What configuration are they doing a CDR against? Very different designs depending upon the Engine selected.
In other words, “keep your Vulcan comments focused on topic!”
Quote from: Ike17055 on 12/08/2017 06:59 pmIn other words, “keep your Vulcan comments focused on topic!”Indeed. If you make comments like ''Vulcan should replace the SLS" - there's a good chance your post will be deleted because a Sheldon Cooper type of person probably objected to it
Quote from: rcoppola on 12/08/2017 06:28 pmWhat configuration are they doing a CDR against? Very different designs depending upon the Engine selected.Good question. It will also have substantial inputs to the "Centaur V/5" CDR if that's separate. The cautious option is to do both engine CDR's and the US CDR against both of those. Note it's not just an engineering issue.While both versions are in play ULA can tell each booster engine mfg that they could go with the other one and press for a better deal. The question is wheather or not ULA is in too deep for such negotiating games and wheather it's time to fully commit to Blue or AJR. I think that depends how well engine tests have been going. I'm betting ULA are much better informed about that than we are. They really need the whole spec to be delivered before commitment. None of that "it's 90% there and we'll get the rest ready for you by the time the stage flies, honest." Ideally that means a full duration, full power test, a virtual flight to 1st stage MECO. Whoever delivers that first should be home and dry. Blue look like they are in pole position for this, but maybe AJR will surprise people, given the consequences for them...
Seems unlikely they would be doing a CDR unless they had narrowed the engine and configuration choices to single booster vendor and similar for second stage (assuming only a single configuration). Construction cannot begin if major options/decisions remain.PDR is usually where the trades on major components are presented and decided...
Did they do a PDR?
Quote from: clongton on 12/09/2017 01:07 pmDid they do a PDR?Completed back in March 2016 for the BE-4 version. [ULA press release]Maybe it's my reading comprehension again but I cant find a similar release for AR1.
Quote from: MATTBLAK on 12/08/2017 11:18 pmThat happens almost organically when a controversial program is discussed.Vulcan is controversial? - Ed Kyle
That happens almost organically when a controversial program is discussed.
...So is AJR still guaranteed business for RL-10s for Centaur 5?...
If these views are correct then it looks like it's game over for the AR-1, unless AJR can find someone who needs a big, US designed and built LOX/RP1 engine in the near future.
Blue for the Booster engines, ULA for the structures Orbital ATK for the SRB's and RUAG for the fairings? So is AJR still guaranteed business for RL-10s for Centaur 5?Or could Centaur 5 be like Atlas V? Like previous Atlases except.....
AJR have been doing lot work to modernise RL10 and reduce its build cost. They need to past those savings onto ULA if what a decent production rate of 20-40, otherwise it is only 4 a year for SLS.
My guess is still that the final, official & public decision comes with the BE-4 performing well in a full length full power run or two. ULA can't afford to be slow in the Vulcan development or to spend lots of money on a shadow design. OTOH they really can't afford a repeat of the RS-68 performance problem either.
As long as AR1 is in the run there is leverage. ARJ gets money so they'll play along. Politicians have one more thing to spend money where they want to, no problem either.
Once there are BE4 test stand runs ULA has leverage against both ARJ and politics. Worst case Blue does not deliver and ULA can pivot the engine choice without eating crow.
L3 for avionics.Looking at Bigelow and Ixion renderings it seems that RL-10 is alive and strong.Still can't put my head around the need to increase head pressure for another 2 of them. Feels to me like they were designing the tank to meet the requirements of several engines at the same time. Go with RL-10 for heritage sensitive customers. Keep the option to swap "just" the engine including its thrust structure to cut cost. Another point to exert leverage. ARJ certainly knows if they need more head pressure to prevent cavitation or not.
AJR have been doing lot work to modernise RL10 and reduce its build cost. They need to pass those savings onto ULA if what a decent production rate of 20-40, otherwise it is only 4 a year for SLS.