On Saturday, NASA called off its latest attempt to launch the groundbreaking Artemis 1 moon rocket due to a fuel leak discovered during tanking. Technical issues had kept the spacecraft on the launchpad for the second time in five days.
After several workarounds to try to plug the leak of liquid hydrogen as it was pumped into the core stage of the Space Launch System (SLS) rocket failed, mission managers at Kennedy Space Center waited until late in the countdown to scrub the liftoff.
“The cost of two scrubs is a lot less than the cost of failure,” NASA Administrator Bill Nelson said during a press conference on Saturday afternoon. Despite its 322-foot height, NASA’s new rocket is not literally too big to fail. However, in terms of the vehicle’s significance to the space agency’s moon plans, it may be.
Because NASA has so much invested in this single rocket, a catastrophic failure would cause the moon program to be delayed by years and may call into question its value. Even those who oppose the Space Launch System agreed that NASA’s caution is prudent.
NASA’s Apollo program was responsible for the moon landings half a century ago. The new mission to return to the moon has been named Artemis. Artemis was Apollo’s twin sister in Greek mythology.
The launch was canceled for Artemis I, a weeks-long uncrewed mission that will test the rocket and the capsule in which future astronauts will ride. Astronauts will be aboard the next Artemis mission, which is currently scheduled for 2024, and the third Artemis mission will land astronauts near the moon’s south pole.
As the countdown clock approached Saturday’s launch, a hydrogen leak was discovered in a connector along the hydrogen fuel line leading to the rocket. The concentrations were two to three times the 4 percent limit for this leak, which Mr. Sarafin described as large. After three attempts to seal the leak failed, the launch attempt was called off at 11:17 a.m. Eastern time by the launch director, Charlie Blackwell-Thompson.
Mr. Sarafin believes the problem was caused by an incorrect command sent to the propellant-loading system on the launchpad, which resulted in excessive pressures — 60 pounds per square inch instead of 20 — in the fuel line for a few seconds. That could have harmed the connector’s gasket.
During the first launch attempt on Monday, a hydrogen leak appeared at the same connector, but it was smaller, and engineers figured out how to keep the hydrogen concentration under 4%, allowing them to fill the rocket with 537,000 gallons of ultracold liquid hydrogen. The launch on Monday was cancelled due to a faulty sensor reporting that one of the rocket’s four core-stage engines was not sufficiently chilled.
