On Wednesday, NASA will attempt to send four astronauts around the moon on a mission called Artemis II. This will be second flight of NASA’s SLS rocket, and the first time the 20-year-old Orion capsule flies with people on board.

The trouble is that the heat shield on Orion blows chunks. Not in some figurative, pejorative sense, but in the sense that when NASA flew this exact mission in 2022, large pieces of material blew out of Orion’s heat shield during re-entry, leaving divots. Large bolts embedded in the heat shield also partially eroded and melted through.

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All of this was kind of preposterous. As the YouTuber Eager Space has pointed out, if a commercial crew capsule (SpaceX Dragon or Boeing Starliner) returned to Earth with the kind of damage seen on Orion, NASA would insist on a redesign and an unmanned test flight to validate it. But the agency does not hold its flagship program to the high standard it demands from commercial crew, even though the same astronaut lives are at stake.

Nor was it lost on observers that the tools and models NASA used to arrive at its new analysis were the same ones that had failed to predict the spalling problem in the first place. While the agency was able to work backwards from flight data to induce flaking in a test coupon of Avcoat, they had no way of predicting how the full-size heat shield would behave in the new flight conditions it would experience on Artemis II.

You don’t have to be a random space blogger to find all this fishy. The most energetic voice of public dissent has been heat shield expert and Shuttle astronaut Charles Camarda, the former Director of Engineering at Johnson Space Center. Aghast at what he saw as a repeat of the motivated reasoning that had led to the loss of Columbia and Challenger, Camarda began making noise both inside and outside the agency, believing that astronauts' lives were at stake.

In a show of openness, NASA invited Camarda and two journalists to attend a briefing on the heat shield in January of 2026, and gave him limited access to some research materials that have not been made public. But the experience only deepened Camarda’s distress, and he ended up publishing a cri de coeur that I encourage everyone to read in full.

Fascinating read.

Artemis II Is Not Safe to Fly (Idle Words)

(idlewords.com)