Written By: Satata Karmakar | Updated : March 19, 2025 10:19 AM IST
Sunita Williams Return To Earth: What Will Happen To NASA Astronaut's Body After Entering Gravity After 9 Months
Sunita Williams Return To Earth News: After spending over 9 months in space, NASA astronauts Sunita Williams and Barry 'Butch' Wilmore, are finally returning back to Earth. According to NASA, Williams and Wilmore undocked from the ISS at 10:35 am IST and set on a 17-hour trip back to Earth. The spacecraft, Elon Musk-led SpaceX's Dragon, will splash down off the coast of the American state of Florida around 3:27 am IST Wednesday.
A short-space mission which was initially planned for 8 days, got extended to 9 months, after their spacecraft suffered severe technical issues, leaving them stranded at the International Space Station (ISS).
While her journey has been groundbreaking, her extended stay in microgravity poses significant physiological challenges. Astronauts who spend long durations in space experience drastic changes in their bodies, ranging from muscle atrophy to cardiovascular deconditioning. As Williams prepares for re-entry, scientists and medical experts are closely monitoring the potential effects on her health. This article explores the physiological transformations that occur after prolonged exposure to microgravity and what Williams might face upon her return to Earth's gravity.
Prolonged exposure to microgravity and space radiation can pose serious health risks to astronauts. While her stay at the ISS was difficult due to isolation, and indefinite extension of the mission, experts have stated that the real challenge for Sunita Williams will begin now - after she re-enters gravity. Here are some of the health challenges that her body will face upon landing:
As per experts, the NASA astronauts' extended stay at space has led to a very serious health concern is muscle weakness. In medical terminology, this is also known as muscle atrophy. This weakness in the muscles mainly happens due to the absence of gravity. When there is no opposite force, the muscles stop acting or functioning like it does when there is gravity - leading to muscle mass deteriorating rapidly. Studies show that astronauts can lose up to 20% of their muscle mass in just a few weeks.
The next health problem that the NASA astronaut is expected to face upon landing, is bone density loss and its side effects. According to the experts, microgravity also impacts bone health, causing a condition similar to osteoporosis. This mainly happens due to the lack of mechanical stress on bones leads to significant calcium loss, which makes bones fragile and more prone to fractures. Astronauts can lose 1-1.5% of bone density per month, primarily affecting their spine, pelvis, and legs.
After spending over 9 months in space, under microgravity, Sunita Williams' and Butch Wilmore's body will also suffer from cardiac issues, such as fluctuating blood pressure leading to rapid heart rate and palpitation. Experts explain the issue this way -- living in microgravity alters blood circulation and the way the cardiovascular system functions. Without gravity, blood tends to pool in the upper body, leading to fluid shifts, puffy faces, and thinner legs (known as "bird leg syndrome"). After landing on Earth, astronauts may also experience orthostatic intolerance, meaning they may feel dizzy or even faint when trying to stand up.
"I am trying to remember how to walk", Sunita Williams said in a recent interview from the ISS.
Many astronauts develop vision problems due to Spaceflight-Associated Neuro-ocular Syndrome (SANS). Microgravity increases fluid retention in the brain, causing pressure on the optic nerve, which leads to blurred vision or difficulty focusing.
Spaceflight weakens the immune system due to factors like radiation exposure, stress, and limited microbial exposure. Studies have shown that astronauts are more susceptible to viral reactivations, skin infections, and slower wound healing. The immune system needs time to adjust back to Earth's environment, meaning Williams may have to take extra precautions against infections.
Exposure to cosmic radiation is a serious concern for astronauts on long-duration missions. Unlike Earth, space lacks the protective shield of the atmosphere, exposing astronauts to high levels of radiation that may increase the risk of cancer and other health issues. NASA monitors astronauts closely for any signs of radiation-induced damage, and Williams will likely undergo medical screenings to assess potential long-term effects.
Apart from these, upon re-entry, the NASA astronauts are also expected to experience motion sickness, nausea, dizziness, and disorientation. The inner ear, which controls balance, adapts to the weightlessness of space, and returning to Earth's gravity requires a recalibration of the vestibular system."Williams and Wilmore have spent over 9 months under microgravity. They may experience difficulty walking, a sensation of floating, or vertigo for several days post-landing. Training, rest, and specialized rehabilitation programs will be crucial in helping her regain her sense of balance."
Far from visible health effects, the two NASA astronauts will also deal with mental health problems -- that they must have developed when they were stranded at the ISS (under total isolation), for over 9 months.
Wilmore and Williams, both seasoned NASA astronauts and retired US Navy test pilots, undocked from the ISS at 1:05 a.m. ET (0505 GMT) alongside two other crew members. The four-person team, part of NASA's Crew-9 mission, is now on a 17-hour trip back to Earth, with splashdown expected off Florida's coast at 5:57 p.m. ET on Tuesday.
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