The Corrosion That Wasn’t Supposed to Happen
The first public indication of a problem emerged during a congressional hearing. In April 2025, NASA Administrator Jared Isaacman disclosed that both delivered habitable modules—the Habitation and Logistics Outpost (HALO) and the International Habitation Module (I-HAB)—had shown signs of corrosion. These components were intended to serve as the foundation of the Lunar Gateway, a planned lunar-orbiting space station supporting the Artemis program. Instead, they arrived with structural concerns that had not been previously communicated.
The corrosion raised immediate questions about the modules’ viability. HALO, developed by Northrop Grumman with its primary structure built by Thales Alenia Space in Italy, exhibited degradation upon delivery in April 2025. I-HAB, part of the European Space Agency’s contribution, presented similar but less severe issues, though it had not yet been shipped to NASA. European Spaceflight reported that ESA confirmed the corrosion in HALO after Isaacman’s testimony, describing the problem as requiring further investigation. The agency’s spokesperson characterized the issue as technically manageable, but the disclosure came after NASA had already decided to halt Gateway development.
The underlying cause of the corrosion remains under review. ESA’s preliminary findings cited multiple factors, including elements of the forging process, surface treatment, and material properties, though specific details about the alloy or environmental conditions were not released. Thales Alenia Space, which has extensive experience constructing pressurized modules for the International Space Station (ISS) and Cygnus spacecraft, has not provided additional information. As Ars Technica noted, the company indicated that HALO’s corrosion would be addressed by late 2025 but did not elaborate on the root cause or corrective measures.
NASA’s Pivot: From Orbit to Surface
The Lunar Gateway was initially scheduled for launch in 2022, but by the time corrosion was publicly acknowledged, the project had already faced years of delays and cost overruns. NASA’s decision to suspend development in March 2025 reflected a broader reassessment of priorities. The agency is now prioritizing lunar surface missions, with an eye toward future crewed exploration of Mars. According to the South China Morning Post, the shift was influenced by concerns from the U.S. Office of Management and Budget regarding rising costs, emerging commercial alternatives, and evolving mission objectives. Despite $2.6 billion allocated for the Gateway in 2020, the project’s path forward had become increasingly uncertain.
The corrosion issue further complicated the timeline. In his testimony, Isaacman suggested that the defects would have pushed the Gateway’s launch beyond 2030, raising doubts about the station’s relevance. His remarks about whether repairs were justified underscored the challenges ahead. NASA’s decision to refocus on lunar surface activities signaled a strategic shift, leaving the fate of the two completed modules unresolved.
Both HALO and I-HAB, representing significant investment and development time, now face an uncertain future. Northrop Grumman has proposed repurposing HALO as a surface habitat, while ESA may explore adapting I-HAB for lunar surface use. Neither option is straightforward. The modules were designed for microgravity environments, not the Moon’s harsh conditions. Modifying them would require extensive redesign and additional funding, raising questions about feasibility and cost-effectiveness.
The Manufacturers’ Muted Response
Thales Alenia Space’s response to the corrosion issue has been limited. The company, known for its work on ISS and Cygnus modules, has not publicly detailed the root cause of the corrosion or outlined preventive measures for future projects. Its statements have focused on assurances that the problem will be resolved, though these claims have not been accompanied by technical explanations.
The lack of transparency has drawn attention to NASA’s reliance on long-standing contractors. ESA’s investigation pointed to potential issues in the forging process, surface treatment, and material properties, but without further disclosure, it remains unclear whether the corrosion was an isolated incident or indicative of broader manufacturing challenges. Thales’ experience with pressurized structures had made it a logical choice for the Gateway, but the current situation has prompted scrutiny of its processes.
Northrop Grumman, which led HALO’s construction, has also faced questions about its role. While the company has suggested repurposing HALO for surface use, it has not addressed the corrosion issue in detail. The broader concern is whether the Gateway’s challenges reflect deeper issues in the oversight of legacy contractors, whose methods may not align with evolving mission requirements.
The Rise of US-Based Competition
The situation has created opportunities for U.S.-based firms. While Thales Alenia Space remains a key player—Axiom Space, for instance, has partnered with the company for its private space station—other competitors are advancing. Vast Space, manufacturing modules in California, and Voyager Space, collaborating with Vivace in Louisiana, are positioning themselves as alternatives to traditional European suppliers.
The shift reflects broader industry dynamics. NASA’s decision to pause the Gateway has highlighted questions about contractor reliability, particularly after the corrosion issue went undisclosed for months. U.S. firms are emphasizing domestic manufacturing capabilities and closer collaboration with NASA to address these concerns. Vast’s California-based production, for example, offers enhanced oversight and faster iteration compared to overseas operations.
The competition is reshaping the space industry. Thales’ challenges have provided U.S. firms with an opening to demonstrate their ability to build reliable, long-duration habitats. However, the transition also carries risks, as the domestic industry is still developing its expertise in pressurized module manufacturing. For now, the momentum appears to favor newer entrants, though the long-term implications remain to be seen.
What Happens to HALO and I-HAB?
The future of the two corroded modules is unclear. Northrop Grumman’s proposal to repurpose HALO as a surface habitat is one possibility, but it remains uncertain whether NASA will allocate additional funding. The same uncertainty applies to I-HAB, which ESA may consider for lunar surface use. Neither module was designed for the Moon’s gravity or radiation environment, and adapting them would require substantial modifications.
The financial implications are significant. The Gateway project had already consumed considerable funding, and salvaging the modules would require further investment. NASA’s decision to halt development reflected a calculation that the costs outweighed the benefits, leaving taxpayers to absorb the expense of hardware that may not be utilized. The question now is whether the modules can be repurposed efficiently or if they will remain unused.
The corrosion issue has also highlighted broader concerns about transparency in space hardware manufacturing. The delay in disclosing the problem—until Isaacman’s testimony—has raised questions about oversight and accountability. To prevent similar issues, NASA may need to implement stricter testing protocols, more frequent audits, or a shift toward domestic suppliers with clearer lines of responsibility.
The Bigger Question: Who Builds the Next Space Station?
NASA’s decision to pause the Lunar Gateway has created a gap in its Artemis program. With the agency’s focus now on lunar surface activities, the next space station—if pursued—will likely involve commercial partners. Companies like Axiom, Vast, and Voyager are already positioning themselves to fill this role, but their success will depend on delivering reliable, long-duration habitats.
The situation has underscored the risks of relying on established contractors while also highlighting the challenges of developing new space infrastructure. The next space station will need to be more durable, adaptable, and transparent than the Gateway. Whether U.S. firms can meet these demands remains an open question, but the stakes are high for the future of lunar and deep-space exploration.
For now, the Gateway’s corrosion issues serve as a case study in the complexities of space hardware development. The project’s challenges were not solely about material degradation but also about the assumptions underlying contractor reliability and mission planning. NASA’s pivot to the lunar surface may have been a strategic necessity, but the circumstances have left engineers, policymakers, and industry observers evaluating the path forward.
