QuoteSo why develop block II if not needed for Lunar?That's what Congress wants. If the aim is Block II, then that is what should be developed. Once developed, it can be flown in a Block IB configuration if desired.
So why develop block II if not needed for Lunar?
@RocketmanUSWhile I somewhat agree that NASA should try to avoid "building" rockets, what commercial options do they have for the payload mass they're talking about? Should they wait for SpaceX's BFR? What happens if it doesn't come to fruition, and if it does, what kind of political fallout would ensue in the event that it's a failure? Besides that, they have no other options.While I do think the SLS is unwarranted for the time being as it doesn't even have any definitive missions, nevermind the extreme cost, I do understand why NASA wants to design a rocket to their spec (and of course you have some in congress demanding it). Sure, they could pour that money in expediting BFR development, but there would be [somewhat understandable] cries coming from all corners of aerospace and government regarding such subsidies of one company, and I doubt SpaceX would want to share development with anyone else on that project.
I wonder how high risk would refueling the EUS be as that could greatly increase the TLI payload?
Here's some preliminary artwork to whet your appetite.
I too would prefer a single-launch Lunar mission like 'the good old days'. But forgive me if I missed anything at some stage: have you ever crunched the numbers for a Lunar mission done with dual launches of an SLS Block 1B or similar? I know that would be an expensive mission; though it should allow for a much bigger LM for pretty long stay times on the surface. Also; should allow cargo-only LM versions in single launches of a Block 1B.
That's a whole lot of rocket for an Apollo "flags and footprints" redux. Heck, SLS is a whole lot of rocket anyways and that's a problem IMO. I previously asked about your excessive core stage's drymass of 123.6mT and your J-2X US at 16.9mT seems quite light. I started with different assumptions, resulting in different masses for each and a different, though just as capable rocket. If you'd allow me ..........
Funding wise; The existing EUS and Advanced Booster programs would be cancelled and resources allocated to common bulkhead development, production and re-engineering the business-end of the SHLV. You proposed and outlined the importance of J-2X (as have I and others), but I'd also cancel the RS-25 program, switch AR's production contract to J-2X and use RS-68s on the core with almost no modifications.
I did not investigate using RS-68 since that would need to be redesigned so that the ablative nozzle (which won't survive the base heating conditions) is replaced with a regenerative nozzle, practically making it a new engine.
He did know better?! That's why he didn't 'use' RS-68s in his proposal. Read about what happened in 'Constellation' history...
Quote from: MATTBLAK on 07/24/2017 01:08 pmHe did know better?! That's why he didn't 'use' RS-68s in his proposal. Read about what happened in 'Constellation' history... Comparing the thermal environment of a 10m core with six engines to an 8.4m core with three engines is as ridiculous as comparing it to a 5m core with one engine, and you needn't be a rocket scientist to know that. SP's work and knowledge deserves respect, but making such a comparison seems -- disingenuous.He, and you, should know better. Quoting an agenda's line doesn't excuse it either.
Quote from: Propylox on 07/25/2017 01:34 amComparing the thermal environment of a 10m core with six engines to an 8.4m core with three engines is as ridiculous as comparing it to a 5m core with one engine It doesn't matter. It was the SRMs that created a thermal environment that is incompatible with the ablative nozzles.
Comparing the thermal environment of a 10m core with six engines to an 8.4m core with three engines is as ridiculous as comparing it to a 5m core with one engine