2 days Ago By TOI Science Desk
After spending over eight months aboard the International Space Station (ISS), Indian-origin NASA astronaut Sunita Williams and her colleague Butch Wilmore are set to return to Earth on March 19, 2025. The two astronauts have been stranded in space since June last year due to technical issues with Boeing’s Starliner spacecraft, which was supposed to bring them back much earlier. However, their return to Earth brings its own set of challenges, particularly the struggle of readjusting to gravity after prolonged exposure to microgravity.
The effects of long-duration spaceflight on the human body are well-documented, and for Williams and Wilmore, even simple tasks like lifting a pencil will initially feel like a strenuous workout. As they prepare for reentry, NASA is planning an extensive rehabilitation program to help them regain strength and adapt back to life on solid ground. Sunita Williams and Butch Wilmore brace for gravity’s challenge on Earth return Astronauts who spend extended periods in space undergo significant physiological changes due to the lack of gravity.
In microgravity, the human body adapts by redistributing fluids, weakening muscles, and reducing bone density. Upon reentry to Earth's gravity, astronauts experience a sudden shift as fluids settle back into their lower extremities, leading to dizziness, swelling, and even temporary difficulties in movement. As per reports, Butch Wilmore has openly discussed the difficulties astronauts face upon returning to gravity.
"Gravity is really tough, and that's what we feel when we get back," Wilmore explained in an interview. He further added, "Fluids will be pulled down, and even lifting a pencil will feel like a workout." Sunita Williams has also acknowledged that readjusting to life on Earth will be a significant challenge, as her body will have to relearn how to function under gravity’s pull after months of floating weightlessly.
Effects of microgravity on the human body Spending extended time in microgravity leads to several physiological effects: Fluid redistribution : In space, bodily fluids shift toward the upper body, causing astronauts to experience "puffy face syndrome" and thinner limbs. Upon returning to Earth, these fluids rapidly redistribute, leading to swelling in the legs and discomfort. Muscle atrophy and bone density loss : Without the need to support body weight, muscles weaken, and bone density decreases.
Studies indicate that astronauts can lose up to 1-2% of their bone mass per month in microgravity. Cardiovascular changes : The heart also adapts to the reduced workload in space. However, upon reentry, it has to work harder to circulate blood under the effects of gravity, leading to temporary dizziness and weakness.
Balance and coordination issues : The vestibular system, responsible for balance, undergoes changes in space. Upon returning, astronauts often experience disorientation and difficulty walking. Preventing cartilage and bone damage in astronauts To mitigate some of the effects of microgravity, researchers have been exploring ways to strengthen astronauts’ bones and joints.
A recent study published in npj Microgravity suggests that jumping exercises may help prevent cartilage damage and maintain bone strength in astronauts during long-duration missions. The study, conducted by researchers at Johns Hopkins University and the European Space Agency (ESA), found that mice subjected to jumping exercises had thicker and healthier knee cartilage, reducing the risk of long-term joint damage. With future space missions aiming for Mars and long-term habitation on the Moon, preventing cartilage degradation is becoming a priority for space agencies.
“Cartilage damage is a major issue that needs to be addressed despite being poorly understood,” said astrophysicist Marco Chiaberge, one of the study’s lead researchers. “The positive effect we saw in these mice was huge, and the magnitude of it was unexpected. Maybe astronauts could use similar training before their flight as a preventive measure.
” Sunita Williams' rehabilitation program post-landing NASA has planned a rigorous rehabilitation program for Sunita Williams and Butch Wilmore upon their return. The process will involve: Physical therapy : To rebuild muscle strength and restore mobility, astronauts undergo weeks of supervised exercise, including resistance training and balance exercises. Cardiovascular conditioning : Since the heart weakens in microgravity, cardiovascular training, including cycling and treadmill workouts, will be essential.
Nutritional support : Specialized diets rich in calcium and vitamin D will help counteract bone loss and support muscle recovery. Neurological readjustment : Training exercises will help astronauts regain their sense of balance and coordination, ensuring a smoother transition back to normal movement on Earth..
