WASHINGTON — NASA has further delayed the next two Artemis missions to the moon, pushing back the first crewed landing of the program to the middle of 2027.
At a press conference Dec. 5, NASA leadership said they were delaying the Artemis 2 and 3 missions after finding the root cause of erosion of the Orion heat shield on the Artemis 1 mission two years ago.
Under the revised scheduled, Artemis 2, which had previously been scheduled to launch in September 2025, is now set to launch in April 2026. That mission will send four American and Canadian astronauts around the moon on the first crewed flight of Orion.
That will delay Artemis 3, which will feature the first crewed landing of the overall exploration campaign using SpaceX’s Starship vehicle. That mission, previously planned for September 2026, is now expected to take place in mid-2027.
NASA revised that schedule after completing an investigation into the heat shield erosion seen on Artemis 1. Agency officials had said in October that they had determined what liberated the heat shield material but did not provide details on the cause or what NASA would do to correct it.
The problem, said NASA Deputy Administrator Pam Melroy, was linked to the “skip” reentry used by Orion, where the capsule dips in and out of the atmosphere to bleed off energy. More heat was retained than expected in the outer layers of the heat shield, forming gases that were trapped in the material. “This caused internal pressure to build up and led to cracking and uneven shedding of that outer layer,” she said.
That conclusion was based on an extensive investigation and verified by an independent review team. “There were a lot of links in the error chain that accumulated over time that led to our inability to predict this in ground tests,” said Amit Kshatriya, deputy associate administrator of NASA’s Moon to Mars Program Office. That included changes in how the heat shield material, called Avcoat, was made, as well as changes in the geometry of the blocks of material.
That was confirmed, he said, in portions of the Avcoat material that had the desired higher permeability that would allow the gases to escape. “In those places, we did not witness in-flight cracking, and that was the key clue for us.”
NASA decided not to replace the completed heat shield for the Artemis 2 mission and will instead modify the reentry profile, including reducing the duration of the skip phase of the reentry. Those changes, he said should be sufficient so that any cracking does not lead to material breaking off, based on ground tests.
While investigating the heat shield issue, the agency has been working on several other issues Orion, including a battery problem reported in January that Kshatriya said has been corrected.
Agency leaders said they made the decision now, despite an impending presidential transition that will likely reexamine the overall Artemis architecture, to avoid further delays. “We’re on a day-for-day slip. We had to make this decision,” Melroy said. “If you’re waiting for a new admininstrator to be confirmed and a team to come up to speed on all this technical work we’ve all been tracking very closely, I think that would be actually far worse.”
NASA Administrator Bill Nelson said he talked with Jared Isaacman, who President-elect Donald Trump announced Dec. 4 he planned to nominate to lead the agency, shortly after that announcement. However, he said that conversation took place before the meetings where he and other officials confirmed the new plan for Artemis 2 and 3. Melroy added that the incoming administration has not sent a transition team to NASA, who could also have been briefed on the decision.
Nelson, though, insisted that despite the issues and delays, the current architecture was still the best approach to returning humans to the moon, noting that even with the latest delay NASA would still return to the moon before China’s anticipated 2030 lunar landing.
“Are they going to axe Artemis and insert Starship?” Nelson said, referring to the incoming Trump administration. He noted that only Orion is rated for human spaceflight beyond Earth orbit. “I expect that this is going to continue.”
