A Costly Lesson Learned: How NASA Fixed Orion‘s Heat Shield
NASA’s Artemis II moon mission will be a crucial step towards returning humans to the lunar surface, but the critical mission percolated unexpected hurdles during its lander.Earthly twin, the Artemis I uncrewed flight, provided essential data and revealed a hitch: foaming. Despite shielding, Orion’s heat shield suffered damage during its fiery descent through Earth’s atmosphere directly upstream of the craft bursts
The culprit? Not the intense heat as you might think. It was something called pyrolytic, generated when amaterial
NASA engineers had ensured the Orion spacecraft’s heat shield could withstand the most extreme reentry temperatures. The issue wasn’t burning off during reentry; it was during a period known as ‘skip dwell’.
"We have since determined that while the capsule was dipping in and out of the atmosphere, as part of that planned skip entry, heat accumulated inside the shield’s outer layer, leading to gases forming
"Pyrolysis is just burning without oxygen," said Amit Kshatriya, deputy associate administrator of NASA’s Grain to Mars
During skip dwell – a more complex maneuver to slow ORION during reentry of the gas produced by the superheated entry, to a problem no one expected during ground testing. concentrations of
"What we missed was this critical region in the middle," explained Kshatriya, noting. "We missed that region because we didn’t have the test facilities to produce those low-level energies wandering eduring skip
To avoid this during Artemis II, NASAAsn’t to limit the spacecraft’s time spent in the atmosphere.
How did NASA determine that pyrolysis, rather than extreme heat, was the cause of the foaming on Orion’s heat shield after re-entry?
A Costly Lesson Learned: How NASA Fixed Orion’s Heat Shield
**Interviewer:** Joining us today is Amit Kshatriya, deputy associate administrator of NASA’s Orion program. Welcome, Amit.
**Amit Kshatriya:** Thanks for having me.
**Interviewer:** Amit, the Artemis I mission was a groundbreaking success, but it wasn’t without its challenges. Can you tell us about the unexpected issue that arose with Orion’s heat shield?
**Amit Kshatriya:** Sure. During Artemis I, we noticed some foaming on Orion’s heat shield after re-entry. It turns out, this wasn’t caused by the extreme heat as we initially thought.
**Interviewer:** So what was the culprit?
**Amit Kshatriya:** It was a process called pyrolysis. Essentially, during a maneuver called skip dwell- where the capsule dips in and out of the atmosphere – heat builds up inside the heat shield’s outer layer. This heat causes gases to form, leading to the foaming we observed.
**Interviewer:** How could NASA have missed this during testing?
**Amit Kshatriya:** It’s tricky to perfectly simulate the conditions of atmospheric reentry on Earth. We simply didn’t have the test facilities capable of replicating the specific, low-level energy conditions that occur during skip dwell.
**Interviewer:** What steps are being taken to ensure this issue doesn’t jeopardize Artemis II, which will carry astronauts?
**Amit Kshatriya:** We’ve learned a valuable lesson. For Artemis II, we’ll be adjusting Orion’s trajectory to limit the amount of time it spends in the atmosphere during skip dwell. This will minimize the buildup of heat and prevent pyrolysis.
**Interviewer:** Some might argue that this highlights the inherent risks of space exploration. How do you respond to those concerns?
