NASA is working toward three launch dates for Artemis 1, an uncrewed test flight around the moon that serves as a testbed for future human missions: August 29, September 2 and September 5. Those dates are pending repairs and modifications, however, to the Space Launch System rocket and related systems in light of results from a June 20 “wet dressing test” that NASA declared a success, officials said in a media conference call on Wednesday (July 20). “It’s not an agency commitment,” Jim Free, NASA’s associate administrator for exploration systems, said of the interim launch dates. NASA will announce a more firm commitment about a week before launch, he said, when the agency completes its standard flight-readiness inspection of the Artemis 1 stack, including SLS and the Orion capsule that sits atop the rocket. However, the interim dates of late August and early September are what “the team is working on and has a plan for,” Free added. “But [we have] there’s a lot of work left to do and probably learn, including close games.” The shutdowns are interim approvals for key systems needed for launch, flight to the moon and return for a launch to Earth. NASA has a checklist of items to perform on the SLS stack before it leaves the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, where work continues to address problems encountered during the wet dress rehearsal. Artemis 1’s most recent wet dress rehearsal has been deemed good enough by NASA to proceed with launch preparations. Engineers fully powered the SLS for the first time during the three-day test. But the team encountered a hydrogen leak from the base stage engine cooling system “umbilical” line. During the test, the leak was resolved by closing a bleed valve in the hydrogen flow path. This solution allowed the team to complete the wet dress, but it would not work during an actual launch because closing the bleed valve leaves the engine’s thermal systems without proper regulation. (Operators ran a software “mask” during the test to allow the countdown to continue while letting the ground-based launch sequencer system flag the temperature variation as it is designed to do.) This was followed by a return to VAB on 2 July for maintenance, including repairs to the quick disconnect fitting in the SLS aft umbilical responsible for the hydrogen leak. Technicians also perform vehicle inspections, repair hydrogen leaks, replace seals on the main stage, install flight batteries, stack payloads and perform power tests on Orion, and perform software uploads to the SLS base and upper stages. NASA officials said during the call Wednesday that they are making good progress on those repairs, but are proceeding cautiously to make sure Artemis 1 is ready before they let it leave the building. Personnel have already replaced a navigation and control assembly unit and are testing batteries and testing the cryogenic propulsion intermediate stage that will give the Orion capsule a kick toward the moon during its mission. Artemis 1 must pass a rigorous set of operational maintenance requirements “to say the vehicle is ready,” said Cliff Lanham, senior director of vehicle operations for NASA’s Ground Systems Exploration Program. Only when the SLS stack completes these tests inside the VAB will it be authorized to move to the pad, which could happen as soon as August 18 if all goes well. While the entire set of tests is long, some key ones the agency is tracking include tests of the SLS’s flight termination system, the rocket’s engine section, the rocket core’s front apron that houses flight computers and electronics, and the Orion spacecraft. The three launch attempts each feature a different mission duration and launch schedule, NASA officials said. The August 29 launch opportunity will open at 8:33 AM. EDT (1333 GMT) and would last two hours. Assuming Artemis 1 launches successfully, the Orion capsule would return to Earth after 42 days for a splashdown on October 10. September 2 offers a two-hour launch window that opens at 12:48 p.m. EDT (1748 GMT). In this scenario, Artemis 1 would return 39 days later, on October 11. The final opportunity, on September 5, includes a 1.5-hour launch window beginning at 5:12 p.m. EDT (2212 GMT) and will see Artemis 1 return 42 days later on October 17. As a backup, the agency has identified several intermediate launch opportunities through mid-2023, in case weather or technical issues delay Artemis 1. NASA discussed the progress of Artemis 1 on the 53rd anniversary of the Apollo 11 landing in 1969 that saw the first human steps on the moon. The agency hopes to return humans there around 2025, pending the results of Artemis 1 and a crewed orbital mission, Artemis 2, due to launch no earlier than 2024. Follow Elizabeth Howell on Twitter @howellspace (opens in new tab). Follow us on Twitter @Spacedotcom (opens in a new tab) or Facebook (opens in a new tab).
