(warning: contains hearsay): materials and labor, I'm told. Like the P&W RL-10, the Aerojet AJ-10 was designed during a period of time when labor was cheap and complex machine tools expensive and unreliable (i.e.before digital computers). In the case of the RL-10, I know that PWR has been desperately trying to get somebody to pay for a major upgrade of the that, among other things, does away with the painstakingly beautiful but high-cost hand-molded and hand-brazen tube-formed nozzle and early bell...(Before somebody asks the question "why don't they pay for that improvement out of their own - or mother United Technologies' - pocket?" I will answer it Very simple: there is no credible business case for PWR to do so without major customer financial support or committment...)
How about the GX engine?
Quote from: Salo on 04/02/2010 08:20 pmMay be NK-31 with TVC?(*Sniff*...) Brings me back memories of the X-34... (somebody get me a Kleenex, please)
May be NK-31 with TVC?
I guess all of these differences reduced the thermal radiative load of the nozzle enough to allow the side-by-side installation on the transtage (how they got two 1.53m nozzles within a 3.05m OUTSIDE DIAMETER airframe I cannot explain, but the Titan transtage was one bizarre bird, with asymmetrical N2O2 and Fuel tanks...) Now, I didn't make up the concern about radiational re-heating of the side-by-side -118K nozzles... we actually analyzed it (no hearsay.)
http://techtran.msfc.nasa.gov/tech_ops/Fastrac_Engine.pdf
Quote from: antonioe on 04/03/2010 03:41 amI guess all of these differences reduced the thermal radiative load of the nozzle enough to allow the side-by-side installation on the transtage (how they got two 1.53m nozzles within a 3.05m OUTSIDE DIAMETER airframe I cannot explain, but the Titan transtage was one bizarre bird, with asymmetrical N2O2 and Fuel tanks...) Now, I didn't make up the concern about radiational re-heating of the side-by-side -118K nozzles... we actually analyzed it (no hearsay.)Probably the reported 1.53m diameter for the -138 nozzle is not correct as the simply do not fit with this diameter.
Just a brief question: Would it be practical to have a three-stage configuration with something similar to the DIIUS mounted on top of the Castor-30?
If that would need more power to get off the pad, what sort of level of enhancement are we talking about? Simple SRM strap-ons or a 'heavy' tri-core?
O.K., O.K.,... now you really want me to break out sobbing... Although I'm told that some Fastrac elements (turbopump?) are alive and well in the design of the SpaceX Merlin.
Either of these would require substantial $$$'s and would put us squarely in the EELV market, which we do not contemplate in the foreseeable future. We would like to steer the government's interest into more medium-class missions vs. few large-class missions, and not just for Orbital's benefit, but to help the U.S. space industrial base, spacecraft and launchers alike (including the second-tier suppliers!)
Quote from: antonioe on 04/03/2010 05:36 pmO.K., O.K.,... now you really want me to break out sobbing... Although I'm told that some Fastrac elements (turbopump?) are alive and well in the design of the SpaceX Merlin.And why then not to use vacuum Merlin? Or you are not ready to co-operate with SpaceX?
QuoteIf that would need more power to get off the pad, what sort of level of enhancement are we talking about? Simple SRM strap-ons or a 'heavy' tri-core?Either of these would require substantial $$$'s and would put us squarely in the EELV market, which we do not contemplate in the foreseeable future. We would like to steer the government's interest into more medium-class missions vs. few large-class missions, and not just for Orbital's benefit, but to help the U.S. space industrial base, spacecraft and launchers alike (including the second-tier suppliers!)Our devious plan for world domination is, in order of priorities:1,2,3 - Deliver what we promised on COTS/CRS4 - Sell Taurus II as an MLV to DoD and NASA (launching as many Orbital-made medium-class spacecraft as possible )5 - Sell the first polar mission and enable West Coast (VAFB or Kodiak, whichever is cheaper) launch capability.In the meanwhile, we are following the current Commercial Crew initiatives at NASA with considerable interest...
Considering they are competing in the same market, I doubt OSC would either ask for or SpaceX would supply the engine, that would be like Toyota asking to buy engines from GM.
It's not likely, but possible. Mazda and Ford share motors, Isuzu and Chevy share almost everything, Hyundai and Mazda share, Porsche and Volkswagen share....
Quote from: SpacexULA on 04/03/2010 08:43 pmIt's not likely, but possible. Mazda and Ford share motors, Isuzu and Chevy share almost everything, Hyundai and Mazda share, Porsche and Volkswagen share....Ummm. Mazda is partly owned by Ford, Isuzu and Porsche are fully owned by GM and VW respectively (OK, the VW/Porsche relationship precedes that date but the two companies have the same founder and the CEO of VW was the biggest shareholder of Porsche at the time...)Bad examples. Although your message was correct, there are LOTS of engines being shared by competitors in the automotive world (know about Mercedes using VW engines and BMW using PSA ones but there'll definitely be more).
Us space flight amateurs may tend to flip through Jane's Spaceflight Directory like it is the Sears catalog,
Quote from: just-nick on 04/04/2010 04:02 amUs space flight amateurs may tend to flip through Jane's Spaceflight Directory like it is the Sears catalog,Us professionals flip Gunter's and Mark's web pages...