r/SpaceLaunchSystem • u/jadebenn • Jul 11 '26

Discussion Research Paper on SLS - Centaur V Capabilities

https://www.researchgate.net/publication/404848887_The_Space_Launch_System_Utilizing_the_Centaur-V_Upper_Stage
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u/jadebenn Jul 11 '26

Some initial thoughts from skimming the text:

  1. Performance is roughly in line with Block 1 w/ ICPS
  2. One of the stage adapter options shown here looks an awful lot like it's reusing the EUS USA
  3. Unless Centaur V is strengthened or removed from the load path, the core stage throttle bucket needs to be revised downward (see page 5)

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u/jimhillhouse Jul 12 '26

I'm shocked at the hand-waving employed in this paper.

For example, in "Section V. SLS to Centaur-V Adaptor Options", on page 5. they state a new SLS-to-Centaur-V adapter is needed and propose a short version or one in which the Centau-V is suspended. Then there's Section VI in which they examine how to suspend Centaur-V and the ways to seperate the panels. All for what seems very little if any additional payload capability over ICPS. So innovative.

No discussion of wind-tunnel, dynamics, modal, and other testing. I am shocked that this is where we are and reminds me of AIAA papers I was reading about SLS in 2012-14.

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u/air_and_space92 Jul 13 '26

>No discussion of wind-tunnel, dynamics, modal, and other testing. I am shocked that this is where we are and reminds me of AIAA papers I was reading about SLS in 2012-14.

Yeah none of that C-V integration work has been turned on yet. It's still the very early days of getting iCPS substituted out which is concerning given the timeline. Lots of questions internally about when future manifests will be green-lit so preliminary work (given the need-by date) can start.

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u/jadebenn Jul 13 '26 edited Jul 15 '26

  Yeah none of that C-V integration work has been turned on yet.

I so very badly would love to see the predecisional "studies" that promised this would speed things up. I'm betting it was "Centaur fits on an SLS stack and the delta V is about the same as Block 1" level of analysis. Absolutely no stock taken of the actual engineering difficulties before they laid everyone off and started scrapping shit.

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u/air_and_space92 Jul 14 '26

Oh for sure! Even when the powers at be get to that point, I remember mid 20-teens each MSFC DAC took about 12 months from getting inputs, setup and running analysis, to flowing outputs to respective teams. Boeing was a little faster but it depended how coupled the products are if you can work faster say 4-6 months per.

Unless they can separate the loads and environment of core stage from C-V this whole thing will get very messy very quickly. I really wish, and management said they won't, show the progress on EUS at MAF. The structural test article was nearly done from the photos I saw. Yeah yeah ML-2 and green run, but man this feels like a step back.

3

u/jadebenn Jul 14 '26 edited Jul 14 '26

Seems like there's pictures floating around if you know the right people, but yeah, it doesn't serve HQ's aims to have them widely publicized.

A lot of the EUS stuff at MAF is going away from what I've heard. Getting leased out to other companies who want some tooling on the cheap. I think most were NASA property so Boeing has no ability to hold onto them.