Quote from: Patchouli on 12/26/2011 04:58 amThe 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.
The closest hydrogen engine for the target payload would be the J-2X but this would not be low cost.
So anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.
The fundamental variable is how many per year?
Quote from: Zed_Noir on 12/26/2011 07:35 pmSo anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.The fundamental variable is how many per year?
Quote from: Zed_Noir on 12/26/2011 07:35 pmSo anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.Based on the numbers I have:RS-68A : $25 mil per launchJ-2X: $40 mil per launchMerlin 1D: $35 mil per launch
Quote from: Downix on 12/27/2011 03:03 amQuote from: Zed_Noir on 12/26/2011 07:35 pmSo anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.Based on the numbers I have:RS-68A : $25 mil per launchJ-2X: $40 mil per launchMerlin 1D: $35 mil per launchThat Merlin 1D figure of $7 million per engine sounds at least a factor of two too high. If that's right the 28 engines on Falcon Heavy would cost $196 million, which is about twice the price of an entire launch!
Quote from: Downix on 12/27/2011 03:03 amQuote from: Zed_Noir on 12/26/2011 07:35 pmSo anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.Based on the numbers I have:RS-68A : $25 mil per launchJ-2X: $40 mil per launchMerlin 1D: $35 mil per launchIMO as @DeltaV and @Robotbeat stated above, $7M per Merlin-1D sounds high. Since that would meant roughly $70M just for the 9 Merlin-1D plus the Merlin-1D Vac engines on a Falcon 9 Block II.
I'm just using what numbers I have, which are extrapolated from current launch costs. Remember, this is for a vac engine, so would be technically for the Merlin 1DV, which would be more expensive than the ground-lit units.
Quote from: Downix on 12/28/2011 02:57 amI'm just using what numbers I have, which are extrapolated from current launch costs. Remember, this is for a vac engine, so would be technically for the Merlin 1DV, which would be more expensive than the ground-lit units.Roughly 3x as much cost for air start and a nozzle optimized for ignition at FL430? Not likely...Not that I see SpaceX selling Stratolaunch individual engines. That's not the SpaceX way- they'll likely sell an integrated launch vehicle. I suspect that there is better margin in tankage (when part of an integrated vehicle) than in merlins, anyway- a fact certainly not lost on SpaceX.Between making some margin on selling the launcher, and being paid to develop component technologies that benefit the overall SpaceX vision, that's the reason for SpaceX to be in this game. IMHO.
Quote from: jimvela on 12/28/2011 04:05 amQuote from: Downix on 12/28/2011 02:57 amI'm just using what numbers I have, which are extrapolated from current launch costs. Remember, this is for a vac engine, so would be technically for the Merlin 1DV, which would be more expensive than the ground-lit units.Roughly 3x as much cost for air start and a nozzle optimized for ignition at FL430? Not likely...Not that I see SpaceX selling Stratolaunch individual engines. That's not the SpaceX way- they'll likely sell an integrated launch vehicle. I suspect that there is better margin in tankage (when part of an integrated vehicle) than in merlins, anyway- a fact certainly not lost on SpaceX.Between making some margin on selling the launcher, and being paid to develop component technologies that benefit the overall SpaceX vision, that's the reason for SpaceX to be in this game. IMHO.Quite true, but remember, I'm also considering a start-date of 2017, so keep inflation in mind here.
Quote from: JAFO on 12/24/2011 01:43 amIf 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.
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....
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.
Quote from: HMXHMX on 12/24/2011 02:36 amFirst, 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. An excellent and informative post. Thank you.Question from someone with apparently limited familiarity with the subject: Why do you cal it "a Vulcan project"?
strangely enough I happened across these two studies on an Air-Launched LV that just "happen" to have a really, really similar Carrier Aircraft in the Eclipse:http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940020540_1994020540.pdf