NASA may take its fourth crack at fueling up the huge Artemis 1 moon rocket as early as next Thursday (April 21), agency officials said.
Artemis 1 will use NASA's new Space Launch System (SLS) megarocket to send an Orion capsule on an uncrewed journey around the moon. The agency aims to launch the mission this summer and has been carrying out a series of crucial tests at Pad 39B at Florida's Kennedy Space Center (KSC) to help get the team and the hardware ready.
This test campaign, called a "wet dress rehearsal," began on April 1 and was supposed to wrap up two days later with the fueling of the SLS and some practice launch countdowns. But several technical issues hampered and delayed the wet dress, and the Artemis 1 team then ended up halting operations to accommodate SpaceX's April 8 launch of the private Ax-1 astronaut mission from KSC's Pad 39A.
The team aimed to resume the test on April 11 but discovered a faulty valve on the mobile launch tower supporting the Artemis 1 stack. This problem pushed things back a day and caused the team to modify the test procedure; they decided to fuel only the SLS core stage, not its upper stage as well.
Fueling began on April 14, but team members halted the procedure after noticing that liquid hydrogen was leaking unexpectedly. (Liquid hydrogen is one of the two propellants used by the SLS, along with liquid oxygen.)
So the Artemis 1 team also called off that attempt, the third try overall to fill up the SLS tanks. (The earlier two came on April 3 and April 4.) But the team plans to get back on the horse again soon.
"We're preserving the option to reattempt the wet dress as early as next week," Mike Sarafin, Artemis mission manager at NASA headquarters in Washington, said during a call with reporters on Friday (April 15). "Thursday the 21st is kind of the earliest time that the team is comfortable with doing that."
The schedule is a bit tricky next week, however, as Sarafin and other NASA officials acknowledged; SpaceX is gearing up to launch the Crew-4 astronaut mission for NASA at 5:26 a.m. EDT (0926 GMT) on April 23 from Pad 39A at KSC.
NASA and SpaceX want a 24-hour buffer between the Artemis 1 wet dress and Crew-4's liftoff, officials said during a different news conference on Friday. So, if tanking of the SLS core stage cannot be completed by the early-morning hours of April 22, the Artemis 1 team will need to wait until after Crew-4 gets off the ground.
No decisions have been made in this regard, NASA officials said; Artemis 1 team members are still analyzing data from the test procedures performed to date and formulating their next steps. But Artemis 1's SLS and Orion remain in good shape, they stressed. And they're hardly daunted by the issues that have cropped up.
The SLS has never flown before, so it's hardly surprising to encounter a few problems during the test campaign. For example, it took five or six tanking attempts to get the space shuttle ready for its first-ever flight in 1981, said Artemis launch director Charlie Blackwell-Thompson, of NASA Exploration Ground Systems program at KSC.
"I would say we're within family of our experience in the past for first-time [operations]," Blackwell-Thompson said during Friday's Artemis 1 news conference.
Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or on Facebook.