Gateway manufacturer finally acknowledges issue, fails to mention "corrosion"

Gateway manufacturer finally acknowledges issue, fails to mention “corrosion”

“At this time, further comments would be premature.”

Eric Berger – Apr 27, 2026 10:02 am | 63

The HALO module arrives in North America from Italy in 2025. Credit: Northrop Grumman

One of the more intriguing space stories in a while broke last week when NASA Administrator Jared Isaacman said during a congressional hearing that the two habitation modules built for the Lunar Gateway had been corroded.

The immediate response to these comments on Wednesday before a House committee from some space industry observers was doubt—Isaacman, they said, must be lying.

However, the primary contractor for the Habitation and Logistics Outpost, Northrop Grumman, soon acknowledged there was a manufacturing irregularity. On Friday, the European Space Agency, providing the other habitation module (I-HAB), acknowledged that there had been “corrosion” observed.

The pressure vessel structures for both modules were manufactured by a French-Italian firm, Thales Alenia Space. On Friday, Axiom Space, which also ordered a pressurized structure for its private space station from Thales, told Ars it had experienced “similar” issues with its Module 1.

Thales finally talks

Thales had remained mum about these various issues and did not offer a comment until Monday morning, nearly five days after Isaacman’s testimony. The company’s statement, in full, reads:

Our teams are working hand in hand with our longstanding customer Northrop Grumman to ensure that the HALO module fully meets the mission’s requirements, using NASA-approved processes. A well-known metallurgical behavior was found at the surface of the module, which will be fixed by the end of the third quarter of 2026. As for Lunar I-HAB, which is still in our facilities to date, we are also teaming up with ESA to fix soon the same related issue.

Our company, together with its customers and partners, is used to face and solve this kind of situations, in this very-challenging space environment. As an example, a metallurgical behavior of this kind occurred decades ago during the manufacturing of elements for the International Space Station (ISS). The ISS’ pressurized modules have proved to be highly performant, and continue to operate reliably, exceeding their original expected lifespan. With nearly 50% of the ISS’ pressurized volume built by our company still functioning after 25 years, we leverage this experience to address the current situation with agility, expertise and full technical control.

At this time, further comments would be premature. For more information, please refer to Northrop Grumman for HALO and ESA for Lunar I-HAB.

Presumably, the “well-known metallurgical behavior” is a euphemism for corrosion.

Is a fix even “warranted”?

The Gateway entities have sought to minimize the habitation module damage due to corrosion, with Northrop and Thales suggesting that the problem with the HALO module will be fixed by the end of the third quarter this year, or five months from now.

However, Isaacman sounds less certain about this, indicating that fixing the problem is not straightforward nor a guarantee. “I am not sure there is a deterministic approach to repair,” Isaacman said Saturday on the social media site X.

During his testimony, Isaacman said the corrosion issues, among other problems, likely would have delayed the launch of the Lunar Gateway beyond 2030. It was originally due to launch in 2022. And in follow-up comments, Isaacman said he was not sure whether efforts to repair HALO and I-HAB were “even warranted at this point.”

It is important for Thales to understand this issue and address the manufacturing process that led to these defects. The company, historically, is the most important provider of pressure vessels in the West, also building the Cygnus spacecraft structure for Northrop.

At the same time, it faces rising competition from US-based companies. Although Axiom chose Thales to build its pressure vessels for a private space station, Vast Space is manufacturing its station modules in California, and Voyager has partnered with Vivace to build its space station structure in Louisiana.