NASA will attempt another repeat of the Space Launch System Countdown in early June, but the space agency has warned that more tests of its finicky rocket may be needed.
SLS returned to the Vehicle Assembly Building at Kennedy Space Center, Florida, on April 26, allowing technicians to replace a faulty upper stage helium check valve and fix a small hydrogen leak on the tail service mast umbilical. These and other “nuisances”, as NASA describes them, prevented ground crews from conducting a fourth wet dress rehearsal, during which the rocket was to be fully loaded with super-cooled thrusters and full countdown exercised. NASA hoped to conduct the fourth test while the 322-foot-tall (98-meter) rocket was still standing on Launch Complex 39B, but it didn’t.
Speaking to reporters yesterday, NASA officials said they would try to do a full wetsuit rehearsal again in early to mid-June. The extra time will allow the team to resolve some lingering technical issues, perform additional rocket checks, and allow an offsite nitrogen gas supplier to perform necessary upgrades to its pipeline system.
SLS is a key part of NASA’s upcoming Artemis program, which aims to bring American astronauts back to the dusty lunar surface for the first time in more than 50 years. NASA also needs the megarocket to build its next Lunar Gateway (a small space station orbiting the Moon) and to enable future crewed travel to Mars. The SLS program suffered from additional costs and delaysthese latest reverses adding insult to injury.
Assuming a successful rehearsal can be completed in June, the rocket will once again return to the Vehicle assembly building for final launch preparations and “some work we’ve deferred to the other side of the wet robe,” as Jim Free, associate administrator for exploration systems development at NASA, explained during the teleconference with the media. Upcoming Unmanned Launch Periods Mission Artemis 1 include July 26-August 9 (Free said NASA was not considering the July portion of this timeframe), August 23-29, and September 2-6. but did not provide specific dates. NASA will wait for the results of the next wet dress to decide when to launch.
Free, explaining that he wanted to be ‘realistic’ and ‘straightforward’, said ‘it may take more than one attempt’ to wrap up a wet dress and to “get procedures where we need them for a smoother launch count that gives us the best chance of making our launch windows when we get to launch day.” Since this is the first time we’ve heard that multiple attempts might be needed, and given the multitude of problems encountered during the first three tests, I asked Free if the rocket turned out to be more complicated than it looks. thought NASA.
“SLS is not more complicated, we knew it was complicated,” he replied. A particular challenge, Free said, has been operating the new ground systems for the first time and seeing how they respond. The team is “not going to take for granted” that the next wet dress “is going to be great” based on what was experienced in the first three attempts, he said. A certain amount of realism is needed in the approach and “the team needs our support”, he added. That includes managing the team’s workload, which “has been at it for quite a while now,” Free said. “It’s really hard work.”
SLS should leave the Vehicle assembly building late May, with the wet coat expected early or late June. This is not a guarantee, as technicians have not yet determined the source of the rubber debris that prevented an upper stage check valve from functioning in a previous test. The umbilical hydrogen leak on the cushion must also be repaired to the satisfaction of the team (the problem is solved by the periodic re-tightening of the bolts), while the nitrogen gas supplier, Air Liquide, must demonstrate that it can supply the gas to SLS as needed, as Cliff Lanham, senior director of vehicle operations at NASA, told reporters.
On a positive note, NASA will have live feedback for the next SLS rehearsal, which had not been done for the first three tests, apparently for Security the reasons.