both eyeballs in and out.[15] These forces were endured with cognitive facilities intact, as subjects were able to perform simple physical and communication tasks. The tests were determined to not cause long or short term harm although tolerance was quite subjective, with only the most motivated non-pilots capable of completing tests.[16] The record for peak experimental horizontal g-force tolerance is held by acceleration pioneer John Stapp, in a series of rocket sled deceleration experiments culminating in a late 1954 test in which he was clocked in a little over a second from a land speed of Mach 0.9. He survived a peak "eyeballs-out" force of 46.2 times the force of gravity, and more than 25 g for 1.1 seconds, proving that the human body is capable of this. Stapp lived another 45 years to age 89, but suffered lifelong damage to his vision from this last test.[17][not in citation given]


NOTE Eyeballs in and Eyeballs out refer to acceleration or deceleration (many tests were made with rocket sleds that accelerated in one direction then decelerated in the other even more harshly with a water breaking system).

Here from the Smithsonian Air & Space web site:
http://www.airspacemag.com/history-of-flight/the-g-machine-16799374/?all (http://www.airspacemag.com/history-of-flight/the-g-machine-16799374/?all)

Quote
I think it started when somebody spun a fish and didn’t notice anything irregular about the fish because of the high Gs,” says Stephen Cloak, a Navy research engineer and veteran centrifuge jockey. “So they postulated that if we put a human encased in water, it would dissipate the G forces and they could take high G.” The Maiden was an aluminum capsule designed by Gray, sculpted roughly in the shape of a seated human, that could be filled with water. Gray stayed alert throughout the 25-second run up to 32 Gs, suffering only mild sinus pain. “He was another one of these late ’50s, early ’60s guys that just kind of kicked the tires and went at it,” says Cloak. Gray wanted to go to the full 40-G capability of the centrifuge, but the Maiden was too big to fit inside the gondola and so had to be mounted farther inward along the arm, where 32 Gs was the maximum acceleration possible.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 09/02/2015 02:27 pm
Big difference between a person in a flight suit in an air-environment and a person encased in a water tank. The latter may prevent high-G induced injuries but is highly impractical on a rocket launch.

I suggest you limit your examples to the 'standard' for orbital launches: persons in a pressure suit in an air-environment. Under that scenario, 15G for more than 10-to-20 seconds will seriously injure -and eventually kill - the exposed subject.

Note the difference - in the quoted source - between the 'less-than-10-seconds' for 20G and the 1 minute figure for 10G? There is your killer right there. You don't think NASA conjured up that 14G out of thin air do you? That number is not for sustained periods of more than 5 seconds. It's for abort scenario's on ascent and thus for very short periods of time.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Danny Dot on 09/02/2015 03:12 pm
Big difference between a person in a flight suit in an air-environment and a person encased in a water tank. The latter may prevent high-G induced injuries but is highly impractical on a rocket launch.

I suggest you limit your examples to the 'standard' for orbital launches: persons in a pressure suit in an air-environment. Under that scenario, 15G for more than 10-to-20 seconds will seriously injure -and eventually kill - the exposed subject.
Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?

I think Dragon V2 crewed flights might require a different ascent profile that might possibly include throttling to limit g forces... more gravity losses(?). Also, a crewed Dragon V2 masses more IIRC.

NASA Standard 3000 says the crew can take 14 G's on ascent.  I don't know why people think the crew can't take this.


Modern fighter pilots with G suits can take about 9g before passing out. 14G is a LOT more than a human can sustainably ensure. 15g for a minute could easily kill you.


Note the difference - in the quoted source - between the 'less-than-10-seconds' for 20G and the 1 minute figure for 10G? There is your killer right there. You don't think NASA conjured up that 14G out of thin air do you? That number is not for sustained periods of more than 5 seconds. It's for abort scenario's on ascent and thus for very short periods of time.

I found an old copy of the acceleration section of NASA STD 3000.  It shows 14 G's for over 2 minutes.  I worked with the human factors people at Johnson Space Center (Smith Johnson) during Constellation work and we came up with 20 G's for about 20 seconds based on centrifuge work done in the 60's.  I couldn't find this newer data.



Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: RonM on 09/02/2015 03:43 pm
Here's the newer file.

Go to page 46.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: symbios on 09/02/2015 04:07 pm
Anyone have a link to Lee Rosen AIAA Space 2015 presentation?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 09/02/2015 04:10 pm
Here's the newer file.

Go to page 46.


Page 47 of the new document: +Gx (Eyeballs in): limit for 16G set to 5 seconds. Fits nicely with my data of 15G for 10-to-20 seconds at most before internal injuries occur. Glad to see NASA uses the same numbers as the folks at NLR.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nadreck on 09/02/2015 04:17 pm
Note that looking for references I several times came across references to 17g for two minutes but without the actual table of data that showed the results.

From wikipedia: https://en.wikipedia.org/wiki/High-G_training#Human_centrifuge_training (https://en.wikipedia.org/wiki/High-G_training#Human_centrifuge_training)

Quote
Early experiments showed that untrained humans were able to tolerate 17 g eyeballs-in (compared to 12 g eyeballs-out) for several minutes without loss of consciousness or apparent long-term harm.[3]

and note 3 there refers to this:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980223621.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980223621.pdf)

Which refers to figures that aren't present in this document that would detail the acceleration levels.

I found several other casual references to >15g or 17g for several minutes.

My memory from reading about the testing in the 70's when I was young was seconds above 20g, minutes between 15 and 20g.

Finally I would like to point out that the quote from the article JamesH cited that I had posted also stated that it was untrained participants and I read other anecdotes of people being effective up to 15gs sustained for minutes with training but that above 15gs operating controls led to injuries of the hand/wrist/arm.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 09/02/2015 04:17 pm
Big difference between a person in a flight suit in an air-environment and a person encased in a water tank. The latter may prevent high-G induced injuries but is highly impractical on a rocket launch.

I suggest you limit your examples to the 'standard' for orbital launches: persons in a pressure suit in an air-environment. Under that scenario, 15G for more than 10-to-20 seconds will seriously injure -and eventually kill - the exposed subject.
Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?

I think Dragon V2 crewed flights might require a different ascent profile that might possibly include throttling to limit g forces... more gravity losses(?). Also, a crewed Dragon V2 masses more IIRC.

NASA Standard 3000 says the crew can take 14 G's on ascent.  I don't know why people think the crew can't take this.


Modern fighter pilots with G suits can take about 9g before passing out. 14G is a LOT more than a human can sustainably ensure. 15g for a minute could easily kill you.


Note the difference - in the quoted source - between the 'less-than-10-seconds' for 20G and the 1 minute figure for 10G? There is your killer right there. You don't think NASA conjured up that 14G out of thin air do you? That number is not for sustained periods of more than 5 seconds. It's for abort scenario's on ascent and thus for very short periods of time.

I found an old copy of the acceleration section of NASA STD 3000.  It shows 14 G's for over 2 minutes.  I worked with the human factors people at Johnson Space Center (Smith Johnson) during Constellation work and we came up with 20 G's for about 20 seconds based on centrifuge work done in the 60's.  I couldn't find this newer data.

You based those numbers on 4+ decades old data? I'm glad the folks at ESA/NLR/TUD chose to base their figures on more recent testing. (late 1990's and early 2000's)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nadreck on 09/02/2015 04:22 pm
Here's the newer file.

Go to page 46.


Page 47 of the new document: +Gx (Eyeballs in): limit for 16G set to 5 seconds. Fits nicely with my data of 15G for 10-to-20 seconds at most before internal injuries occur. Glad to see NASA uses the same numbers as the folks at NLR.

Those are stated to be limits for a flight system (in emergency mode), that is not saying that people die at higher rates, but that the risk is unacceptable. I am not saying that the recommendations are incorrect, I am saying that human endurance is much higher than was being asserted. The original thread was:

Why would SpaceX even need to do prop densification for crew dragon flights? Do they really need the extra performance; the vehicle is only going to LEO? Do they need the extra performance to do 1st stage RTLS? Or can Falcon 9 v1.2 and launch pad infrastructure only support densified prop?

I think Dragon V2 crewed flights might require a different ascent profile that might possibly include throttling to limit g forces... more gravity losses(?). Also, a crewed Dragon V2 masses more IIRC.

NASA Standard 3000 says the crew can take 14 G's on ascent.  I don't know why people think the crew can't take this.


Modern fighter pilots with G suits can take about 9g before passing out. 14G is a LOT more than a human can sustainably ensure. 15g for a minute could easily kill you.

The 14G number is for ascent abort scenario's lasting a very short time (mere seconds). I fully agree with you that sustained high G-levels will cause major injuries and possibly death.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 09/03/2015 09:29 pm
For some reason I just noticed the updated legs design. Interesting how they altered the cut-out from an angular design to a circular one. Pardon if this has been brought up. I wonder what else they did to them.

Elon Musk had announced they want to deploy the legs earlier and cut the descent speed in half reducing fuel needs for the landing burn. The new animation did not show this though, I watched out for it and they deploy late as before.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cambrianera on 09/03/2015 09:38 pm
For some reason I just noticed the updated legs design. Interesting how they altered the cut-out from an angular design to a circular one. Pardon if this has been brought up. I wonder what else they did to them.

Every set that flew had a circular cut-out.
Only the prototype set had the angular one.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rcoppola on 09/03/2015 09:50 pm
For some reason I just noticed the updated legs design. Interesting how they altered the cut-out from an angular design to a circular one. Pardon if this has been brought up. I wonder what else they did to them.

Every set that flew had a circular cut-out.
Only the prototype set had the angular one.
HA, probably why I never noticed. I suppose it's the black that through me off. Or not.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: zlsa on 09/04/2015 02:30 am
Hi all, here are some close-up renders from my WIP Falcon 9 v1.2 model. At the moment, there's no feature on my model that definitively places it at either version but I will reference it off of the v1.2 and update it over time. I started work on this model sometime earlier this year (I think May-ish) and it's been getting dusty until now (since SpaceX updated the images on their website to the Falcon 9 v1.2). My goal is to make the most detailed Falcon 9 model publicly available.

To the moderators: I don't know of any art threads, so I made one here; please move it if it belongs somewhere else.

And to everyone, please don't hold yourselves back; correct and nitpick to your heart's content. It's easier to change things now rather than later.

(Apologies for the grain; these were relatively low-quality renders).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 09/04/2015 03:58 am
No nitpicks yet, but I just realized from the renders that once an F9 has landed, you can walk under it and look up at the engines.

Not that I couldn't have figured this out without the renders, but it just never occurred to me...  looking at them, that was my first thought :)

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: NovaSilisko on 09/04/2015 04:43 am
No nitpicks yet, but I just realized from the renders that once an F9 has landed, you can walk under it and look up at the engines.

True, but I can't say I would. Even in photos the Dangling Dragon at Hawthorne makes me uncomfortable. I'd trust the legs to land it, but not if I'm under it  :P
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: edkyle99 on 09/05/2015 03:21 pm
For the "Falcon 9 Upgrade" (some have called it "Falcon 9 v1.2" unofficially), SpaceX claims a 33 percent increase in performance.  Has anyone seen any number indicating which performance the company is describing?  LEO performance is different than GTO performance, for example.  A 33% in LEO performance would not result in an identical increase in GTO performance.  Or vice versa.

 - Ed Kyle
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: philw1776 on 09/05/2015 04:13 pm
No nitpicks yet, but I just realized from the renders that once an F9 has landed, you can walk under it and look up at the engines.

True, but I can't say I would. Even in photos the Dangling Dragon at Hawthorne makes me uncomfortable. I'd trust the legs to land it, but not if I'm under it  :P

Yes, I would wait until well after it landed.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 09/05/2015 04:59 pm
No nitpicks yet, but I just realized from the renders that once an F9 has landed, you can walk under it and look up at the engines.

True, but I can't say I would. Even in photos the Dangling Dragon at Hawthorne makes me uncomfortable. I'd trust the legs to land it, but not if I'm under it  :P

Yes, I would wait until well after it landed.

I am certainly not advocating doing it before it landed.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: zlsa on 09/06/2015 12:07 am
Here's some renders of the mostly finished interstage area. The end of the conduit features a bit of artistic liberty as I couldn't find any pictures of that area; as before, please point out any errors I've made.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: S.Paulissen on 09/06/2015 12:32 am
Here's some renders of the mostly finished interstage area. The end of the conduit features a bit of artistic liberty as I couldn't find any pictures of that area; as before, please point out any errors I've made.

Here's an image of, what I believe, is the distal side of the rocket from the conduit. 
http://www.space.com/images/i/000/033/199/original/spacex-falcon-9-upgrade-version-pad.jpg?1380461952

EDIT: attached below is a very high resolution picture that might help you with the conduit(s).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: savuporo on 09/06/2015 12:51 am
For the "Falcon 9 Upgrade" (some have called it "Falcon 9 v1.2" unofficially), SpaceX claims a 33 percent increase in performance.  Has anyone seen any number indicating which performance the company is describing? 
.. could be 5-60mph time from a rolling start ? :p
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Hywel1995 on 09/06/2015 01:10 am

Here's an image of, what I believe, is the distal side of the rocket from the conduit. 
http://www.space.com/images/i/000/033/199/original/spacex-falcon-9-upgrade-version-pad.jpg?1380461952

EDIT: attached below is a very high resolution picture that might help you with the conduit(s).

Which flight was this from? CRS-7? Looking at the image just to the top of stage one if you zoom in is that wire, space tape or a crack? I'm just curious now.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 09/06/2015 12:21 pm
]

Which flight was this from? CRS-7? Looking at the image just to the top of stage one if you zoom in is that wire, space tape or a crack? I'm just curious now.

That was the first VAFB launch
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Hywel1995 on 09/06/2015 12:50 pm
I meant the attached one that was added in the edit... Sorry for not making it clear.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: zlsa on 09/07/2015 01:55 am
I've added more detail to the interstage, conduits, and landing legs, as well as the SpaceX and Falcon 9 logos. Barring any inaccuracies, the booster should be complete, so I'll be moving on to the upper stage now.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: 411rocket on 09/07/2015 02:23 am
Here's some renders of the mostly finished interstage area. The end of the conduit features a bit of artistic liberty as I couldn't find any pictures of that area; as before, please point out any errors I've made.

It looks like the Grid Fins are too low, they should be on the lower portion, of the interstage.

As seen on the picture, below this quoted post.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 09/07/2015 04:27 am
I've added more detail to the interstage, conduits, and landing legs, as well as the SpaceX and Falcon 9 logos. Barring any inaccuracies, the booster should be complete, so I'll be moving on to the upper stage now.

Great work! But it looks like you base a lot of the details on the new SpaceX F9/FH renders - but they do not match cure early flying hardware well at all, especially interstate details. (Locations of fins and thrusters)

It is possible that the "v1.2" will look more like those renderings, but before that happens you should probably use hardware photos for details - if accuracy is your ultimate goal.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: PreferToLurk on 09/07/2015 06:17 am
I've added more detail to the interstage, conduits, and landing legs, as well as the SpaceX and Falcon 9 logos. Barring any inaccuracies, the booster should be complete, so I'll be moving on to the upper stage now.

Super work! All very impressive. But I too echo the sentiments about sticking to flying hardware details over "1.2" renders.  I think SpaceX has good reason to move the grid fins out of the interstage -- stage commonality being foremost. The FH side boosters don't have an interstage, only a nosecone. A nosecone which doesn't appear to have space for the gridfins. But again, maybe the side booster nosecones aren't correctly rendered either and the gridfins will stay in the interstage/nosecap section.

IMHO the grid fins will move below the interstage, but that might not happen with the initial "1.2" update.

But being as no one has photos of a 1.2 stage, everything you model is going to be speculative to some degree. I wont really fault minimal artistic license, but be prepared to make changes once the real thing goes vertical on the pad. i'd bet my hat that the renders will have differences from the flight hardware somewhere.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 09/07/2015 12:27 pm

IMHO the grid fins will move below the interstage, but that might not happen with the initial "1.2" update.


Why?  It isn't feasible.  The fins are on the interstage because of the systems on the inside of the interstage that support the fins.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: PreferToLurk on 09/07/2015 02:23 pm

IMHO the grid fins will move below the interstage, but that might not happen with the initial "1.2" update.


Why?  It isn't feasible.  The fins are on the interstage because of the systems on the inside of the interstage that support the fins.

Yup. that's why they are there now, and why I supported keeping them there in the models (for the time being).  I also don't think that the grid fins will ever sit directly over a propellant tank.
What I really think will happen is that there will be a blurring of where the interstage begins and the first stage ends.  Right now IIRC, the first stage ends just about exactly where the tank ends and there is very little/no space between the end of the tank and where the composite interstage connects.  There is also a clear visual indication on the rocket where the interstage begins.  In the "1.2" renders that visual cue is still there but might not actually be at true beginning of the interstage.

Maybe they will extend an aluminum skin past the end of the tank to allow the FH stage connections attach to aluminum instead of composite. It is my understanding that connection points and openings for gridfin mechanisms, etc, really complicate the construction of the composite interstage.  Moving those things into aluminum might be of benefit to SpaceX. (makes intuitive sense to me, but i have no proof)

This is why I think that the renders might actually represent how SpaceX wants to build their rocket.   

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: zlsa on 09/07/2015 03:19 pm
It looks like the Grid Fins are too low, they should be on the lower portion, of the interstage.

As seen on the picture, below this quoted post.

I'm basing my model mostly off of this image: http://www.spacex.com/sites/all/themes/spacex2012/images/falcon9/falcon9-render.png

despite knowing for a fact that SpaceX's renders and models are very inaccurate (just compare their Falcon 9 image to their Falcon Heavy image: http://www.spacex.com/sites/all/themes/spacex2012/images/falconheavy/falcon-heavy-render.png; especially the leg area).

I don't mind moving the grid fins or other parts around after SpaceX shows the upgraded F9; but I want to avoid following the exact current revision too closely and continually moving things around to copy the last flown vehicle. I'd much prefer to get the "paper" Falcon 9 v1.2 correct, and update it to match what SpaceX will eventually fly.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 09/07/2015 07:25 pm
despite knowing for a fact that SpaceX's renders and models are very inaccurate (just compare their Falcon 9 image to their Falcon Heavy image: http://www.spacex.com/sites/all/themes/spacex2012/images/falconheavy/falcon-heavy-render.png; especially the leg area).

I don't mind moving the grid fins or other parts around after SpaceX shows the upgraded F9; but I want to avoid following the exact current revision too closely and continually moving things around to copy the last flown vehicle. I'd much prefer to get the "paper" Falcon 9 v1.2 correct, and update it to match what SpaceX will eventually fly.

So despite knowing that SpaceX renders rarely (if ever) are 100% accurate, you would rather be rendering accurate than hardware accurate? Even if the current configuration has been stable for many flights?

It makes little sense to me, but whatever floats your boat. :)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 09/07/2015 07:42 pm
despite knowing for a fact that SpaceX's renders and models are very inaccurate (just compare their Falcon 9 image to their Falcon Heavy image: http://www.spacex.com/sites/all/themes/spacex2012/images/falconheavy/falcon-heavy-render.png; especially the leg area).

I don't mind moving the grid fins or other parts around after SpaceX shows the upgraded F9; but I want to avoid following the exact current revision too closely and continually moving things around to copy the last flown vehicle. I'd much prefer to get the "paper" Falcon 9 v1.2 correct, and update it to match what SpaceX will eventually fly.

So despite knowing that SpaceX renders rarely (if ever) are 100% accurate, you would rather be rendering accurate than hardware accurate? Even if the current configuration has been stable for many flights?

It makes little sense to me, but whatever floats your boat. :)

Except sometimes SpaceX renders are prescient...  Curious, that.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: zlsa on 09/07/2015 10:47 pm
If the next F9 flight is a v1.1 then I will update to that configuration; however, we know that the next flight will (almost definitely) be a v1.2/upgraded F9, and there are going to be differences between that and the (stable) current configuration.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Coastal Ron on 09/07/2015 11:16 pm
If the next F9 flight is a v1.1 then I will update to that configuration; however, we know that the next flight will (almost definitely) be a v1.2/upgraded F9, and there are going to be differences between that and the (stable) current configuration.

Except for the single v1.1 reserved for Jason-3, which won't be the next payload to launch, all future launches should be of the new baseline configuration that includes the full thrust Merlin 1D and other improvements.  And from what we've heard, that should be a stable configuration - as long as there are no flight issues.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: zlsa on 09/08/2015 12:57 am
Fairing and placeholder upper stage is complete.

The Merlin 1D-Vac isn't modeled yet since I can't find any images of that area with resolutions much greater than thumbnails.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lee Jay on 09/08/2015 01:09 am
Am I the only one that thinks "full thrust" is a silly name?  It implies there will never be another thrust upgrade.  What would they call it?  "Full thrust plus"?  "More than full thrust"?  "Full thrust and then some"?

It's a name that implies a dead end to the design.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: clongton on 09/08/2015 01:10 am
Am I the only one that thinks "full thrust" is a silly name?  It implies there will never be another thrust upgrade.  What would they call it?  "Full thrust plus"?  "More than full thrust"?  "Full thrust and then some"?

It's a name that implies a dead end to the design.

You are not the only one. It is a silly name.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Impaler on 09/08/2015 01:14 am
Am I the only one that thinks "full thrust" is a silly name?  It implies there will never be another thrust upgrade.  What would they call it?  "Full thrust plus"?  "More than full thrust"?  "Full thrust and then some"?

It's a name that implies a dead end to the design.

Double Plus Good Thrust!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: the_other_Doug on 09/08/2015 01:18 am
Here's an echo of the early-mid '60s -- the Uprated Falcon 9 v1.1.

:)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: savuporo on 09/08/2015 01:51 am
You are not the only one. It is a silly name.

They shoulda named a certain retired fleet as '104 percenters'
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: edkyle99 on 09/08/2015 03:50 am
Am I the only one that thinks "full thrust" is a silly name?  It implies there will never be another thrust upgrade.  What would they call it?  "Full thrust plus"?  "More than full thrust"?  "Full thrust and then some"?
"Falcon 9 v1.1 Full Thrust" is the worst name for a rocket ever.  For me, the main reason is that the name is too long, which will make reporting difficult.  Also, I don't think that SpaceX will like the giggles triggered by the shorthand version of the name that might result (the last two words by themselves).

 - Ed Kyle
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: sublimemarsupial on 09/08/2015 03:59 am
Am I the only one that thinks "full thrust" is a silly name?  It implies there will never be another thrust upgrade.  What would they call it?  "Full thrust plus"?  "More than full thrust"?  "Full thrust and then some"?
"Falcon 9 v1.1 Full Thrust" is the worst name for a rocket ever.  For me, the main reason is that the name is too long, which will make reporting difficult.  Also, I don't think that SpaceX will like the giggles triggered by the shorthand version of the name that might result (the last two words by themselves).

 - Ed Kyle

That's why the official, public name has been and will continue to be just "Falcon 9". As to the the giggles, I'm sure it gives all those young overworked engineers in their sweatshop of a rocket company a small glimmer of humor to brighten their otherwise dark days ....
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 09/08/2015 05:44 am
F9FT.  It's fine.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 09/08/2015 07:54 am
Am I the only one that thinks "full thrust" is a silly name?  It implies there will never be another thrust upgrade.  What would they call it?  "Full thrust plus"?  "More than full thrust"?  "Full thrust and then some"?

It's a name that implies a dead end to the design.

You are not the only one. It is a silly name.
Fully agree on the sillyness. But heck, we don't get to name those vehicles. Otherwise the CST-100 never would have been nick-named Starliner and we wouldn't have had that silly 'Galaxy One' entry in the Vulcan naming-contest.
Fortunately, it's not just SpaceX and Boeing coming up with silly names. 'DreamChaser' from SNC was not exactly a brilliant name either IMO. Mostly it was predictive in nature as SNC is still chasing dreams with that machine.
Another blunder is the SpaceShipOne and SpaceShipTwo designations from VirginGalactic. They would have been more appropriate for Vostok-1 and Vostok-2 IMO.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: woods170 on 09/08/2015 07:55 am
F9FT.  It's fine.
Unless you are Elon Musk. He doesn't like acronyms.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: pippin on 09/08/2015 11:07 am

F9FT.  It's fine.
Unless you are Elon Musk. He doesn't like acronyms.
BFR? MCT?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: su27k on 09/08/2015 11:45 am
Am I the only one that thinks "full thrust" is a silly name?  It implies there will never be another thrust upgrade.  What would they call it?  "Full thrust plus"?  "More than full thrust"?  "Full thrust and then some"?

It's a name that implies a dead end to the design.

If they name it "v1.1 Full Thrust" then it's a very appropriate name, it tells you exactly what this version is about, it coveys a lot more information then the other names. If they are planning another major upgrade of F9 (I doubt it), they can just name it "v1.2".
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Billium on 09/08/2015 01:10 pm
I think they would have liked to have named it f9 v1.2, however they want to avoid that so they can avoid arguments that it must be recertified. So they have to name it something to differentiate from just normal v1.1, so "full thrust" seems as good as they can do. And I know that something as big as certification should not be based on a name, but we're starting to get into politics which never has to make any sense.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Zed_Noir on 09/08/2015 01:14 pm
Am I the only one that thinks "full thrust" is a silly name?  It implies there will never be another thrust upgrade.  What would they call it?  "Full thrust plus"?  "More than full thrust"?  "Full thrust and then some"?

It's a name that implies a dead end to the design.

You are not the only one. It is a silly name.

It is a silly name. However the Golden rule of naming applies in this case. The one with the most gold gets to make up the rules.

It could be worse. We have the Insane, the Ludicrous & the Maximum Plaid speed modes for the Tesla cars.  ;D
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DavidH on 09/08/2015 02:47 pm
Good Lord! Get over the name already. SpaceX_MS called it Falcon9. It's simple.

There've been some mods, yeah (maybe a bunch), but can we please stop wasting all these precious bits ;) on this?

Whatever.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mme on 09/08/2015 03:19 pm
[rant]
Jiminy Crickets people.  The name of the rocket is the "Falcon 9."  Full Thrust is the designation that differentiates it from the pre-densified, slightly shorter incarnation.  The entire point of this incarnation is to run the M1D at, wait for it ... full thrust.

SpaceX's customers (NASA, commercial and the AF) are not idiots.  Not even Congress is that dumb. No wool is being pulled over their eyes.  They know what all the differences in the rocket are.  SpaceX is, after all, giving public presentations listing the difference, as well as the much greater insight actual customers have.  They will decide what level of recertification they require based on actual facts.

Mass confusion and hysteria is not imminent even though SpaceX used the term "Full Thrust" rather than the number 2, or letter C or initialism FT to label this incarnation.  In 2525 when students look up the history of spaceflight in the early 21st century they will not be confused that the 3rd upgrade to the F9 was designated "Full Thrust."

And finally, even though Elon Musk once sent a cranky email because 1000s of engineers were inventing 1000s of unnecessary acronyms, we can call it the F9-FT on those incredibly rare occasions that just saying F9 is not sufficient.
[/rant]
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Confusador on 09/08/2015 03:22 pm
Good Lord! Get over the name already. SpaceX_MS called it Falcon9. It's simple.

There've been some mods, yeah (maybe a bunch), but can we please stop wasting all these precious bits ;) on this?

Whatever.

No, we can't.  Otherwise there'd be a lot of discussion of the difference in performance between the Falcon 9 and the Falcon 9.  This forum is interested in details, so we need to be able to distinguish, and the discussion about names needs to happen so the distinctions are clear.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JamesH on 09/08/2015 04:11 pm
Good Lord! Get over the name already. SpaceX_MS called it Falcon9. It's simple.

There've been some mods, yeah (maybe a bunch), but can we please stop wasting all these precious bits ;) on this?

Whatever.

No, we can't.  Otherwise there'd be a lot of discussion of the difference in performance between the Falcon 9 and the Falcon 9.  This forum is interested in details, so we need to be able to distinguish, and the discussion about names needs to happen so the distinctions are clear.

What discussion? It's F91.1FT or F9FT. Not much there to discuss. In a couple months, you can just call it F9, as there won't be any non-FT versions!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: dror on 09/08/2015 04:26 pm
I think that by using the term 'full thrust' they imply that this version was planed since the conception of merlin 1d and falcon v1.1.
so actually, we should be discussing the differences between falcon 9 v1.1 and falcon 9 v1.1 intermediate.

the v 1.2 will be with a different engine version.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: oldAtlas_Eguy on 09/08/2015 04:41 pm
In the assignment of numbers for a version it goes something like this

v.mj.mi.f

v - complete reviision such as what is going on with Dragon

mj - major changes/upgrades such as stage stretch and new engine version

mi - minor changes/upgrades such as the M1DFT with other additional features such as use of densified prop and stage stretch of just US

f - an engineering fix like the struts, the grid fins or the increase in hydraulic fluid for the grid fins.

Following this then the new "version" would be more like a v1.1.1.n
Most shorthand for versions do not state the minor or fix versioning numbers but for manufacturing and use the full versioning number is used for tracking compatibility issues with other interfacing systems such as the GSE and test equipment (Test stands, launch process flow etc).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 09/08/2015 04:44 pm
If they change the interstage color this forum's going to go ape!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 09/08/2015 05:02 pm
In the assignment of numbers for a version it goes something like this

v.mj.mi.f

v - complete reviision such as what is going on with Dragon

mj - major changes/upgrades such as stage stretch and new engine version

mi - minor changes/upgrades such as the M1DFT with other additional features such as use of densified prop and stage stretch of just US

f - an engineering fix like the struts, the grid fins or the increase in hydraulic fluid for the grid fins.

Following this then the new "version" would be more like a v1.1.1.n
Most shorthand for versions do not state the minor or fix versioning numbers but for manufacturing and use the full versioning number is used for tracking compatibility issues with other interfacing systems such as the GSE and test equipment (Test stands, launch process flow etc).

While interesting, this is meaningless and not that helpful, since versioning and naming standards can vary significantly between different organizations. We are not creating a versioning system for SpaceX. They have one. We just follow it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: savuporo on 09/08/2015 05:30 pm
What discussion? It's F91.1FT or F9FT. Not much there to discuss. In a couple months, you can just call it F9, as there won't be any non-FT versions!
It's somewhat relevant if you want to ask a question of type 'so how many flights has this rocket had since last failure?'. The original Falcon 9 stands at 1 ( or 5, depends on how you count ) , v1.1 obviously at 0.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 09/08/2015 05:43 pm
What discussion? It's F91.1FT or F9FT. Not much there to discuss. In a couple months, you can just call it F9, as there won't be any non-FT versions!
It's somewhat relevant if you want to ask a question of type 'so how many flights has this rocket had since last failure?'. The original Falcon 9 stands at 1 ( or 5, depends on how you count ) , v1.1 obviously at 0.

The distinction means less than you think. All rockets - from all launch providers - receive minor upgrades between flights. Rarely does a single configuration go unchanged for many flights.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: savuporo on 09/08/2015 05:50 pm
The distinction means less than you think. All rockets - from all launch providers - receive minor upgrades between flights. Rarely does a single configuration go unchanged for many flights.
We have had this discussion before somewhere. Rarely, if ever, have i spotted Arianes or Soyuz-FGs sprout random legs or other appendages ;) Also, Long March 3B, 3C , Ariane GS, ECA, ES are all pretty clearly labeled.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 09/08/2015 06:10 pm
The distinction means less than you think. All rockets - from all launch providers - receive minor upgrades between flights. Rarely does a single configuration go unchanged for many flights.
We have had this discussion before somewhere. Rarely, if ever, have i spotted Arianes or Soyuz-FGs sprout random legs or other appendages ;) Also, Long March 3B, 3C , Ariane GS, ECA, ES are all pretty clearly labeled.

I'm not sure what you think you are arguing. Do you think that all Long March 3B that have flown were identical? And not even all "v1.1" have legs, if that matters...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Prettz on 09/09/2015 12:15 am
Here's an echo of the early-mid '60s -- the Uprated Falcon 9 v1.1.

:)
In keeping with 60s naming, the engine powering it is the Merlin 1C-III2-A.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 09/09/2015 07:52 pm
I suggest we name the version in retrospects, relative to the current version, so F9 1.1 will be called F9 (-0.01) and F9 1.0 will be called F9 (-0.11).
(The previous rocket can also be called F9 Partial Thrust)

F1 will be renamed F9 (-8.11)

This is a lot like the ancient coins that have "400 B.C." minted on them.  If it was good for the Greeks, it is certainly good enough for us.

Once BFR gets going, we'll rename the entire F9 lineup to "SFR" and be done with.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: savuporo on 09/09/2015 08:23 pm
I'm not sure what you think you are arguing. Do you think that all Long March 3B that have flown were identical? And not even all "v1.1" have legs, if that matters...
There is a difference between a hardware revision and a new version with different characteristics. Component changes, factory flow and supply chain optimizations and so on often result in small, but always recorded, engineering change notices in my industry. If you go and add or remove a feature or change basic operating characteristics or performance of a product, we call it a new version though.
But of course everyone is free to define their own nomenclatures and conventions, unless they get subjected to some industry standards.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Ronpur50 on 09/10/2015 01:02 am
Just call it the Millennium Falcon, like it was named for.  If Disney will let them!!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Giovanni DS on 09/10/2015 09:50 am
Falcon 1.1.1
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Semmel on 09/10/2015 11:13 am
Can we go back to being serious now? This thread has become a party thread and it would be sad if it stayed that way.

Question on topic: How much cargo could a Dragon V2 transport to the ISS if no people were on board? I know that the hatch is smaller than the cargo dragon, but some things can still fit. How much would it be? Thx!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 09/10/2015 03:52 pm
Can we go back to being serious now? This thread has become a party thread and it would be sad if it stayed that way.

Question on topic: How much cargo could a Dragon V2 transport to the ISS if no people were on board? I know that the hatch is smaller than the cargo dragon, but some things can still fit. How much would it be? Thx!

Good question. If they ever decide to replace the on station capsule for some reason but don't need to send people. The problem is, if it was set up for return crew, it would have to be jury rigged with racks and whatever to hold cargo but be easily convertible back to manned configuration. But since most of the high volume stuff seems to be in those soft bags, it seems like they could still stuff quite a bit in there without too much trouble.
 I've always wondered about contingency plans to send a ride for the Russians if something unpleasant happens with the Soyuz. Even if Dragon is set up for seven, you'd hate to have to empty the station just because one or two people needed to head downstairs.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: The_Ronin on 09/10/2015 04:37 pm
Well, ATV managed to do a lot of cargo with a small docking hatch.  The cargo will just need to packed accordingly with no racks, bulky stuff, etc.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: catdlr on 09/10/2015 09:25 pm
Crew Dragon | Interior

Published on Sep 10, 2015
Step inside Crew Dragon, SpaceX’s next-generation spacecraft designed to carry humans to the International Space Station and other destinations: www.spacex.com/crew-dragon

https://www.youtube.com/watch?v=xjSb_b4TtxI
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: catdlr on 09/10/2015 09:26 pm
Crew Dragon | In Orbit

Published on Sep 10, 2015
Step inside Crew Dragon, SpaceX’s next-generation

https://www.youtube.com/watch?v=a1EB5BQpm7w
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 09/11/2015 01:34 am
 One thing I didn't think of. Would Dragon2 be allowed to dock unmanned? Progress and ATV do, but that's Russian ports.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 09/11/2015 01:50 am

One thing I didn't think of. Would Dragon2 be allowed to dock unmanned? Progress and ATV do, but that's Russian ports.

Why not? Besides, isn't that how their first missions to ISS will happen? (Unless I'm mistaken) but I do believe it is a requirement that they can be flown/docked unmanned.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MattMason on 09/15/2015 03:35 pm
Quote
Peter B. de Selding ‏@pbdes
Minor modification? Here's a graphic showing SpaceX Falcon 9 Upgrade, to debut w/ SES-9 sat in Nov/Dec. #WSBW 
https://twitter.com/pbdes/status/643713181047767040 (https://twitter.com/pbdes/status/643713181047767040)

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mto on 09/15/2015 04:25 pm
There's a clearer version of that graphic at
http://spacenews.com/ses-betting-on-spacex-falcon-9-upgrade-as-debut-approaches/
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mme on 09/15/2015 08:12 pm
There's a clearer version of that graphic at
http://spacenews.com/ses-betting-on-spacex-falcon-9-upgrade-as-debut-approaches/
Thanks!  Lots of good tidbits in there:
Quote
But Halliwell, long a supporter of Hawthorne, California-based SpaceX, said his SES team has had enough access to the Falcon 9 failure review to assume a return to flight carrying the SES 9 satellite before the end of the year, but no earlier than Nov. 17.

“Frankly, I don’t think they could have done any better in terms of giving us access to the failure review, and we’ve got some experience with launch-failure reviews,” Halliwell said, referring to SES participation in past failure investigations relating to Russia’s Proton rocket and the European Ariane 5.
and
Quote
Halliwell said SES recently reiterated to SpaceX that the fleet operator would like to be the “the first satellite operator to use the same rocket twice to get to orbit,” Halliwell said, meaning to reuse a first stage that had already launched an SES satellite.

SpaceX has said it will attempt a barge landing of the first stage used for the SES-9 launch, the first such attempt following a launch to geostationary transfer orbit, the destination of most telecommunications satellites.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: feynmanrules on 09/16/2015 08:37 pm
this diagram above comparing 1.1 and 1.1FT is super cool.

(http://spacenews.com/wp-content/uploads/2015/09/falcon9_upgrades.jpg)

can somebody correct me if i'm understanding incorrectly or missing something re: purpose or source of upgrades?

1. fairing : no change.   presumably because primary goal of 30%+ thrust increase is for reusability and not larger payloads per say.    or at least no larger fairing is needed for next set of flights.

2. stage2 length increased.   this is in order to increase fuel capacity of 2nd stage, so that less thrust is required from first stage to reach a given orbit... leaving more for 1st stage boost back and landing.    can't increase the width much because they still want to be able to flat bed the stage.

3. mvac thurst increased w/longer nozzle.   similiar to #2, getting more out of 2nd stage leaves less work for 1st stage.   

4. center pusher added.   this as i understand it is either a change to explosive bolts that seperate the stages, or in addition to the bolts?   presumably it doesn't relate to extra thurst or reuse so much as flight success by having cleaner seperations.   anything missing here?

5. interstage longer and stronger.   to accomodate the more massive 2nd stage and the longer 2nd stage nozzle.

6. stage1 structure upgraded.   per others comments here and elsewhere on 1.1ft, this is necessary because of increased dynamic stresses from extra thrust in first stage, as well as extra mass from bigger inter and 2nd stages?   and probably also higher quality / better tested struts and support structure as part of crs7 fixes aka RTF efforts.

7. landing legs upgraded.   maybe for extra mass being carried in stage1, plus that we saw some leg failures in ASDS landing attempts?   hadn't heard of this before.

8. octaweb modified.   not sure on this, no info here.   perhaps increasing merlins to full thrust meant/allowed reoptimizing the engine placement.  similiar to when they went to octaweb in first place in 1.1 (from the grid layout they used with the m1cs).

9. m1d thrust increased.   this has been discussed before.   apparently the reason it's still 1.1ft vs 1.1 is because the 1st stage engines aren't changing, they were always designed to deliver this extra thrust it just wasn't enabled for realiability and testing reasons in previous m1d flights.   

appreciate any info.  such gr8 site thx.



Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Zed_Noir on 09/16/2015 09:14 pm
...   
4. center pusher added.   this as i understand it is either a change to explosive bolts that seperate the stages, or in addition to the bolts?   presumably it doesn't relate to extra thurst or reuse so much as flight success by having cleaner seperations.   anything missing here?
...
SpaceX does not use explosive bolts for stage separations.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: feynmanrules on 09/16/2015 09:22 pm

thanks for clarification.   i knew that spx used used explosive bolts for the falcon1 and i incorrectly assumed that had been carried over to the f9.

their website now suggests that ground-based testing ability played a role in switching it :

"Falcon 9 uses an all-pneumatic stage separation system for low-shock, highly reliable separation that can be tested on the ground, unlike pyrotechnic systems used on most launch vehicles."

via http://www.spacex.com/falcon9

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kansan52 on 09/16/2015 09:29 pm
"9. m1d thrust increased.   this has been discussed before.   apparently the reason it's still 1.1ft vs 1.1 is because the 1st stage engines aren't changing, they were always designed to deliver this extra thrust it just wasn't enabled for realiability and testing reasons in previous m1d flights."

From other posts here, SX needed a place to freeze the 1.1 from the 1. They knew the M1ds could produce this much thrust but that meant the denser fuel and O2. So it was a practical decision.

If memory serves, the change in the octoweb was more thrust meant more heat and the change helped keeping their (M1ds) cool!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Paul_G on 09/16/2015 09:33 pm
I think the new central pusher on the interstate is due to there being less space between the enlarged vacuume novel and the interstage. The central pusher helps reduce the chance of the separation not happening cleanly.

Rgds

Paul
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: symbios on 09/16/2015 10:26 pm
I'm curious if they have incorporated the ability to open the legs earlier both to reduce speed and as a control surface for better control of the decent.

Quote
7. landing legs upgraded.   maybe for extra mass being carried in stage1, plus that we saw some leg failures in ASDS landing attempts?   hadn't heard of this before.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 09/17/2015 06:56 am
I'm curious if they have incorporated the ability to open the legs earlier both to reduce speed and as a control surface for better control of the decent.

Quote
7. landing legs upgraded.   maybe for extra mass being carried in stage1, plus that we saw some leg failures in ASDS landing attempts?   hadn't heard of this before.

If they can open these legs earlier as Elon Musk had mentioned, it does not show on the CGI-video. On that they open as late as we are used to.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cambrianera on 09/17/2015 06:07 pm
4. center pusher added.   this as i understand it is either a change to explosive bolts that seperate the stages, or in addition to the bolts?   presumably it doesn't relate to extra thurst or reuse so much as flight success by having cleaner seperations.   anything missing here?

Transferring kinetic energy of first stage to second stage is a positive outcome of stage separation.
Normally this has very small value due to the forces involved (no way to fit a very big device, and not worth the mass)..
In the case of F9R the benefit is twofold:
-small increase in kinetic energy of second stage (still small)
-decrease of kinetic energy of first stage.
This second part could be of bigger value, considering that every m/s lost this way saves propellant otherwise needed for the braking burn.
I'm waiting to see the details to understand if this could be the case.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ISP on 09/17/2015 06:45 pm
I honestly thought the center pusher was added b/c the extra mass of the upper stage would've prevented adequate clearance on S2 separation & ignition...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cambrianera on 09/17/2015 07:49 pm
I honestly thought the center pusher was added b/c the extra mass of the upper stage would've prevented adequate clearance on S2 separation & ignition...
Separation is given mainly by first stage decelerating, much less by second accelerating.
First stage dry mass is 20-25 ton, add propellant for recover and still under 50 ton.
Second stage w payload is over 100 ton in F9 1.1.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 09/17/2015 08:30 pm
I honestly thought the center pusher was added b/c the extra mass of the upper stage would've prevented adequate clearance on S2 separation & ignition...
Separation is given mainly by first stage decelerating, much less by second accelerating.
First stage dry mass is 20-25 ton, add propellant for recover and still under 50 ton.
Second stage w payload is over 100 ton in F9 1.1.

Keep in mind that some of the changes are probable to increase commonality between FH and F9FT.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 09/18/2015 01:31 am
I honestly thought the center pusher was added b/c the extra mass of the upper stage would've prevented adequate clearance on S2 separation & ignition...
I assumed the added pusher was to insure a smoother separation to avoid contact with the larger exhaust nozzle.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JamesH on 09/18/2015 08:43 am
4. center pusher added.   this as i understand it is either a change to explosive bolts that seperate the stages, or in addition to the bolts?   presumably it doesn't relate to extra thurst or reuse so much as flight success by having cleaner seperations.   anything missing here?

Transferring kinetic energy of first stage to second stage is a positive outcome of stage separation.
Normally this has very small value due to the forces involved (no way to fit a very big device, and not worth the mass)..
In the case of F9R the benefit is twofold:
-small increase in kinetic energy of second stage (still small)
-decrease of kinetic energy of first stage.
This second part could be of bigger value, considering that every m/s lost this way saves propellant otherwise needed for the braking burn.
I'm waiting to see the details to understand if this could be the case.

Interesting thought. I wonder how much fuel might it be possible to 'save' for 1st stage return by giving the 2nd stage a good shove? I suspect 'not a lot'.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Roy_H on 09/18/2015 02:15 pm
4. center pusher added.   this as i understand it is either a change to explosive bolts that seperate the stages, or in addition to the bolts?   presumably it doesn't relate to extra thurst or reuse so much as flight success by having cleaner seperations.   anything missing here?

Transferring kinetic energy of first stage to second stage is a positive outcome of stage separation.
Normally this has very small value due to the forces involved (no way to fit a very big device, and not worth the mass)..
In the case of F9R the benefit is twofold:
-small increase in kinetic energy of second stage (still small)
-decrease of kinetic energy of first stage.
This second part could be of bigger value, considering that every m/s lost this way saves propellant otherwise needed for the braking burn.
I'm waiting to see the details to understand if this could be the case.

There are two issues, one it that the stages are coasting during separation, there is no acceleration of the second stage yet. There is some danger of the booster moving sideways (twisting rotating slowly) and hitting the second stage nozzle so this can be minimized by ensuring the stages move away from each other rapidly. The center pusher allows much more distance (and time) during which the actuator can force them apart at greater speeds. I would say that this is primarily a safety/reliability issue, and any benefit in terms of accelerating the second stage or decelerating the booster is bonus. This bonus in performance I would expect to be greater than the loss in performance by the mass of the large center pusher.

Edit: I just thought of an additional reason, SpaceX seems to like to fire the second stage as soon as possible, so this pusher will help that without the flame from the second stage damaging the booster.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 09/18/2015 02:23 pm
The new merlins supercool their propellants.  The LOX can get colder than the RP1, so you can shove more extra LOX in than you can extra RP1.  Some of the stage length rejiggering is to fix up the tank size ratios to account for the new propellant densities.  They seem to be doing this by stretching the RP1 tank (presumably?) rather than shrinking the LOX tank, resulting in longer stages.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Roy_H on 09/18/2015 02:33 pm

1. fairing : no change.   presumably because primary goal of 30%+ thrust increase is for reusability and not larger payloads per say.    or at least no larger fairing is needed for next set of flights.

9. m1d thrust increased.   this has been discussed before.   apparently the reason it's still 1.1ft vs 1.1 is because the 1st stage engines aren't changing, they were always designed to deliver this extra thrust it just wasn't enabled for realiability and testing reasons in previous m1d flights.   

appreciate any info.  such gr8 site thx.

I believe the Merlin thrust increase is 15%. I think it was the mass to GTO that is increased 30% as a result.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Impaler on 09/18/2015 08:39 pm
I suspect that 'octoweb modified' means a modification to the plumbing system to accommodate higher flow rates and potentially colder denser propellants.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 09/18/2015 08:56 pm
I suspect that 'octoweb modified' means a modification to the plumbing system to accommodate higher flow rates and potentially colder denser propellants.

I would expect it is about different hold down points and connection points for the Heavy.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 09/19/2015 01:18 am
Has the NSF collective ever figured out if SpaceX will always have hot fires before launch, or will they probably forego those when confidence gets to a certain point?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 09/19/2015 03:09 am
Has the NSF collective ever figured out if SpaceX will always have hot fires before launch, or will they probably forego those when confidence gets to a certain point?

We've done even better.  We came up with not just one but actually THREE answers for you to choose from.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: okan170 on 09/20/2015 02:47 am
I've been working out the logistics of doing a few animations for NSF in the future, and I did a quick 3-second test animation to test most of it all out I thought I'd share.  Just a simple fly-by of a Crew Dragon and some maneuvers to get the thrusters animating.  Hopefully more to come this year, but for now, just this quick animated test!

https://www.youtube.com/watch?v=Sc4yvlwhMFY
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mr. mark on 09/21/2015 02:20 pm
Elon Musk in SpaceX spacesuit prototype and sitting inside Dragon interior.
Title: General Falcon and Dragon discussion (Thread 12)
Post by: kevinof on 09/21/2015 02:27 pm
Wow. Now that's what I call a space suit. Hope it's the real deal. Very different.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: parham55 on 09/21/2015 02:43 pm
I'm probably missing something obvious; what is preventing the astros feet from falling off the foot rest during launch? It seems you'd need something behind the heel while lying on your back.
Thanks,
Rob
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mr. mark on 09/21/2015 03:30 pm
Believe it or not Vogue magazine. http://www.vogue.com/13349221/elon-musk-profile-entrepreneur-spacex-tesla-motors/  SpaceX tends to use non traditional means to get their message out there. You would think this would come from a space related publication.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rpapo on 09/21/2015 03:33 pm
The picture of Musk in the space-suit seems somehow photoshopped, at least to me.  There's little doubt about the other shot, though: it matches up with the video released not long ago.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: acsawdey on 09/21/2015 03:36 pm
I'm probably missing something obvious; what is preventing the astros feet from falling off the foot rest during launch? It seems you'd need something behind the heel while lying on your back.

I think he's not actually all the way in the seat. If you compare to the one next to him, he is sitting on the edge of the seat. If he was all the way back into it, his heels would be more naturally on the foot rest. Probably the picture was taken while he was climbing into or out of the seat.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mr. mark on 09/21/2015 03:46 pm
Photos were taken by Annie Leibovitz. She tends not to photo shop her work. It's most likely the real deal. She has very high standards.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mfck on 09/21/2015 04:09 pm
The suit photo is somewhat Reich... though, it lacks a peak cap to really get in style.

 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Dante80 on 09/21/2015 04:20 pm
Believe it or not Vogue magazine. http://www.vogue.com/13349221/elon-musk-profile-entrepreneur-spacex-tesla-motors/ (http://www.vogue.com/13349221/elon-musk-profile-entrepreneur-spacex-tesla-motors/)  SpaceX tends to use non traditional means to get their message out there. You would think this would come from a space related publication.

Vogue is pretty relevant when you take pictures about space fashion. And both of those pictures fit the purpose. XD
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mr. mark on 09/21/2015 04:23 pm
Looks like the  rescue bed on the lower left slides in to the center box on the floor. At first I couldn't figure out if it was for small cargo or what but now I am rethinking that. The box acts as a retainer holding the bed snuggly to the floor.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Joaosg on 09/21/2015 04:37 pm
I'm just gonna leave here the full size pictures of the Vogue website if someone wants to see all the details.

Thanks for the great post mr.mark!

In the lower left corner it is indeed an emergency kit!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DanielW on 09/21/2015 05:45 pm
Any ideas what the mini ping-pong table behind the pilot seats is for? magnetic bulletin board?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mr. mark on 09/21/2015 05:52 pm
Don't see the point if it's just a funny looking graphic. Maybe considering position possible window placement or transparent video screens. Shuttle had windows in a similar position. Transparent video screen windows could give on approach gauging while getting a real eye view. https://www.youtube.com/watch?t=18&v=R4NGB8OWnXg
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jarnis on 09/21/2015 06:01 pm
That suit looks mighty interesting. Can't wait until the full gory details about it - I don't think there has been a genuinely new pressure suit design in decades...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mvpel on 09/21/2015 06:01 pm
Photos were taken by Annie Leibovitz. She tends not to photo shop her work. It's most likely the real deal. She has very high standards.

I think the Photoshopped appearance arises from the reflections in the outside surface of the faceplate around the left and right sides of his face. If you look at the full size one, it's evident that it's the real deal. Which is impossibly cool.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: 216pi on 09/21/2015 06:09 pm
Photos were taken by Annie Leibovitz. She tends not to photo shop her work. It's most likely the real deal. She has very high standards.
Leibovitz Photoshops all the time, any time. Her last picture set with Queen Elizabeth was a 15 minutes inside session. Yet they released an iconic photo of the queen, outside in stormy weather.

Ninja edit: https://iconicphotos.wordpress.com/2009/06/10/queen-elizabeth-by-annie-leibowitz/ and https://www.youtube.com/watch?v=meTECfGfoMI
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rcoppola on 09/21/2015 06:12 pm
WRT the Controls Panel. Is it still moveable or now stationary? It looks as if the new panel design is not meant to move but rather integrated into the structure. Not sure. From the angle, I suppose I could see being able to still fold it backwards against the rear wall. Seems like the corners of the panels would clear the indented curve.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rcoppola on 09/21/2015 06:26 pm
Can we please not get into a Photoshop debate? Whether they composited his head in there or not and/or used whatever collection of filters to compose the final published image, really doesn't matter.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cambrianera on 09/21/2015 07:22 pm
4. center pusher added.   this as i understand it is either a change to explosive bolts that seperate the stages, or in addition to the bolts?   presumably it doesn't relate to extra thurst or reuse so much as flight success by having cleaner seperations.   anything missing here?

Transferring kinetic energy of first stage to second stage is a positive outcome of stage separation.
Normally this has very small value due to the forces involved (no way to fit a very big device, and not worth the mass)..
In the case of F9R the benefit is twofold:
-small increase in kinetic energy of second stage (still small)
-decrease of kinetic energy of first stage.
This second part could be of bigger value, considering that every m/s lost this way saves propellant otherwise needed for the braking burn.
I'm waiting to see the details to understand if this could be the case.

Interesting thought. I wonder how much fuel might it be possible to 'save' for 1st stage return by giving the 2nd stage a good shove? I suspect 'not a lot'.

Your suspicion is right; a little bit of calculations after posting showed me that saving more than few hundred kg of propellant is very difficult.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: FishInferno on 09/21/2015 08:39 pm
The new suit loos awesome, the astronauts should have much more freedom of movement.  But is black really the best color? I suspect the actual suits will be white.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: StuffOfInterest on 09/21/2015 08:54 pm
The new suit loos awesome, the astronauts should have much more freedom of movement.  But is black really the best color? I suspect the actual suits will be white.
If these are primarily to act as launch and reentry suits then you can probably bet on orange for high visibility in rescue situations.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mr. mark on 09/21/2015 08:55 pm
Why should they be white? These are flight suits not EVA suits. Aside from ISS transfer and Dragon flight they are not going anywhere.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: laika_fr on 09/21/2015 08:57 pm
Forget about photoshop, that's one small step for manned spaceflight.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: LastStarFighter on 09/21/2015 09:14 pm
Why should they be white? These are flight suits not EVA suits. Aside from ISS transfer and Dragon flight they are not going anywhere.

I agree these are most definitely just launch and return pressure suits. Does anyone know what NASA set as the requirements for these and how they compare to past/current launch and return suits?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: starsilk on 09/21/2015 09:19 pm
The new suit loos awesome, the astronauts should have much more freedom of movement.  But is black really the best color? I suspect the actual suits will be white.
If these are primarily to act as launch and reentry suits then you can probably bet on orange for high visibility in rescue situations.

that would ruin the aesthetics! but seriously, you don't have to wear orange clothes when you go out on a boat, you just put on an orange life preserver before you abandon ship...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Zed_Noir on 09/21/2015 09:27 pm
The new suit loos awesome, the astronauts should have much more freedom of movement.  But is black really the best color? I suspect the actual suits will be white.
If these are primarily to act as launch and reentry suits then you can probably bet on orange for high visibility in rescue situations.

My preference is the scarlet & gold colour scheme like the one on the statue (http://forum.nasaspaceflight.com/index.php?topic=35381.msg1424744#msg1424744) in the Hawthorne lobby.  ;D
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 09/21/2015 11:52 pm
Maybe it turns orange if exposed to water :)   I hope it doesn't turn black when exposed to heat.

That would be a cool heat management trick though on an EVA suit though.  Color change in general, that is
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: savuporo on 09/22/2015 12:14 am
Forget about photoshop, that's one small step for manned spaceflight.

One small step for a manned spaceflight, one huge trip for an ego ;)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: TrevorMonty on 09/22/2015 03:28 am
The new suit loos awesome, the astronauts should have much more freedom of movement.  But is black really the best color? I suspect the actual suits will be white.
If these are primarily to act as launch and reentry suits then you can probably bet on orange for high visibility in rescue situations.
I doubt colour is that important when it comes to being rescued.
If you are not in the capsule when they rescue you, they are probably looking for a body or parts of.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 09/22/2015 04:16 am
The new suit loos awesome, the astronauts should have much more freedom of movement.  But is black really the best color? I suspect the actual suits will be white.
If these are primarily to act as launch and reentry suits then you can probably bet on orange for high visibility in rescue situations.
I doubt colour is that important when it comes to being rescued.
If you are not in the capsule when they rescue you, they are probably looking for a body or parts of.

There's the scenario that the capsule is in the water and sinking and the crew gets out - it could be quite a while before the rescue teams arrive.   

Why is the capsule sinking?  Maybe damage from the exploding rocket.

Then there's the famous Soyuz cliff hanger (which almost happened)  Capsule lands on a slope, is unstable, the crew gets out, the capsule rolls away.

But there are other visual aids that can replace orange.  For example Strobe lights and retro-reflectors can be very effective, especially when lighting is poor. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JamesH on 09/22/2015 08:37 am
The new suit loos awesome, the astronauts should have much more freedom of movement.  But is black really the best color? I suspect the actual suits will be white.
If these are primarily to act as launch and reentry suits then you can probably bet on orange for high visibility in rescue situations.

that would ruin the aesthetics! but seriously, you don't have to wear orange clothes when you go out on a boat, you just put on an orange life preserver before you abandon ship...

I wear yellow reflective sailing gear when offshore.....it's a free safety feature - why wouldn't you do it? There may not be time to put on a life jacket.....
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JasonAW3 on 09/22/2015 03:48 pm
Forget about photoshop, that's one small step for manned spaceflight.

One small step for a manned spaceflight, one huge trip for an ego ;)

He may have an ego, but he's certainly getting the job done! Can't argue with results.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: AncientU on 09/22/2015 08:11 pm
Dragon 2 is designed to land on land; suit as designed would be for that end.

Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 09/22/2015 08:43 pm
Dragon 2 is designed to land on land; suit as designed would be for that end.

That is the eventual goal, but Dragon 2 must always be capable of landing in water during abort scenarios. So the suit must be designed for that.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 09/22/2015 10:00 pm
Dragon 2 is designed to land on land; suit as designed would be for that end.

It is designed to land on land if everything goes well, but it is also designed to offer survivability if there was an abort anytime between launch and orbit.  Airplanes are designed to land on runways at airports, but they carry life-jackets and inflatable chutes just in case they don't.  And those have been used many times, they're are definitely not dead weight.



Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cebri on 09/26/2015 08:55 am
Falcon 1.2 First-Stage Static Fire  ;)

https://www.youtube.com/watch?v=qbe1KNUBEEU
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Roy_H on 09/27/2015 06:11 pm
Does anyone know how much water is used for the flame trench in these static fires? ISTM that at Canaveral, they have a large pond of water and have this "Niagra" water system dumping tons of water on the pad and into the flame trench. Presumably this is to minimize damage to the flame trench as well as reducing noise from take-off. All this water for a few seconds before the rocket is clear of the pad. But at McGregor, they talk of full duration filght simulation static fire and no apparent large water supply.  Am I wrong in my assumptions?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 09/27/2015 09:05 pm
Presumably this is to minimize damage to the flame trench

No, it is just for sound suppression to protect the payload.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 09/27/2015 11:44 pm
Does anyone know how much water is used for the flame trench in these static fires? ISTM that at Canaveral, they have a large pond of water and have this "Niagra" water system dumping tons of water on the pad and into the flame trench. Presumably this is to minimize damage to the flame trench as well as reducing noise from take-off. All this water for a few seconds before the rocket is clear of the pad. But at McGregor, they talk of full duration filght simulation static fire and no apparent large water supply.  Am I wrong in my assumptions?
They can get salt water with a deep enough well there, but that seems like a bad idea.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 09/28/2015 03:12 pm
There is a large water tower at MacGregor, take a look at some of the pics posted here.  Presumably each test uses a large fraction of the capacity of that tower.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 09/28/2015 03:55 pm
The tower holds 500,000 gallons and is 280 feet tall.

Waco Tribune.... (http://www.wacotrib.com/waco_today_magazine/spacex-blasting-into-the-future-a-waco-today-interview-with/article_6710295c-9151-59ba-b091-99aeade5beff.html)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: edkyle99 on 09/29/2015 02:19 am
Falcon 1.2 First-Stage Static Fire  ;)
In this video SpaceX calls it the "Upgraded Falcon 9".  At a recent conference is was "Falcon 9 Upgrade".  It is supposedly formally called "Falcon 9 v1.1 Full Thrust" by the company.  The only thing SpaceX has never called it to my knowledge is "Falcon 9 v1.2", and certainly never "Falcon 1.2".

 - Ed Kyle
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: wannamoonbase on 09/29/2015 03:40 am
There is a large water tower at MacGregor, take a look at some of the pics posted here.  Presumably each test uses a large fraction of the capacity of that tower.

Hopefully it's sized for a full duration test of a FH.  500,000 gallons over approximately 3 minutes.   2800 gallons per second.  Hope that covers it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DatUser14 on 09/29/2015 11:21 am
I had a thought. Could the crew dragon trunk have a sturdy stiffener ring that goes around the bottom of the entire trunk, and could this be used to support its own weight (this would imply the trunk survived entry without the heat shield, maybe use this for non atmospheric missions).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: oiorionsbelt on 10/05/2015 04:18 am
This has been my wallpaper for awhile.
I can't wait to see few frames forward.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: oiorionsbelt on 10/05/2015 04:30 am
Next time we will be seeing a F9 v1 FT at minimum thrust
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: tyrred on 10/05/2015 05:44 am
Took me a sec to process, but yeah... Maximizing the most of what the rocket can't least do best?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 10/05/2015 06:17 am
Took me a sec to process, but yeah... Maximizing the most of what the rocket can't least do best?

Almost (but not quite) not too badly said.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 10/05/2015 03:30 pm
Next time we will be seeing a F9 v1 FT at minimum thrust
F9 v1.1 FT, right?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: spacenut on 10/05/2015 03:37 pm
Does the increased thrust help slow down the landing of the booster? 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: FishInferno on 10/05/2015 03:46 pm
Does the increased thrust help slow down the landing of the booster?

I doubt they will run the deceleration burn at a higher thrust than they do currently, as the TWR is already very high on a spent stage running minimum throttle.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: zlsa on 10/08/2015 06:39 pm
A render of the Falcon 9 booster after landing at LC-1.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 10/08/2015 07:23 pm
A render of the Falcon 9 booster after landing at LC-1.

Points for being a tad off-center!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MattMason on 10/08/2015 07:51 pm
A render of the Falcon 9 booster after landing at LC-1.

Hey! I won the targeting game! :)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: xpete on 10/26/2015 05:00 pm
Dragon photos shared by Elon on twitter:
https://www.flickr.com/photos/nasa2explore/sets/72157657540415831?utm_content=bufferda58e&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: NovaSilisko on 10/30/2015 07:52 pm
Slow motion footage of pad abort test! https://twitter.com/SpaceX/status/660195847599091712
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 10/31/2015 12:22 am
Outstanding!

(wish it were longer)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Vultur on 11/23/2015 02:14 am
Does anyone know the structure fraction/mass ratio of a F9v1.1 first stage with landing legs attached?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Dante80 on 11/23/2015 07:33 am
Does anyone know the structure fraction/mass ratio of a F9v1.1 first stage with landing legs attached?

I get this from here (http://spaceflight101.com/spacerockets/falcon-9-v1-1-f9r/).

Total Mass ~ 421,300kg
Inert Mass ~25,600kg
Propellant Mass 395,700kg
LOX Mass 276,600kg
RP-1 Mass 119,100kg
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 11/23/2015 03:15 pm
Does anyone know the structure fraction/mass ratio of a F9v1.1 first stage with landing legs attached?

I get this from here (http://spaceflight101.com/spacerockets/falcon-9-v1-1-f9r/).

Total Mass ~ 421,300kg
Inert Mass ~25,600kg
Propellant Mass 395,700kg
LOX Mass 276,600kg
RP-1 Mass 119,100kg
The article admits that empty mass is just a guess.

"The empty mass of the first stage is not known, but can be estimated at around 23 to 26 metric tons"
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: philw1776 on 11/23/2015 03:23 pm
Old, not SX site.  No leg mass. No mass for "improved" fins and thruster fuel for landing, etc.
We really don't know.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cambrianera on 11/23/2015 07:08 pm
This was my take on F9 v1.1 first stage mass, based on AF documents on F9 v1.0 mass:
http://forum.nasaspaceflight.com/index.php?topic=31514.msg1034291#msg1034291
No legs, no internal stiffeners for legs, no grid fins.
Legs should be about 2000 kg (old Elon tweet).
Here is the thread generated by CRS-6 post launch briefing, stating a mass of 60-70 klbs for the landing stage.
https://forum.nasaspaceflight.com/index.php?topic=37304.msg1358917#msg1358917

23000 to 26000 kg seems fine for dry mass
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MarekCyzio on 11/24/2015 05:27 pm
Not sure if this is the right thread, but The Wall Street Journal published a video and a bunch of photos from inside of SpaceX factory:
http://www.wsj.com/articles/model-karlie-kloss-takes-off-1448295895

Yeah, there is a model on them, but if you ignore her, you will see the new "sport" interstage I believe + many more.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DatUser14 on 11/24/2015 06:04 pm
Some shots of nosecones, falcon heavy?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ugordan on 11/24/2015 06:09 pm
Ahh, so that's what SpaceX was up to while some other folks were busy with soft-landing their returned stage.

/snark
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DatUser14 on 11/25/2015 12:15 am
Is it known how high the first stage gets in altitude post separation from the second stage and before boostback, I looked in the graph that Spacex posted before CRS-6 but it has no altitude numbers.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Coastal Ron on 11/25/2015 01:37 am
Is it known how high the first stage gets in altitude post separation from the second stage and before boostback, I looked in the graph that Spacex posted before CRS-6 but it has no altitude numbers.

If the January 2015 SpaceX-5 CRS flight is any indication, SpaceFlightNow is showing (http://spaceflightnow.com/2015/01/05/falcon-9-spacex-5-launch-timeline/) that MECO happens at 80km in altitude at a velocity of Mach 10.  We know from the flight profile graphic SpaceX has provided that the stage "boostback burn" which gains altitude as it reduces forward velocity.  I haven't noticed anyone referencing what the highest altitude is though.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Craig_VG on 11/25/2015 03:06 am
Some shots of nosecones, falcon heavy?

Yes, I remember reading an article where they talked about the nosecones sitting in the factory. It seems they've been waiting for the rest of the vehicle for some time now.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: 2552 on 11/29/2015 01:58 am
New Falcon 9 User's Guide (http://www.spacex.com/sites/spacex/files/falcon_9_users_guide_rev_2.0.pdf) available on spacex.com, linked from the Falcon 9 page.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 11/29/2015 02:14 am
New Falcon 9 User's Guide (http://www.spacex.com/sites/spacex/files/falcon_9_users_guide_rev_2.0.pdf) available on spacex.com, linked from the Falcon 9 page.
...and with almost no information about payload capability. :C
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: deltaV on 11/29/2015 04:05 am
1. That users guide mentions that Falcon uses an "Iridium/GPS tracker" and "radar altimeter" during "stage recovery". This is not at all surprising but it's nice to keep track of what SpaceX has confirmed.

2. The payload's acoustic environment is 131.4 dB. For comparison that's over 10,000 times more power than 85 dB, which is already enough to damage human hearing if prolonged!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: CyndyC on 11/29/2015 08:23 pm
After separating from the 2nd stage at 80km and Mach 10, the 1st stage continues to an apogee of about 140km, according to a description towards the end of the section "First Stage Re-Use" in the middle of the page at http://spaceflight101.com/spacerockets/falcon-9-v1-1-f9r/.

Some of the info on that page you'll see is a bit dated though, considering they're saying SpaceX will be changing their engines from a tic-tac-toe arrangement to an octaweb, and from the Merlin 1Cs to the Merlin 1Ds, but they're saying those changes will be occurring with the switch from Falcon v1.0 to v1.1. I thought the v1.1 was the version they are just now changing to. The Wikipedia page on Merlin engines seems to indicate the 1D has been in use for awhile, and I think everyone already knows the octaweb has. The 1C had no throttle capability, whereas the 1D does, and the seconds off timing of a throttle valve command was what skewed the last landing attempt. 


Is it known how high the first stage gets in altitude post separation from the second stage and before boostback, I looked in the graph that Spacex posted before CRS-6 but it has no altitude numbers.

If the January 2015 SpaceX-5 CRS flight is any indication, SpaceFlightNow is showing (http://spaceflightnow.com/2015/01/05/falcon-9-spacex-5-launch-timeline/) that MECO happens at 80km in altitude at a velocity of Mach 10.  We know from the flight profile graphic SpaceX has provided that the stage "boostback burn" which gains altitude as it reduces forward velocity.  I haven't noticed anyone referencing what the highest altitude is though.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: edkyle99 on 11/29/2015 08:35 pm
Some of the info on that page you'll see is a bit dated though, considering they're saying SpaceX will be changing their engines from a tic-tac-toe arrangement to an octaweb, and from the Merlin 1Cs to the Merlin 1Ds, but they're saying those changes will be occurring with the switch from Falcon v1.0 to v1.1. I thought the v1.1 was the version they are just now changing to. The Wikipedia page on Merlin engines seems to indicate the 1D has been in use for awhile, and I think everyone already knows the octaweb has. The 1C had no throttle capability, whereas the 1D does, and the seconds off timing of a throttle valve command was what skewed the last landing attempt. 
Falcon 9 v1.1 with Octaweb first flew on September 29, 2013.  The next launch will be performed by the first "Falcon 9 v1.1 Full Thrust", which many have taken to calling "Falcon 9 FT" because it is much easier to type and say.  "Falcon 9 FT" also uses Octaweb and Merlin 1D, but ratchets up the engine's chamber pressure a bit to get more thrust and ISP.  The rocket itself will use a stretched second stage and a lengthened interstage, among other changes.

 - Ed Kyle
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: CyndyC on 11/29/2015 09:01 pm
Ok, but without going back and looking, pretty sure the talk on these boards in only recent months was that the newly upgraded version was called 1.1, and it wasn't until later the name was changed as if for a 2nd time, to Full Thrust. There was some confusion over that for awhile, in L2 even, and your post makes the issue clearer than before. I think Chris and SpaceX_MS were saying there's one last 1.0 still around too, so maybe they meant the pre-upgraded 1.1, but whichever, last I read the thread myself, they'll be using it for Jason 3.

Some of the info on that page you'll see is a bit dated though, considering they're saying SpaceX will be changing their engines from a tic-tac-toe arrangement to an octaweb, and from the Merlin 1Cs to the Merlin 1Ds, but they're saying those changes will be occurring with the switch from Falcon v1.0 to v1.1. I thought the v1.1 was the version they are just now changing to. The Wikipedia page on Merlin engines seems to indicate the 1D has been in use for awhile, and I think everyone already knows the octaweb has. The 1C had no throttle capability, whereas the 1D does, and the seconds off timing of a throttle valve command was what skewed the last landing attempt. 
Falcon 9 v1.1 with Octaweb first flew on September 29, 2013.  The next launch will be performed by the first "Falcon 9 v1.1 Full Thrust", which many have taken to calling "Falcon 9 FT" because it is much easier to type and say.  "Falcon 9 FT" also uses Octaweb and Merlin 1D, but ratchets up the engine's chamber pressure a bit to get more thrust and ISP.  The rocket itself will use a stretched second stage and a lengthened interstage, among other changes.

 - Ed Kyle
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 11/29/2015 09:03 pm
No, Ed is correct.

The board wanted to call the new version v1.2, the confusion was that SpaceX is keeping the 1.1 version number and just adding "full thrust" to the end of the name, as Ed says.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Zed_Noir on 11/29/2015 09:40 pm
From page 17 of the new 2015 Falcon 9 user guide
Quote
Secondary payloads may be manifested on a variety of secondary payload adapters
including an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) ring, a
SpaceX-developed Surfboard, or other mission-unique secondary deployment structures.

Anyone know what the Surfboard is?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Coastal Ron on 11/29/2015 09:46 pm
I think Chris and SpaceX_MS were saying there's one last 1.0 still around too, so maybe they meant the pre-upgraded 1.1, but whichever, last I read the thread myself, they'll be using it for Jason 3.

Jason 3 will be the last of what has been the current Falcon 9 configuration, which is the v1.1.

Falcon 9 version 1.0 had the 3x3 engine arrangement, Merlin 1C engines, and smaller 1st stage tanks.  Plus they had no landing legs.  The last of those was flown over two years ago on March 13, 2013.

Falcon 9 v1.1 has the octaweb engine layout, stretched 1st stage tanks, and all the enhancements for landing.  The Merlin 1D engine it uses was built to produce "full thrust", but as I recall they weren't done certifying the high end of the thrust range, so they decided to "derate" them (reduce the amount of thrust they could produce) but still use them.

So the "Full Thrust" version is essentially what is flying today, but with the Merlin 1D's being certified for the thrust range they were designed to handle.  And though they may have made minor tweaks to some of the other parts on the Falcon 9, especially the landing system, SpaceX doesn't feel that merits a version bump.

Hope that helps.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: AnalogMan on 11/29/2015 09:54 pm
From page 17 of the new 2015 Falcon 9 user guide
Quote
Secondary payloads may be manifested on a variety of secondary payload adapters
including an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) ring, a
SpaceX-developed Surfboard, or other mission-unique secondary deployment structures.

Anyone know what the Surfboard is?

• SpaceX Surfboard
  – Mounting tray installed on aft‐end of 2nd stage carries several 3U or 6U [cubesat] dispensers
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: RoboGoofers on 11/30/2015 03:01 pm
From page 17 of the new 2015 Falcon 9 user guide
Quote
Secondary payloads may be manifested on a variety of secondary payload adapters
including an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) ring, a
SpaceX-developed Surfboard, or other mission-unique secondary deployment structures.

Anyone know what the Surfboard is?

• SpaceX Surfboard
  – Mounting tray installed on aft‐end of 2nd stage carries several 3U or 6U [cubesat] dispensers

Is that an official bulletpoint? I would think the most surfboard-like thing they have is the fairings, a la Darkstar.

This video makes me think they were interested in what happens to the fairings on descent:
https://www.youtube.com/watch?v=4_sLTe6-7SE

maybe mount a couple experiments on the fairing?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: AnalogMan on 11/30/2015 06:47 pm
From page 17 of the new 2015 Falcon 9 user guide
Quote
Secondary payloads may be manifested on a variety of secondary payload adapters
including an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) ring, a
SpaceX-developed Surfboard, or other mission-unique secondary deployment structures.

Anyone know what the Surfboard is?

• SpaceX Surfboard
  – Mounting tray installed on aft‐end of 2nd stage carries several 3U or 6U [cubesat] dispensers

Is that an official bulletpoint? [...]

Page 17 of this presentation:

Secondary Payload Adapters and Interfaces - Technical Committee Report
https://www.sprsa.org/sites/default/files/conference-presentation/Rideshare2015_Secondary-Adapters_Tech-Committee_Maly-Rev0.pdf (https://www.sprsa.org/sites/default/files/conference-presentation/Rideshare2015_Secondary-Adapters_Tech-Committee_Maly-Rev0.pdf)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Llian Rhydderch on 12/06/2015 03:14 am
This was posted on the Spaceport America thread:

Nice aerial view:

https://www.youtube.com/watch?v=oxgE02nhOL8

What is it that is shown at 0:41?  Is it possibly related to SpaceX's F9R-Dev ground support equipment there?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Comga on 12/06/2015 03:23 am
This was posted on the Spaceport America thread:

Nice aerial view:

What is it that is shown at 0:41?  Is it possibly related to SpaceX's F9R-Dev ground support equipment there?

It does look like the four piece mount on shore in Jaxsonville that is somewhat visible in the cruise ship webcam images (http://forum.nasaspaceflight.com/index.php?topic=36326.msg1453340#msg1453340) as the ship turns away from the ASDS.

Most of this video looks computer generated. Maybe because there hasn't been enough activity to mar the freshly built surfaces.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: chalz on 12/06/2015 07:49 pm

Most of this video looks computer generated. Maybe because there hasn't been enough activity to mar the freshly built surfaces.

In case you are not being facetious I think the clear desert air and bright sun can give it that appearance. Also drones can do camera movements that previously were only possible in computer graphics or very expensive film productions.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 12/06/2015 10:27 pm
Clear desert air, bright sun, and no actual use to dirty things up.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: intrepidpursuit on 12/07/2015 06:29 pm
...
2. The payload's acoustic environment is 131.4 dB. For comparison that's over 10,000 times more power than 85 dB, which is already enough to damage human hearing if prolonged!

They quote 131.4 dB as including margin for qualification testing, i.e. worst possible case scenario and then some. The highest actual real reading they show is ~126 dB and that is at 120hz. It also mentions that the worst case numbers these are derived from only happen at liftoff and or at transonic speeds. Since these are numbers for inside the fairing, as soon as they go supersonic they aren't hearing the engines anymore, and at transonic speeds it is the atmospheric excitation that is making all the noise.

All this being said, that number is flat, not A-weighted as hearing damage numbers would be measured. Looks like A-weighted the numbers would never breach 115db. Plus, a human would probably have more protection than the PLF. So all in all, not so bad. :-)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: OxCartMark on 12/08/2015 03:01 am
I'm curious to know how sound levels in a payload fairing compare with those in a capsule / Dragon.  How loud is it in a capsule?  How much of the sound is coming from the flexing of the PLF walls which I presume wouldn't be much of a factor in the more heavily built pressure vessel of a capsule?

And while we're on the topic of sound, did anyone ever hear anything on the sound levels in Dragon 2 during the 8x SD pad abort test?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Roy_H on 12/09/2015 02:38 pm
...
2. The payload's acoustic environment is 131.4 dB. For comparison that's over 10,000 times more power than 85 dB, which is already enough to damage human hearing if prolonged!

They quote 131.4 dB as including margin for qualification testing, i.e. worst possible case scenario and then some. The highest actual real reading they show is ~126 dB and that is at 120hz. It also mentions that the worst case numbers these are derived from only happen at liftoff and or at transonic speeds. Since these are numbers for inside the fairing, as soon as they go supersonic they aren't hearing the engines anymore, and at transonic speeds it is the atmospheric excitation that is making all the noise.

All this being said, that number is flat, not A-weighted as hearing damage numbers would be measured. Looks like A-weighted the numbers would never breach 115db. Plus, a human would probably have more protection than the PLF. So all in all, not so bad. :-)

I doubt that. You are making the assumption that the sound in the fairing is mostly transmitted via the outside air. I maintain the sound is transmitted through the structure of the rocket and has nothing to do with the speed of the rocket.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jim on 12/09/2015 02:58 pm
The primary acoustic environment is from liftoff and reflection of the sound from the ground.

The next is from the PLF vents and shockwaves passing by.

What is transmitted through the airframe is called random vibration.  Acoustical environment is energy transmitted by air pressure.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Rei on 12/09/2015 04:08 pm
Falcon 9 v1.1 has the octaweb engine layout, stretched 1st stage tanks, and all the enhancements for landing.  The Merlin 1D engine it uses was built to produce "full thrust", but as I recall they weren't done certifying the high end of the thrust range, so they decided to "derate" them (reduce the amount of thrust they could produce) but still use them.

So the "Full Thrust" version is essentially what is flying today, but with the Merlin 1D's being certified for the thrust range they were designed to handle.

The "Full Thrust" difference is that they're using supercooled propellants, including having the liquid oxygen only a degree over its freezing point. This increases their density.  More density means more fuel flow. More fuel flow means more thrust.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Coastal Ron on 12/09/2015 09:44 pm
The "Full Thrust" difference is that they're using supercooled propellants...

That was part of it, but not all of it.  There were structural changes and improvements too.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nomadd on 12/10/2015 12:51 am


The "Full Thrust" difference is that they're using supercooled propellants, including having the liquid oxygen only a degree over its freezing point. This increases their density.  More density means more fuel flow. More fuel flow means more thrust.

You get a little more fuel flow for the same turbopump rpm, but that's not really the point since the pumps would still need to be more powerful because they're moving greater mass. More density means more fuel.  You need full thrust with super cooled fuel because you're carrying more fuel and the rocket weighs more.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 12/10/2015 04:23 am
Pump power is more directly related to volume than to mass, actually.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Zed_Noir on 12/10/2015 06:08 am
Got a question about the Boca Chica launch site. Will the USAF/NRO considered using that site for some missions, Like for GEO orbits?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Rei on 12/10/2015 10:15 am
You get a little more fuel flow for the same turbopump rpm, but that's not really the point since the pumps would still need to be more powerful because they're moving greater mass.

It works in both directions - the energy that turbopumps need to expend increases with increased propellant density, but their turbines also produce more power as propellant density increases.

The overall forces on the system are greater and they have to be able to handle that (also the viscosity is greater and a number of other differences), but if the system can take the loading, the additional power should roughly cancel out the increased load from having to pump a greater mass of fuel.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JBF on 12/10/2015 01:26 pm
Got a question about the Boca Chica launch site. Will the USAF/NRO considered using that site for some missions, Like for GEO orbits?

Probably not; the site won't be securable to MILSPEC based on current plans available.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: CraigLieb on 12/10/2015 02:24 pm
Will launches to MARS not be considered national security missions?   
       "Hey let's take over an entire new planet. Departure from Boca Chica!"
 It may be the most important launch site in the history of man-kind.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 12/10/2015 03:49 pm
Will launches to MARS not be considered national security missions?   
       "Hey let's take over an entire new planet. Departure from Boca Chica!"
 It may be the most important launch site in the history of man-kind.


If Mars was considered a national security destination, Constellation would never have been cancelled, or at least the SLS would have been prioritized along with real exploration hardware.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 12/10/2015 04:45 pm
Mostly because congress doesn't have the vision to understand just how important a Mars colony will be.


Will launches to MARS not be considered national security missions?   
       "Hey let's take over an entire new planet. Departure from Boca Chica!"
 It may be the most important launch site in the history of man-kind.


If Mars was considered a national security destination, Constellation would never have been cancelled, or at least the SLS would have been prioritized along with real exploration hardware.

Will launches to MARS not be considered national security missions?   
       "Hey let's take over an entire new planet. Departure from Boca Chica!"
 It may be the most important launch site in the history of man-kind.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: RonM on 12/10/2015 05:32 pm
Let's not confuse importance with national security.

National security is the safety of a nation against threats such as terrorism, war, or espionage. Basically, protecting the state and its citizens. Unless the US is planning on moving the entire country to Mars in the greatest act of isolationism of all time, a Mars colony doesn't add to US national security.

NASA isn't going to colonize Mars. Fortunately, SpaceX is going to give it a try. Maybe NASA can chip in by paying to putting instruments on a Red Dragon or two.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mader Levap on 12/10/2015 06:42 pm
NASA isn't going to colonize Mars. Fortunately, SpaceX is going to give it a try.
Um, no, SpaceX won't. They will provide service for someone that can afford "colonizing Mars", whatever that soundbite actually means.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 12/10/2015 08:44 pm
NASA isn't going to colonize Mars. Fortunately, SpaceX is going to give it a try.
Um, no, SpaceX won't. They will provide service for someone that can afford "colonizing Mars", whatever that soundbite actually means.

That was his aim initially. However with his Seattle presentation it became clear that he has realized he needs to get the ball rolling himself because no one else would do it. So he has taken on the task of at least initiating colonization himself. True that he cannot go it alone and is counting on others stepping in, once he has proven it can be done and give it a price tag.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Nilof on 12/11/2015 06:39 am
Will launches to MARS not be considered national security missions?   
       "Hey let's take over an entire new planet. Departure from Boca Chica!"
 It may be the most important launch site in the history of man-kind.

For the same reason that boat trips to Greenland weren't considered a national security mission in the 1400s. Remote desolate places are rarely particularly strategic unless they have something that they can meaningfully export back to the homeland at a profit.

The moon on the other hand was definitely viewed as a national security destination in the 60s, before the OST. Beyond restoring a wounded national prestige it was considered to be a good place for a nuclear missile base by a lot of people in the USAF, and this was used as an argument for going to the moon in the very early days of the space program.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Bynaus on 12/11/2015 07:05 am
I think (perhaps rather: hope) there is a chance we might see the Falcon Heavy Demo mission sending the "Pad Abort" Dragon 2 on a free-return trajectory around the moon next year (unmanned, of course). Just because they can and that unit is of no particular use anymore (in-flight abort test will use the re-used orbital test Dragon 2). While technically not "lunar orbit", it would still be a first for a commercial company, a stunner if it works and it would clearly show the whole world where SpaceX stands in comparison with its competition (home and abroad). So my guess is: private.
While I appreciate your enthusiasm, even if they used the FH demo mission for something like this, which I personally think they will not, that still doesn't get you to Human return, which is what the poll is about.

Also, the Pad Abort vehicle is absolutely being used for other purposes.

Agreed, it would not be an immediate return of humans to the Moon, but it could set the stage and show what is possible. A manned mission with a similar profile (e.g., commercial, perhaps the long-rumored Space Adventures circumlunar excursion rebooted with SpaceX hardware) could come a few years later, once manned Dragon 2s have flown repeatedly to the ISS and back. That would be still long before 2023, when NASA plans to be in the vicinity of the Moon, or whenever the Chinese feel ready to go.

What is the Pad Abort vehicle used for? As far as I know, the evolution of Crew Dragon (or Dragon 2) has moved beyond that piece of hardware, so I am not sure it can still play a significant role. The only thing I am not sure is whether it actually has a fully functional heat shield.
In answer to your Pad Abort Vehicle use question:

http://www.nasaspaceflight.com/2015/10/spacex-dragonfly-arrives-mcgregor-testing/
Ok, but that is not mutually exclusive: FH Demo will be NET April 2016, plenty of time to do some DragonFly tests...
We're off topic, so I'll end with this. I respectfully suggest, if you haven't already, that you read further on the DragonFly testing program. These tests are critical to their multi-billion dollar D2 CC program. This testing program will be lengthy and exhaustive to prove out and refine propulsive landing profiles/capabilities. That is the first and only priority for this vehicle. And there is no guarantee that it will not be tested to its limits and/or, that it will survive the testing regime. FH will fly in the configuration they will need for AF certification, meaning it will have a fairing, not a Dragon for the initial fights. If you're interested in the most likely scenario for a Dragon variant launching on a FH, I suggest you search on Red Dragon.

I'll answer here since we were off-topic in the other thread. You are right that it seems likely that this idea (using the Pad Abort Dragon for an unmanned circum-lunar mission on the first FH launch) will not work out, and yes, it would also seem likely that the first FH will have a payload shroud to demonstrate this technology for the most likely customers of FH. Okay.

I still wonder, then, if SpaceX might launch the FH Demo upper stage to a free-return trajectory around the Moon (or towards Mars, if the launch happens in time to make the spring 2016 launch window, which seems a bit dubious since it ends in April...). Like I said, it would be a very inspiring feat, even if the stage burns up in the Earth's atmosphere upon return (or fly-bys at Mars). If it's sent towards Mars, it could be seen as a proof of principle for a Red Dragon delivery (I am well aware of that project).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mader Levap on 12/11/2015 11:40 am
That was his aim initially. However with his Seattle presentation it became clear that he has realized he needs to get the ball rolling himself because no one else would do it.
Geee, wonder why. Let me guess three reasons. Money, money and money. Did I mentioned money?

So he has taken on the task of at least initiating colonization himself.
He will never have sort of money needed for that...

True that he cannot go it alone and is counting on others stepping in, once he has proven it can be done and give it a price tag.
...and lack of money is exactly why he cant go alone.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: guckyfan on 12/11/2015 12:34 pm
So he has taken on the task of at least initiating colonization himself.
He will never have sort of money needed for that...

I will take Elon Musks opinion on this over yours any day. If you wonder what I refer to. Listen to his Seattle presentation, he was quite clear. Since then and even before that he has not mentioned that he wants to be only the transport provider. That's an old position.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JasonAW3 on 12/11/2015 01:50 pm
So he has taken on the task of at least initiating colonization himself.
He will never have sort of money needed for that...

I will take Elon Musks opinion on this over yours any day. If you wonder what I refer to. Listen to his Seattle presentation, he was quite clear. Since then and even before that he has not mentioned that he wants to be only the transport provider. That's an old position.

Hmmm,

     That presents a whole new infrastructure potentile.  Bigalow based Armstrong Cyclers, with SpaceX MCT craft and fuel tankers docking with them for the round trip to Mars, Venus, Earth and all points in between.

     This could also allow for more fuel and consumible economical flights to some of the NEO's both asteroid and cometary, that are near to the cycler's flight path.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: whitelancer64 on 12/11/2015 03:00 pm

The "Full Thrust" difference is that they're using supercooled propellants, including having the liquid oxygen only a degree over its freezing point. This increases their density.  More density means more fuel flow. More fuel flow means more thrust.

Do you (or any reader) have a source for your statement that SpaceX is cooling the LOX down to just a degree above its freezing point?

It's common knowledge that they are decreasing the temperature of the LOX, but I have not seen a source to determine the temperature to which it is being chilled.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 12/11/2015 03:11 pm
There is a source, though I can't dig it up from my phone.  The temperature is "just a degree above the triple point temperature of oxygen", which is well-defined. (Freezing point varies with pressure, and it's possible to be just a degree above triple point and yet relatively far from freezing if you manipulate the pressures.)

Edit: http://spaceflight101.com/spacerockets/falcon-9-ft/ is one source, though not a primary one.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: whitelancer64 on 12/11/2015 03:53 pm
There is a source, though I can't dig it up from my phone.  The temperature is "just a degree above the triple point temperature of oxygen", which is well-defined. (Freezing point varies with pressure, and it's possible to be just a degree above triple point and yet relatively far from freezing if you manipulate the pressures.)

Edit: http://spaceflight101.com/spacerockets/falcon-9-ft/ is one source, though not a primary one.

Thank you very much, cscott!!

I've been looking around for that information for ages! Though of course, if there's a more direct source I'd certainly appreciate seeing that as well.

By the way, have you launched your Falcon Heavy model rocket yet?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 12/11/2015 04:01 pm
There is a source, though I can't dig it up from my phone.  The temperature is "just a degree above the triple point temperature of oxygen", which is well-defined. (Freezing point varies with pressure, and it's possible to be just a degree above triple point and yet relatively far from freezing if you manipulate the pressures.)

Edit: http://spaceflight101.com/spacerockets/falcon-9-ft/ is one source, though not a primary one.

Actually, that website cites a LOX temperature one degree "below" the triple point, not "above." Even better!  ;)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 12/11/2015 05:42 pm
Ha!  A typo, for sure.  I found a source in L2 ( http://forum.nasaspaceflight.com/index.php?topic=37710.msg1417824.msg#1417824 ) but it mentions this temperature being "as discussed" which matches my recollection that there was a public statement of the 1-degree-above-triple-point target around the same time, which is where spaceflight101 would have inaccurately transcribed it from.

For the record, I believe this to be a target design temperature, not a definitive final measurement.  Now that SpaceX actually has their operational chillers online, I wouldn't be surprised if the actual achieved temperature is a little bit higher.  It certainly can't be much lower, though---unless you're launching a rocket pop.

(PS. I've fallen in love with my FH model, and no launch site has seemed "good enough" for a launch yet.  It's always too small, too windy, etc to risk my baby.  I did make a 3d-printed 3x 1/2A-scale FH, though, which seemed safer to test.  First flight ended in pieces, partly because my launch rod mount was mispositioned.  I'll have to print off another copy of that one with a few tweaks...)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: meekGee on 12/11/2015 05:55 pm
NASA isn't going to colonize Mars. Fortunately, SpaceX is going to give it a try.
Um, no, SpaceX won't. They will provide service for someone that can afford "colonizing Mars", whatever that soundbite actually means.

That was his aim initially. However with his Seattle presentation it became clear that he has realized he needs to get the ball rolling himself because no one else would do it. So he has taken on the task of at least initiating colonization himself. True that he cannot go it alone and is counting on others stepping in, once he has proven it can be done and give it a price tag.

I don't even believe that.  I think he said it since even what he was proposing was considered crazy.

However, I think privately he's been selling the full-on Mars vision for a while now.  He might have financial partnerships, but he was going to have SpaceX do the entire core effort, from day 1.

IMO of course.

And I think he's already sold the grand vision to enough major backers.  They may not have put in the money yet, but if he keeps delivering, this program will be financed.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Misha Vargas on 12/11/2015 06:16 pm
There is a source, though I can't dig it up from my phone.  The temperature is "just a degree above the triple point temperature of oxygen", which is well-defined. (Freezing point varies with pressure, and it's possible to be just a degree above triple point and yet relatively far from freezing if you manipulate the pressures.)

Edit: http://spaceflight101.com/spacerockets/falcon-9-ft/ is one source, though not a primary one.

Actually, that website cites a LOX temperature one degree "below" the triple point, not "above." Even better!  ;)

Yeah, the author seemed confused about how temperature is measured. However, isn't is possible to go below the triple point's temperature at pressures higher or lower than the triple point?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Kabloona on 12/11/2015 07:53 pm
There is a source, though I can't dig it up from my phone.  The temperature is "just a degree above the triple point temperature of oxygen", which is well-defined. (Freezing point varies with pressure, and it's possible to be just a degree above triple point and yet relatively far from freezing if you manipulate the pressures.)

Edit: http://spaceflight101.com/spacerockets/falcon-9-ft/ is one source, though not a primary one.

Actually, that website cites a LOX temperature one degree "below" the triple point, not "above." Even better!  ;)

Yeah, the author seemed confused about how temperature is measured. However, isn't is possible to go below the triple point's temperature at pressures higher or lower than the triple point?

Below triple point temperature, oxygen becomes a solid at the pressures in question. That's why they're trying to get as close as possible to the triple point temp without going lower.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DAZ on 12/11/2015 09:23 pm
I remember reading someplace that it was possible to take cryogenic fuels down below the triple point.  The idea in doing this is to create something resembling a slushy.  Although it may be possible to do this with oxygen, from what I remember from my reading, this was mostly considered for hydrogen.  For hydrogen this could be quite advantageous, from the density point of view, but not so much for oxygen.  This would entail of course a whole new level of engineering complexity and probably would not be worth the bother for oxygen in this application.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: OxCartMark on 12/13/2015 06:44 pm
Seems as if I recall that the oxygen in the Apollo service module tanks was slushy, at least initially, thus the need for cryo stirring.  Can someone refresh what I think is my memory of this?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DAZ on 12/13/2015 07:10 pm
Seems as if I recall that the oxygen in the Apollo service module tanks was slushy, at least initially, thus the need for cryo stirring.  Can someone refresh what I think is my memory of this?

I don’t know whether or not the oxygen tanks in the Apollo service module were slushy but you would need to stir them regardless.  These tanks were used to provide oxygen to the fuel cells.  This oxygen was gaseous not liquid.  In 0G the LOX would float around the tanks in globules.  The fuel cells would draw off the gaseous oxygen and the pressure in the tanks would decrease.  When the pressure reached a certain point you would need to boil some of the LOX back into gas.  This is what the cryo- stirring did.  They would turn on a heater and a device that was like a fan.  The floating LOX would come in contact with the fan and would start moving around incoming contact with the heater or the heated gaseous oxygen would cause some of the LOX to turn to gaseous oxygen.  This would increase the pressure in the tank.  In the unintended overvoltage test event some of the protective coating was burned off of the heating element.  When the heating element was submerged in LOX it was not critical.  But when the heating element was not exposed to the LOX it got hot enough that when it came in contact with the gaseous oxygen it burned violently thus raising the pressure in the oxygen tank above its bursting point.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: SWGlassPit on 12/14/2015 02:41 pm
I'm pretty sure that at the pressures and temperatures involved, the oxygen in the Apollo SM was a supercritical fluid.  The term "slushy" was a bit of artistic language used in the book Lost Moon to try to impart some understanding to how the fluid behaves, since most people never interact with supercritical fluids.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: jak Kennedy on 12/14/2015 03:23 pm
We're off topic, so I'll end with this. I respectfully suggest, if you haven't already, that you read further on the DragonFly testing program. These tests are critical to their multi-billion dollar D2 CC program. This testing program will be lengthy and exhaustive to prove out and refine propulsive landing profiles/capabilities. That is the first and only priority for this vehicle. And there is no guarantee that it will not be tested to its limits and/or, that it will survive the testing regime. FH will fly in the configuration they will need for AF certification, meaning it will have a fairing, not a Dragon for the initial fights. If you're interested in the most likely scenario for a Dragon variant launching on a FH, I suggest you search on Red Dragon.

I'll answer here since we were off-topic in the other thread. You are right that it seems likely that this idea (using the Pad Abort Dragon for an unmanned circum-lunar mission on the first FH launch) will not work out, and yes, it would also seem likely that the first FH will have a payload shroud to demonstrate this technology for the most likely customers of FH. Okay.

I still wonder, then, if SpaceX might launch the FH Demo upper stage to a free-return trajectory around the Moon (or towards Mars, if the launch happens in time to make the spring 2016 launch window, which seems a bit dubious since it ends in April...). Like I said, it would be a very inspiring feat, even if the stage burns up in the Earth's atmosphere upon return (or fly-bys at Mars). If it's sent towards Mars, it could be seen as a proof of principle for a Red Dragon delivery (I am well aware of that project).

Couldn't the Dragon be encapsulated in the fairing? Like an Easter egg! I think this could be Elon's surprise  ;D
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: NovaSilisko on 12/15/2015 05:58 pm
Interesting tidbit from Musk's talk at AGU 15:

Quote
Alexandra Witze @alexwitze
[email protected]: Falcon 9 rocket is $16m to build, $200k to fuel. #AGU15

https://twitter.com/alexwitze/status/676837502959771648


Have we ever heard actual construction cost figures before?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DanseMacabre on 12/15/2015 06:32 pm
Interesting tidbit from Musk's talk at AGU 15:

Quote
Alexandra Witze @alexwitze
[email protected]: Falcon 9 rocket is $16m to build, $200k to fuel. #AGU15

https://twitter.com/alexwitze/status/676837502959771648


Have we ever heard actual construction cost figures before?

FYI - This link doesn't work. (Either deleted or mis-linked?)
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Silmfeanor on 12/15/2015 06:35 pm
Interesting tidbit from Musk's talk at AGU 15:

Quote
Alexandra Witze @alexwitze
[email protected]: Falcon 9 rocket is $16m to build, $200k to fuel. #AGU15

https://twitter.com/alexwitze/status/676837502959771648


Have we ever heard actual construction cost figures before?

FYI - This link doesn't work. (Either deleted or mis-linked?)
https://twitter.com/alexwitze/status/676843266403270656 (https://twitter.com/alexwitze/status/676843266403270656)

Quote
[email protected] @Rand_Simberg Now doubting whether I heard that number right - was it $60m not $16m? Will check tape afterwards.

So some confusion I guess.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: notsorandom on 12/15/2015 06:58 pm
If it really costs $60 million then SpaceX is basically selling them at cost. Iridium has contracted for 7 launches at $453.1 million, or $62.2 each. If a Falcon costs $16 million then Elon has to be talking about a constrained accounting definition such as raw materials, or excluding all labor. I doubt SpaceX is making $42 million of pure profit every launch.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: intrepidpursuit on 12/15/2015 07:14 pm
"
If it really costs $60 million then SpaceX is basically selling them at cost. Iridium has contracted for 7 launches at $453.1 million, or $62.2 each. If a Falcon costs $16 million then Elon has to be talking about a constrained accounting definition such as raw materials, or excluding all labor. I doubt SpaceX is making $42 million of pure profit every launch.

The overhead costs of all the pads, testing, transportation, ships, launch flow labor, etc. are not insignificant and I would not think they'd be included in a "cost of an F9" generalized estimate. Calculating manufacturing cost is harder than people think it is. With most companies the overhead and packaging costs add up to at least as much as the manufacturing itself and with a super low volume product like the F9 I don't see how it could cost much more than $16m without them hemorrhaging money.

If he did say $60m then I'd strongly suspect he is giving the "cost to buy" number, which is the only number I'd give if it were me.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: abaddon on 12/15/2015 08:35 pm
If it were really $16 million, then either SpaceX would be charging way more than their cost (no way they're doing that) or the processing/services etc would make up the rest of the difference.  If the latter, then stage reuse would be a peculiar thing to work on...

Bottom line, I'm confident this will turn out to be $60 million and will be price, not cost.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Mader Levap on 12/15/2015 09:05 pm
Sixteen vs sixty? Misheard is theoretically possible...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cscott on 12/15/2015 09:10 pm
If it were really $16 million, then either SpaceX would be charging way more than their cost (no way they're doing that) or the processing/services etc would make up the rest of the difference.  If the latter, then stage reuse would be a peculiar thing to work on...

Bottom line, I'm confident this will turn out to be $60 million and will be price, not cost.
Well, a significant part of the  "processing/services" has to be testing.  One of the benefits of reuse is that you know the stage and engines are still assembled correctly.  But I agree that $60 million is a much more likely figure to quote.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: intrepidpursuit on 12/15/2015 09:35 pm
If it were really $16 million, then either SpaceX would be charging way more than their cost (no way they're doing that) or the processing/services etc would make up the rest of the difference.  If the latter, then stage reuse would be a peculiar thing to work on...

Bottom line, I'm confident this will turn out to be $60 million and will be price, not cost.

Why do you think that SpaceX couldn't possibly make a decent profit on things? What company doesn't? As with any company, but on a larger scale, there are massive expenses involved in things that aren't manufacturing stages. They have built or are building 6 different launch pads, 2 major test facilities, 1 massive manufacturing plant, they have thousands of employees and they have investors to answer to. Companies do not charge exactly their manufacturing costs and survive.

One big advantage to outsourcing most of the work like many government contractors and launch providers do is that it makes it easy divide manufacturing costs and overhead. There is more overall overhead, but it gets neatly packaged into the contracts with the manufacturers. When you manufacture in house a common way to calculate cost is to separate fixed and operating costs from the added cost to manufacture. And likely neither of those include "launch costs" including testing, transportation, pad and range fees, fuel, etc. It is completely plausible that the "cost to manufacture" an F9 is $16m and that would be the extra sustained cost to build an "extra" core for something like the grasshopper program where it does not sustain launch costs and it does not carry the operating overhead. That does not mean they are pocketing the rest. If those other costs were insignificant then shuttle would have been as cheap as advertised.

Reuse still makes sense because they could increase launch rate and revenue without increasing overhead enough to support the additional manufacturing, transportation, testing, etc. That is the trick that so many are waiting to see; whether or not SpaceX could lower the costs as significantly as they say just by eliminating manufacturing costs. That has to do with many factors including how robust the design is to be reused with low man hours and facility costs and how well they can optimise the reuse flow to take advantage of that. Otherwise there would be no doubt.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MikeAtkinson on 12/15/2015 09:53 pm
Here is a post of mine from another thread:

Since we are talking about ~30 engines on a BFR next is how much each of them would cost. The estimate for M1D's range from $1-2M but when I back out the values I get $15M for 9 engines or ~$1.67M per engine. A full 1st stage cost to manufacture ~$31.5M based on 20% profit $62.5->$52M, $7M for operations/launch costs ->$45M, and 70% of manufacturing cost for cost of manufacture of 1st stage->$31.5M. The US has a $13.5M build costs which would make the much bigger tank on the first stage + avionics to be ~$16.5M. The numbers could be off but probably not by much.

My estimates of F9 manufacturing costs are lower (assuming about non-reusable 15 F9 flights per year).

The major costs of a F9 flight are: R&D, capital costs (pads, etc.), corporate overhead (general admin, PA, etc.), sales and marketing, manufacturing and operations. Putting some numbers to those and assuming long term aim to break even (i.e. no profit)

___________________Total cost___Per flight cost___Notes
R&D$2 B$12 Massumes payback in 10 years at average of 17 flights per year
Capital$1 B$6 M4 pads, 4 landing pads, 4 integration buildings, 2 barges
Corporate overhead$5 MComplete guess
Sales and marketing$6 M10%
Operations$7 M
Manufacturing$25 M

So to break even manufacturing costs are about $25M and hence 1st stage is about $18M, so Merlin 1D is about $500K.

At 30 flights per year and reusing each core 5 times the cost per flight would be about $35M.

Note that this way of looking at things assumes that F9 generates enough revenue to pay for its own development and an exponentially increasing flight rate at decreasing cost, but does not generate "profit" for other SpaceX developments, they use venture capital for development and in turn pay their way over the long term.

This is different from CRS (and CRS2) where SpaceX takes a decent "profit" on each flight.

Bringing this back to SpaceX's Mars ambition costs, note the difference between initial F9 and Merlin 1C development costs (of about $400M) and the 'final' F9 v1.1 FT development and capital cost which (I'm estimating at $3B). I think there will be a similar ratio for BFR/MCT, first flight to LEO will be 10 - 20% ($2B - $4B) of the total development and capital costs ($10B-$20B). For F9 SpaceX had customer revenue from before the first flight which helped pay for development and capital expenditure on pads, etc.

The trick for SpaceX will be to get similar short term revenue for BFR/MCT so that they can continue development & testing of their architecture. I have some ideas on how they might do it, but that is the subject of another post.

If manufacturing costs are $16M then either I've underestimated some of the other costs or SpaceX are making a good profit on each launch.

As always when Elon gives figures there seems to be more than one possible interpretation.

Manufacturing cost could be the cost of a finished stage as it leaves Hawthorne, or the cost after test when it leaves McGregor.

If it were really $16 million, then either SpaceX would be charging way more than their cost (no way they're doing that) or the processing/services etc would make up the rest of the difference.  If the latter, then stage reuse would be a peculiar thing to work on...

Bottom line, I'm confident this will turn out to be $60 million and will be price, not cost.

A low manufacturing cost is not inconsistent with trying to reduce it further, even at $16M it would still be the biggest cost. More importantly taking out the fixed costs (which are reduced per launch as the number of launches increase), it still would make manufacturing over 50% of these.

Decreasing the "manufacturing" cost per flight by reuse allows SpaceX to win more business. It also means that the incremental cost is low, for 5 reuses incremental cost would be only about $10M (for internal flights e.g. hence no sales cost). Incremental costs are  not often useful as no customer sees them.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Jeff Lerner on 12/15/2015 10:11 pm
Today's aborted  autommated KURS Soyuz docking and subsequent manual successful docking clearly demonstrates the need for a pilot. I may not have this right but I'm under the impression that the Dragon 2 is to be so automated  that no pilot will ever be required....doesn't today's great piloting job by the Russian Soyuz pilot demonstrate the continued need for at least one pilot position  aboard Dragon 2 ??
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: nadreck on 12/15/2015 10:12 pm
Today's aborted  autommated KURS Soyuz docking and subsequent manual successful docking clearly demonstrates the need for a pilot. I may not have this right but I'm under the impression that the Dragon 2 is to be so automated  that no pilot will ever be required....doesn't today's great piloting job by the Russian Soyuz pilot demonstrate the continued need for at least one pilot position  aboard Dragon 2 ??

Not if a pilot is available on the ISS
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: matthewkantar on 12/15/2015 10:30 pm
Not sure if the manual docking demonstrates good piloting or bad spacecraft engineering.

Matthew
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: mme on 12/15/2015 11:05 pm
Today's aborted  autommated KURS Soyuz docking and subsequent manual successful docking clearly demonstrates the need for a pilot. I may not have this right but I'm under the impression that the Dragon 2 is to be so automated  that no pilot will ever be required....doesn't today's great piloting job by the Russian Soyuz pilot demonstrate the continued need for at least one pilot position  aboard Dragon 2 ??
I think NASA will always (well, my lifetime "always") require a manual override and the crew to be trained in manual docking.  Commercial space stations may choose differently when they exist and we have enough experience.  Or they'll rotate professional crew with launches.  Or, as @nadreck pointed out, the backup pilot will be on the Space Station.

The Crew Dragon has a joystick and will fly with actual trained astronauts for the near term.  But I think assuming that will always be the case is a bit extreme.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: whitelancer64 on 12/15/2015 11:06 pm
Today's aborted  autommated KURS Soyuz docking and subsequent manual successful docking clearly demonstrates the need for a pilot. I may not have this right but I'm under the impression that the Dragon 2 is to be so automated  that no pilot will ever be required....doesn't today's great piloting job by the Russian Soyuz pilot demonstrate the continued need for at least one pilot position  aboard Dragon 2 ??

Like the Soyuz, the Dragon will be capable both of automatic docking and manual docking. If I recall correctly, one part of the crewed flight test will have it automatically dock with the ISS, then undock, and then have the crew dock manually.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 12/15/2015 11:49 pm
$16 million sounds right for the marginal construction cost.

But there are a lot of tests that need to be done. Transport costs. Range fees. Development costs. Etc, etc, etc.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: bstrong on 12/16/2015 03:43 am
An article sourced from the same interview that quotes $16M manufacturing cost:

http://mashable.com/2015/12/15/elon-musk-mars-ambitions/ (http://mashable.com/2015/12/15/elon-musk-mars-ambitions/)

Add:

And here's a video (quote is at about 16:04):

https://www.youtube.com/watch?v=WwFa3nk1V0I?t=16m4s

I listened to it several times, and it sure sounds like $60M to me. But that may be just because that's what I would expect him to say (since I would think actual manufacturing costs would be a closely held secret, plus a larger number makes his point more strongly).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: QuantumG on 12/16/2015 05:20 am
This is what happens when people get their "quotes" from sitting in the audience of a conference. He said $60 million.. ya know, the list price for the Falcon 9.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: notsorandom on 12/16/2015 03:15 pm
Not to beat a now dead horse, but a rocket's manufacturing cost must be a overwhelmingly large portion of what it costs for SpaceX to launch a payload. Here is the thought experiment that lead me to that conclusion. If the marginal manufacturing costs are low then reusing the first stage doesn't drop the total price by all that much. Say it a first stage costs $10 million and they reuse it 10 times. Every launch they save $9 million dollars. That sounds like a good savings but the total launch cost is not that much less than the cost for an expendable first stage. That is less than the difference SpaceX has already achieved over their competitors (and themselves). If the first stage is $30 million and reused 10 time then the savings is $27 million per flight. That SpaceX has expended so much money, time, and effort to work on reusability leads me to think that the cost of a first stage is a very large part of the total launch cost.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Roy_H on 12/16/2015 05:39 pm
Keep in mind that Elon expects to get all the costs reduced, not just re-flying the first stage. And his very optimistic low prices are for some far off future date where the number of flights is very high and the BFR is working.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Coastal Ron on 12/16/2015 09:33 pm
This is what happens when people get their "quotes" from sitting in the audience of a conference. He said $60 million.. ya know, the list price for the Falcon 9.

That's what I think he meant too, even though he said "build".  If what he meant to say was "$60 to buy", then it makes better sense in the context of what he was saying at that moment in time (i.e. cost of fuel is $200K vs $60M price of rocket).

Hopefully someone can get him to confirm what he was saying, one way or the other.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: bstrong on 12/17/2015 02:13 am
The official video with higher-quality audio is available on the AGU website now, and FWIW, it sounds much more like $16M to me in this recording.

There's no way to link to it directly, but if you're interested:

1) Go to http://fallmeeting.agu.org/2015/virtual-options/
2) Sign up for a free AGU On Demand account
3) In the "View Channels" menu select "Union Channel"
4) Select the "On Demand" tab
5) Select "U21B: Presidential Forum"
6) Quote is at 0:22:00
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: RocketGoBoom on 12/17/2015 02:51 am
Let's assume that SpaceX gets re-use of 1st stage down pat and they start re-using those stages/engines about 10 times each.

With the even lower volume of production for 1st stages and Merlin engines, won't that just drive up those per unit manufacturing costs?

Surely it has to cost more per unit of production when you are only making 40 engines per year instead of 400 engines per year.

So while there are likely some significant savings available for re-use, there are going to be some higher costs elsewhere in the process.

We are not going to see a 10X decline in pricing for SpaceX launches. A huge cost is the manpower, the testing, the infrastructure, logistics, etc. R&D expenses are never going away. They will have to continually improve on design.

I suspect we might see a 20% to 30% decline in costs for SpaceX.
But SpaceX might not pass that savings along to customers.
But with the lowest costs, SpaceX has the most flexibility on bidding against their competitors.

SpaceX will likely bid lower on launches just enough to beat ULA or Ariane 6.

SpaceX won't be dropping prices 50% below their competitors just to be nice.
They are more likely to keep it about 20% cheaper just so that it is a measurable customer savings enough to grab market share. The rest of the savings from re-use will be higher profit margins for SpaceX.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 12/17/2015 02:56 am
Their whole argument so far is they don't want to just grab market share, they want to increase the overall size of the market.  They can't do this if their prices are simply marginally lower.


If their stated goals are their true goals, then they will drastically decrease the cost of launch as soon as they can economically do it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: bstrong on 12/17/2015 03:44 am
Because I love to overanalyze things, here's the quote at full speed and slowed down using a couple of different techniques.

I'm back to $60M. For the record, I think $16M sounds about right for manufacturing costs, but I don't think that's what he said.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Tonioroffo on 12/17/2015 10:36 am
How will SpaceX get their hands on a nuclear reactor, or the fuel for it? 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DanseMacabre on 12/17/2015 10:44 am
How will SpaceX get their hands on a nuclear reactor, or the fuel for it?

They would contract out to an experienced third party, who would purchase the fuel through their normal channels.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Tonioroffo on 12/17/2015 10:45 am
Yes, can't see how this can be kept in house.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Zed_Noir on 12/17/2015 12:02 pm
How will SpaceX get their hands on a nuclear reactor, or the fuel for it? 
They would contract out to an experienced third party, who would purchase the fuel through their normal channels.
Yes, can't see how this can be kept in house.

Sure you can. Just acquire the contractor or parts of it. It isn't very likely, but the SpaceX CTO may think otherwise.

Presuming the nuclear reactor is a small one for use on a spacecraft.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Herb Schaltegger on 12/17/2015 01:16 pm

How will SpaceX get their hands on a nuclear reactor, or the fuel for it? 
They would contract out to an experienced third party, who would purchase the fuel through their normal channels.
Yes, can't see how this can be kept in house.

Sure you can. Just acquire the contractor or parts of it. It isn't very likely, but the SpaceX CTO may think otherwise.

Presuming the nuclear reactor is a small one for use on a spacecraft.

Um, the DOE and/or NRC will have a lot to say about whether or not SpaceX will be able to count on nuclear power for their Mars ambitions. If you think otherwise, you don't understand the politics and bureaucratic infrastructure that surrounds all things nuclear in this country.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JBF on 12/17/2015 02:03 pm

How will SpaceX get their hands on a nuclear reactor, or the fuel for it? 
They would contract out to an experienced third party, who would purchase the fuel through their normal channels.
Yes, can't see how this can be kept in house.

Sure you can. Just acquire the contractor or parts of it. It isn't very likely, but the SpaceX CTO may think otherwise.

Presuming the nuclear reactor is a small one for use on a spacecraft.

Um, the DOE and/or NRC will have a lot to say about whether or not SpaceX will be able to count on nuclear power for their Mars ambitions. If you think otherwise, you don't understand the politics and bureaucratic infrastructure that surrounds all things nuclear in this country.

There are other nuclear powers in the world among our close allies; one of them might be willing to allow it if the US does not.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Herb Schaltegger on 12/17/2015 02:18 pm


How will SpaceX get their hands on a nuclear reactor, or the fuel for it? 
They would contract out to an experienced third party, who would purchase the fuel through their normal channels.
Yes, can't see how this can be kept in house.

Sure you can. Just acquire the contractor or parts of it. It isn't very likely, but the SpaceX CTO may think otherwise.

Presuming the nuclear reactor is a small one for use on a spacecraft.

Um, the DOE and/or NRC will have a lot to say about whether or not SpaceX will be able to count on nuclear power for their Mars ambitions. If you think otherwise, you don't understand the politics and bureaucratic infrastructure that surrounds all things nuclear in this country.

There are other nuclear powers in the world among our close allies; one of them might be willing to allow it if the US does not.

As a US company, headquartered and operating out of the US, SpaceX is bound by US law. They'd be playing a very dangerous game in acquiring and operating heavily regulated technologies like nuclear power outside of US government oversight and control. If you think ITAR restrictions are tough, just try fooling with the provisions of international nuclear mon-proliferation rules.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 12/17/2015 02:56 pm
If, like Shuttle, BFS were capable of rendezvous with a payload and bringing it into a cargo bay, an international partner could build and launch an encapulated reactor core for pickup at the refuelling staging area. US regulators could go fish.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: RonM on 12/17/2015 03:12 pm
If, like Shuttle, BFS were capable of rendezvous with a payload and bringing it into a cargo bay, an international partner could build and launch an encapulated reactor core for pickup at the refuelling staging area. US regulators could go fish.

SpaceX would be operating the reactor at their Mars base and under the OST the SpaceX base would be under US law. US regulators would still have some say in it.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Herb Schaltegger on 12/17/2015 05:12 pm

If, like Shuttle, BFS were capable of rendezvous with a payload and bringing it into a cargo bay, an international partner could build and launch an encapulated reactor core for pickup at the refuelling staging area. US regulators could go fish.

Um, no. US regulators would quite rightfully - and fully legally - punish SpaceX for violations of US and international controls on nuclear technology proliferation (e.g., cancel contracts; place liens; seize property; prosecute executives). I don't think you realize the nature of the issue.

Can the issue be worked out and worked through if SpaceX wants nuclear for their future plans? Sure. But not by ignoring existing US and international laws and regulations.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: JBF on 12/17/2015 05:19 pm

If, like Shuttle, BFS were capable of rendezvous with a payload and bringing it into a cargo bay, an international partner could build and launch an encapulated reactor core for pickup at the refuelling staging area. US regulators could go fish.

Um, no. US regulators would quite rightfully - and fully legally - punish SpaceX for violations of US and international controls on nuclear technology proliferation (e.g., cancel contracts; place liens; seize property; prosecute executives). I don't think you realize the nature of the issue.

Can the issue be worked out and worked through if SpaceX wants nuclear for their future plans? Sure. But not by ignoring existing US and international laws and regulations.

If SpaceX secured the cooperation of another current nuclear power the non-poliferation agreements would be moot.  In any case most objections come not from operating a nuclear power plant, but from the hazards associated in getting the material to orbit. 
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Herb Schaltegger on 12/17/2015 05:23 pm


If, like Shuttle, BFS were capable of rendezvous with a payload and bringing it into a cargo bay, an international partner could build and launch an encapulated reactor core for pickup at the refuelling staging area. US regulators could go fish.

Um, no. US regulators would quite rightfully - and fully legally - punish SpaceX for violations of US and international controls on nuclear technology proliferation (e.g., cancel contracts; place liens; seize property; prosecute executives). I don't think you realize the nature of the issue.

Can the issue be worked out and worked through if SpaceX wants nuclear for their future plans? Sure. But not by ignoring existing US and international laws and regulations.

If SpaceX secured the cooperation of another current nuclear power the non-poliferation agreements would be moot.  In any case most objections come not from operating a nuclear power plant, but from the hazards associated in getting the material to orbit.

Again, no. The specific objections are really about moving operating nuclear technology beyond the reach of governmental powers (proliferation). And sidestepping US regulators to spread technology through other nations - regardless of whether those nations have signed the NNPT - has had serious repercussions for others in the past.

You're free to disbelieve me. SpaceX - I hope - knows better.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Lars-J on 12/17/2015 05:27 pm
If SpaceX secured the cooperation of another current nuclear power the non-poliferation agreements would be moot.  In any case most objections come not from operating a nuclear power plant, but from the hazards associated in getting the material to orbit.

Just stop. You thinking this is true DOES NOT make it true.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: docmordrid on 12/17/2015 05:29 pm
If SpaceX only supplied transport and the supplying nuclear power provided support crew and maintained jurisdiction over the reactor to and on Mars I fail to see the proliferation issue. The chain of custody is intact from their launch to landing and operation.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 12/17/2015 05:43 pm
If SpaceX can gather and process the fuel on Mars itself, they may have an out.  As long as nuclear fuel is going to be launched from Earth, they are going to have to go through the proper channels.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: RocketGoBoom on 12/17/2015 06:51 pm
How will SpaceX get their hands on a nuclear reactor, or the fuel for it?

Elon's buddy Peter Thiel owns a nuclear energy startup.

http://bostinno.streetwise.co/2015/02/10/peter-thiel-fund-backs-mit-nuclear-startup-transatomic-power-3/

I wish I had friends like that.
Must be cool to go to their parties.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Herb Schaltegger on 12/17/2015 06:56 pm

If SpaceX only supplied transport and the supplying nuclear power provided support crew and maintained jurisdiction over the reactor to and on Mars I fail to see the proliferation issue. The chain of custody is intact from their launch to landing and operation.


Why don't you read the NNTP, OST and then all the provisions of the Code of Federal Regulations governing the Department of Energy and Nuclear Regulatory Commission regarding civilian nuclear power before you handwave away the complexities.

Look, to make this dirt simple (which I already did above), I'm not saying SpaceX can't go nuclear for their future plans. I'm saying they can't just sidestep the very real political and regulatory issues involved. People who think they can are just wrong.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DigitalMan on 12/17/2015 08:42 pm
If SpaceX were to partner with another country (Russia for example) which would provide and operate the nuclear reactor on Mars the US would have no jurisdiction over this.  See the outer space treaty.


If SpaceX only supplied transport and the supplying nuclear power provided support crew and maintained jurisdiction over the reactor to and on Mars I fail to see the proliferation issue. The chain of custody is intact from their launch to landing and operation.


Why don't you read the NNTP, OST and then all the provisions of the Code of Federal Regulations governing the Department of Energy and Nuclear Regulatory Commission regarding civilian nuclear power before you handwave away the complexities.

Look, to make this dirt simple (which I already did above), I'm not saying SpaceX can't go nuclear for their future plans. I'm saying they can't just sidestep the very real political and regulatory issues involved. People who think they can are just wrong.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: MP99 on 12/17/2015 09:10 pm

If SpaceX only supplied transport and the supplying nuclear power provided support crew and maintained jurisdiction over the reactor to and on Mars I fail to see the proliferation issue. The chain of custody is intact from their launch to landing and operation.


Why don't you read the NNTP, OST and then all the provisions of the Code of Federal Regulations governing the Department of Energy and Nuclear Regulatory Commission regarding civilian nuclear power before you handwave away the complexities.

Look, to make this dirt simple (which I already did above), I'm not saying SpaceX can't go nuclear for their future plans. I'm saying they can't just sidestep the very real political and regulatory issues involved. People who think they can are just wrong.
And this is reasonable.

Imagine MCT docks with a reactor, and then someone takes control of it and crashes it to the ground.

Cheers, Martin
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Herb Schaltegger on 12/17/2015 10:26 pm
If SpaceX were to partner with another country (Russia for example) which would provide and operate the nuclear reactor on Mars the US would have no jurisdiction over this.  See the outer space treaty.

Look, this is among the most pointless arguments currently happening on NSF right now; and even for a SpaceX thread, that's saying something ...

Yeah, sure the U.S. couldn't claim legal jurisdiction over the spaceborn reactor. But if such an event happened without at least the tacit backing of prominent members of Congress and/or POTUS, SpaceX itself as a U.S. corporate entity would suffer the inevitable repercussions - cancellation of any national security launch contracts, "delays" in commercial FAA launch/landing licenses, etc.

You guys are clearly conflating the idea of what may be theoretically "possible" with reality as it exists in our world.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DigitalMan on 12/18/2015 12:13 am
If spacex were to partner with Russia there is not a shred of evidence you could stop Russia from launching whatever they want in support of a Mars base.

Sure if spacex want to do it themselves there are procedures and policies to follow this should have been obvious to various folks posting otherwise above.  If another country does it, U.S. Attempts to stop foreign space exploration activities would be illegal in itself.

Probabilities are that a lot of groups would have to be involved to make a sustaining Mars civilization.  SpaceX cannot do it alone.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Herb Schaltegger on 12/18/2015 12:56 am
If spacex were to partner with Russia there is not a shred of evidence you could stop Russia from launching whatever they want in support of a Mars base.


Where have I or anyone else said anything to the contrary? Please read what I wrote rather than what you apparently THINK I wrote.
Quote
Sure if spacex want to do it themselves there are procedures and policies to follow this should have been obvious to various folks posting otherwise above.

You would think so, wouldn't you? Yet ... here we are.

Quote
If another country does it, U.S. Attempts to stop foreign space exploration activities would be illegal in itself.

Who said anything about the U.S. attempting to stop other countries from exploring space? We've been talking about SpaceX trying to launch nuclear-powered spacecraft and/or colonial power sources without first going through U.S. regulatory hoops. What other countries do is up to them. What U.S.-based corporations do is under the legal jurisdiction of the U.S. - FAA for launch/entry, FCC for telemetry and comms, Dept. of State for technology transfer activities and those that RISK technology transfer, etc.

Quote
Probabilities are that a lot of groups would have to be involved to make a sustaining Mars civilization.  SpaceX cannot do it alone.

I have never even addressed that point. You're just changing the subject now, whether you realize it or not.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: LouScheffer on 12/18/2015 01:33 am
How will SpaceX get their hands on a nuclear reactor, or the fuel for it? 
The technology is not that hard.  In pre-terrorism days, lots of universities ran their own small nuclear reactors.

The main problem was that a physically small reactor requires enriched uranium.  Since universities are not that well guarded, the worry that terrorists might steal the fuel has closed most of these reactors.   This should be less of a problem on Mars; any adversary who can get there to steal the uranium probably has their own atomic weapons already (except maybe Japan and *wink,wink" Israel).
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: jg on 12/18/2015 07:11 am
http://web.mit.edu/nrl/www/reactor/reactor.htm
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: tyrred on 12/18/2015 08:34 am
Reality check.  Falcon/Dragon are generally not going to be taking nuclear reactors anywhere. 




Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: DanseMacabre on 12/18/2015 09:55 am
Reality check.  Falcon/Dragon are generally not going to be taking nuclear reactors anywhere.
Correct. This discussion belongs in the BFR section.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: cdleonard on 12/18/2015 01:41 pm
Elon spoke at the AGU 2015 conference. One tidbit (https://www.youtube.com/watch?v=WwFa3nk1V0I&feature=youtu.be&t=1250) I found interesting is a mass figure for the upper stage of "120 tons". This number is higher than the estimate I found on SpaceFlight 101 (http://spaceflight101.com/spacerockets/falcon-9-ft/) and nearly 20% higher than the 1.1 version.

It seems to me that the Falcon 9 upper stage is one of the largest in history.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: llanitedave on 12/18/2015 03:22 pm
If spacex were to partner with Russia there is not a shred of evidence you could stop Russia from launching whatever they want in support of a Mars base.


Where have I or anyone else said anything to the contrary? Please read what I wrote rather than what you apparently THINK I wrote.
Quote
Sure if spacex want to do it themselves there are procedures and policies to follow this should have been obvious to various folks posting otherwise above.

You would think so, wouldn't you? Yet ... here we are.

Quote
If another country does it, U.S. Attempts to stop foreign space exploration activities would be illegal in itself.

Who said anything about the U.S. attempting to stop other countries from exploring space? We've been talking about SpaceX trying to launch nuclear-powered spacecraft and/or colonial power sources without first going through U.S. regulatory hoops. What other countries do is up to them. What U.S.-based corporations do is under the legal jurisdiction of the U.S. - FAA for launch/entry, FCC for telemetry and comms, Dept. of State for technology transfer activities and those that RISK technology transfer, etc.

Quote
Probabilities are that a lot of groups would have to be involved to make a sustaining Mars civilization.  SpaceX cannot do it alone.

I have never even addressed that point. You're just changing the subject now, whether you realize it or not.

Yep.  Not only have the goal posts moved, they've actually left the stadium.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Endeavour126 on 12/18/2015 03:51 pm
Just a question. More thrust from the F9 1.1 FT it means more thrust also when first stage land? It could be more complicate to manage the last meters before thouching down?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: rpapo on 12/18/2015 04:01 pm
Just a question. More thrust from the F9 1.1 FT it means more thrust also when first stage land? It could be more complicate to manage the last meters before thouching down?
Not the way we understand things right now.  The Merlin 1D was supposedly running in the 65% to 85% throttle range before.  Now it will be running in the 65% to 100+% range.  So the lowest throttle setting, which is what matters for landing, is supposedly the same as before.  And supposedly the first stage empty weight is the same as before.

So the landing parameters should not have changed.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Endeavour126 on 12/18/2015 04:05 pm

Not the way we understand things right now.  The Merlin 1D was supposedly running in the 65% to 85% throttle range before.  Now it will be running in the 65% to 100+% range.  So the lowest throttle setting, which is what matters for landing, is supposedly the same as before.  And supposedly the first stage empty weight is the same as before.

So the landing parameters should not have changed.

Yes, you are right. Thank you!
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: edkyle99 on 12/18/2015 04:14 pm
Elon spoke at the AGU 2015 conference. One tidbit (https://www.youtube.com/watch?v=WwFa3nk1V0I&feature=youtu.be&t=1250) I found interesting is a mass figure for the upper stage of "120 tons". This number is higher than the estimate I found on SpaceFlight 101 (http://spaceflight101.com/spacerockets/falcon-9-ft/) and nearly 20% higher than the 1.1 version.

It seems to me that the Falcon 9 upper stage is one of the largest in history.
He said that the first stage can boost "120 tons" to 8,000 km /hour.  That mass would include payload and the perhaps 2,000 kg payload fairing, and if he was talking short tons the metric number would be 108,860 kg-ish.

 - Ed Kyle
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: SVBarnard on 12/22/2015 12:24 am
wait a second so this orbcomm lanuch isnt going to GEO but just to LEO and the payload is a very light one, not a heavy one at all, how the heck do we know that they can launch and try to land the first stage back on land with a hypothetical heavy GEO payload? Does it require less energy to land it downrange on the barge in situations like this?

Im very worried here that they're overhyping this thing.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: abaddon on 12/22/2015 01:04 am
Don't worry, they were going to do SES first but chose the easier mission instead.

Some GEO launches will require the barge, so there is still that milestone to hit...
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: pathfinder_01 on 12/22/2015 02:04 am
wait a second so this orbcomm lanuch isnt going to GEO but just to LEO and the payload is a very light one, not a heavy one at all, how the heck do we know that they can launch and try to land the first stage back on land with a hypothetical heavy GEO payload? Does it require less energy to land it downrange on the barge in situations like this?

Im very worried here that they're overhyping this thing.

There are an number of LEO payloads for one(basically every ISS mission).  The Barge is planned to be used for flights that can't make it to land and expending an spent stage is still an option for other flights.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: abaddon on 12/22/2015 02:30 am
He said that the first stage can boost "120 tons" to 8,000 km /hour.  That mass would include payload and the perhaps 2,000 kg payload fairing, and if he was talking short tons the metric number would be 108,860 kg-ish.

 - Ed Kyle
From http://www.spacex.com/news/2015/12/21/background-tonights-launch:
Quote
In the case of the Falcon 9 rocket, the boost stage is able to accelerate a payload mass of 125 metric tons to 8000 km/h and land on an ocean platform or to 5000 km/h and land back at the launch site.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: ulm_atms on 12/22/2015 03:11 am
wait a second so this orbcomm lanuch isnt going to GEO but just to LEO and the payload is a very light one, not a heavy one at all, how the heck do we know that they can launch and try to land the first stage back on land with a hypothetical heavy GEO payload? Does it require less energy to land it downrange on the barge in situations like this?

Im very worried here that they're overhyping this thing.

That's when they would move the launch to a Falcon Heavy.  At least...that's there plan.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 12/22/2015 03:46 am
wait a second so this orbcomm lanuch isnt going to GEO but just to LEO and the payload is a very light one, not a heavy one at all, how the heck do we know that they can launch and try to land the first stage back on land with a hypothetical heavy GEO payload? Does it require less energy to land it downrange on the barge in situations like this?

Im very worried here that they're overhyping this thing.

That's when they would move the launch to a Falcon Heavy.  At least...that's there plan.
They haven't scrapped all their barges! Down-range barge landings (bargings? bargings.) will likely be attempted for F9 flights that need more performance. Then, Falcon Heavy launches, too.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: somepitch on 12/22/2015 04:11 am
wait a second so this orbcomm lanuch isnt going to GEO but just to LEO and the payload is a very light one, not a heavy one at all, how the heck do we know that they can launch and try to land the first stage back on land with a hypothetical heavy GEO payload? Does it require less energy to land it downrange on the barge in situations like this?

Im very worried here that they're overhyping this thing.

That's when they would move the launch to a Falcon Heavy.  At least...that's there plan.
They haven't scrapped all their barges! Down-range barge landings (bargings? bargings.) will likely be attempted for F9 flights that need more performance. Then, Falcon Heavy launches, too.

Some good info in Elon's post from earlier about the case for the barges.

http://www.spacex.com/news/2015/12/21/background-tonights-launch (http://www.spacex.com/news/2015/12/21/background-tonights-launch)

Quote from: Elon Musk
In the case of the Falcon 9 rocket, the boost stage is able to accelerate a payload mass of 125 metric tons to 8000 km/h and land on an ocean platform or to 5000 km/h and land back at the launch site.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Robotbeat on 12/22/2015 04:58 am
So will SES be a barging*?

*is a word now.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: HIP2BSQRE on 12/22/2015 05:55 am
How does successful RTF and rocket stage landing hurt/impact ULA?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Darkseraph on 12/22/2015 06:09 am
I wouldn't be terribly surprised if that barge landing idea is quietly dropped. And that there will be a next generation of wider single core rockets that can pull off falcon heavy class missions while landing back on land.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: SVBarnard on 12/22/2015 06:44 am
I wouldn't be terribly surprised if that barge landing idea is quietly dropped. And that there will be a next generation of wider single core rockets that can pull off falcon heavy class missions while landing back on land.

Yeah what yur describing is the BFR thats what. I mean do you think the BFR will be light enough to land on a barge? The only option is a a land landing for it. So yes I agree with you they will eventually drop the barge and build a wider core booster.
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: SVBarnard on 12/22/2015 06:48 am
How does successful RTF and rocket stage landing hurt/impact ULA?

They dont have reusable VT/VL booster now do they? ULA is gonna pursue their semi reusable rocket plan and its not even slated fly until the 2020s right? ULA is great but they are going to go the way of the dinosaurs, extinct. Its like ULA is flying prop airplanes and Spacex is flying jet airplanes get my point?
Title: Re: General Falcon and Dragon discussion (Thread 12)
Post by: Darkseraph on 12/22/2015 07:04 am
I wouldn't be terribly surprised if that barge landing idea is quietly dropped. And that there will be a next generation of wider single core rockets that can pull off falcon heavy class missions while l