by WASHINGTON – Boeing has opened the manufacturing facility that will build a new upper stage for an improved version of the space launch system.
The Company held an opening ceremony for the Exploration Upper Stage (EUS) Gray Box, part of the expansive building there on February 13, at the Michoud Assembly Facility in New Orleans, where the Company will construct this upper stage.
The name “Gray Box” comes from a previous use of this part of the building, said John Shannon, vice president of missions at Boeing Exploration Systems, in an interview after the event. Lockheed Martin used this area to manufacture LNG tanks, which were separated from the rest of the facility with dark gray walls and curtains to prevent dust from this work from migrating to other parts of the building. “It just got the nickname Gray Box.”
The refurbished grey-box facility, now pristine white, houses equipment used to manufacture the EUS. This phase will be used in the Block 1B version of the SLS, which will enter service with the Artemis 4 mission later in the decade.
Upon completion of the sweat testing, Boeing will manufacture an EUS structural test article, which will then be tested at the Marshall Space Flight Center. Steve Snell, Boeing EUS program manager, said the structural test article should be ready in the first half of 2024.
This will be followed by the first flight version of the EUS, which will undergo static fire tests at the Stennis Space Center, such as the green run test conducted on the SLS first core stage. These tests use versions of the Aerojet Rocketdyne RL10 engine designed to operate at sea level.
At least two lights on the stage are planned. “It’s supposed to show that we can restart the engine after it’s fired,” Snell said. The second shot would take place on the same day.
The opening of the EUS Gray Box is part of broader changes Boeing is making to the production of the SLS core and upper stages. In December, NASA and Boeing announced that they were moving some major assembly work from Michoud to Kennedy Space Center to utilize unused KSC properties such as the Space Station Processing Facility and a Vehicle Assembly Building bay.
Those changes, Shannon said, were driven by a NASA request to be able to produce two SLS core stages and exploration upper stages per year. “We just couldn’t do two a year in our footprint,” he said. The transfer of some work to the KSC, such as Improvements such as outfitting the engine module and integrating it with the rest of the core stage has freed up space at Michoud for increased production of the core stage. “We revised our works model and were able to come up with two a year.”
These changes will come into effect when the SLS for Artemis 3 is built and the engine section for that vehicle is delivered to KSC in December. At the time of the dedication ceremony, workers were preparing to install the engine section on the core stage for the Artemis 2 SLS, which is due to be completed in May.
NASA’s current plans are to use only one SLS per year until at least the end of the decade. However, Shannon said there is interest from others in the heavy-lift rocket. “Since Artemis 1, we’ve gotten a lot of interest from a lot of different places,” he said, as well as unnamed “other government agencies” interested in its payload performance.
However, he said he expects SLS to be used for non-Earth orbit missions regardless of the customer. “It really is a spacecraft. I would never compete with SLS for low earth orbit activity.”
Among those looking forward to the EUS is NASA astronaut Stan Love. Speaking at the EUS Gray Box ceremony, he said the astronaut office appreciated the fact that the EUS was designed from the start to be human evaluated and that human evaluation was not “tacked on” like the The preliminary cryogenic propulsion stage is the upper stage based on the stage built for Delta 4 used in the current Block 1 version of the SLS.
This includes more control over the stage during flight, especially in abort scenarios. “We’re really looking forward to EUS,” he said. “There is a lot of performance and safety in there. It’s part of the way we like to operate spacecraft, which isn’t meant to be some stupid payload that sits on top.”
