The head of the US space agency suggests that the first test flight will probably be delayed until mid-October.
NASA on Saturday called off its latest attempt to launch the groundbreaking Artemis 1 moon rocket after it failed to stop a fuel leak discovered during tanking. This was the second time in five days that the spacecraft was technically prepared for the launchpad.
Mission managers at Kennedy Space Center waited long in the countdown to clear liftoff after the failure of several workarounds to prevent leakage of liquid hydrogen as it was pumped Into the main stage of the SLS (Space Launch System) rocket.
US Space Agency chief Bill Nelson indicated that the gravity of the problem, deep inside one of the rocket engines, would make it not possible to fix the launchpad, and Artemis would likely have to be moved back to the Vehicle Assembly Building. More important repairs.
That would mean Monday’s next backup launch opportunity is also untenable, and further delays in the first test flight of humanity’s first crewed Moon mission in 50 years. Senior NASA officials said the next attempt would be delayed until at least the end of September.
“It’s part of the space business,”he said. “When it’s ready we’ll go. We won’t go until then, and especially on a test flight because we’re going to be thrusting on it and test it, and test that heats up the shield and it Makes sure it’s right before putting four humans on top.
“Although the [next launch] window opens in early October, I suspect it will be more like the middle”
Nelson said mission managers will meet later on Saturday to make a final decision.
NASA’s Artemis launch director, Charlie Blackwell-Thompson, agreed with the fuel systems team’s recommendation and called off the launch at 11.17 a.m. (4.17 a.m. BT) local time, with 2 hours and 30 minutes on the countdown.
The fuel leak, which became apparent during the morning tanking of 2.76m liters (730,000 gallons) of liquid hydrogen and oxygen, is separate from the engine cooling issue that forced the first launch attempt last Monday to be postponed. Officials said they had identified that problem as a faulty sensor, not a problem with the cooling system or engine.
Blackwell-Thompson and his team had barely started refueling early in the morning when a major leak occurred in the engine section below. Ground controllers tried to plug it the way they handled previous, small leaks: stopping and restarting fuel flow in hopes of closing the gap around a seal in the supply line. He tried twice, and also flushed helium through the line, but the leak persisted.
Blackwell-Thompson stopped the countdown after three to four hours of fruitless efforts.
The mission manager, Mike Sarafin, told reporters that it was too early to tell what caused the leak, but it may have been due to an unintentional excessive pressure on the hydrogen line in the morning when someone sent a command to the wrong valve.
“It was not a manageable leak,” he said, adding that the escaping hydrogen exceeded the flammability limit two or three times.
During Monday’s attempt, some sources of small hydrogen leaks appeared on the rocket and elsewhere. Technicians tightened the fittings over the following days, but Blackwell-Thompson said they would not know if everything was tight until Saturday’s refueling.
NASA’s latest setback will be a disappointment for an agency eager to demonstrate the progress it has made in getting humans back to the lunar surface for the first time since the 1972 Apollo 17 mission.
This 38-day mission is 40,000 miles to the Moon and back, but it must be successful before astronauts can board a second test flight planned for 2024, then a moon landing on Artemis III currently in late 2025. Not scheduled before.
More than a quarter-million visitors packed the beaches and proceedings of Florida’s Space Coast over the Labor Day holiday weekend, eager to witness a moment in history.
Mission managers indicated that the liquid hydrogen leak was inside one of the four RS-25 engines on the SLS, which would eventually become the most powerful rocket to ever leave Earth when launched.
The engines are recycled from the long-retired Space Shuttle program and combine to provide 15% more thrust than the Saturn V rockets of the Apollo era.