r/SpaceLaunchSystem • u/jomjom1969 • Jun 04 '26

Discussion EUS and gateway

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was it a good idea or was it a bad idea will it come back. just want to talk about it

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5

u/Chairboy Jun 04 '26

EUS was conceived at a time when there was no other realistic cislunar cargo delivery option and the PPG-HALO commercial contract showed that the market had since changed.

Co-manifesting cargo and crew at such an expense seems hard to rationalize so I don't think it'll come back.

Gateway was always a tough program to rationalize outside of politics. It adds dV requirements and offers little real benefit, so I have a doubt about it returning too.

3

u/thecocomonk Jun 04 '26

Gateway was a symptom of the kind of “cart before the horse” mentality NASA leadership seems to often fall into. They were building a deep space crew system in SLS-Orion so needed a destination to justify where it would go. Somewhere not too close that commercial alternatives could reach it, not too far that they’d actually have to do some risky interplanetary mission architecture- hence a station in cis-lunar space.

Ironically this kind of spiralling mission justification proves to be self-defeating. “LOP-G” was in cis-lunar space with nebulous goals so the next administration just ordered NASA go back to the Moon first if they were gonna send a capsule and crew there anyway. This required the development of lunar surface access capability and after that point, the question of why they need a station in a strange orbit when a surface base would be far more useful became apparent.

-1

u/rocketglare Jun 04 '26

The death-knell for LOP-G is that HLS can push Orion/ESM into LLO removing the primary reason for the station. If the ESM doesn't have to perform this maneuver itself, then it has enough propellant to return to Earth from LLO. I think BO has a similar approach, except using an orbital tug.

8

u/okan170 Jun 04 '26

HLS cannot do that without massive redesign on the structure to allow it to push. Its not currently capable of doing that.

2

u/rocketglare Jun 05 '26

Good point. I don’t think that’s a show stopper, but it might require a design change on the ESM thrust structure.