HUNTSVILLE, Ala. — NASA has determined why the Orion heat shield lost more material than expected on the Artemis 1 mission but won’t disclose details until after it completes more tests.
In the months after the Orion spacecraft returned to Earth on the uncrewed Artemis 1 mission in December 2022, NASA disclosed there had been more “char loss” on the ablative heat shield at the base of the capsule than expected. That did not pose a risk to the spacecraft itself, but agency officials said they wanted to understand what happened to prepare for Artemis 2, the first crewed flight of the spacecraft.
NASA has provided few specifics about that investigation, and the only images of the heat shield itself came in a report by the agency’s inspector general in May. At an Aug. 29 meeting of the NASA Advisory Council’s human exploration and operations committee, Amit Kshatriya, deputy associate administrator for the Moon to Mars Program, said an independent review team has completed its analysis of the heat shield erosion but did not provide additional details.
Asked about the status of the heat shield at an Oct. 28 meeting of the Lunar Exploration Analysis Group (LEAG) in Houston, Lori Glaze, acting deputy associate administrator in NASA’s Exploration Systems Development Mission Directorate, said those reviews had determined what caused the additional char loss.
“We have conclusive determination of what the root cause is of the issue,” she said. “We have been able to demonstrate and reproduce it in the arc jet facilities out at Ames.” The Arc Jet Complex at NASA’s Ames Research Center can reproduce the heating conditions seen on reentry.
However, she declined to identify what that root cause is. “I’m not going to share right now,” she said when asked about it. “When it comes out, it will all come out together.”
Another NASA official confirmed that in a panel discussion at the American Astronautical Society’s von Braun Space Exploration Symposium here later the same day.
“We have gotten to a root cause. We are having conversations within the agency to make sure we have we have a good understanding of what’s going on not only with the heat shield but also next steps in how that actually applies to Artemis 2,” said Lakiesha Hawkins, assistant deputy associate administrator in the Moon to Mars office. She also declined to identify the specific root cause.
Glaze said that NASA was performing additional testing to study ways to mitigate the heat shield loss for Artemis 2. “We know what needs to be done for future missions, but the Artemis 2 heat shield is already built, so how do we assure astronaut safety with Artemis 2?”
She said the testing would be complete by the end of November. “We then anticipate discussions with the administrator, who will make the final decision on how to proceed,” she said. “We’re moving as quickly as it possibly can move, and there will be decisions forthcoming.”
Hawkins said she expected NASA to provide more details on the heat shield problem and plans for Artemis 2 “hopefully before the end of the year.”
The heat shield erosion was one of three factors that led NASA in January to announce it was delaying the Artemis 2 launch from late 2024 to no earlier than September 2025. At the time NASA said that one of the other reasons, replacing electronics in the life support system on Orion, was the key factor in selecting the new launch date.
NASA has retained the September 2025 launch date even though there is widespread industry skepticism that Artemis 2 can launch before 2026. NASA has, for example, not yet started the months-long process of assembling, or “stacking,” the Space Launch System rocket that will launch the mission, although all the components of the rocket are now at the Kennedy Space Center.
In her LEAG presentation, Glaze noted that early this month NASA rolled back the mobile launch platform to the Vehicle Assembly Building from Launch Complex 39B, where NASA had been performing tests, “and is ready to have the SLS stacked.” She did not state when that stacking would begin.
