NASA scrubbed the “wet dress rehearsal” of its gigantic Space Launch System (SLS) rocket for the third time. In a mission update shared recently, the agency revealed that the test was halted after engineers found a leak of liquid hydrogen (LH2) from the base of the rocket's mobile launcher which connects to its core stage. NASA informed that the leak was discovered during liquid hydrogen loading operations and the mishap prevented the team from completing the test.

The SLS rocket is being tested for the first Artemis mission which is scheduled to take off later this year. As for the halted operations, NASA stated that the teams met their objectives for the interim cryogenic propulsion stage by chilling down the lines used to load propellant into the upper stage. However, they did not take the risk of passing any propellant to the stage owing to a malfunction in a helium check valve identified several days ago.

"When teams paused propellant loading, the rocket’s core stage liquid oxygen tank was about 49% filled and the liquid hydrogen tank had been loaded to about 5% capacity prior to the hydrogen leak. Teams are now working to drain propellant from the rocket. They will inspect the umbilical connection, review data, and establish a go-forward plan to address the hydrogen leak", the agency informed.

Under these rehearsals, engineers are testing the rocket before launching it for the uncrewed Artemis-I mission. NASA would fill the tanks of the SLS rocket with propellants, and its engines would be fired to conduct a full launch countdown at Launch Pad 39B at NASA’s Kennedy Space Centre. The tanks will be loaded with a whopping 7,00,000 gallons of cryogenic, or super cold, propellants, including liquid hydrogen and liquid oxygen. Initially planned to last for just two days, the tests have far exceeded their deadline. As for Artemis I, the mission will certainly be delayed due to these technical faults from its scheduled launch in May.