NASA's Kennedy Space Center@NASAKennedyArtemis II Wet Dress Rehearsal: Entering Terminal Count at T-10 Minuteshttps://twitter.com/NASAKennedy/status/2018552808463647179Terminal count is designed to confirm that all systems can perform flawlessly under launch conditions, ensuring readiness for Artemis II – the first crewed mission of the Artemis campaign.
NSF - NASASpaceflight.com@NASASpaceflight·6sArtemis II WDR:Clock is ticking! Terminal Count!
NSF - NASASpaceflight.com@NASASpaceflightHOLD! They will have hit a snag (which is why they do these tests).They can only hold for around three minutes at this point.
The Artemis II wet dress rehearsal countdown was terminated at the T-5:15 minute mark due to a liquid hydrogen leak at the interface of the tail service mast umbilical, which had experienced high concentrations of liquid hydrogen earlier in the countdown, as well. The launch control team is working to ensure the SLS (Space Launch System) rocket is in a safe configuration and begin draining its tanks.
The launch control team is working to ensure the SLS (Space Launch System) rocket is in a safe configuration and begins draining its tanks.
NSF - NASASpaceflight.com@NASASpaceflight·1mArtemis II WDR scrubbed. Hydrogen leak during terminal count.NASA "The Artemis II wet dress rehearsal countdown was terminated at the T-5:15 minute mark due to a liquid hydrogen leak at the interface of the tail service mast umbilical, which had experienced high concentrations of liquid hydrogen earlier in the countdown, as well. The launch control team is working to ensure the SLS (Space Launch System) rocket is in a safe configuration and begin draining its tanks."
With the conclusion of the wet dress rehearsal today, we are moving off the February launch window and targeting March for the earliest possible launch of Artemis II.With more than three years between SLS launches, we fully anticipated encountering challenges. That is precisely why we conduct a wet dress rehearsal. These tests are designed to surface issues before flight and set up launch day with the highest probability of success.During the test, teams worked through a liquid hydrogen leak at a core stage interface during tanking, which required pauses to warm hardware and adjust propellant flow. All core stage and interim cryogenic propulsion stage tanks were successfully filled, and teams conducted a terminal countdown to about T-5 minutes before the ground launch sequencer halted operations due to an increased leak rate. Additional factors included extended Orion closeout work, intermittent ground audio dropouts, and cold-weather impacts to some cameras, along with the successful demonstration of updated Orion closeout purge procedures to support safe crew operations.As always, safety remains our top priority, for our astronauts, our workforce, our systems, and the public. As noted above, we will only launch when we believe we are as ready to undertake this historic mission.This is just the beginning. It marks the start of an Artemis program that will evolve to support repeated and affordable missions to the Moon, in line with President Trump’s national space policy. Getting this mission right means returning to the Moon to stay and a future to Artemis 100 and beyond.I want to thank the talented workforce at NASA, along with our industry and international partners, who are working tirelessly on this effort. The team will fully review the data, troubleshoot each issue encountered during WDR, make the necessary repairs, and return to testing. We expect to conduct an additional wet dress rehearsal and then target the March window.We will continue to keep the public and the media informed as readiness progresses.
NASA concluded a wet dress rehearsal for the agency’s Artemis II test flight early Tuesday morning, successfully loading cryogenic propellant into the SLS (Space Launch System) tanks, sending a team out to the launch pad to closeout Orion, and safely draining the rocket. The wet dress rehearsal was a prelaunch test to fuel the rocket, designed to identify any issues and resolve them before attempting a launch. Engineers pushed through several challenges during the two-day test and met many of the planned objectives. To allow teams to review data and conduct a second wet dress rehearsal, NASA now will target March as the earliest possible launch opportunity for the flight test.Moving off a February launch window also means the Artemis II astronauts will be released from quarantine, which they entered in Houston on Jan. 21. As a result, they will not travel to NASA’s Kennedy Space Center in Florida Tuesday as tentatively planned. Crew will enter quarantine again about two weeks out from the next targeted launch opportunity.NASA began the approximately 49-hour countdown at 8:13 p.m. EST on Jan. 31. Leading up to, and throughout tanking operations on Feb. 2, engineers monitored how cold weather at Kennedy impacted systems and put procedures in place to keep hardware safe. Cold temperatures caused a late start to tanking operations, as it took time to bring some interfaces to acceptable temperatures before propellant loading operations began. During tanking, engineers spent several hours troubleshooting a liquid hydrogen leak in an interface used to route the cryogenic propellant into the rocket’s core stage, putting them behind in the countdown. Attempts to resolve the issue involved stopping the flow of liquid hydrogen into the core stage, allowing the interface to warm up for the seals to reseat, and adjusting the flow of the propellant. Teams successfully filled all tanks in both the core stage and interim cryogenic propulsion stage before a team of five was sent to the launch pad to finish Orion closeout operations. Engineers conducted a first run at terminal countdown operations during the test, counting down to approximately 5 minutes left in the countdown, before the ground launch sequencer automatically stopped the countdown due to a spike in the liquid hydrogen leak rate.In addition to the liquid hydrogen leak, a valve associated with Orion crew module hatch pressurization, which recently was replaced, required retorquing, and closeout operations took longer than planned. Cold weather that affected several cameras and other equipment didn’t impede wet dress rehearsal activities, but would have required additional attention on launch day. Finally, engineers have been troubleshooting dropouts of audio communication channels across ground teams in the past few weeks leading up to the test. Several dropouts reoccurred during the wet dress rehearsal. The team carried out updated procedures to purge the Orion service module’s cavities with breathing air during closeout crew operations rather than gaseous nitrogen to ensure the team assisting the crew into their seats and closing Orion’s hatches can safely operate in the White Room.With March as the potential launch window, teams will fully review data from the test, mitigate each issue, and return to testing ahead of setting an official target launch date.Crew safety will remain the highest priority, ensuring NASA astronauts Reid Wiseman, Victor Glover, and Christina Koch, and CSA (Canadian Space Agency) astronaut Jeremy Hansen, return home at the end of their mission.In addition to a statement from NASA Administrator Jared Isaacman released Tuesday, agency leaders will discuss initial results from the wet dress rehearsal during a news conference at 1 p.m. on Tuesday. Previously, NASA was targeting the news conference to begin at 12 p.m. The agency will stream the news conference live on its YouTube channel.
NASA@NASANASA completed a wet dress rehearsal for the Artemis II mission in the early morning hours on Feb. 3. To allow teams to review data and conduct a second wet dress rehearsal, NASA will now target March as the the earliest possible launch opportunity for the Artemis II mission.
Following the conclusion of the Artemis II wet dress rehearsal, tune in as agency leaders provide updates on the test and our Artemis II mission around the Moon.Participants will include: • Amit Kshatriya, NASA Associate Administrator • Lori Glaze, acting associate administrator for NASA's Exploration Systems Development Mission Directorate • Shawn Quinn, program manager, Exploration Ground Systems • John Honeycutt, chair, Artemis II Mission Management Team Engineers pushed through several challenges during the two-day test and met many of the planned objectives. To allow teams to review data and conduct a second wet dress rehearsal, NASA now will target March as the earliest possible launch opportunity for the flight test.
