NASA says Orion’s heat shield is good to go for Artemis II—but does it matter?
Ars Technica 2024-12-05
Two years ago next week, NASA's Orion spacecraft splashed down in the Pacific Ocean to wrap up what, at first glance, seemed to be a highly successful unpiloted test flight that made a return to the Moon feel within reach.
The Orion capsule descended under parachutes, right on target near a US Navy recovery ship on December 11, 2022. In 25-and-a-half days, the Orion spacecraft entered the Moon's sphere of influence, flew within about 60 miles (100 kilometers) of the lunar surface, and, for the most part, worked as designed in deep space. On top of that, the rocket's launch vehicle, NASA's heavy-lift Space Launch System, also performed near-flawlessly on its first flight, known as Artemis I.
However, once NASA engineers got a closer look at the Orion spacecraft, their optimism faded. They saw cracks in the craft's heat shield and divots in the ablative thermal protection layer resembling potholes on a neglected street. This isn't what engineers expected, and they spent the next two years investigating the cause of the problem and determining whether it posed a safety risk for NASA's next Artemis mission, Artemis II. If the results weren't favorable, NASA might have to disassemble the Orion spacecraft, pushing back the flight a year or more beyond the Artemis II mission's already-delayed launch date.