The astronauts who flew around the moon and back in NASA’s landmark Artemis II mission said their re-entry into Earth’s atmosphere was smooth, but the mission’s commander described some charring on the Orion capsule’s critical heat shield.
The four Artemis II astronauts splashed down in the Pacific Ocean last Friday, capping a nearly 10-day test flight in which they reached the farthest distance in space any humans have gone before as their gumdrop-shaped Orion capsule sailed around the moon’s far side.
Speeding back into Earth’s atmosphere at roughly 32 times the speed of sound, the finale of the high-stakes mission was a crucial test of the Lockheed Martin-built Orion capsule before NASA plans to use it again for another pre-lunar landing flight in Earth’s orbit next year.
“We came in fast, and we came in hot,” Artemis II mission commander Reid Wiseman told reporters in the crew’s first press conference since returning to Earth.
In the months following the flight, NASA engineers will comb through hoards of data illustrating how well the Orion vehicle performed.
They are likely to pay close attention to the capsule’s heat shield, a critical barrier that protects the crew from temperatures of up to 5,000 degrees Fahrenheit (2,760 degrees Celsius) during the descent from space.
In the 2022 Artemis I uncrewed mission, Orion’s heat shield sustained far more damage than NASA had expected, showing small cracks and some layers charred off by its re-entry, leading to an intense two-year investigation.
NASA did not upgrade the heat shield, but it changed the angle and trajectory in which the Artemis II crew entered Earth’s atmosphere to reduce heat.
Wiseman said he and mission pilot Victor Glover “maybe saw two moments of a touch of char loss” during re-entry.
When they examined the capsule on the naval ship that recovered them from the ocean, Wiseman said he saw “a little bit of char loss on what’s called the shoulder,” referring to the edge of the heat shield.
Falling at least 32 times the speed of sound
Photos of the capsule after the Artemis II crew’s return showed an unusual white mark on the edge of the heat shield, but NASA Administrator Jared Isaacman downplayed concerns and said it had behaved similarly in high-heat ground testing.
“No chunks missing,” Isaacman told Reuters on Monday, saying he has seen underwater photos of the heat shield bobbing in the ocean shortly after splashdown.
“The heat shield performed as expected, and I’m thrilled, because now we’re done with this thing.”
Glover described the crew’s re-entry as “a very intense 13 minutes and 36 seconds.”
NASA officials at the time said the crew’s maximum speed at re-entry was 24,664 mph (39,692 kph), or roughly Mach 32, 130 mph short of the Apollo 10 record reached in 1969 for the fastest humans have ever travelled.
But Glover on Thursday told reporters Orion’s onboard screens showed they reached speeds of Mach 38.89, or 29,839 miles per hour.
He added that NASA might release a new number “when we figure it out” because it is challenging to measure speeds in space.
After the atmospheric friction slowed their speed, an initial set of parachutes slowed them further once they entered Earth’s lower atmosphere before detaching ahead of a final set of chutes that carried them to a gentle 17 mph on the ocean surface.
When the initial parachute set cut away, Glover said, “We went back to free fall… I’ve never been BASE jumping, I’ve never been skydiving, but if you dove off a skyscraper backwards, that’s what it felt like.”
While Orion is the capsule that sends humans to and from space, launching off Earth on the agency’s Space Launch System rocket, a future crew will use the capsule to dock with moon landers built by Elon Musk’s SpaceX and Jeff Bezos’ Blue Origin that will land them on the moon as soon as 2028, though engineering challenges with both landers could push that date back.
Those landers will be tested in Earth’s orbit for the first time in the Artemis III mission planned for next year.
In his personal opinion, Wiseman said, “They could put the Artemis III Orion on the Space Launch System tomorrow and launch it and the crew would be in great shape.”
