NASA ran into fuel leaks during a make-or-break countdown practice test for a new moon rocket Monday, injecting fresh uncertainty into when it can send a crew on the Artemis program’s first lunar voyage in more than half a century.
The leaks surfaced just a couple hours into a daylong fueling operation at Kennedy Space Center, officials said, and they were “exasperating” enough that launch controllers had to intervene during the flow of super-cold hydrogen and oxygen intended to mimic later stages of an actual launch countdown. The problem was notable because NASA’s new rocket’s earlier debut also slipped after hydrogen leaks, and Monday’s issues unfolded during a rehearsal that was meant to clear lingering readiness questions.
The fueling process began with launch controllers loading the 322-foot (98-meter) rocket with super-cold hydrogen and oxygen at midday, according to the Associated Press. More than 700,000 gallons (2.6 million liters) had to flow into the rocket’s tanks and remain aboard for several hours as part of the demonstration. But excessive hydrogen built up near the bottom of the rocket within the first hours of the operation, and fueling was halted at least twice as the team worked to address the buildup using techniques developed during the previous Space Launch System countdown in 2022.
The timeline for the crewed mission depends on how quickly NASA can manage the leak issue, the AP reported. At best, NASA could launch commander Reid Wiseman and his crew to the moon no sooner than Sunday. NASA also said the rocket must be flying by Feb. 11 for the mission to proceed; if that requirement is missed, the mission would be called off until March, with launch opportunities limited to only a few days each month. Extreme cold had already shortened February’s launch window by two days, and NASA’s countdown clocks began running Saturday night to work through possible problems.
The rehearsal is intended to culminate at the point just before engine ignition: the countdown clocks were set to stop a half-minute before reaching zero during the practice. The crew’s nearly 10-day mission concept does not include entering lunar orbit or attempting a landing. Instead, the astronauts would travel past the moon, go around the far side, and return straight to Earth while testing the capsule’s life support and other vital systems.
Wiseman and the other assigned astronauts were not at the launch site. The four crew members—three Americans and one Canadian—monitored the dress rehearsal from nearly 1,000 miles (1,600 kilometers) away in Houston, home to NASA’s Johnson Space Center. The astronauts had been in quarantine for the previous 1½ weeks, awaiting the fueling demonstration’s outcome.
NASA last sent astronauts to the moon during the 1960s and 1970s Apollo era, and the Artemis program is intended to support a longer-term lunar presence. Wiseman’s mission is framed as a stepping-stone for future moon landings by other astronauts, with the rehearsal’s results serving as a key checkpoint for the program’s next launch attempt.