NASA Completes Design Review of the SLS Exploration Upper Stage
HUNTSVILLE, Ala. (NASA PR) — The Exploration Upper Stage (EUS) for future flights of NASA’s Space Launch System rocket has passed its Critical Design Review, or CDR.
A panel of experts evaluated the EUS in the latest review to determine that the stage’s design meets requirements for future missions. This most recent assessment certifies the EUS meets critical design requirements to withstand deep space environments and when completed will ensure astronaut safety.
The review board also evaluated testing processes, the ability of the industrial base to supply parts and tooling, and production plans. Boeing, the prime contractor for the EUS as well as the core stage, will manufacture and assemble the upper stage at NASA’s Michoud Assembly Facility in New Orleans.
A structural test article of the stage will undergo testing at NASA’s Marshall Space Flight Center in Huntsville, Alabama, where the SLS Program is managed. The flight article will undergo Green Run testing at the agency’s Stennis Space Center near Bay St. Louis, Mississippi, before its first flight, similar to the SLS core stage Green Run testing currently in progress, including a hot firing of the engines.
NASA is working to land the first woman and the next man on the Moon by 2024. SLS and Orion, along with the human landing system and theGateway in orbit around the Moon, are NASA’s backbone for deep space exploration.
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5 responses to “NASA Completes Design Review of the SLS Exploration Upper Stage”
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Is this design refuelable in space ? What’s the deep space loiter time between relights ?
Good questions. Another would be why does this design have no common tank dome to save mass? Both upper stages of the Saturn V did. It’s not like hydrolox common dome technology is exactly cutting-edge.
IIRC loiter time = 8 hours
For the absurdly long development time and cost of EUS, I would have expected some interesting new technology like slush-hydrogen storage, but no. The EUS seems like hardly anything more ambitious than an enlarged Delta cryogenic upper stage.
IIRC the RL-10 was about $24M each. So unless the price have change drastically, just the engines is about $92M. The EUS stage might have a unit price of roughly $200M in my estimation excluding R&D..
IIRC the FY 2021 NASA budget includes at least $300 million for EUS.
Assuming that level of NASA spending on EUS is pretty consistent year by year, that’s the equivalent of the price SpaceX would charge to put 125 metric tons of payload into LEO, every year, using the Falcon Heavy.
So if the very first flight of EUS is in 2025 on the fourth launch of the SLS (optimistic, I know), for all the money that NASA would have plowed into EUS by then, instead NASA could have put over 600 metric tons of payload into LEO or sent 200 metric tons of payload towards the Moon!