Stratolaunch: General Company and Development Updates and Discussions

[Robotbeat]

Almost any oxidizer, for the simple fact that one mistake can produce a high explosive.

[iamlucky13]

Sorry, but isn't the B-52 already doing this?

I've never heard of a B52 launching space missions, do you have any examples?

I read the question as being in relation to the previous 3 out of 4 comments that were about flying deterrence missions.

To the best of my knowledge, we haven't conducted deterrence flights of nuclear-armed bombers in several decades. Rather, the bombers wait on the ground, and rapid response falls to the responsibility of the Minutemen and Titan missiles.

Anyways, the Stratolauncher aircraft would be rather oversized for the task. The Peacekeeper's were huge as ICBM's go, but still half the mass of the Falcon V being discussed. The smaller Minutemen are about 1/6th the mass.

Air-launched ballistic missiles was a concept the military largely rejected in the 60's as submarine launched missiles gained credence:

http://en.wikipedia.org/wiki/GAM-87_Skybolt

Someone else mentioned the C-5 + Minuteman test:

http://en.wikipedia.org/wiki/Air-launched_ballistic_missile

[Zed_Noir]

Anyways, the Stratolauncher aircraft would be rather oversized for the task. The Peacekeeper's were huge as ICBM's go, but still half the mass of the Falcon V being discussed. The smaller Minutemen are about 1/6th the mass.

Not really. You could have kinetic penetrator packages on Midgetman size ballistic missiles hung from a multiple ejector rack. Giving you the option to cover multiple targets and/or do a successive follow on attacks on more robust or large targets.

[Chris Bergin]

I like this

[JohnFornaro]

Wow. 43 pages and 46K views since December.

I take it that the idea is that WhiteKnight was the demo project? And that now is the time to scale up the effort?  After all, Mr. Allen has three commas in his checkbook, and much startup cred, so investment capital can feel that risk is adequately covered?  More power to him.

A structural aside.  F9, or what, F5?, as currently manufactured, is not engineered to be hung from its mid-point.  So those assymetrical loads must be accounted for inside the geometry of the fairing itself.  Seems to me that the shape of the rocket would be more ellipsoidal, around its horizontal axis, than circular.

[hop]

I take it that the idea is that WhiteKnight was the demo project?

Huh ? Where do you get that from ? The success of the SS1 project and  successful (so far) development of SS2 may have given them confidence, but I don't see any indication there was some overall plan from the start. It wouldn't make sense without something like F9 already being developed, which was not the case when they set out to do SS1

Seems to me that the shape of the rocket would be more ellipsoidal, around its horizontal axis, than circular.

No. They explicitly stated it would be a shortened F9 stage. Cylinders are great for light, rigid structures. They may need to add structure, but they aren't going to change the whole shape.

[JohnFornaro]

I take it that the idea is that WhiteKnight was the demo project?

Huh ? Where do you get that from ? (1) The success of the SS1 project and  successful (so far) development of SS2 may have given them confidence, but I don't see any indication there was some overall plan from the start. ...

Seems to me that the shape of the rocket would be more ellipsoidal, around its horizontal axis, than circular.

No. (2) They explicitly stated it would be a shortened F9 stage. Cylinders are great for light, rigid structures. They may need to add structure, but they aren't going to change the whole shape.

(1)  From my own brain, mostly. I notice the parallels in the launch scheme.  Then I bactracked and thought, huh.  They turned this into a plan?  Not a plan from the start, but a plan from the workability of SS1.  YMMV.

(2)  Understood.  Just my intuitive design sense.  So the internal structure must be accomodated within the cylindrical fairing.  Not my design.  Not judging either.  Asking only.

[JAFO]

If it was anyone but Burt Rutan I'd think "Not a chance.". But I'll bet Rutan has done "black projects" that won't see the light for decades, and if anyone can do it....

[HMXHMX]

If it was anyone but Burt Rutan I'd think "Not a chance.". But I'll bet Rutan has done "black projects" that won't see the light for decades, and if anyone can do it....

Earlier, I said I wouldn't comment about Stratolaunch, but I have an view to share (that is carefully worded to avoid issues with proprietary or private confidences). 

First, people are ascribing way too much involvement by Burt (and maybe others like Griffin and Elon) to the Stratolaunch venture.  This is a Vulcan project that seems to have its center of gravity located in Huntsville. 

When I saw Burt a few days ago, he was very clear that he has no management role whatever, and only sits on the Board; otherwise he strongly reiterated "I'm retired."  He has said this publicly before, so this doesn't constitute betraying a confidence.  But people don't listen.

He didn't design the aircraft, he has no real part in the launch vehicle, and he has no role in day-to-day Stratolaunch management.  Plus Scaled is on their own with this aircraft; Burt is not working on it.

(Also, I don't interact with Griffin at all, but I get the impression from his equivocal statements at the press conference that he too is only a Board member and has no management role.  Elon has in the past disparaged air-launching, and I see no reason to think he has changed his view.  SpaceX is quite willing to sell stuff to legitimate purchasers, so when Stratolaunch asked for a launch system, SpaceX apparently said "yes."  They're in business, after all.)

So Stratolaunch might be a good idea or a bad idea, but Burt is not sprinkling Rutan Pixie Dust over the project.  It will stand or fail on engineering and business choices, and those choices won't be made by Burt.  That's my opinion.

[Hotdog]

From comments made by Burt Rutan in the press conference and in the past, he was not responsible for designing WK2/SS2. He did the concept design but left the detailed engineering to be performed by the Scaled Composites team. For Stratolaunch, he said he performed the concept design prior to his retirement (they are now at PDR level) and the Scaled team will do the detailed engineering. I am sure he will still have some sort of oversight role though as he remains chairman emeritus.

My point is that he has obviously created a very capable team at Scaled. The success of WK2/SS2 so far gives the indication that they may be capable of scaling up WK2 to the monster carrier aircraft required for Stratolaunch.

If it was anyone but Burt Rutan I'd think "Not a chance.". But I'll bet Rutan has done "black projects" that won't see the light for decades, and if anyone can do it....

Earlier, I said I wouldn't comment about Stratolaunch, but I have an view to share (that is carefully worded to avoid issues with proprietary or private confidences). 

First, people are ascribing way too much involvement by Burt (and maybe others like Griffin and Elon) to the Stratolaunch venture.  This is a Vulcan project that seems to have its center of gravity located in Huntsville. 

When I saw Burt a few days ago, he was very clear that he has no management role whatever, and only sits on the Board; otherwise he strongly reiterated "I'm retired."  He has said this publicly before, so this doesn't constitute betraying a confidence.  But people don't listen.

He didn't design the aircraft, he has no real part in the launch vehicle, and he has no role in day-to-day Stratolaunch management.  Plus Scaled is on their own with this aircraft; Burt is not working on it.

(Also, I don't interact with Griffin at all, but I get the impression from his equivocal statements at the press conference that he too is only a Board member and has no management role.  Elon has in the past disparaged air-launching, and I see no reason to think he has changed his view.  SpaceX is quite willing to sell stuff to legitimate purchasers, so when Stratolaunch asked for a launch system, SpaceX apparently said "yes."  They're in business, after all.)

So Stratolaunch might be a good idea or a bad idea, but Burt is not sprinkling Rutan Pixie Dust over the project.  It will stand or fail on engineering and business choices, and those choices won't be made by Burt.  That's my opinion.

[HMXHMX]

From comments made by Burt Rutan in the press conference and in the past, he was not responsible for designing WK2/SS2. He did the concept design but left the detailed engineering to be performed by the Scaled Composites team. For Stratolaunch, he said he performed the concept design prior to his retirement (they are now at PDR level) and the Scaled team will do the detailed engineering. I am sure he will still have some sort of oversight role though as he remains chairman emeritus.

My point is that he has obviously created a very capable team at Scaled. The success of WK2/SS2 so far gives the indication that they may be capable of scaling up WK2 to the monster carrier aircraft required for Stratolaunch.

If it was anyone but Burt Rutan I'd think "Not a chance.". But I'll bet Rutan has done "black projects" that won't see the light for decades, and if anyone can do it....

Earlier, I said I wouldn't comment about Stratolaunch, but I have an view to share (that is carefully worded to avoid issues with proprietary or private confidences). 

First, people are ascribing way too much involvement by Burt (and maybe others like Griffin and Elon) to the Stratolaunch venture.  This is a Vulcan project that seems to have its center of gravity located in Huntsville. 

When I saw Burt a few days ago, he was very clear that he has no management role whatever, and only sits on the Board; otherwise he strongly reiterated "I'm retired."  He has said this publicly before, so this doesn't constitute betraying a confidence.  But people don't listen.

He didn't design the aircraft, he has no real part in the launch vehicle, and he has no role in day-to-day Stratolaunch management.  Plus Scaled is on their own with this aircraft; Burt is not working on it.

(Also, I don't interact with Griffin at all, but I get the impression from his equivocal statements at the press conference that he too is only a Board member and has no management role.  Elon has in the past disparaged air-launching, and I see no reason to think he has changed his view.  SpaceX is quite willing to sell stuff to legitimate purchasers, so when Stratolaunch asked for a launch system, SpaceX apparently said "yes."  They're in business, after all.)

So Stratolaunch might be a good idea or a bad idea, but Burt is not sprinkling Rutan Pixie Dust over the project.  It will stand or fail on engineering and business choices, and those choices won't be made by Burt.  That's my opinion.

I have no doubt Scaled can build the aircraft; I know the folks working on it well and have worked with them on other efforts.  I'm just pointing out Scaled doesn't manage the LV effort, Stratolaunch does.  The aircraft is fairly straightforward compared to the LV and ASE.  Scaled will deliver the aircraft if they are paid to do so.  You can bank on that.

But Burt has no oversight role of which I am aware.  He no longer even has an email address at Scaled.  The man has earned his retirement and now I am pretty sure intends to enjoy it – we should all let him.

[NotGncDude]

I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.

Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

Jim is right, for an air-launched vehicle there's got to be a pretty strong argument AGAINST LH2 not to use it.

True. Given that you're already going through the pain in the a** of airlaunching, may as well use LH2.

[Patchouli]

True. Given that you're already going through the pain in the a** of airlaunching, may as well use LH2.

Development cost for one the Merlin engine already is existing and lox and kerosene are much easier to handle.

Plus they're going for best possible cost per pound vs maximum performance from the system.

For a two stage system hydrocarbon seems to be cheaper then hydrogen for a given payload.

[Robotbeat]

...
For a two stage system hydrocarbon seems to be cheaper then hydrogen for a given payload.

The situation is not the same for ground launch vs. air launch in that regard. With ground launch, if you get a better, upgraded thrust first stage engine, you can firm up the structure a bit, stretch the tank, and get significantly more performance out of it. For airlaunch, you're severely limited by max carry weight. A higher thrust engine helps you in no way. If you run into performance issues or find you need a little extra performance to serve a considerably more profitable part of the market, you can't just increase first stage thrust and stretch your tank, like Falcon 9 is doing (and did a similar thing with the transition from Falcon 5 to Falcon 9). Because your carrier aircraft is so expensive, there's a very strong motivation to maximize your return on that investment by getting the highest performance you can from your rocket for a given takeoff weight.

[Zed_Noir]

I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.

Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

Jim is right, for an air-launched vehicle there's got to be a pretty strong argument AGAINST LH2 not to use it.

True. Given that you're already going through the pain in the a** of airlaunching, may as well use LH2.

Actually I agree with Jim that LH2 is a better air-launched propellant. Just that the large development cost of a new cryogenic engine stage as compare to the relative simple conversion of a ground launched kerolox stage make it less likely to be realize.

[neilh]

I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.

Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

Jim is right, for an air-launched vehicle there's got to be a pretty strong argument AGAINST LH2 not to use it.

True. Given that you're already going through the pain in the a** of airlaunching, may as well use LH2.

Actually I agree with Jim that LH2 is a better air-launched propellant. Just that the large development cost of a new cryogenic engine stage as compare to the relative simple conversion of a ground launched kerolox stage make it less likely to be realize.

If/when Raptor is developed, I wonder if it would be at all practical to use Stratolaunch to launch a LH2 rocket using Raptor engines on both stages.

[NotGncDude]

True. Given that you're already going through the pain in the a** of airlaunching, may as well use LH2.

Development cost for one the Merlin engine already is existing and lox and kerosene are much easier to handle.

Plus they're going for best possible cost per pound vs maximum performance from the system.

For a two stage system hydrocarbon seems to be cheaper then hydrogen for a given payload.

Agreed. I'm sort of making fun of purely theoretical statements detached of practical reality. So, to continue in that vein:

Aw c'mon, RL-10's and SSME's are already developed. What are you talking about?

[baldusi]

...SSME's are already developed. What are you talking about?

SSME can't be air launched AND needs to be vertical to ignite. So it's no use. Keep in mind that the max launcher weight would be around 500klbs, thus, needing something between 600klbf to 750klbf in thrust. The SSME is too small (as a single engine) or too powerful (for clustering). The RS-68 is sort of a shoe in, though. And two J-2X would be about just right, too.

[Patchouli]

The situation is not the same for ground launch vs. air launch in that regard. With ground launch, if you get a better, upgraded thrust first stage engine, you can firm up the structure a bit, stretch the tank, and get significantly more performance out of it. For airlaunch, you're severely limited by max carry weight. A higher thrust engine helps you in no way. If you run into performance issues or find you need a little extra performance to serve a considerably more profitable part of the market, you can't just increase first stage thrust and stretch your tank, like Falcon 9 is doing (and did a similar thing with the transition from Falcon 5 to Falcon 9). Because your carrier aircraft is so expensive, there's a very strong motivation to maximize your return on that investment by getting the highest performance you can from your rocket for a given takeoff weight.

The big issues here is cost there simply are not any low cost air startable hydrogen engines in the right thrust class.
The closest hydrogen engine for the target payload would be the J-2X but this would not be low cost.

If they need future improvements they could add a hydrogen upper stage later on.

But adopting Falcon gets them a low cost rocket quickly they also could have used a cut down Atlas CCB.
The RD-180 would be over kill in that case they could use the RD-191.

As for hydrocarbons being no use for airlaunch at subsonic speeds.
If this was 100% true the Russians would not have bothered with developing the RD-701.

http://www.buran.ru/htm/molniya6.htm

Actually if I were to start with a clean sheet air launch system vs adopting an existing booster I'd go with the RD-701 or just go with a simple pressure feed system like QuickReach.

[simonbp]

The closest hydrogen engine for the target payload would be the J-2X but this would not be low cost.

That's in the eye of the beholder. If you had a recoverable first stage, I bet you could make J-2X just as "reusable" as SSME (i.e. requiring a complete teardown after every flight), if not much more reusable.