NASA’s moon program continues to drive cost overruns, government auditors said in a new report, led by the space agency’s troubled Orion crew module.

In a review of 38 current NASA projects that cost $250 million or more, the Government Accountability Office found Artemis-related programs accounted for most of the $500 million in cost overruns since last year. The human spaceflight crew capsule, known as the Orion Multi-Purpose Crew Vehicle program, accounted for over $360 million of that total.

Orion’s overruns resulted from several “technical and development issues,” auditors wrote, including performance problems with the crew capsule’s heat shield that were identified during the Artemis I flight, design issues within the life-support system and software development delays.

Artemis is NASA’s $93 billion, decade-long human lunar exploration program, which includes plans for a permanent colony on the moon as a step toward crewed Mars missions. Marshall Space Flight Center manages many aspects of the program, including the Space Launch System rocket and Orion.

“As the number of Artemis projects grows, so does the challenge of integrating them together,” auditors wrote. “These highly complex and interdependent systems will need to be successfully integrated to support individual Artemis missions, which are more complex than any previous human space flight programs.”

In December, NASA released findings from its two-year-long investigation into “unexpected behavior” of the protective coating on the Orion capsule that emerged after it returned from the uncrewed Artemis 1 mission.

Testing revealed 100 spots where charring formed and then flaked off the 16-foot-diameter heat shield, which the agency called “unexpected behavior.” It intends to address the issue by modifying the trajectory of Artemis II, which will send a crew into lunar orbit and then back to Earth.

That launch has been delayed until April 2026, with Artemis III planned for mid-2027. The agency had intended to launch the program’s second flight in September, with the third – which will land humans on the moon for the first time since Apollo 17 in 1972 – in September 2026.

Against a backdrop of other big-ticket programs, the Artemis issues are more glaring. Auditors found that most major projects launched since NASA’s last evaluation in 2009 — 30 out of 53, or 56.6% — have avoided major additional costs.

Yet three Artemis projects – SLS Block 1, Orion and Exploration Ground Systems — accounted for nearly $7 billion of total cost overruns. That comprises almost half of the total overruns racked up by the 53 projects since 2009.

The report followed weeks of uncertainty surrounding NASA’s flagship human spaceflight program. President Donald Trump proposed phasing out SLS and Orion in the White House’s budget outline for NASA, but the House and Senate added back nearly $10 billion for those and related programs into the president’s tax and spending bill.

Trump was expected to sign the bill Friday.