NASA is delaying its return to the Moon with the Artemis program. "To give Artemis teams more time to work through the challenges with first-time developments, operation and integration, we're gonna give more time on Artemis 2 and 3," NASA Administrator Bill Nelson told reporters on a call.

As such, Artemis 2, which had been scheduled for a November 2024 launch, is now targeting September 2025. That four-person mission is set to fly around the Moon, in a similar fashion to the uncrewed Artemis 1. As for Artemis 3, which will take humans back to the lunar surface for the first time since 1972, that's now targeted for September 2026, marking a nine-month delay.

Those are the only delays NASA has announced for now. Nelson said "Artemis 4 remains on track for September 2028." Along with a lunar landing, that mission will mark the delivery of a habitat module to the Lunar Gateway, a space station that's planned for lunar orbit.

The delays are for safety reasons. "For Artemis 2, there are new capabilities being on-ramped for the mission," Amit Kshatriya, deputy associate administrator of the Moon to Mars Program said. Those include propellant loading, crew loading and egress and fresh abort and life support systems.

Kshatriya said NASA is learning from both the data it obtained from Artemis 1 and the production of components for future missions. "From the test flight in particular, we had one major finding that we need a little bit more time to work [on] and that is the performance of the thermal protection system on the spacecraft, on the heat shield," Kshatriya said.

While the heat shield performed well overall during the Artemis 1 landing in terms of thermal protection, it experienced "some unexpected phenomena we need to make sure we understand perfectly," namely some charred material. NASA doesn't want to leave anything to chance when it comes to astronauts' safety and it spent "the bulk of 2023 investigating" that concern, Kshatriya noted. NASA hopes to identify the root cause of the issue in the spring.

Meanwhile, among other concerns, NASA encountered some issues with the life support system. "During the acceptance of some components for Artemis 3, we noticed a failure in some motor valve circuitry," Kshatriya said. "These components passed acceptance testing for Artemis 2, but did not pass them for Artemis 3. That gave us pause to stop and look at that circuit in a more detailed way." As such, NASA found a design flaw in the circuit. 

Given its importance to the life support system, the agency deemed the system unacceptable as is. "We have to replace it to guarantee the safety of the crew," Kshatriya said. It's likely to take quite some time to resolve the issue as NASA will have to carefully test every change, but Kshatriya added the agency knows how to solve the problem. 

The Artemis delays follow the failure of a mission that sought to transport the first US commercial payload to the Moon. Astrobotic had hoped to make a soft landing on the lunar surface with its Peregrine lander. However, due to some post-launch issues (in particular, a propellant leak) the soft landing is no longer possible.

"Given the propellant leak, there is, unfortunately, no chance of a soft landing on the moon. However, we do still have enough propellant to continue to operate the vehicle as a spacecraft," Astrobotic wrote on X. "The team continues to work to find ways to extend Peregrine's operational life."