NASA astronauts Sunita Williams and Butch Wilmore, originally set for a shorter mission, have been in space for over nine months due to technical concerns with the Boeing Starliner spacecraft. They are now scheduled to return no earlier than March 19 aboard a SpaceX Crew Dragon capsule.
Astronauts experience a loss of foot calluses in space, a condition known as “baby feet.” Former NASA astronaut Leroy Chiao explained that weightlessness causes the thickened skin on the soles to disappear, making it painful to walk upon returning to Earth.
NASA research indicates that astronauts lose about 1% of bone density per month in space. After 10 months on the ISS, Williams and Wilmore will require extensive rehabilitation to counteract bone weakening and muscle atrophy caused by prolonged exposure to microgravity.
The heart adapts to space by becoming more spherical, and blood vessels shrink due to reduced physical stress. This can lead to difficulties in blood pressure regulation, causing dizziness, nausea, and fainting when astronauts return to Earth’s gravity.
Fluid shifts in space can increase pressure on the brain, leading to Spaceflight-Associated Neuro-ocular Syndrome (SANS). This condition affects vision, hearing, and overall brain function. Some astronauts experience lasting changes in eyesight due to the pressure buildup.
Extended space missions expose astronauts to high levels of cosmic radiation. NASA warns that this increases the risk of cancer, degenerative diseases, and central nervous system disorders, requiring continuous medical monitoring after their return.
Former astronauts have likened the post-space experience to severe flu, with symptoms including dizziness and weakness. Williams and Wilmore will undergo extensive physical therapy and medical evaluations to regain strength and adapt back to Earth’s gravity.