NASA's Artemis II mission, the first crewed flight of the Orion spacecraft around the Moon since 1972, has encountered a helium leak in its service module but officials say it poses no threat to the crew's return. The spacecraft, carrying astronauts Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen, launched on April 1 and is set for splashdown in the Pacific Ocean on Friday evening. Ground teams adjusted the flight plan to study the leak while maintaining nominal performance.
The Orion spacecraft Integrity, on a free-return trajectory that used the Moon's gravity to loop back to Earth, experienced a small internal helium leak in the oxidizer side of its propulsion system. Jeff Radigan, NASA's lead flight director for Artemis II, said the leak occurs across valves in the European-built service module and does not vent to space. Mission controllers canceled a manual piloting demonstration on Wednesday to run propulsion tests instead, gathering data on the leak under varying thermal conditions, according to Branelle Rodriguez, NASA's Orion vehicle manager for the mission. All burns so far have performed nominally, and the crew module has independent systems for reentry steering, officials confirmed Thursday. The service module, including the leaky valves, will be jettisoned before atmospheric entry and burn up, preventing recovery and inspection. Amit Kshatriya, NASA's associate administrator, noted the leak rate rose during the trans-lunar injection burn but remains acceptable for this test flight. Engineers observed similar issues on Artemis I in 2022 and pre-launch ground tests, but proceeded because the mission required minimal propulsion. The leak, now an order of magnitude higher than expected, will necessitate a redesign of the valves for Artemis IV in 2028, Kshatriya said, though manufacturing of that service module is largely complete. NASA aims to address it with the European Space Agency and Airbus. As the astronauts approach reentry at 25,000 mph, they reflected on their experiences 252,000 miles from Earth. Commander Reid Wiseman described chills from watching Earth eclipse behind the Moon, while pilot Victor Glover called the lunar eclipse a 'greatest gift' and reentry 'profound.' The crew shared an emotional moment proposing to name a lunar crater 'Carroll' for Wiseman's late wife; Hansen radioed the request, leading to tears and deepened bonds. Mission specialist Christina Koch praised Orion's livability in microgravity and the team's relay-race ethos for future crews.