NASA Slips Artemis II Crewed Lunar Flyby to April 2027 Following Heat-Shield Data Review

NASA Administrator Bill Nelson confirmed on Wednesday that the Artemis II crewed lunar flyby mission has been slipped from September 2026 to no earlier than April 2027, citing the need to complete a full review of the Orion heat-shield performance data from the uncrewed Artemis I mission. The delay does not affect the Artemis III surface-landing target at this time, the agency said.

What Triggered the Slip

The decision follows the Artemis I review board's finding that the Orion heat shield experienced a larger-than-expected amount of char loss during re-entry, along with an unexpected liberation of gas from the underlying Avcoat material. The board concluded that the underlying design is sound, but recommended 11 changes to the heat-shield manufacturing process, the re-entry trajectory, and the post-flight recovery procedure. NASA has now decided to implement all 11 before the crewed mission, which pushes the launch date by eight months.

「We are not going to fly a crew on a heat shield that we don't fully understand. The schedule slip is a cost of being a careful agency,」 Nelson said in a press conference at NASA Headquarters.

What the Crew Will Do With the Extra Time

The four-person crew — Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen — will now spend an additional eight months in training, with a focus on the modified re-entry profile, additional rendezvous and proximity-operations simulations with the Human Landing System, and a series of integrated simulations with the European Service Module. ESA, which provides the service module, has indicated it can support the extended training schedule without additional funding.

Knock-On Effects

The slip does not move the Artemis III surface-landing target, which remains no earlier than mid-2028. However, the gap between Artemis II and Artemis III is now longer, and NASA will need to weigh whether to add an additional uncrewed test of the Human Landing System in the interim. SpaceX's Starship, which is the Artemis III lander, has now completed three successful V3 flights and the first orbital refueling demonstration.