Since returning to the spacecraft assembly building (VAB) at the Kennedy Space Center in Florida, NASA's ground systems team has been working hard to prepare the Artemis I space launch system (SLS) rocket and Orion spacecraft to return to launch pad 39B at the end of May and complete the "wet rehearsal" (WDR) test from early June to mid June**
In the VAB at NASA's Kennedy Space Center, engineers replaced a faulty helium check valve on the temporary cryogenic propulsion stage (ICPs), which was found after the second wet rehearsal attempt. The engineers checked the valve and found that a small piece of rubber prevented the valve from sealing correctly. The team is looking for possible sources of debris, but did not find any problems with the valve itself, and plans to test the newly installed valve later this week to confirm that it operates as expected.
Engineers also conducted tests to solve the problem of hydrogen leakage in one of the umbilical cords of the two tail service masts between the mobile launcher and the rocket. These umbilical cords provide liquid oxygen and liquid hydrogen propellants, as well as electrical connections, from the mobile launcher to the core stage of the rocket during the launch countdown. The team checked all joints for leakage and tightened several flange bolts or fasteners used as washers to increase compressive strength. These bolts will loosen over time and are the most likely source of leakage. The team re tightened the flange bolts of the umbilical between the liquid hydrogen, liquid oxygen and the core level fuel tank. The engineers found no leakage in the subsequent ambient air temperature test and will continue to monitor the leakage when loading supercooled propellant on the launch pad.
Suppliers providing gaseous nitrogen for operations during canning are upgrading their facilities to meet the requirements of the next wet rehearsal attempt and Artemis I launch. The team is completing this work as planned early next week, followed by testing to ensure that the system is ready for canning. During testing, the team pumped gaseous nitrogen into the dry structure to protect avionics during propellant loading.
Once all the main work is completed, the team will take back the work platform and prepare for the second journey to the launch pad for the integrated SLS rocket and Orion spacecraft. Once the work in VAB is nearing completion, NASA will announce the date of going to the launch pad and the next WDR attempt.