Thermal shield improved on Artemis II

NASA reported that the thermal shield of the Orion capsule performed significantly better during the return of the four astronauts from the Artemis II mission compared to the previous Artemis I mission. The shield showed ten times fewer cracks and material detachments during Artemis II, which took place in April 2026, compared to Artemis I in 2022.

Material issues identified after Artemis I

The thermal shield, made of avcoat, an ablative material inherited from the Apollo capsules, was the only protection against the extreme heat of atmospheric reentry for the four astronauts—Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen—who orbited the Moon. Following Artemis I, engineers discovered that the avcoat material had issues with permeability, causing gases to become trapped and leading to the detachment of material during reentry.

Adjustments led to fewer damages

NASA identified the cause in December 2024 and adjusted the capsule's trajectory during Artemis II's return to Earth to reduce the time spent in the temperature range that had caused damage during Artemis I. This adjustment resulted in nine damaged areas instead of 103.

Orion's reentry performance

During the reentry on April 10, Orion reached 39 times the speed of sound and endured more than 2,200 °C outside the capsule, while the temperature inside the cabin remained around 24 °C. The shield consists of 186 avcoat blocks, with engineers finding only nine areas of material loss.

Landing precision and ongoing analysis

The rear hull, covered with 1,300 ceramic tiles, showed no signs of overheating, including around the windows and the hatch. Orion entered the atmosphere less than 60 meters from the target point and landed less than a kilometer from the planned area off the coast of San Diego. NASA is still conducting an interim assessment by comparing laser scans made after the flight with pre-departure measurements to determine the thickness of the consumed material.

Future improvements planned

Ongoing sample collection started in August. Despite the good performance of the Artemis II thermal shield, NASA has planned adjustments for Artemis III. The Orion capsule will be protected by modified avcoat blocks to be more uniform and more permeable, reducing the likelihood of sudden material detachment. The avcoat blocks were fixed on the capsule beginning in July at the Kennedy Center in Florida.

Artemis III and future missions

The Artemis III mission is scheduled for 2027 and will test rendezvous with prototypes of landers from Blue Origin and SpaceX. The first moon landing is planned for Artemis IV in 2028, unless the schedule is delayed.