Since concluding a wet dress rehearsal Feb. 3 ahead of Artemis II, technicians have replaced two seals in an area where operators saw higher than allowable hydrogen gas concentrations during the test. Engineers are analyzing the removed seals and developing plans to address all issues ahead of the next rehearsal.
Once the SLS (Space Launch System) rocket’s tanks were drained of cryogenic propellant following the previous test, technicians immediately began work to access the tail service mast umbilical on the mobile launcher and detach rocket and ground-side interface plates to inspect the area of the elevated gas levels, and replace seals around two fueling lines.
Two tail service masts, each about three stories tall, provide cryogenic propellant lines and electrical cable connections to the SLS core stage. The tail service masts tilt back before launch and include “quick disconnects,” mechanisms that instantaneously disconnect at liftoff to ensure a safe and reliable retraction at launch.
While teams continue evaluating the cause of the leak, reconnecting the interfaces is expected to be complete on Monday, Feb. 9. Testing is planned to occur at NASA’s Stennis Space Center in Bay St. Louis, Mississippi, to evaluate additional dynamics of the plates. Engineers are reviewing options to test the repair work prior to the next wet dress rehearsal to ensure the seals are performing as expected.
NASA also will update several operations for the next wet dress rehearsal to focus on fueling activities. The Orion crew module hatch will be closed prior to the test, and the closeout crew responsible on launch day for assisting the Artemis II crew into their seats and closing Orion’s two hatches will not be deployed to the launch pad. The crew access arm will not be retracted during the next rehearsal, after engineers successfully demonstrated the ground launch sequencer can retract it during the final phase of the countdown.
Additionally, NASA has added 30 minutes of extra time during each of two planned holds in the countdown before and after tanking operations to allow more time for troubleshooting, increasing the total time of the countdown by one hour. The additional time will not affect the crew’s timeline on launch day.
Since emerging from quarantine, NASA astronauts Reid Wiseman, Victor Glover, and Christina Koch, and CSA (Canadian Space Agency) astronaut Jeremy Hansen, have continued training activities, ensuring their familiarity with Orion spacecraft systems is second nature. The astronauts also have been reviewing the details of each flight day for the mission, bolstering their knowledge of test objectives planned during the flight.
While NASA continues to eye March as the next potential launch opportunity, the agency will not set a targeted launch date until after completing a successful wet dress rehearsal and reviewing the data.