Christina Koch splashed down off the coast of San Diego on April 10, 2026, after a 10-day lunar flyby that carried her farther from Earth than any human has ever traveled.
The mission marked the first time a woman journeyed beyond low Earth orbit, with Koch manually piloting the Orion spacecraft around the far side of the Moon on April 6, reaching a peak distance of 252,756 miles from Earth.
Upon return, Koch described ongoing challenges with balance and spatial orientation, sharing a video of herself attempting a tandem walk with eyes closed — a task she said remains difficult due to temporary disruption of her vestibular system.
She explained that in microgravity, the body’s vestibular organs, which normally signal movement to the brain, are ignored by the nervous system, making reliance on visual cues necessary when gravity returns.
Despite the disorientation, Koch noted adaptation is underway, stating she is already readjusting to Earth’s gravity seven days after splashdown.
The Artemis II crew, including Reid Wiseman, Victor Glover, and Jeremy Hansen, underwent extensive post-flight medical testing to assess balance, vision, muscle strength, and coordination, with exercises conducted in suits simulating lunar gravity to inform future moonwalks.
Koch emphasized that the scientific value of the mission extends beyond space exploration, suggesting insights from vestibular readaptation could improve treatments for vertigo, concussions, and other neuro-vestibular conditions on Earth.
Her qualifications for the mission were highlighted by her record-breaking 328 consecutive days aboard the International Space Station, six spacewalks totaling 42 hours and 15 minutes, and prior work in extreme environments including Antarctic winter-over service and instrument development for NASA and NOAA missions.
Koch noted the global public’s support was as vital to the mission’s success as its technical achievements, calling Artemis II “the world’s mission” during a public panel shortly after return.
How long did Christina Koch spend in space before Artemis II?
Prior to Artemis II, Koch spent 328 consecutive days aboard the International Space Station in 2019 and 2020, setting the record for the longest single spaceflight by a woman.
What specific balance test is Koch struggling with after returning from the Moon?
Koch is having difficulty performing a tandem walk with her eyes closed, a task that challenges her vestibular system as it readapts to Earth’s gravity.
Could the vestibular changes observed in astronauts like Koch help patients on Earth?
Yes, Koch said studying how the brain reinterprets balance signals after spaceflight could inform treatments for vertigo, concussions, and other neuro-vestibular conditions.