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NASA working through issues ahead of Artemis II

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A report from the NASA Office of Inspector General (OIG) provides new insight into the heat shield and power problems that bedeviled its Orion capsule in the uncrewed Artemis I mission and delayed the agency's first crewed mission to the Moon in more than half a century.

Artemis I was finally launched as 2022 came to a close and was a significant achievement for NASA. The monster rocket had been monstrously delayed, but the launch, which suffered a number of setbacks, including a hydrogen leak on the pad, appeared to go off without a hitch.

However, there were issues. Even to the eye of an untrained observer, the launch tower appeared to have taken quite a beating as the SLS left the pad. The Orion capsule also encountered power issues during its mission, and NASA admitted that there were some problems with the spacecraft's heat shield during entry into the Earth's atmosphere, which merited further investigation before astronauts could ride the rocket to the Moon.

In a section entitled "Orion Anomalies Pose Significant Safety Risks to the Crew," the OIG's report details the problems that cropped up during the mission.

The first is the heat shield, in which NASA has identified over 100 locations where bits of ablative material chipped away unexpectedly during reentry. While the shield would have protected the crew and capsule from the heat of reentry, it didn't melt as expected. Instead, a trail of fragments was left as portions of the shield cracked and broke away.

The fragments didn't impact the crew module or cause damage to the parachute mechanisms, but according to the OIG: "Should the same issue occur on future Artemis missions, it could lead to the loss of the vehicle or crew."

"Unexpected behavior" are two words an astronaut never wants to hear when discussing a component on which their life depends.

The issue has proven challenging to recreate. Due to the greater distances involved, Orion's velocity is, according to the OIG, approximately 40 percent faster than that of a SpaceX Crew Dragon. However, engineers expect to come up with answers in the first half of 2024.

Other problems included melting and erosion of the separation bolts used to attach the crew module to the service module and "uncommanded power disruption" during the mission. The latter, according to the OIG, "are similar to a circuit breaker tripping in a home's electrical panel."

NASA wasn't expecting either scenario but has determined that radiation was the root cause of the power disruption. A hardware fix won't be ready in time for Artemis II, but the flight software has been tweaked, and the Orion team trained to deal with it.

The bolt problem, however, is trickier to deal with. The bolts are supposed to remain flush with the heat shield following separation from the service module. However, on Artemis I, three of the four bolts "experienced an exposed gap that allowed for increased heating." The prospect of hot gas getting behind the heat shield is a nightmarish scenario, and pending a redesign of the separation bolt, NASA intends to add additional protective material and possibly change the reentry trajectory to reduce heating on the bolts.

Finally, the Mobile Launcher 1 (ML-1) required more than five times the expected $5 million to repair the damage caused by the launch. Tubing, electrical equipment, panel doors, and elevators all needed to be repaired. Getting both elevators up and running again took approximately four months due to bent elevator car tracks.

The OIG said: "According to an Agency official, going into the Artemis I mission it was not known that the elevator 'blast doors' were not in fact blast doors but rather fiberglass doors."

Still, some comfort can be drawn from the fact that while there was a risk of bits of the ML-1 damaging the SLS during the first launch, it could have been much, much worse. The first Starship launch resulted in chunks of concrete from the launch platform being spread over a wide area.

NASA pushed Artemis II back to September 2025 to give itself more time to understand the issues that arose during the Artemis I mission, a decision applauded by the OIG. However, the clock is ticking. China launched its Chang'e 6 sample return mission to the far side of the Moon on May 3, and NASA is still proclaiming 2026 as the year in which Artemis III will launch and return astronauts to the Moon.

There is, however, a US election between now and then. ®

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