Weather delays Artemis 2 wet dress rehearsal

ORLANDO, Fla. — NASA is delaying a key fueling test for the Artemis 2 mission because of weather, reducing the chances the launch can take place during its February window.

The agency said in a Jan. 30 statement that it was postponing the wet dress rehearsal, or WDR, scheduled for Jan. 31. During the WDR, the Space Launch System is loaded with liquid oxygen and liquid hydrogen propellants and proceeds through a practice countdown that stops at T-minus 29 seconds.

NASA said it delayed the test by 48 hours because forecasts call for low temperatures and high winds at Kennedy Space Center. Launch criteria prohibit tanking the Space Launch System if the average temperature at the launch pad over the previous 24 hours is below 5.2 degrees Celsius. A launch is prohibited if temperatures fall within a range of 3.3 to 9.4 degrees Celsius, depending on winds and humidity, for at least 30 minutes. Wind limits range from 53.7 to 72.2 kilometers per hour, depending on altitude.

The National Weather Service has forecast subfreezing temperatures and gusty winds for the Cape Canaveral area Jan. 31, with cold conditions expected to continue Feb. 1 and possibly Feb. 2, prompting NASA to delay the WDR.

“We like to test like we fly, and frankly, the conditions for this weekend were something we would never launch in,” Casey Swails, NASA deputy associate administrator, said during a speech at the SpaceCom Expo here Jan. 30.

The delay reduces the number of launch opportunities for Artemis 2 in February. While the February launch period opens Feb. 6, NASA said launch windows on Feb. 6 and 7 are no longer available because of the time required to review WDR data and prepare for launch.

The earliest remaining launch opportunity is Feb. 8, with a two-hour window opening at 11:20 p.m. Eastern. Two additional two-hour windows are available Feb. 10 starting at 12:06 a.m. Eastern and Feb. 11 starting at 1:05 a.m. Eastern. After that, the next launch opportunity will not occur until March 6.

NASA will not set a launch date until after completing the WDR. “You need to get through wet dress, and then you need to get through the FRR [flight readiness review] and give everybody some time to rest,” NASA Administrator Jared Isaacman said in a Jan. 30 interview with SpaceNews.

Isaacman declined to estimate the likelihood of a February launch, saying that assessment would come after the WDR and subsequent reviews. “Then we’ll know what our true probabilities of success are in February,” he said. “But we have less of a window now than we did before.”

Artemis 2 has been a top priority for Isaacman since he became administrator in mid-December. That has included a review of heat shield data after Artemis 1 experienced greater-than-expected erosion of its heat shield. Isaacman agreed with NASA’s earlier conclusion that the Artemis 2 heat shield is safe to fly with mitigations, including changes to the spacecraft’s reentry trajectory.

“I was very impressed with how the team was progressing toward wet dress and how energized and motivated the team is,” he said. “Unfortunately, the information we need to make the call is slipping to the right, and that eats into the window. The probabilities of hitting the February window have gone down.”

Artemis 2 scheduling also affects Crew-12, the next mission to the International Space Station. Crew-12 was scheduled to launch no earlier than Feb. 15, but NASA announced Jan. 28 that it was moving the launch up to as soon as Feb. 11 to reduce the period in which the station would have a three-person crew following the early return of Crew-11 earlier this month.

The actual Crew-12 launch date will depend on Artemis 2. During a Jan. 30 briefing, Steve Stich, NASA’s commercial crew program manager, said that if Artemis 2 launches during the February window, NASA would wait until after the conclusion of the approximately 10-day mission before launching Crew-12. If Artemis 2 launches Feb. 8, that would place the earliest possible Crew-12 launch on Feb. 19.

If NASA attempts an Artemis 2 launch Feb. 8 but scrubs it, Crew-12 would be scheduled for no earlier than Feb. 13, assuming no additional Artemis 2 launch attempts before the February window closes, Stich said.

Operational conflicts include the use of suit-up rooms for crews and the availability of rescue forces from the Defense Department’s Detachment 3, which would be positioned in different locations for the two missions.

Another constraint is communications, particularly use of the Tracking and Data Relay Satellite network. “Artemis does utilize the TDRS communication assets not only for on-pad operations but also with Orion in the early part of the mission,” Stich said. While Orion later transitions to the Deep Space Network, he said NASA would still need to deconflict communications to ensure beams do not overlap with Crew-12 operations.