First component of upgraded moon rocket stage completed

Team finishes structure used in testing the Exploration Upper Stage that will power missions to deep space.

BNN

Tuesday, July 15, 2025

Above, teammates review computerized illustration of Exploration Upper Stage (EUS) Thrust Structure. (Boeing/Liz Morrell photo)

Boeing teams at NASA’s Michoud Assembly Facility have made significant progress on the next moon rocket’s Exploration Upper Stage (EUS) with the completion of the thrust structure, a major part of the structural test article. This more-powerful stage is what will propel the Artemis IV mission to deep space.

Why it matters: Completion of the thrust structure marks the first major component of the Exploration Upper Stage’s structural test article.

Teams use the thrust structure for testing to assess its strength and stability, ensuring it can meet the requirements set by NASA for its deep space missions.

“This build marks a huge milestone for EUS, as it demonstrates our processes and successful cross-functional teaming complete the first structural test article assembly and first full-size determinant assembly structure,” said Zach Kloss, EUS thrust structure sub-IPT lead. “This piece will play a vital role in supporting NASA’s goals for deep space exploration, showcasing our team's dedication to advancing exploration to the outermost parts of the universe.”

This is a computed assisted design (CAD) image of the EUS thrust structure. (Boeing image)

This is a CAD image of the EUS thrust structure and the equipment shelf. (Boeing image)

What’s next: Boeing technicians at MAF, in partnership with NASA’s Michoud Test Engineering organization, have been leading efforts to improve the processes for application of strain gauges. Collaborating with different teams including Quality Assurance, Engineering, Materials & Processes and Tooling, the team not only resolved key issues, but has maintained a consistent 90% or better first-time quality pass rate.

The EUS team has also continued production efforts on the EUS flight thrust structure and the structural test article mid-body.
“This team’s efforts reflect brightly and are a true example of Boeing values at work,” said Zach Kloss. “We as a team are continuing to move forward together, committed to each other and to the mission.”

By Casey Cappa

Go deeper:

It’s alive! Moon rocket powers up

Integrated testing energizes the core stage for the first time, another step towards second Artemis launch.

Orange coat complete: Moon rocket on the move

Teams transport the core stage for NASA’s Artemis III lunar mission after applying thermal protection foam.

NASA’s Space Launch System (SLS) rocket – the nation’s next-generation, super heavy-lift rocket – will enable NASA’s Artemis campaign and will carry people and cargo to the moon, Mars and beyond. Boeing was selected by NASA to design, develop, test and produce the core stages, upper stages, and avionics suite for the SLS fleet of rockets. The first SLS rocket – featuring the Boeing-built Core Stage – successfully launched at 1:47 AM ET on November 16, 2022, as part of the Artemis I Mission. Production is currently underway for the Boeing-built core stages, upper stages, including Exploration Upper Stage – which enables a 40% increase in payload capacity for the Space Launch System (SLS) rocket's Block 1B configuration, propelling deep space exploration to new heights – and avionics for future Artemis missions. Read more on BNN about SLS.