NASA delays next 2 Artemis moon missions to address heat shield, other issues
Less than a year after announcing major delays for the next two Artemis moon missions, NASA managers said Thursday the projected flight dates are slipping once again, with the first piloted voyage around the moon now expected in the April 2026 timeframe, and the first lunar landing in mid 2027.
NASA Administrator Bill Nelson said the delays are needed to revise the Orion crew capsule's re-entry trajectory to reduce stress and prevent the sort of unexpected heat shield damage seen after an unpiloted 2022 test flight — and to complete extensive testing of the capsule's environmental control and life support systems.
"Based on the data, we have decided, unanimously, to move forward with the current Artemis 2/Orion capsule and heat shield with a modified entry trajectory...to lessen the heat coming back into the Earth's atmosphere," Nelson said.
"Additionally, we need to complete our updates to the Orion environmental controls and the life support systems that were identified earlier this year."
Future heat shields for the Artemis 3 moon landing mission and subsequent flights will use essentially the same materials but with modifications to improve their performance during re-entry.
In the meantime, Nelson said, "We are planning for Artemis 2 to launch in April of '26 and we're going to do all in our power, with our commercial partners, to launch earlier."
The Artemis program aims to send astronauts to the moon's south polar region where ice deposits may allow crews to one day extract oxygen and hydrogen to produce air, water and rocket propellants that would not have to be carried up, at great expense, from Earth.
Following the launch of Artemis 2, Nelson said NASA is going "to make (any) adjustments that are necessary, and we plan to launch Artemis 3, the first landing on the moon in over a half century. Assuming the SpaceX lander is ready, we plan to launch Artemis 3 in mid-2027. That will be well ahead of the Chinese government's announced intention (of sending taikonauts to the moon in) 2030...We need to get this Artemis 2 test flight right to ensure the success of our return to the moon."
NASA launched the Artemis program's first test flight, Artemis 1, in November 2022, using the agency's new Space Launch System, or SLS, rocket to send an unpiloted Lockheed Martin-built Orion capsule on a looping flight around the moon and back.
NASA had planned to launch the Artemis 2 mission at the end of this year to carry a three-man one-woman crew around the moon to thoroughly test the spacecraft's life support, propulsion and other systems.
But after the Artemis 1 flight, engineers discovered the Orion capsule's 16-foot-wide heat shield suffered unexpected damage during it's high-speed return from the moon using a technique called a "skip entry."
In a skip entry, the capsule dips into the atmosphere, slows and rises back up before dropping back into the atmosphere for the final descent. The idea is similar to how a flat rock can skip across a still pond. Skip entries provide a number of benefits, including a wider range of splashdown targets.
The Orion heat shield is designed to ablate, or char, during re-entry when the spacecraft enters Earth's atmosphere at more than 25,000 mph. But the charred material is intended to stay in place, providing a layer of insulation. During the Artemis 1 re-entry, more charred material separated from the heat shield than computer models predicted.
While the unexpected "liberation" had no impact on the spacecraft — NASA said astronauts would not have even noticed had any been on board — engineers wanted to make sure they understood the underlying cause so they could update computer models to accurately predict re-entry effects across multiple trajectories.
After hundreds of tests and an exhaustive engineering analysis, NASA has "since determined that while the capsule was dipping in and out of the atmosphere as part of that planned skip entry, heat accumulated inside the heat shield's outer layer," said Pam Melroy, a former shuttle commander and now deputy administrator of NASA.
That heat build up led to "gases forming and becoming trapped inside the heat shield," she said. "This caused internal pressure to build up and led to cracking and uneven shedding of that outer layer."
While the same type of heat shield will be used for the Artemis 2 mission in April 2026, the crew will use a modified re-entry trajectory to reduce the sort of heating that damaged the Artemis 1 heat shield.
As for the Artemis 3 lunar landing flight, the new mid-2027 target launch date assumes SpaceX's lunar lander, a variant of the upper stage used by the company's new Super Heavy-Starship rocket, completes multiple test flights in Earth orbit, along with at least one unpiloted lunar landing.
On Wednesday, President-elect Donald Trump announced that he was selecting billionaire Jared Isaacman, a space veteran with strong ties to SpaceX founder Elon Musk, to serve as NASA's next administrator.
During the news conference Thursday, Nelson was asked whether he was concerned that the next administration might make major changes to the Artemis program given SpaceX's development of the new Super Heavy-Starship rocket.
"First of all, there is one human-rated spacecraft that is flying and that has already flown beyond the moon, and that's the SLS (Space Launch System) combined with Orion," Nelson said. "Secondly, this is a partnership. It's a commercial partnership. It's an international partnership.
"I think what is going to happen over time is you're going to have a number of years that we're going to have the partners flying with NASA, and then whatever the technologies that are developed later on will dictate what is going to be the system that's flying."
He concluded by saying, "I don't see the concern that your question raises, although it's a legitimate question, that you're suddenly going to have Starship take over everything."
