Hey, I'm not really a fan of DIVHUS (JUS is, after all, the triumph of DIRECT), but articles on NSF pointed towards the possibility of using Centaur, DIVHUS, or a stretched DIVHUS on SDHLV. OV-106 is, IIRC, particularly an advocate of this as an interim approach. There might be Boeing/LockMart/ULA/NASA contracting issues, but I assume that if these speakers are looking at the idea, such issues can be worked around. You certainly can build a stage from the AIUS tooling, but if you want to do payload EOR with it, you'll either have to do rapid double-SLS LC-39 A/B launch and immediate rendezvous, or essentially develop ACES independently. -Alex
Key words going forward IMO:1. Affordable2. Low boiloff/long duration3. DEPOTS DEPOTS DEPOTS4. ACES derived.
5. Maintain Strong Bipartisan Congressional SupportNote: ACES is nifty. However, what ACES has, many others will also eventually develop. Cheers!
What are the drawbacks, if any, of an 8.4m diameter stage of <some> length on either the Atlas-V or the Delta-IV?
What are the drawbacks, if any, of an 8.4m diameter stage of <some> length on either the Atlas-V or the Delta-IV?...
ULA would prefer 5/5.3m
Quote from: Jim on 10/12/2010 06:09 pmULA would prefer 5/5.3mWhat about a compromise between 8.4M and 5M since one extreme is too big for ULA and the other is too small for exploration?Maybe go with 6 to 6.6M or the diameter of the S-IVB which should still fit inside a 747 LCF or Airbus Beluga.
Quote from: Patchouli on 10/12/2010 07:20 pmQuote from: Jim on 10/12/2010 06:09 pmULA would prefer 5/5.3mWhat about a compromise between 8.4M and 5M since one extreme is too big for ULA and the other is too small for exploration?Maybe go with 6 to 6.6M or the diameter of the S-IVB which should still fit inside a 747 LCF or Airbus Beluga.Why such a bizarre compromise? Without 8.4m you'll loose the PLF volume capability, and if you can't do that - you might as well go down to 5.3 to take advantage of existing assets/capabilities of ULA/Boeing/LM.Nothing in between makes sense IMO.
The way it looks something based off the Ares I US might be the best option for an upper stage for SLS.The next question finish the J2 or go with a cluster of RL-10s or RL-60s?
Quote from: Patchouli on 10/12/2010 07:36 pmThe way it looks something based off the Ares I US might be the best option for an upper stage for SLS.The next question finish the J2 or go with a cluster of RL-10s or RL-60s?RL-10 (of some flavor) for sure. Excellent Isp, which is the most important thing for an EDS. And an EDS is what we want more than anything, right? To depart Earth?J-2x is a waste, IMO.
One can have commonality without being identical. Think for a second, you make a control system, and a thrust base consisting of two RL-10's. For a ULA 5m US, you have two of these base, all using the same control system. For the SLS 8.4m US, you have three of these bases, and again using the same control system. The tank tooling and building is not the real cost saver, the engine and control systems are. Having a common component which can be adapted to both designs would bring along mass production quantity without limiting either designs.