Orion crew safely back on Earth following historic lunar flyby

NASA’s Orion spacecraft and its four-member crew emerged from a harrowing six-minute communications blackout Friday evening as the capsule exceeded 25,000 mph and 5,000-degree temperatures while hurtling through Earth’s atmosphere on its way to a successful splashdown in the Pacific Ocean off the coast of San Diego just after 6 p.m. MDT.

Massive parachutes slowed the capsule down to about 17 mph before entering the water as Navy ships and aircraft raced to the landing site to assist the astronauts who traveled nearly 700,000 miles on their 10-day mission which took them on a journey that included a record-setting lunar flyby on Monday.

While an initial February launch date was delayed by a string of issues including hydrogen leaks and problems with the rocket booster’s pressurization systems, Artemis II blasted off April 1 from Kennedy Space Center in Cape Canaveral, Florida. Except for some minor glitches, it completed all of its major goals. Those included setting a new distance record for human space travel on a route that took the crew past the moon, over 252,000 miles from Earth. That mark surpassed the previous record, set by the Apollo 13 mission in 1970, by over 4,000 miles. The crew traveled nearly 700,000 total miles on its journey.

The successful splashdown marks the end of the second mission of the Artemis program, a NASA effort aiming to ratchet up the frequency of manned space missions with even bigger goals than a lunar landing on the long-term horizon.

Artemis II began its mission just weeks after new NASA administrator Jared Isaacman announced accelerated plans, fueled by a $20 billion budget over the next seven years, to build a lunar base near the moon’s south pole. The revised strategy aims to launch two moon missions a year to accelerate the moon base construction and set the table for a future manned mission to Mars.

“This revised, step-by-step approach to learn, to build muscle memory, to bring down risk and gain confidence is exactly how NASA achieved the near impossible in the 1960s,” he said in a late March announcement, referring to the agency’s Apollo program. “But this time, the goal is not flags and footprints. This time, the goal is to stay.”

Before a crew heads to the moon for a surface landing attempt in 2028, however, a mission planned for next year aims to test out the process of docking the Orion capsule with lunar landers currently being developed in separate competitive tracks by SpaceX and Blue Origin.

A historic crew for a historic mission

The Artemis II crew was composed of three NASA astronauts including mission commander Reid Wiseman, pilot Victor Glover and mission specialist Christina Koch as well as mission specialist Jeremy Hansen from the Canadian Space Agency. The team trained for almost three years for the mission and looks quite different from the astronaut corps of the Apollo program, which was composed of white, male test pilots recruited from U.S. military branches.

The Artemis II crew, collectively, represents the first woman, first person of color and first non-American to travel to the moon.

Koch already holds the record for the longest single spaceflight by a woman, according to an Associated Press report. During her 328-day mission at the International Space Station spanning 2019 and 2020, she took part in the first all-female spacewalk.

Glover, a Navy test pilot, was the first Black astronaut to live and work aboard the space station in 2020 and 2021, per AP. He also was one of the first astronauts to launch with SpaceX.

The Canadian Space Agency’s Hansen, a former fighter pilot, is the lone space rookie. Artemis II mission commander Wiseman is a retired Navy captain who lived aboard the space station in 2014 and later headed NASA’s astronaut corps. They range in age from 47 to 50.

Orion heat shield performance was a lingering question

While Orion’s return went off without a hitch, some experts raised questions ahead of the mission’s final phase about the capsule’s readiness for its fiery reentry into Earth’s atmosphere.

Surprisingly, perhaps, the heat protection material deployed to keep Orion and its crew safe during the critical reentry phase has not changed much from the days of the Apollo program.

Orion’s heat shield is made of Avcoat, a mixture of silica, epoxy and resins that was also used for the original Apollo lunar missions, according to a report from Scientific American. Avcoat is designed to degrade when exposed to extreme temperatures, carrying the heat away from space vehicles as it chars and flakes away. While the Apollo-era heat shields were composed of thousands of small cells of Avcoat, Orion is protected by some 200 large tiles of the material.

In its only real world shakedown, an unmanned test flight in 2022, Orion’s heat shield kept the interior of the capsule within an acceptable temperature range but the degradation of the protective material was much more extreme than expected. On inspection after the capsule’s return, NASA engineers found large chunks of the Avcoat tiles had broken off amid the heat and friction of reentry conditions.

While the level of damage experienced in the Artemis I flight was unexpected, NASA said it had devised a solution that would reduce the wear and tear on the heat protection and keep Orion’s crew safe. That fix wasn’t about making modifications to the heat shield itself but instead altering the space capsule’s reentry trajectory on Friday, opting for a steeper angle that led to higher heat levels but reduced the amount of time Orion and its crew spent while enduring the most intense atmospheric resistance of the journey.

Some scientists, however, had shared concerns over NASA’s solution to the heat shield issue for the Artemis II mission.

Heat shield expert Ed Pope said the design of Orion’s heat protection is problematic and NASA is moving forward in spite of acknowledged risk factors.

“This approach doesn’t mitigate the flaws in the design and manufacture of the original heat shield itself,” he told Scientific American earlier this week. He pointed out that the agency is using a different heat shield design and yet another formulation of Avcoat for the next Artemis mission, currently scheduled for mid-2027. “That change is an acknowledgement that there’s a known risk to the current design and manufacturing method, in my opinion,” Pope said.