WASHINGTON — An ongoing review of data from the Artemis 1 mission revealed no issues that would delay the crewed Artemis 2 mission, scheduled for launch late next year.
In a March 7 briefing, NASA managers said that analysis of data from the Space Launch System, Orion spacecraft and ground systems found only minor issues that could be addressed before Artemis 2.
The biggest problem, which had not been disclosed before, was the heat shield on the Orion crew capsule. Howard Hu, NASA’s Orion program manager, said the materials on the heat shield faded differently than engineers expected from ground tests and computer models.
“We had more freedom from the charred material during re-entry than we would have expected,” he said. Engineers are just beginning a detailed analysis of the heat shield to determine why it behaves differently than expected.
However, he said the difference in performance was not a safety issue. “We have quite a bit of margin remaining” in the form of untouched or “virgin” Avcoat, which is the traction material used in the heat shield. “I don’t think we’ve reached any limits. From a margin perspective, he’s certainly removed more from Avcoat than we expected.”
Hu said work is continuing on an issue with the Orion service module’s power system called the shutdown current limiter, which was opened without being asked more than twenty times during Artemis 1.
The European Space Agency and Airbus, the prime contractor for the service module, plan to conduct a test at the end of the month to better understand the causes of unwanted events, such as electromagnetic interference. If those tests don’t find a root cause, he said, controllers on Earth, or astronauts inside Orion, can continue to manually close the limiters on future missions. A software update can also fix the problem.
Ground systems engineers repair damage to the mobile launcher from the SLS launch. “There are some things that took more damage than we expected,” said Sean Quinn, who succeeded Mike Bolger as director of the Exploration Ground Systems program after the Artemis 1 mission.
This damage includes pneumatic lines corroded by remnants of the solid rocket boosters; He said that a problem with the gaseous nitrogen system delayed the supply of water to wash away the residue. The elevators on the mobile launch tower have also been decommissioned, but one is now back in service.
Some work after 11 December, notably the removal of avionics modules from the Artemis 1 Orion capsule for refurbishment and reinstallation on Artemis 2 Orion, was done ahead of schedule. This is unlikely to change the planned launch of Artemis 2, currently scheduled for late November 2024.
“I don’t think it helps us transition to it,” said Jim Frye, NASA’s associate administrator for Exploration Systems Development, of Artemis 2’s schedule. “We’ll definitely look for ways that we can build margin into our schedule. That’s how we look at it.”
That schedule anticipates shipping the SLS core stage from the Michôd Assembly Facility in New Orleans to Kennedy Space Center in June or July, said John Honeycutt, NASA SLS program manager, an “earlier” date when it is needed. Other SLS components are either at KSC or ready to ship when needed.
Hu said he expects the Orion crew module to mate with the service module in late June. Quinn said that by the first quarter of 2024 workers will begin stacking the compact SLS/Orion vehicle to support launch in late 2024.
Free said NASA still expects to launch the next mission, Artemis 3, about a year after Artemis 2, but noted that it will depend on the progress of other items, such as SpaceX’s lunar lander and new spacesuits in development by Axiom Space. . “Our plan has always been 12 months, but there are important developments that need to happen,” he said. “That’s just the nature of trying to land people on the moon.”
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