PBS NOVA

How Artemis II Re-Entry Differed From Artemis I

NASA concluded that the heat‑shield damage on Artemis I was not a design flaw but a consequence of the skip‑entry trajectory used to shed lunar return velocity. After a two‑year forensic review, engineers found that the first atmospheric dip trapped pockets of gas inside the ablative shield; on the second dip those gases expanded, cracking the tiles and shedding fragments. The phenomenon was traced to the lift‑generated “skip” maneuver, which deliberately re‑enters, exits, then re‑enters the atmosphere. Mission officials described the maneuver as “a technique we use coming back from the moon because the velocity is much greater than coming back from low Earth orbit.” They contrasted it with the new plan: a straight, steeper ballistic trajectory—“as if the capsule has been fired like a bullet”—that avoids a second atmospheric pass. By retaining the proven heat‑shield architecture and abandoning the skip profile, Artemis II reduces thermal‑stress risk while preserving schedule. The change signals NASA’s cautious approach to crewed lunar return safety and may influence re‑entry strategies for future deep‑space missions.