Following an try earlier this month, NASA is now focusing on Thursday for the ultimate fueling check and simulated launch countdown of the Artemis 2 mission.
The Artemis 2 Area Launch System (SLS) rocket and Orion spacecraft at NASA’s Kennedy Area Heart in Florida on Feb. 1, moments after the countdown started for the mission’s first moist costume rehearsal. Credit score: NASA/John Kraus
After points with a liquid hydrogen leak thwarted an try earlier this month, NASA is focusing on Thursday, Feb. 19, for a second Artemis 2 moist costume rehearsal tanking day.
Artemis 2 represents humanity’s return to the Moon for the primary time in additional than 50 years, however it could actually’t depart the bottom till it passes one last hurdle — a moist costume rehearsal.
The upcoming moist costume rehearsal try follows a number of days of testing and repairs. After the preliminary moist costume rehearsal on Feb. 3, technicians changed two seals close to the “tail service mast umbilical” — the three-story construction that connects fueling traces to the rocket — the place the leaking hydrogen was detected.
To confirm these fixes, NASA performed a partial fueling on Feb. 12. Whereas the brand new seals carried out as anticipated, a separate situation emerged when a filter within the ground-side tools restricted the circulation of liquid hydrogen. Engineers changed that filter and ready the techniques for this second full-scale rehearsal.
Whereas the first fueling actions happen on Thursday, the official countdown begins tonight at 6:40 p.m. EST. Launch controllers will arrive at Kennedy Area Heart to start the two-day countdown sequence main as much as a simulated launch time of 8:30 p.m. on Feb. 19.
NASA won’t schedule a particular launch date till the outcomes of the second moist costume rehearsal are clear, however the earliest out there launch window opens on March 6.
Moist costume rehearsals are the ultimate check earlier than a launch takes place. For Artemis 2, engineers will load the roughly 700,000 gallons of cryogenic liquid gas into the SLS rocket and simulate a full launch countdown, working via a number of potential launch situations, like holding or recycling the countdown clock. Though the astronauts won’t be on board, a specialised floor workforce can be on the pad to follow the precise steps for sealing the Orion spacecraft’s hatches.
The second try will observe a lot of the identical script as the primary. The workforce will try two runs via the ultimate ten minutes earlier than launch, a window referred to as the terminal countdown. They may pause the depend at T-1 minute and 30 seconds, maintain the countdown for as much as three minutes, then resume the countdown earlier than holding it once more at T-33 seconds. Then, operators will recycle the countdown again to T-10 minutes and run via the terminal countdown one final time earlier than emptying the gas tanks and wrapping up the check.
Not solely does a moist costume rehearsal permit the workforce to follow for real-world situations that might impede the launch, however they could additionally must cease the countdown to troubleshoot any points that come up in actual time.
Throughout the first Artemis 2 moist costume rehearsal, unexpected points with leaking liquid hydrogen led to unplanned holds and the eventual termination of the check. Whereas engineers initially managed to troubleshoot the temperamental gas line by permitting {hardware} interfaces to heat up and reseat the seals, the leak recurred. A spike in gas ranges recorded on the T-5 minute 15-second mark compelled officers to wash the rest of the rehearsal earlier than they may display the deliberate recycles or transition the rocket to its personal inner energy. Assembly these incomplete goals is now a excessive precedence for the upcoming check on Feb. 19.
