NASA astronaut (retired) Sunita Williams spoke about the physical challenges astronauts face after returning from long-duration space missions, noting that the human body takes time to readjust to Earth’s gravity after months in space.
Speaking on a podcast with entrepreneur Raj Shamani, Williams said prolonged exposure to microgravity can have lasting effects on the body, some of which continue to concern astronauts and scientists. “Some of the long-term health effects of being in space are, in general, a little concerning,” she said, adding that astronauts take as many precautions as possible.
Williams said astronauts usually don’t feel well immediately after landing, although the discomfort subsides over time. Recalling her 286-day mission, she said nausea was one of the biggest challenges, particularly because the spacecraft landed in water, which made disorientation worse after splashdown.
She explained that in space, the body’s balance system is largely inactive because gravity no longer affects the inner ear. When astronauts return to Earth, gravity suddenly becomes dominant again, often leading to dizziness and nausea that can last up to two days. “For me, I felt pretty nauseous for about 24 hours,” Williams said.
Even small movements, such as lifting or tilting the head while removing a spacesuit, can intensify discomfort. Due to balance problems, astronauts receive assistance when leaving the spacecraft to prevent falls and injuries. Once removed from their suits, they are able to walk short distances with assistance, including to a waiting helicopter.
Williams said the body also needs time to retrain muscles essential for balance on Earth but weakened in microgravity, particularly the small stabilizing muscles of the neck. Full recovery, she explained, is gradual and can take about a month, during which astronauts work closely with physical trainers and undergo regular medical evaluations.
She added that astronauts sometimes briefly forget how gravity works after returning, for example by instinctively letting go of objects — a habit formed in space that quickly corrects itself back on Earth. Balance support, she noted, is usually only needed for the first few days.
Williams also said that astronauts avoid driving immediately after returning because reaction times may be slower during the initial recovery phase.
Beyond physical adaptation, she explained how sensory experiences on Earth feel stronger after spaceflight. Remembering her first mission, she said the smell of the ground after landing was a powerful reminder of being back home. “That smell was so predominant,” she said.
She added that astronauts miss simple sensations in space, like wind, running water and daily routines, noting that ordinary activities like taking a shower or washing hands feel especially meaningful after months in orbit.
