If everything works out,could finally blast off for the first time from Florida's Kennedy Space Center as soon as Friday, Sept. 27.
The space agency has repaired a leak that scrubbed the Sept. 3 launch and is now working to test that the issue is resolved with a propellant loading demonstration by Sept. 21 to be ready for a launch attempt on the 27th.
"Over the weekend, Artemis I teams completed repair work to the area of a hydrogen leak," read an NASA said on Monday. "The demonstration will allow teams to confirm the hydrogen leak has been repaired, evaluate updated propellant loading procedures designed to reduce thermal and pressure-related stress on the system, conduct a kickstart bleed test, and evaluate pre-pressurization procedures."
The space agency also still needs to get special permission from the US Space Force, which oversees rocket launches from Florida. NASA is required to have the batteries rechecked on the SLS rocket's flight termination system, which destroys the rocket if it veers off course to prevent a threat to the public. This has to happen every 25 days, and Sept. 27 is outside that window.
The problem for NASA is that checking the batteries requires rolling SLS all the way back to the Vehicle Assembly Building or VAB. This could add several days to the process and SLS is only certified to make the trip from its hangar to the launch pad so many time, according to Eric Berger of Ars Technica.
"So if they were to roll back to VAB this month and then back to the pad, they would have just one roundtrip left," Berger wrote on Twitter.
All this means the Artemis I mission managers would prefer to fix the propellant leak, pass a tanking test and blast off with the blessing of the Space Force without having to move the rocket at all.
During a press call Thursday, Jim Free, NASA's associate administrator for exploration systems development, confirmed the agency has requested a waiver from the Space Force that would allow SLS to stay put.
If the waiver is granted and the tanking demonstration goes well, the launch could move forward on Sept. 27 with a possible backup date of Oct. 2.
The long-awaited debut of SLS, the Orion crew capsule and the first major Artemis program mission was scrubbed twice earlier, first on Aug. 29 due to engine issues and then on Sept. 3 because of the leak.
The mission will see SLS send an uncrewed Orion on a weeks-long flight around the far side of the moon and back for a high speed reentry into Earth's atmosphere followed by a splashdown landing.
Artemis 1 is designed to pave the way for the first crewed Orion mission in 2024 and eventually for the return of NASA astronauts to the surface of the moon and then on to Mars in the 2030s.
Theon Sept. 27 opens at 8:37 a.m. PDT, with Orion returning to Earth on Nov. 5.