NASA cleared its Artemis moon rocket Thursday for an April launch attempt carrying four astronauts, completing a new round of repairs, NASA officials said. The 322-foot (98-meter) rocket is set to move out of its hangar and back to the pad next week at Florida’s Kennedy Space Center, leading to a launch attempt as early as April 1, according to the agency. NASA said the planned mission is humanity’s first trip to the moon in more than 50 years.
NASA’s timeline for the launch has been shaped by earlier issues with the Space Launch System rocket that powers Artemis II. NASA said Artemis II was originally scheduled to conduct a lunar flyaround earlier this year, but fuel leaks and other problems with the SLS rocket disrupted that plan. NASA also said it had plugged hydrogen fuel leaks at the pad in February, but a helium-flow issue later forced the rocket back to the Vehicle Assembly Building for repairs, bumping the mission to April.
NASA said it has only a limited window at the start of April to attempt the launch before standing down until April 30 into early May. At the end of a two-day flight readiness review, NASA’s Lori Glaze told reporters, “It’s a test flight and it is not without risk, but our team and our hardware are ready.”
Glaze and other NASA officials declined to provide risk probabilities for the upcoming mission. John Honeycutt, chair of the mission management team, said, “History has shown that a new rocket has essentially a 50% chance of success,” adding that there is limited basis for risk-assessment numbers given the gaps since the last SLS flight with no crew aboard more than three years ago. Glaze also said, “It’s not the first flight,” but, “we’re also not in a regular cadence,” describing how the mission’s risk profile differs from a system that flies regularly.
The readiness announcement came after NASA’s new administrator, Jared Isaacman, outlined an overhaul of the Artemis program aimed at accelerating the schedule and reducing risk. Isaacman said the plan includes adding an extra practice flight in orbit around Earth for next year, which he described as a new Artemis III, with the moon landing by two astronauts shifting to Artemis IV. Isaacman said he was targeting one and maybe even two lunar landings in 2028.
In parallel with NASA’s push to speed up the program, the agency’s Office of Inspector General this week warned NASA it needs to come up with a rescue plan for lunar crews. The inspector general said landing near the moon’s south pole will be riskier than it was for the Apollo astronauts closer to the equator, according to the report. The report cited the lunar landers as a top contributor to potential loss of crew during the first few Artemis moon landings.
The inspector general’s report also described specific thresholds NASA has set for crew loss. It listed the space agency’s loss-of-crew threshold at 1-in-40 for lunar operations and 1-in-30 for Artemis missions overall, according to the report. NASA said it has contracted SpaceX and Blue Origin to provide the moon landers for the astronauts, and the inspector general said those companies have accelerated work to help meet the new 2028 target date, even as the office said technical challenges remain, including refueling their landers in orbit around Earth before flying to the moon.
NASA has said the Artemis program is the next step after the Apollo era, when NASA sent 24 astronauts to the moon and 12 landed on it. NASA also noted that all but one of the Apollo moonshots—Apollo 13—achieved their prime objectives, and that the program ended with Apollo 17 in 1972.