NASA's Artemis II Moon Mission Faces Reentry Challenges

Experts raise concerns over the Orion capsule's heat shield as the mission nears splashdown in the Pacific Ocean.

Apr. 9, 2026 at 10:00am

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A bold, abstract painting in muted earth tones, featuring sweeping geometric arcs, concentric circles, and precise botanical spirals, conveying the intricate scientific forces at play during the Artemis II mission's reentry.As the Artemis II mission nears its climactic reentry, NASA's engineers must navigate a complex web of scientific forces to ensure the safe return of the astronauts.San Diego Today

NASA's Artemis II moon mission is set to return to Earth on Friday, with the Orion capsule named Integrity scheduled to splash down in the Pacific Ocean off the coast of San Diego, California. However, the mission faces a critical challenge during the capsule's reentry into Earth's atmosphere, as the heat shield designed to protect the spacecraft and astronauts has raised concerns among experts.

Why it matters

Reentry is a crucial and perilous phase of any space mission, as the spacecraft must withstand extreme temperatures and forces as it plummets through the atmosphere. The Orion capsule's heat shield, made of a specialized material called AVCOAT, has been a point of contention, with some experts questioning the design and manufacturing process, even after issues were identified during the uncrewed Artemis I mission.

The details

The Orion capsule is expected to reenter Earth's atmosphere at a speed of nearly 24,000 miles per hour, with temperatures inside the crew cabin potentially reaching as high as 5,000 degrees Celsius. The heat shield is designed to protect the spacecraft by charring, melting, and ablating away, carrying excess heat with it. However, during the Artemis I mission, the heat shield cracked and shed more material than expected, prompting an investigation by NASA. While the agency adjusted the reentry trajectory for Artemis II to minimize the risk, some experts remain skeptical about the decision to not change the heat shield design, citing the known issues.

  • On Friday at approximately 8:07 P.M. EDT, the Orion capsule is due to splash down into the Pacific Ocean off the coast of San Diego, California.
  • The Orion capsule is projected to reenter Earth's atmosphere on Friday at approximately 7:45 P.M., traveling at nearly 24,000 miles per hour.

The players

Integrity

The Orion capsule that will be used for the Artemis II moon mission.

Reid Wiseman

One of the astronauts aboard the Artemis II mission.

Christina Koch

One of the astronauts aboard the Artemis II mission.

Victor Glover

One of the astronauts aboard the Artemis II mission.

Jeremy Hansen

One of the astronauts aboard the Artemis II mission.

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What they’re saying

“I am confident in the NASA approach and solution. It was a rigorous study using ground-based experimentation at representative pressures, temperatures, and—crucially—temperature ramp rates.”

— Jud Ready, Materials expert and executive director of the Space Research Institute at Georgia Institute of Technology

“This approach doesn't mitigate the flaws in the design and manufacture of the original heat shield itself. That change is an acknowledgement that there's a known risk to the current design and manufacturing method, in my opinion.”

— Ed Pope, Heat shield expert

“For me, this will be the most stressful part of the entire mission.”

— Jordan Bimm, Space historian at the University of Chicago

What’s next

After Integrity bleeds off most of its speed during reentry and is deeper in Earth's atmosphere, it will use its thrusters and, eventually, parachutes to slow down, reaching a stately 17 miles an hour. The entire process should take about 13 minutes, according to Artemis II entry flight director Rick Henfling.

The takeaway

The Artemis II mission's reentry challenges highlight the ongoing concerns about the Orion capsule's heat shield design and manufacturing, even after adjustments were made following the Artemis I mission. This critical phase of the mission will be closely watched, as the safety of the astronauts and the success of the overall mission depend on the heat shield's performance.