NASA to repair SLS liquid hydrogen leak on pad – SpaceNews

WASHINGTON — NASA will try and safe the cushion to a liquid hydrogen seal that induced the House Launch System to gum up, retaining open the choice of constructing one other launch try later this month.

In a late September 6 assertion, NASA stated technicians would proceed with plans to interchange the joint on the interface known as the short disconnect between a liquid hydrogen provide line and the SLS core stage. This work will probably be carried out on the platform fairly than returning the automobile to Kennedy House Heart’s Car Meeting Constructing (VAB).

An issue with that seal led to what officers known as a big leak of liquid hydrogen throughout core stage refueling throughout the Sept. 3 launch try. A number of efforts to reattach the short disconnect, by heating it then cooling it and making use of helium gasoline stress to the becoming, didn’t cease the leak, and NASA known as off the launch try. of Artemis 1 three hours earlier than the opening of the two-hour launch window.

Throughout a Sept. 3 post-scrub briefing, NASA officers stated they had been contemplating choices to restore the quick-disconnect joint whereas remaining at Launch Complicated 39B fairly than returning to VAB. Staying on the pad has “a couple of execs and cons related to it,” stated Artemis mission supervisor Mike Sarafin. “The downsides occur nearly each afternoon right here whenever you get a downpour or thunderstorm.”

NASA stated in its newest assertion that earlier than starting to interchange the gasket, technicians would place an enclosure across the interface “to guard the {hardware} from climate and different environmental situations.” The company didn’t say how lengthy this preparatory work or the substitute of the seal itself would take.

One of many benefits of doing the work on the pad is that the employees can then take a look at the becoming utilizing liquid hydrogen, which isn’t an possibility if the work is being finished on the VAB. “It is the one place we are able to get a full cryo take a look at and ensure we do not have a further subject with leaks on the temperatures we have to fill the automobile on launch day,” stated stated Sarafin.

Doing the work on the pad would additionally protect the flexibility to proceed with one other launch try with out returning to the VAB. This, nonetheless, is barely doable if the US House Power’s House Launch Delta 45, which operates the Japanese Vary, extends Flight Termination System (FTS) certification on the rocket. This certification expired on September 6 and NASA ought to return to the VAB to reset the FTS, which is in part of the rocket that’s not accessible on the pad.

“We should not have an FTS waiver presently past 25 days. Till we have now that, we have now to return,” Jim Free, NASA affiliate administrator for exploration programs improvement, stated throughout the Sept. 3 briefing. He stated the company would contemplate asking for an extension, however must decide how lengthy of an extension it wanted in opposition to the quantity the japanese chain would award. “That negotiation did not occur, so so far as I am involved, we have now to return.”

If, nonetheless, the japanese vary extends FTS certification, it might be doable to aim one other SLS launch throughout the subsequent launch window, which opens September 20 and ends October 4. “I feel it is too early to say ‘whether or not a late September launch is feasible,’ Sarafin stated. “It actually comes right down to what the fault tree evaluation is telling us and what modifications are wanted and what mitigations are wanted to be assured that we have mounted this subject.”

Free stated different components may weigh into the choice to stay on the pad, together with constraints for the Orion spacecraft remaining on the pad. “On the finish of the day, we’re guided by the FTS.”

If NASA decides to return to the VAB, which could possibly be to carry out additional work on the automobile or due to climate as Florida enters the height of hurricane season, it could delay the launch by a number of weeks. , stated Sarafin. That might push the launch again to at the least the subsequent launch window, which runs from October 17 to October 31.

NASA’s Sept. 6 replace didn’t present further particulars on the reason for the leaking quick-disconnect seal. Company officers speculated after the scrub that “unintentional overpressure” of the liquid hydrogen line throughout refueling preparations may have broken the seal, however stated they wanted extra time to research the issue.

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