NASA’s SLS amplifier, left on Pad B, at the Kennedy Space Center in Florida last week, is being tested for Artemis 1 launch on Tuesday. The “wet dress rehearsal” is plagued by delays, most recently a valve failure that officials are working on to complete the tests. Photo by Joe Marino / UPI | License photo
ORLANDO, Florida, April 11 (UPI) – NASA plans to conduct modified tests on Tuesday before launching the next big moon rocket, the Space Launch System. The tests have been delayed due to a problem with the valve on the upper stage of the rocket, service officials said on Monday, but will work on it – not fully feeding the rocket – to complete the tests. Problems with the rocket’s helium pressure system – specifically a faulty valve – first surfaced during a previous attempt to complete the wet dress rehearsal, forcing officials to delay and eventually modify the test. “The vehicle is in really good condition and is doing what we ask it to do, except for this one issue,” John Blevins, chief SLS engineer at NASA’s Marshall Spaceflight Center, told UPI. “The modified wet dress rehearsal will [still] let’s try the majority of our goals. It is much more than just a tank [or fueling] test.” Originally scheduled for April 3, the wet dress rehearsal is a series of launch day activities, culminating in rocket power, data collection and ensuring the proper operation of both the rocket and ground system. Multiple delays continued to push the test back, with engineers now hoping to complete it by April 14th. The faulty valve is part of the upper stage of the rocket, called the temporary cryogenic propulsion stage or ICPS. Made by the United Launch Alliance, the tent is a modified version of the same upper tier that was flown with ULA’s current heavy-duty rocket, the Delta IV Heavy. The scene is powered by an RL10 engine, built by Aerojet Rocketdyne, and according to Blevins, the affected valve is part of the ICPS but is not located in the engine itself. “It’s about 3 inches long and easy to reach,” Blevins said. “It’s not really accessible from the launch pad, but when we get back to VAB, we should be able to reach it and see why it failed.” The valve is part of the upper stage helium pressure system, which is used to keep the upper stage of the rocket under pressure during refueling and drainage. To this end, the team will focus only on loading propulsion into the basic stage, which is the largest component of the SLS missile. The valve is just the latest in a series of malfunctions that have plagued wet dress rehearsals, delaying it by more than a week. NASA officials said, however, that they could still achieve the main objectives of the test, even if it were modified. “Teams have faced a number of challenges so far and have handled every issue with grace under pressure,” Mike Sarafin, director of NASA’s Artemis mission, told UPI. “This test is designed to prepare us for Artemis 1, which is a test flight without a crew that will prepare us for a test flight with a crew around the moon with Artemis 2,” he said. Sarafin said he and the rest of SLS leadership believe the test can achieve its main objectives without fully fueling the upper echelon. “Loading and draining the base stage is a big part of our test,” Charlie Blackwell-Thompson, the mission’s launch director, told a news briefing. “But we also test functions to make sure we can perform the count and implement the necessary launch day procedures on the day it is provided.” “We have to finish the test on Thursday and see the performance of the vehicle,” Blackwell-Thompson said. “The data will tell us how to proceed next.” Blevins did not want to speculate on what caused the valve to fail, but said it would be a simple solution if it needed to be replaced. Engineers will learn more after the test is completed on Thursday and the vehicle returns to the vehicle assembly building. The teams are currently aiming for a release date sometime between June 6 and 16, but said they may need to start looking at the next window, which is in July, based on where they are now.
