NASA inspector general finds Orion heat shield issues ‘pose significant risks’ to Artemis 2 crew safety

NASA’s moon program still has some work to do before it can put human boots back on the lunar surface.

The agency’s Office of Inspector General (OIG) released a report on Wednesday (May 1) titled “NASA’s Readiness for the Artemis 2 Crewed Mission to Lunar Orbit,” which aims to determine how ready NASA is to launch its Artemis 2 moon mission, currently scheduled for late 2025.

The inspector general writes that the Artemis 1 test flight of the Orion spacecraft “revealed anomalies with the Orion heat shield, separation bolts, and power distribution that pose significant risks to the safety of the crew.”

Resolution of these anomalies is among the most significant factors impacting NASA’s readiness for Artemis 2, the report adds.

The report says NASA found over 100 areas on Orion’s heat shield — where thermal material protects the spacecraft from the heat of reentry — had worn away “differently than expected” during the spacecraft’s reentry to Earth’s atmosphere.

A video released by the agency in December 2023, in fact, clearly showed charred heat-shield material flying off of the spacecraft as it reentered the atmosphere at the end of the Artemis 1 mission. Some of that material is also seen briefly clinging to Orion’s windows as the capsule made its way from space to the Pacific Ocean, west of Baja California.

images of a charred cone-shaped spacecraft — Images from the NASA OIG report “NASA’s Readiness for the Artemis 2 Crewed Mission to Lunar Orbit” that show damage to the Orion spacecraft’s heat shield. (Image credit: NASA OIG)

In a Jan. 9, 2024 teleconference announcing delays to the Artemis program timeline, Amit Kshatriya, deputy associate administrator for NASA’s Moon to Mars program, directly addressed that particular heat shield issue.

“We did see the the off-nominal recession of some char that came off the heat shield, which we were not expecting,” Kshatriya said during the briefing. “Now, this heat shield is an ablative material — it is supposed to char — but it’s not what we were expecting, with some pieces of that char to be liberated from the vehicle.”

NASA is already making modifications to the heat shield to help mitigate the charring issue. In addition, the agency is altering how it bolts the spacecraft’s crew capsule to its service module, hoping to mitigate unwanted melting around the bolts.

The OIG report also cited anomalies in Orion’s electrical system that affected how power is distributed throughout the spacecraft.

a white-and-silver cone-shaped spacecraft is held aloft by a crane inside a room full of machinery and scientists — The Artemis 2 moon spacecraft lifts into a vacuum chamber at NASA’s Kennedy Space Center on April 4, 2024. The Orion spacecraft will undergo electromagnetic compatibility and interference testing inside the chamber at the Operations and Checkout Building. (Image credit: NASA/Amanda Stevenson)

NASA believes radiation caused these anomalies; as such, the agency is developing “operational workarounds,” although the OIG report adds that, without a permanent change in the spacecraft’s electrical hardware, there is an “increased risk that further power distribution anomalies could lead to a loss of redundancy, inadequate power, and potential loss of vehicle propulsion and pressurization.”

Additional issues cited in the report include a 4.5-hour communication loss that occurred during an outage of one of NASA’s Deep Space Network facilities, as well as unexpected damage to the Artemis 1 mobile launcher imparted during launch. The latter will cost NASA over 5 times more than expected, adding up to a total of $26 million.