One of the astronauts who splashed back on Earth last Friday after going further into space than any other person, has revealed the devastating impact that 10 days in zero gravity has on the human body.
Christina Koch, one of four crew members on the landmark Artemis II mission that travelled to the far side of the moon, has been documenting what it’s really like to recover once the spacecraft is safely down. In posts shared online, she made clear that the return to Earth doesn’t end at splashdown off the California coast.
In a video update, Koch showed how difficult it has been to adjust to gravity again after a week and a half confined inside a small capsule. That’s despite the crew completing daily countermeasures, including 30 minutes of resistance exercise designed to reduce physical deconditioning.
The 47-year-old astronaut—also the first woman to fly around the moon—said she wanted to help her nearly two million followers understand why recovery can take time, adding with humor: “Guess I’ll be waiting a minute to surf again.”
The footage shows Koch struggling to stay upright and move in a straight line even a week after returning—an illustration of how the brain can still be recalibrating basic orientation after time in microgravity.
She explained: “When people live in microgravity, the systems in our body that have evolved to tell our brains how we’re moving, the vestibular organs, don’t work correctly.”
Koch emphasized that the issue isn’t simply fragility—it’s also the brain doing what it’s built to do: adapt. As she put it: “Our brains learn to ignore those signals and so when we first get back to gravity, we are heavily reliant on our eyes to orient ourselves visually.
“A tandem walk with eyes closed can be quite the challenge!
Observations like these don’t just help scientists understand the toll of living in near weightlessness; they can also translate into research and treatment strategies back on Earth.
Koch noted that ‘learning about this can help inform how we treat vertigo, concussions and other neuro-vestibular conditions on Earth,’ while also assuring viewers that what they were seeing was part of a normal, structured recovery process.
She said: “Luckily we’re already adapting back to gravity at 7 days post-splashdown!”
The mission’s impact is expected to extend beyond biomedical findings. Artemis II has also reignited public attention around lunar exploration, placing renewed focus on humanity’s closest celestial neighbor.
Speaking at a press conference on Thursday with fellow crew members Reid Wiseman, Victor Glover, and Jeremy Hansen, Koch described the broader purpose behind the flight and the team effort supporting it. She said: “I cannot overstate how important that was to us.
“It was every bit as important as accomplishing the technical goals and being there for our NASA teammates was to make this the world’s mission.”