The Artemis II astronauts are set to return to Earth Friday evening after a remarkable ten-day journey around the moon. This marks the first U.S. mission to the moon in over half a century.
However, the journey isn’t over just yet. The astronauts face the challenges of a perilous splashdown and various health effects that may linger after their mission.
NASA astronaut Andreas Mogensen once described how difficult it was to walk straight with his eyes closed post-flight, highlighting some of the struggles that come with returning from space.
The crew includes Reed Wiseman, Victor Glover, Christina Koch, and Canadian astronaut Jeremy Hansen. They are approaching a critical moment as they re-enter Earth’s atmosphere at an astonishing 25,000 miles per hour.
The success of their re-entry relies heavily on Orion’s 16-foot-wide heat shield, which needs to endure temperatures soaring to 5,000 degrees Fahrenheit. It’s a risky situation, especially given the challenges previously noted during unmanned missions.
Landing on Water
If all goes smoothly, Orion is expected to parachute and splash down near San Diego at 8:07 a.m. ET on April 10, making it the farthest humans have ever traveled from Earth — over 252,756 miles.
Once they land, the astronauts will shut down the spacecraft, and the subsequent recovery operation will be managed by the Department of Defense.
Jason Ensley, chief ground instrumentation engineer for Amentum, which partners with NASA, emphasized their role in recovering the crew module. They plan to use a stability collar to keep Orion upright in what could be choppy waters, though the weather forecast looks favorable right now.
After they open the hatch, U.S. Navy medics will assess the astronauts, and recovery divers will help them ascend to an inflatable platform where they’ll wear special recovery vests.
This gear will assist in hoisting them onto a helicopter bound for the USS John P. Murtha, where they will undergo medical examinations before eventually heading to Houston. It’s crucial that the entire operation runs seamlessly to prevent any issues during splashdown.
Meanwhile, the Orion module will arrive at the ship via a floating dock, and a truck will transport it to Kennedy Space Center in Florida after it reaches land.
Feeling Spacey
Returning astronauts often deal with health challenges related to the abrupt transition back to Earth’s gravity.
NASA crew members previously noted that returning from microgravity can throw their inner ears off balance. They often face difficulties, such as struggling to walk both with their eyes open and shut. Crew member Jasmine Moghbeli likened her first fitness test post-landing to “a nice tap dance.” She mentioned feeling groggy for the first couple of days and her neck grew tired from the effort of holding up her head.
Nausea is another common side effect, with many crew members experiencing discomfort simply from looking down. Don Pettit, the oldest active astronaut at 70, recalled significant nausea after a substantial stint aboard the International Space Station, candidly sharing that he struggled during descent.
Other health effects may include compromised immune response, sleep disturbances, and vision issues due to blood pooling in the head. Some problems can actually begin manifesting within just a couple of weeks in space.
Additionally, the loss of muscle and bone density caused by zero gravity can be significant — astronauts can lose about 20% of their muscle mass after two weeks and may experience up to 2% bone density loss per month.
Adapting to Earth
Fortunately, astronauts can mitigate these effects through rigorous onboard training regimens.
During their time on the ISS, astronauts engage in about two and a half hours of exercise each day, incorporating squats, deadlifts, and other resistance exercises to combat muscle atrophy.
For the Artemis II mission, they utilized a flywheel machine designed to provide resistance and simulate various workouts. Canadian astronaut Jeremy Hansen compared it to a rowing machine that allows effective cardiovascular training.
Generally, most astronauts find their balance returns within a few months of coming back to Earth. Nicole Ayers, who participated in her first mission on SpaceX Crew-10, remarked on how quickly the body can readjust.
