Artemis 2 astronaut Christina Koch of NASA looks at Earth as her Orion spacecraft heads toward the moon in April 2026. (Image credit: NASA) A week after her historic moon mission ended, NASA astronaut Christina Koch struggled to walk in a straight line during a blindfold test. After posting a video showing her wobbling and nearly tipping over — nearly enough, in fact, that attendants jumped in ready to help — Artemis 2 's Koch joked about her recovery on Instagram : "Guess I'll be waiting a minute to surf again." In microgravity , she added, the brain learns how to ignore signals our body automatically generates when moving around. Astronauts thus face similar issues when returning to Earth as do people with certain medical conditions, including concussions and vertigo, which is where physical therapy — and a bit of humor, as evidenced by Koch's smiles as she wobbled — is helpful.…