NASA’s New Moon rocket suffered another dangerous fuel leak on Saturday, forcing launch controllers to abort their second attempt this week to send a crew capsule into lunar orbit with test dummies. The inaugural flight is now closed for weeks, if not months. Monday’s earlier attempt to launch the 322-foot-long (98-meter) Space Launch System rocket, the most powerful ever built by NASA, was also troubled by hydrogen leaks, albeit smaller ones. This was in addition to the leaks identified during countdown exercises earlier in the year. After the latest failure, mission managers decided to pull the rocket off the pad and into the hangar for further repairs and system updates. Some of the work and testing may take place on the pad before the rocket is moved. Either way, it will take several weeks of work, officials said. With a two-week launch shutdown period approaching in just a few days, the rocket is now grounded until late September or October. NASA will work around a high-priority SpaceX astronaut flight to the International Space Station scheduled for early October. NASA Administrator Bill Nelson stressed that safety is the top priority, especially on a test flight like this where everyone wants to verify the rocket’s systems “before we put four people on top of it.” “Just remember: We’re not going to launch until it’s right,” he said. NASA already waited years to send the crew capsule atop the rocket around the moon. If the six-week demonstration is successful, astronauts could fly around the moon in 2024 and land on it in 2025. Humans last walked on the moon 50 years ago. Launch Manager Charlie Blackwell-Thompson and her team had just begun loading nearly 1 million gallons of fuel into the Space Launch System rocket at dawn when the large leak appeared in the engine compartment at the bottom. Ground controllers tried to plug it the way they handled previous, smaller leaks: by stopping and restarting the flow of ultra-cold liquid hydrogen in hopes of closing the gap around a seal in the supply line. They tried it twice, actually, and also shot helium through the line. But the leak continued. Blackwell-Thompson finally stopped the countdown after three to four hours of futile attempts. Mission Director Mike Sarafin told reporters it was too early to say what caused the leak, but it may have been due to an inadvertent overpressurization of the hydrogen line earlier in the morning when someone sent commands to the wrong valve. “This was not a manageable leak,” Sarafin said, adding that the escaping hydrogen exceeded flammability limits by two or three times. During Monday’s attempt, a number of small hydrogen leaks appeared there and elsewhere on the rocket. Technicians tightened the components over the next few days, but Blackwell-Thompson had warned she wouldn’t know if everything was tight until Saturday’s refueling. Hydrogen molecules are extremely small – the smallest there are – and even the tiniest gap or crevice can provide a way out. NASA’s space shuttles, now retired, were plagued by hydrogen leaks. The New Moon rocket uses the same type of main engines. Even more of a problem on Monday was that a sensor indicated that one of the rocket’s four engines was too hot, although engineers later verified that it was actually quite cold. The launch team planned to ignore the faulty sensor this time and rely on other instruments to ensure each main engine was properly cooled. But the countdown never got that far. Thousands of people who jammed the coast over the long Labor Day weekend, hoping to see the Space Launch System rocket soar, left disappointed. The $4.1 billion test flight is the first step in NASA’s Artemis program for renewed lunar exploration, named after the twin sister of Apollo in Greek mythology. Years behind schedule and billions over budget, Artemis aims to establish a permanent human presence on the moon, with crews eventually spending weeks there at a time. It is considered training for Mars. Twelve astronauts walked on the moon during the Apollo program, the last time in 1972.
The Associated Press Health and Science Section is supported by the Howard Hughes Medical Institute Science Education Division. AP is solely responsible for all content. Marcia Dunn, The Associated Press
