After spending nine months in space, NASA astronauts Sunita Williams and Butch Wilmore have now begun a 45-day rehabilitation program to help them readjust to Earth's gravity.

The duo returned early Wednesday (Indian time) aboard SpaceX's Crew-9 mission, making a safe splashdown off the Florida coast. Their extended stay aboard the International Space Station (ISS) posed significant physical challenges, making rehabilitation a crucial part of their recovery process.

Following their prolonged exposure to microgravity, the astronauts will now undergo structured physical training designed to counteract the effects of weightlessness on their bodies.

Physical Challenges After Spaceflight

Astronauts returning from space often experience physiological changes, including fluid shifts causing puffy faces, muscle atrophy leading to "chicken legs," temporary height increase, and reduced bone density.

Microgravity affects multiple aspects of an astronaut's health, including aerobic capacity, muscle strength, endurance, balance, coordination, and neurovestibular function.

Rehabilitation Program for Recovery

The Astronaut Strength, Conditioning, and Rehabilitation (ASCR) specialists have designed a structured reconditioning program aimed at restoring physical health.

The rehabilitation process begins immediately upon landing and involves two-hour daily sessions, seven days a week, for 45 days. The program is customized for each astronaut based on medical assessments, test results, and mission roles.

Three Phases of Rehabilitation

The recovery program is divided into three phases:

Phase 1 – Starts on landing day, focusing on mobility, flexibility, and muscle strengthening.
Phase 2 – Introduces proprioceptive exercises and cardiovascular training.
Phase 3 – The longest phase, prioritizing functional development and full-body strength recovery.
Past studies have shown that astronauts often regain, and sometimes even surpass, their pre-flight physical condition after completing this program.

Unplanned Extended Stay in Space

Williams and Wilmore’s mission was originally planned for just eight days after they launched aboard Boeing’s Starliner on June 5 last year. However, technical issues with the spacecraft's propulsion system forced it to return without them, extending their stay aboard the ISS.

Their unexpected situation gained widespread attention, sparking debates about space travel safety and political discussions.

Safe Return to Earth

The return process began after Crew-10 arrived at the ISS on Sunday, allowing Williams, Wilmore, NASA’s Nick Hague, and cosmonaut Aleksandr Gorbunov to prepare for their journey home.

Seventeen hours after departing the ISS, their SpaceX Dragon capsule safely splashed down at 3:27 a.m. IST. Following their retrieval from the capsule, they underwent immediate medical evaluations before starting their rehabilitation program.