NASA Skips February Moon Launch After Hydrogen Leaks Halt Artemis II Test

NASA said early Tuesday, Feb. 3, that it will pass on its February launch window for Artemis II, the first crewed flight around the moon in more than 50 years, after hydrogen leaks interrupted a full fueling rehearsal at Kennedy Space Center in Florida. NBC News reported that the announcement came shortly after 2 a.m. Eastern time and that the window, which ran through Feb. 11, will be skipped while engineers review data and prepare to repeat the test.

The rehearsal, known as a wet dress rehearsal, is a practice countdown with the rocket fully loaded. NBC reported that fueling began around 12:30 p.m. Monday, Feb. 2, and loaded more than 700,000 gallons of cryogenic propellant. Mission managers paused fueling twice to look at hydrogen leaks at the tail end of the Space Launch System rocket. Leaks returned in the final minutes of the simulated countdown, and automatic systems halted the count when the leak rate spiked, with about 5 minutes and 15 seconds left.

CBS News, in a later source dated Feb. 19, described the problem in more technical terms: sensors in a cavity between fueling umbilical plates detected hydrogen building up after flow rates were increased, and late in the countdown the concentration in the inert nitrogen purge gas rose toward 16 percent, a level at which fire risk becomes a concern. That report said the test was ended before options for recycling the countdown could be tried.

Mission manager John Honeycutt told reporters, as NBC reported, that hydrogen is a small, highly energetic molecule that is hard to contain and prone to leaking. The uncrewed Artemis I flight in 2022 was delayed about six months by similar leaks during its first rehearsal, NBC noted.

NASA is now targeting March as its earliest opportunity, with launch dates of March 6 through 9 and March 11 available and more in April. Lori Glaze, acting head of the agency’s Exploration Systems Development Mission Directorate, said the full test results must be analyzed before another rehearsal is scheduled, NBC reported. If repairs prove extensive, the rocket could be rolled back to the Vehicle Assembly Building, which would likely mean a longer delay.

NASA Administrator Jared Isaacman wrote that the team “fully anticipated encountering challenges” given the more than three years since the last launch of the rocket, and that the agency “will only launch when we believe we are ready,” according to NBC. Launch director Charlie Blackwell-Thompson said the team would “figure it out.” NBC also said NASA will look into audio problems on ground-team communication channels during the test.

The four astronauts, NASA’s Reid Wiseman, Christina Koch and Victor Glover and Jeremy Hansen of the Canadian Space Agency, had been in quarantine in Houston since Jan. 21, NBC reported. They have been released and are resuming training Wednesday, and are expected to re-enter quarantine about two weeks before the next launch opportunity. Wiseman posted on X that he felt immense pride at seeing the rocket reach a full fuel load.

Artemis II will be the second flight of the SLS rocket and Orion capsule and the first with people aboard. CBS described it as the first piloted flight to the moon since the last Apollo landing in 1972, and a step toward Artemis III, which aims to land astronauts near the lunar south pole. NBC reported that the program’s goal is returning astronauts to the lunar surface.