NASA’s new moon rocket sprang another dangerous fuel leak Saturday, forcing launch controllers to call off their second attempt to send a crew capsule into lunar orbit with test dummies.
The first attempt earlier in the week was also marred by escaping hydrogen, but those leaks were elsewhere on the 322-foot (98-meter) rocket, the most powerful ever built by NASA.
Launch director Charlie Blackwell-Thompson and her team tried to plug Saturday’s leak the way they did the last time: stopping and restarting the flow of super-cold liquid hydrogen in hopes of removing the gap around a seal in the supply line. They tried that twice, in fact, and also flushed helium through the line. But the leak persisted.
For the second time this week, the launch team began loading nearly 1 million gallons of fuel into the 322-foot (98-meter) rocket, the most powerful ever built by NASA. Monday’s attempt was halted by a bad engine sensor and leaking fuel.
As the sun rose, an over-pressure alarm sounded and the tanking operation was briefly halted, but no damage occurred and the effort resumed. But minutes later, hydrogen fuel began leaking from the engine section at the bottom of the rocket. NASA halted the operation, while engineers scrambled to plug what was believed to be a gap around a seal in the supply line.
The countdown clocks continued ticking toward an afternoon liftoff; NASA had two hours Saturday to get the rocket off.
NASA wants to send the crew capsule atop the rocket around the moon, pushing it to the limit before astronauts get on the next flight. If the five-week demo with test dummies succeeds, astronauts could fly around the moon in 2024 and land on it in 2025. People last walked on the moon 50 years ago.
Forecasters expected generally favorable weather at Kennedy Space Center, especially toward the end of the two-hour afternoon launch window.
On Monday, hydrogen fuel escaped from elsewhere in the rocket. Technicians tightened up the fittings over the past week, but launch director Charlie Blackwell-Thompson stressed that she wouldn’t know whether everything was tight until Saturday’s fueling.