Whether or not the Dynetics/PWR bid is being handicapped well at this time, I'm heartily encouraged to see another bidder taking a swing at the competition.
My own personal opinion? It'll come down to F-1A versus ATK's advanced SRB; because let's be honest; Aerojet has never once built a complete NK-33 engine -- all they've done is refurbish old Soviet engines with modern electronics and gimbal systems and change the nameplate to read AJ-26. Now they want to build a massively upscaled version of the NK-33 called the AJ-1000? Doesn't pass my technology readiness level smell test.F-1A restart already had detailed work done on it in the 1990s for George H.W. Bush's Space Exploration Initative (SEI) regarding a restart.In the 1990s, Rocketdyne estimated that a F-1A Restart program would cost $315 million in FY92 dollars in non-recurring costs to restart production and re-certify the engine. Recurring costs would have been $1,080 million in FY92 dollars for 72 engines at an average cost of $15m FY92 dollars per engine, with deliveries over a five year period. Deliveries would have commenced four years after authority to proceed, with a peak delivery rate of 16 engines per year.Link to 1994 F-1A Restart CostingBasically, they worked out in 1994 what had to be replaced -- such as Beryllium and Cadmium alloys, which were no longer allowable under OSHA regulations along with Abestos, and stuff that just plain got obsolete, like Inconel X-750 and Hastelloy C.The MK10A turbopump of the F-1A used TENS 50 aluminum in a number of castings. TENS 50 has beryllium at a level over 1994 OSHA standards. It would be replaced with A356 Aluminum or A357 Aluminum which uses beryllium in levels acceptable to OSHA.This form of conversion was actually done in real life when Rocketdyne restarted Atlas and Delta engine production -- they had to convert the turbopumps/impellers/volutes from TENS 50 to A356/A357.The abestos thermal insulation blanket used on the Apollo Era F-1s would simply be replaced with the same type of thermal blanket developed for the RS-27 engine restart.Other changes such as producibility changes would have been implemented -- these were also done during the Atlas/Delta engine restart programs.One such producibility enhancement would have been the LOX Dome. The original Apollo-Era design had sixty different details such as shell segments, pins, flanges, bosses, spacers, brackets, etc which all had to be individually machined and/or formed; then welded together -- all of which required a lot of joint preparation, fit up work, welding, inspection and rework as necessary.Under the F-1A restart, the LOX Dome would have been changed to a single piece casting, eliminating all that.Source for the above:Advanced Transportation System StudiesTechnical Area 3Alternate Propulsion Subsystem ConceptsNAS8-39210DCN 1-1-PP-02147Volume IFinal ReportDR-4Executive SummaryApril 2000Prepared forNASA Marshall Space Flight CenterThe Boeing CompanyRocketdyne6633 Canoga AvenueCanoga Park, California 91303
Excellent post. Also, wouldn't this make a decent booster in its own right? Topped with J2X US & Orion/Mission Module?
Quote from: JosephB on 04/20/2012 12:44 pmExcellent post. Also, wouldn't this make a decent booster in its own right? Topped with J2X US & Orion/Mission Module?You mean like Jarvis? http://www.astronautix.com/lvs/jarvis.htm
I disagree, Ryan... If Aerojet is hungry, they have a chance. PWR will have lots of other engines, the RS-25E, the RL-10 (iCPS/CPS), and the J-2X... and that's just on the various versions of SLS...
Quote from: Lobo on 04/19/2012 11:47 pmAS cool as it would be to see the F-1 come back, I’m surprised that’s what PWR is considering offering. I’d think their RS-84 would be a better choice, as you say. More modern design, and a more useful size really. I think the SLS LRB is going to be required to be about 3 Mlb. If F-1A is 1.8-2.0 M lbs each. One isn’t enough, but two is about a million lbs thrust more than SLS is asking for.That extra thust will only help on liftoff and early phase of the flight, gravity losses will be much smaller. Problems come if it cannot be throttled back enough.And those 2 F-1A's weight less than 3 RS-84's would weight.RS-84 has definite advantage in isp, but F-1A saves so much on smaller gravity losses, and also saves little on engine weights, so overall performance should be quite close.And RS-84 being new high-tech engine means it's more expensive to manufacture? (in addition to the cost of finalizing the design)
AS cool as it would be to see the F-1 come back, I’m surprised that’s what PWR is considering offering. I’d think their RS-84 would be a better choice, as you say. More modern design, and a more useful size really. I think the SLS LRB is going to be required to be about 3 Mlb. If F-1A is 1.8-2.0 M lbs each. One isn’t enough, but two is about a million lbs thrust more than SLS is asking for.
If the production rate is several per year, than having an extra one lying around isn't a big deal. If it's one every two years, it is.
...any advanced booster is supposed to get 35mt over the 5-seg. 70mt to 105mt.
My own personal opinion? It'll come down to F-1A versus ATK's advanced SRB;
because let's be honest; Aerojet has never once built a complete NK-33 engine -- all they've done is refurbish old Soviet engines with modern electronics and gimbal systems and change the nameplate to read AJ-26. Now they want to build a massively upscaled version of the NK-33 called the AJ-1000? Doesn't pass my technology readiness level smell test.
F-1A restart already had detailed work done on it in the 1990s for George H.W. Bush's Space Exploration Initative (SEI) regarding a restart.
Problems come if it cannot be throttled back enough.
Dynetics is an integration/design firm, they don't really do big rocket core manufacture.
Quote from: hkultala on 04/20/2012 07:19 am Problems come if it cannot be throttled back enough.And don't forget that with its 5 engine configuration, Saturn V was able to go center engine out partway through the S-I burn which helped cut the Delta V increase as propellant mass bled down. I don't think you could take one of two out in this configuration, could you? (Although Atlas V-411 makes me think maybe you could.) Also, on the Saturn V, you still had a significant percentage of the original mass in the stack at the end of the S-I burn. With SLS Block IA (having no US) the launch mass has decreased by a much greater percentage by the end of the boosters' burn when contrasted with Block II or Saturn V. Ability to deep throttle does seem important with this configuration. I suppose an advantage of 3 RD-180s on each booster would be that you could take one out on each booster midway through their burn and still have symmetrical thrust.