NASA announced another stand down of the Artemis I launch on September 3 after engineers could not overcome a hydrogen leak. The leak stemmed from a quick disconnect, an interface between the liquid hydrogen fuel feed line and the Space Launch System (SLS) rocket.
“Mission managers met and decided they will forego additional launch attempts in early September,” NASA said in a press release.
Engineers discovered a leak in a cavity between the ground and rocket side plates surrounding an 8-inch line used to fill and drain liquid hydrogen from the SLS rocket during the September 3 launch attempt. Three attempts to reset the seal were unsuccessful.
During the “chill down” phase of hydrogen loading operations, an inadvertent command was sent that temporarily raised the pressure in the system. Launch controllers must cool down the lines and propulsion system before flowing super cold liquid hydrogen into the rocket’s tank at negative 423 degrees Fahrenheit.
NASA engineers said it is too soon to tell if the inadvertent bump in pressure caused the leaky seal. However, they insist that the rocket remained safe, and they are continuing to investigate the problem.
The launch of Artemis I, the first integrated test of NASA’s Orion spacecraft, SLS rocket, and ground systems, was initially scheduled for August 29 but was postponed until September 3 because of the same leak issue, NASA stated.
Because of the complex orbital mechanics involved in launching to the Moon, the last day to launch Artemis under the current window of opportunity would have been Tuesday. The next potential launch period is between September 19 and October 4, 2022, at the agency’s Kennedy Space Center in Florida.
NASA said teams would establish access to the leak area at Launch Pad 39B over the next few days, while also conducting a schedule assessment to determine whether to replace the seal at the launch pad, where it can be tested under cryogenic conditions, or move the rocket inside the Vehicle Assembly Building (VAB).
At some point before the next launch, NASA will need to return the rocket and spacecraft to the VAB to reset the flight termination system’s batteries. To ensure public safety, all rockets must have a flight termination system, NASA said.