NASA finds damage on Artemis hydrogen seal, still on for fueling test
NASA teams investigating pad hardware at Kennedy Space Center found a potential culprit behind a leaky hydrogen line that scrubbed the Artemis I moon mission’s last attempt, making way for a fueling test this week.
Managers and engineers have already started preparing for their arrival at the Launch Control Center starting Monday evening, a process that will run through what is essentially a mock countdown similar to launch day. At 3:40 a.m. EDT Wednesday, Sept. 21, teams will clear the Space Launch System rocket’s pad 39B and slowly begin what until now has been a finicky fueling process.
The necessity for Wednesday’s test is being driven by two previous launch attempts, both of which had to be scrubbed due to technical issues with the 322-foot rocket, which uses leftover space shuttle program hardware. If all goes well, it could lead to a third launch attempt at 11:37 a.m. EDT Tuesday, Sept. 27.
In late August, it appeared one of four RS-25 main engines failed to reach the right pre-launch temperature, but NASA officials later determined the bad reading was due to a faulty sensor. During the second attempt earlier this month, a major leak of liquid hydrogen – one of SLS’ two propellants along with liquid oxygen – forced a scrub after the tank couldn’t be filled.
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Now teams think at least part of the second issue was caused by damage to a seal in a hydrogen quick-disconnect, or QD. A NASA official said the “witness mark,” or indentation, was likely caused by foreign object debris in the system and, despite its small size at 0.01 inches, can’t be ruled out as a contributor.
“That doesn’t sound like a lot, but we’re dealing with hydrogen, the smallest particle on the atomic chart,” Mike Sarafin, NASA’s Artemis I mission manger, said during a pre-test briefing Monday. “So an indentation of that size does provide an opportunity for a pressurized gas to leak through.”
Liquid hydrogen is a finicky propellant. Not only does it need to be chilled to colder temperatures than other options like kerosene or methane, but its small size means it can even be “absorbed” by metals and cause damage. It also has to be seriously pressurized, easily exposing flaws or leaks in the loading system.
Artemis I plan moving forward
By 3 p.m. EDT Wednesday, or about 12 hours after teams clear pad 39B, NASA hopes to have conducted a successful propellant loading test. But in order to get there, officials said some modifications will be made during the countdown and fueling processes.
First, the seals in the hydrogen QD at pad 39B were replaced. That will allow for a “kinder, gentler” loading process designed to pump the chilled hydrogen at slower rates and hopefully avoid thermal shock.
“We’re trying to minimize both pressure spikes and thermal spikes,” Jeremy Parsons, deputy manager of ground systems at KSC, said Monday. “What we’re going to be doing is…
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