Damage to Orion heat shield caused during re-entry in 2022,
including “cavities resulting from the loss of large chunks”

In a tweet yesterday afternoon, NASA administration Isaacman essentially endorsed the decision of the NASA managers and engineers in its Artemis program who decided they could live with the engineering issues of Orion’s heat shield (as shown in the image to the right) and fly the upcoming Artemis-2 mission around the Moon carrying four astronauts with that same heat shield design.

Isaacman’s statement however suggests to me that he is not looking at this issue as closely as he should.

Human spaceflight will always involve uncertainty. NASA’s standard engineering process is to identify it early, bound the risk through rigorous analysis and testing, and apply operational mitigations that preserve margin and protect the crew. That process works best when concerns are raised early and debated transparently.

I appreciate the willingness of participants to engage on this subject, including former NASA astronaut Danny Olivas, whose perspective reflects how serious technical questions can be addressed through data, analysis, testing, and decisions grounded in the best engineering judgment available. [emphasis mine]

The highlighted sentence is fundamentally wrong. Instead of recognizing that the unexpected damage to Orion’s heat shield after the 2022 Artemis-1 test flight around the moon made that heat shield unacceptable on the next flight, and immediately begin work on a new shield, NASA went dark, providing no information for two years. The agency realized that replacing the shield would cause a delay, and rather than fix the engineering it decided maintaining the Artemis program schedule was more important. Its subsequent actions since seem more designed to rationalize away the problem then deal with it, a conclusion that NASA’s own inspector general came to in 2024.

The agency’s lack of transparency was made very evident when Freedom of Information requests finally forced it to release the conclusions of its own engineering investigation, and it redacted every single word.. If Isaacman was so committed to transparency and truly believes NASA’s investigation was based on “the best engineering judgment available”, why doesn’t he release that report, unredacted? Has he even looked at it himself?

I and many others pray that the Orion crew comes home safe. Good engineering management however would never allow this mission to fly manned, considering the heat shield uncertainties as well as other issues (such as flying the capsule manned using an untested life support system). That NASA’s Artemis work force is willing to do this tells us the culture that killed the astronauts on Challenger and Columbia remains unchanged. They still put schedule above engineering, and are still willing to risk lives unnecessarily.

It also tells us that Isaacman appears unwilling to stand up to this culture and force it to change. If Orion comes home safe, that will only reinforce this unsafe culture, and future missions will thus be as unsafe and unreliable.