Astronauts Suni Williams and Butch Wilmore returned to Earth on March 18, 2025, after an extended mission that faced complications with their Boeing capsule.

Following their return, a research team at Massachusetts General Hospital (MGH) is closely monitoring both astronauts to study the effects of space travel on their readjustment to Earth's gravity.

Vladimir Ivkovic, the director at MGH's Center for Space Medicine, emphasizes the importance of understanding how astronauts adapt to extreme conditions during their transition back to Earth.

The research aims to explore the 'yo-yo effect' of adaptation to space flight, focusing on how quickly astronauts can return to baseline conditions after their missions.

Mass General Hospital's Center for Space Medicine, established in January 2024, is specifically monitoring Williams after her nine-month space mission.

Upon returning, astronauts typically face muscle and bone weakness, increased heart strain, and fatigue due to the resumption of gravity.

The initial effects of readjustment are most pronounced within the first 48 hours, but full acclimatization can take several weeks.

To aid their recovery, both Williams and Wilmore will engage in cardiovascular and resistive exercises aimed at regaining their physical strength post-mission.

One significant physical change experienced by astronauts in space is the redistribution of bodily fluids due to the absence of gravity.

Emotional and psychological challenges may also arise as astronauts reintegrate with their families and the outside world after prolonged isolation.

Although MGH does not have direct communication with the astronauts, they track their progress through NASA and social media.

Ivkovic's team is gathering data from other astronauts, which may provide insights into various conditions and disorders experienced on Earth.