Fuel Leak Ruins NASA’s Second Attempt to Launch Moon Rocket

CAPE CANAVERAL, Fla. (AP) – NASA’s new lunar rocket caused another dangerous fuel leak on Saturday, forcing launch controllers to call off their second attempt this week to send a crew pod into orbit with test dummies. The inaugural flight will now take at least a few weeks, if not months.

Monday’s previous attempt to launch the 98-meter-long Space Launch System rocket, the most powerful ever built by NASA, also suffered from hydrogen leaks, although they were smaller. That came on top of leaks discovered during countdowns earlier this year.

After the latest setback, mission managers decided to tow the missile from the pad to the hangar for further repairs and system updates. Some of the work and testing can be done on the pad before the missile is moved.

With a two-week launch blackout period looming in just a few days, the rocket is now grounded until later this month or even October. NASA will work around a high-priority SpaceX astronaut flight to the International Space Station, scheduled for early October.

NASA administrator Bill Nelson emphasized that safety is a 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.”

“Remember, we won’t launch until it’s right,” he said.

NASA has been waiting for years to send the crew pod on top of the rocket around the moon. If the six-week demo succeeds, astronauts could fly around the moon in 2024 and land on it in 2025. Humans last walked on the moon 50 years ago.

Launch director Charlie Blackwell-Thompson and her team had only just started loading nearly 1 million gallons of fuel into the Space Launch System rocket at daybreak when the large leak surfaced in the underside engine compartment.

Ground controllers tried to plug it the way they’ve dealt with previous leaks: stopping and restarting the flow of super-cold liquid hydrogen in hopes of plugging the gap around a seal in the supply line. They even tried that twice and flushed helium down the line as well. But the leak persisted.

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Blackwell-Thompson finally stopped the countdown after three to four hours of futile efforts.

Mission manager Mike Sarafin told reporters it was too early to say what caused the leak, but it may have been due to an accidental overpressure of the hydrogen line earlier in the morning when commands were sent to the wrong valve.

“This was not a manageable leak,” Sarafin said.

During Monday’s attempt, a series of smaller, unrelated hydrogen leaks surfaced inside the rocket. Technicians tightened the fittings over the next few days, but Blackwell-Thompson had warned that she wouldn’t know until Saturday when refueling that everything was tight.

Hydrogen molecules are extraordinarily small – the smallest in existence – and even the smallest opening or fissure 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 Monday, a sensor indicated that one of the rocket’s four engines was too hot, but engineers later confirmed it was actually cold enough. The launch team planned to ignore the faulty sensor this time and rely on other instruments to make sure each main engine was properly cooled. But the countdown never got that far.

Mission managers accepted the added risk of the engine problem and a separate problem: cracks in the rocket’s insulating foam. But they acknowledged that other problems — such as fuel leaks — could cause yet another delay.

That didn’t stop thousands of people from blocking the coast in hopes of seeing the Space Launch System rocket soar. Local authorities expected massive crowds due to the long Labor Day weekend.

The $4.1 billion test flight is the first step in NASA’s Artemis lunar re-exploration program, named after Apollo’s twin sister in Greek mythology.

Years behind schedule and billions over budget, Artemis strives for a lasting human presence on the moon, with crews eventually spending weeks at a time there. It is considered a training ground for Mars.

Twelve astronauts walked on the moon during the Apollo program, the last time in 1972.


The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

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