The NASA Artemis II mission ended successfully: four astronauts flew around the Moon and returned to Earth. It was the first crewed flight of the Orion spacecraft and preparation for future landings on the lunar surface.
During atmospheric entry, Orion accelerated to 39 times the speed of sound. Outside, temperatures rose above 2200 degrees Celsius, but inside the cabin it was relatively cool. The heat shield is made of 186 individual blocks of ablative Avcoat material. Ablation means the coating gradually breaks down and carries heat away with it, protecting the spacecraft.
After analyzing the results of the first Artemis I mission, the descent trajectory was changed: the maximum distance the spacecraft travels from atmospheric entry to splashdown was reduced. This reduced the time the shield spent in the dangerous temperature range.
The descent went precisely: Orion entered the atmosphere within 59 meters of the calculated point and splashed down 0.95 kilometers from the predicted location off the coast of San Diego. An initial inspection showed that the shield performed as expected, and there were significantly fewer cracks and charring than after Artemis I.
After the spacecraft was returned to the Kennedy Space Center in Florida, specialists began additional study of the shield and then sent it to the Marshall Space Flight Center in Huntsville, Alabama. There, sample extraction and internal X-ray scans began in August.
The analysis confirmed that Orion's aerodynamic and thermal characteristics, including the shield and the aft bay protection, matched engineering predictions based on pre-launch calculations and ground tests. Reducing the allowable descent range cut cracking and loss of the charred layer by a factor of 10 compared with Artemis I. Only nine areas of charring of varying size were found on the Artemis II shield, versus 103 on Artemis I.
The shield design remained the same as in the first mission: this was confirmed by the seams between the Avcoat blocks and the material around the bolts. Inspection of the aft part of the spacecraft, covered with 1,300 ceramic tiles, found no overheating. Laser scanning of the shield surface is being compared with pre-launch measurements to assess material loss.
Work on extracting samples and further tests continues. For Artemis III, the shield design was refined so that the Avcoat blocks are uniform and allow air to pass evenly. In early July the shield was installed on the Orion spacecraft for Artemis III, in late July the service module and crew module were joined, and then power was supplied for the first time.
The next Artemis III mission is currently being prepared for a flight to low Earth orbit next year. The crew will include NASA astronauts Randy Bresnik, Frank Rubio and Andre Douglas, as well as European Space Agency astronaut Luca Parmitano. They will meet with test mockups of landers from Blue Origin and SpaceX to practice systems for future Moon landings, starting with Artemis IV in 2028.