NASA's Mega Moon Rocket Test Called Off After Battling Issues With Launcher

NASA called off the wet dress rehearsal of its Artemis I moon rocket on Monday due to "an issue with a panel on the mobile launcher," according to a press release by the agency.

This is the second time an issue with the mobile launcher has forced NASA to press pause on its wet dress rehearsal. NASA tweeted on Monday: "This is why we test."

The wet dress rehearsal is necessary for NASA to test out basically every system leading up to launch of its mega moon rocket, the Space Launch System, aka SLS, without actually launching the rocket. It's the final hurdle for the rocket to clear before it launches to the moon -- a feat scheduled to occur sometime in mid-2022. 

On Sunday morning, the propellant tanks of the SLS were due to be loaded but NASA said it lost the ability to pressurize the mobile launcher, the platform providing all the vital connections to the rocket, because of an issue with two fans designed to create a positive pressure and "keep out hazardous gasses." 

Artemis launch director Charlie Blackwell-Thompson said the team made the decision to stand down to troubleshoot the issue and "make another run" at the wet dress rehearsal on Monday. 

Restarting the test Monday, NASA says that while it was chilling down the lines to feed in propellant to the huge fuel tanks of the SLS, it spotted an issue with a panel that controls the vent valve of the rocket's core stage (that big ol' orange tank in the middle). The launch director then made the call to stand down for the day, as "teams were nearing the end of their shifts."

It's another setback, however small, for the SLS, which has long been over budget and behind schedule during its decade of development. 

"I'm confident we're going to get through the wet dress in fairly short order, we just gotta work through these problems," added Mike Sarafin, Artemis I mission manager, during a NASA media teleconference on April 3 after the pressure issue.

The wet dress rehearsal has also had to contend with some nasty Florida weather. The SLS rocket and Orion capsule are both currently stationed at Launch Complex 39B in Kennedy Space Center, Cape Canaveral. The severe weather that rolled by resulted in lightning strikes around the pad.

"It turned out we had not one, but we had four lightning strikes inside the pad perimeter," said Sarafin. "We had prepared for lightning strike as part of our mission preps," he noted. 

The fourth was the strongest lightning strike, though it did no damage, with the SLS rocket and the Orion capsule both not powered. However, the weather did set the team back by about four hours according to Blackwell-Thompson.