Orion is set to pierce through Earth’s atmosphere at speeds exceeding 30 times that of sound, signifying what NASA expects to be the most formidable segment of the Artemis II lunar mission. On the landing day, Artemis II entry flight director Rick Henfling and his mission control team will supervise the concluding stage of the 10-day space journey. Once awake, controllers will brief the four astronauts — Commander Reid Wiseman, pilot Victor Glover, Christina Koch, and Jeremy Hansen — on the weather conditions at the splashdown location, subsequently permitting them to secure loose items and don their pressure suits.

A final minor steering burn in space will guide the Orion spacecraft toward a specific area of the Pacific Ocean, situated west of San Diego, California, where a Navy vessel will be poised on Friday evening. Ground engineers will also activate backup flight software to ensure the capsule can navigate through the atmosphere in the event of main computer failures.

This concluding phase is marked by heightened tension following Artemis I, when segments of Orion’s heat shield unexpectedly detached during the uncrewed test flight’s descent. Engineers later determined that the problem arose from hot gas accumulating more swiftly than it could escape during the mission’s “skip” entry. Rather than redesigning the shield, NASA opted to adjust the capsule’s atmospheric trajectory to steer clear of the highest temperatures.

Long prior to launch, the heat shield was Wiseman’s foremost concern for Jim Free, who headed NASA’s Artemis rocket and spacecraft initiatives in 2023. “Every time you see me come in, you take a step back,” Wiseman remarked to Free at a press conference, “because I’m coming about the heat shield.”

After NASA retrieved the Orion spacecraft post-Artemis I, engineers detached the heat shield from the crew module to assess the charring damage.

Instead of replicating the deep bounce from the initial flight, Artemis II will utilize a gentler “lofted” technique, as noted by Henfling. Orion will still oscillate in and out of the atmosphere before the final descent, albeit with a less intense ascent and descent. This adjustment reduces the distance to splashdown and keeps the gas-pressure spikes seen on the previous flight within a controllable level. NASA consulted an independent review team prior to sanctioning the revised strategy.

Glover has been mulling over re-entry since April 3, 2023, the day he was assigned to the Artemis II crew. “During one of the initial press conferences, we were asked what we were looking forward to, and I said, ‘Splashdown,'” he stated during a remote call with reporters from the capsule Wednesday night. “Riding a fireball through the atmosphere is profound.”

Despite concerns, NASA officials declared in 2024 that the damage to Artemis I’s heat shield would not have posed a threat to a crew. “They would not have sensed any disruption inside the vehicle, there would not have been any excessive heating on the structure, and the guidance would have positioned them precisely where the Navy required for recovery,” said Amit Kshatriya, a senior NASA official.

As Orion nears Earth, communication will shift from the expansive moon-tracking antennas of the Deep Space Network to near-Earth relay satellites. About 20 minutes prior to entry, the service module — the component containing solar arrays and the main engine — will separate and incinerate over the ocean, leaving solely the crew capsule to withstand the extreme heat.

Entry commences roughly 75 miles above, with Orion traveling at 25,000 mph. Air accumulating in front of the capsule will heat to around 5,000 degrees Fahrenheit, surrounding it in plasma that may momentarily disrupt radio communications. Inside, the crew will endure approximately 3.9Gs — a force four times their body weight.

Although the astronauts have frequently regarded potential records as mere distractions, Wiseman conceded there is one he has mentally noted during their training — possibly exceeding previous reentry speeds by roughly 200 miles per hour. Apollo 10’s speed translated to approximately Mach 37, according to its 1969 press materials. “We still chuckle a bit when we see a click over Mach 39 on entry,” he noted months prior to the April 1 launch.

Once Orion decelerates sufficiently, a precise parachute deployment sequence will initiate. A cover over the nose will detach, two small drogues will deploy to stabilize the capsule, then three large orange parachutes will open sequentially to decrease its speed for a safe splashdown. Small thrusters will correct the capsule’s angle to ensure it impacts the water at the safest angle near the California coast.

Post-splashdown, NASA will maintain Orion’s power for roughly two hours to monitor how temperatures inside the capsule fluctuate as it cools in the Pacific, even after the astronauts have boarded the recovery ship.

Dan Flores, part of the recovery team, may have a bias, but he considers this his favorite segment of the mission. “We have our friends flying around the moon,” he stated. “This is when we get to bring our friends back home to their families.”