NASA Ends Dress Rehearsal with SLS Only Partially Loaded with Liquid Oxygen

NASA’s Space Launch System (SLS) rocket with the Orion spacecraft aboard is seen atop a mobile launcher as it rolls out to Launch Complex 39B for the first time, Thursday, March 17, 2022, at NASA’s Kennedy Space Center in Florida. Ahead of NASA’s Artemis I flight test, the fully stacked and integrated SLS rocket and Orion spacecraft will undergo a wet dress rehearsal at Launch Complex 39B to verify systems and practice countdown procedures for the first launch. (Credit: NASA/Aubrey Gemignani)

KENNEDY SPACE CENTER, Fla. (NASA PR) — The Artemis I team has ended today’s attempt at the wet dress rehearsal  test at 5 p.m. The countdown ended after partially loading liquid oxygen into the Space Launch System core stage tank. This provided the teams a valuable opportunity for training and to make sure modeled loading procedures were accurate. This was the first time using new systems at NASA’s Kennedy Space Center Launch Complex 39B. The team was able to monitor the Artemis I core stage as it was exposed to cryogenic liquids and gather data that will inform updates to propellant loading procedures.

After troubleshooting a temperature limit issue for the liquid oxygen, which delayed the countdown by several hours, the team successfully developed a new procedure for loading the liquid oxygen and filled the tank to 50 percent. Liquid oxygen is an extremely cold, or cryogenic, propellant that is maintained at minus 297 degrees Fahrenheit.

During chilldown of the lines in preparation for loading the liquid hydrogen, the teams encountered an issue with a panel on the mobile launcher that controls the core stage vent valve. The purpose of the vent valve is to relieve pressure from the core stage during tanking. Given the time to resolve the issue as teams were nearing the end of their shifts, the launch director made the call to stop the test for the day. A crew will investigate the issue at the pad, and the team will review range availability and the time needed to turn systems around before making a determination on the path forward.

The wet dress rehearsal is the last major test before launch. This test allows the team to practice propellant loading and thoroughly check out the Artemis I rocket systems as they are exposed to cryogenics.