idlewordsArtemis II is not safe to fly
https://idlewords.com/2026/03/artemis_ii_is_not_safe_to_fly.htm
> “Our test facilities can’t reach the combination of heat flux, pressure, shear stresses, etc., that an actual reentering spacecraft does. We’re always having to wait for the flight test to get the final certification that our system is good to go.”—Jeremy VanderKam, deputy manager for Orion’s heat shield, speaking in 2022
This is a strange claim, considering NASA used to have 2 facilities that were capable of this - one at Johnson and one at Ames. They were consolidated (https://ntrs.nasa.gov/api/citations/20160001258/downloads/20...) but it seems like the Arc Jet Complex at Ames is still operational https://www.nasa.gov/ames/arcjet-complex/
The Orion heat shield is sixteen feet across. NASA's test facilities can only test small material samples in these facilities, not capture how the entire heat shield will behave.
How does SpaceX test it? Have they needed to solve this problem?
By having a much higher launch cadence and then analyzing the flight hardware afterwards.
Also, they don't have anything human rated going beyond LEO. Coming back from the moon means you're going significantly faster and thus need a better heat shield