Well, this is embarrassing: The Lunar Gateway’s primary modules are corroded

For a decade, NASA promoted the idea of building a space station around the Moon known as the Lunar Gateway. It touted the facility as both a platform for exploring the lunar environment and testing the technology needed for deep-space habitation.

Like many major space projects, it faced delays. Originally, the first component of the space station was due to launch in 2022. Later, it was decided that this module, to provide power and propulsion, would launch in tandem with a habitable volume known as the Habitation and Logistics Outpost (HALO) in 2024. This core was slated to be joined by another pressurized habitation module contributed by international partners I-HAB in 2026.

These dates, of course, have come and gone. And in March, NASA Administrator Jared Isaacman announced that the Gateway was being “paused” so the space agency could focus on the lunar surface.

The decision to end the Gateway experiment is entirely justifiable—NASA and its partners were spending billions of dollars to make it more difficult to reach the lunar surface and faced the prospect of watching Chinese astronauts wander around on the Moon from orbit instead of being there themselves.

But this week, we learned another reason that Gateway is going away, and it’s pretty shocking.

Came out during Congressional testimony

During testimony before the US House Committee on Science, Space, and Technology, Isaacman faced questions about NASA’s budget. As House members often do, Rep. Suhas Subramanyam, D-Virginia, asked about parochial matters. His district includes major elements of Northrop Grumman, the primary contractor for the HALO module. “You’ve also canceled an order for the Habitation and Logistics Outpost,” Subramanyam said. “Do you know what will happen to that large investment that was made?”

Since the demise of Gateway, Northrop has been pushing NASA to re-purpose the HALO module for use on the lunar surface as part of the space agency’s Moon base.

“I appreciate the contributions and look forward to working with them on how we could potentially repurpose hardware to surface applications,” Isaacman replied. But he did not stop there. He then publicly confirmed rumors (reported last month by Ars) that there is corrosion in both the HALO and I-HAB modules of the Gateway. “The only two habitable volumes that were delivered—both were corroded,” Isaacman said. “And that’s unfortunate because it would have delayed, probably beyond 2030, the application of Gateway.”

How could both a module being provided by Northrop Grumman, a major US defense contractor, and I-HAB from Europe be corroded? It seems like a fantastic claim. However, half a dozen sources who worked on or near the Lunar Gateway program confirmed to Ars that the corrosion Isaacman mentioned was real and serious.

In a statement, Northrop confirmed the issue as well. “Using NASA-approved processes, Northrop Grumman is completing repairs to HALO after a manufacturing irregularity,” a company spokesperson told Ars. “We expect to complete repairs by the end of the third quarter. HALO can still be repurposed for any mission, and it’s the most mature technology to support a deep space or lunar habitat.”

By referring to a “manufacturing irregularity,” Northrop answered the central mystery here: how corrosion could appear in both modules. This is because a French-Italian space and defense company, Thales Alenia Space, built the primary structure of HALO for Northrop Grumman. The module was delivered from Italy to the United States about a year ago.

Thales silent, but ESA comments

Thales is a powerhouse of the European space industry. It built several pressurized modules of the International Space Station, and it’s working with Axiom Space to build its commercial space station. The company also had a big piece of the Lunar Gateway in addition to HALO, developing the I-HAB module and a future communications and refueling module known as ESPRIT.

“Through these contracts, Thales Alenia Space will call on the full sum of our expertise to expand our knowledge base and push back the frontiers of the cislunar exploration,” Massimo Claudio Comparini, a senior official, said in 2020 when the contracts were announced.

Ars reached out to Thales on Wednesday evening for a comment about the corrosion issues. We received no reply until Friday morning, when a spokesperson said, “We are working on a statement. We will come back to you early next week.”

Northrop Grumman provided a comment within several hours of a request on Wednesday.

The European Space Agency, which was overseeing European contributions to the Gateway, finally offered a comment on Friday. The agency attributed the issue to a “combination of factors,” including materials.

“Following the identification of corrosion on HALO, a comprehensive investigation was promptly initiated,” a European Space Agency spokesperson said. “Preliminary findings indicate that the issue likely results from a combination of factors, including aspects of the forging process, surface treatment, and material properties.”

After the issue was discovered, the European Space Agency established a “tiger team” to investigate. “Based on the investigation and available data, the corrosion issue was understood to be technically manageable and did not constitute a showstopper for I‑HAB, which was, in any case, in better conditions than HALO from [a] corrosion point of view,” the spokesperson said.

The I-HAB module remains under construction and has not yet been delivered to NASA. Its fate remains unclear as European space officials contemplate their participation in the Moon base initiative.

After publication of this story on Friday, Axiom Space confirmed that it has also experienced corrosion issues. In a statement, the company said: “Axiom Space has experienced a similar phenomenon with the first module; we are leveraging the expertise of NASA and Thales Alenia Space to address the issue. Module 1 is on track to launch in 2028.”