Sunita Williams return: Baby feet, dizziness, weightless tongue—astronauts face health challenges after months in space

Sunita Williams return: NASA astronauts Sunita Williams and Butch Wilmore are finally on their way back home to Earth, ending an extended nine-month stay on the International Space Station (ISS), but it seems that space travel isn't their biggest challenge yet.

After months in microgravity or 'zero-G', astronauts often face health challenges, ranging from dizziness to ‘baby feet’ to a ‘weightless tongue’ and even impaired vision. 

Sunita Williams and Butch Wilmore's journey home began at 10.35 am IST on March 18, when the SpaceX Dragon spacecraft successfully undocked from the ISS, beginning the crew's 17-hour voyage to Earth.

Alongside Sunita Williams and Butch Wilmore, aka ‘Butch and Suni’ — who were stuck on the ISS since June 2024 (in a trip that was originally meant to last eight days), are NASA astronaut Nick Hague and Roscosmos cosmonaut Aleksandr Gorbunov.

We take a look at the health challenges that these astronauts, especially Sunita Williams and Butch Wilmore, may face upon their return to our gravity-ruled planet.

Sunita Williams, NASA Astronauts Face Health Challenges After Prolonged Space Stay  

While weightlessness in space is fun to watch (we see astronauts float and “swim” around the ISS), long-duration space travel takes a toll on the body.

Upon return to Earth, astronauts often experience dizziness, nausea, and unsteady feet as they readjust to gravity.

Notably, for Butch and Suni, their scheduled eight-day trip to the ISS stretched into nine months due to a series of thruster failures and helium leaks in the Boeing Starliner capsule that carried them spaceward. As a result, the capsule was flown back empty in early September 2024, leaving Butch and Suni in need of a new ride back to Earth. 

Health Challenges Sunita Williams and Butch Wilmore Will Face Post-Spaceflight

Among the health issues that Sunita Williams and Butch Wilmore could face include baby feet (a condition where space travellers lose the thicker skin on their soles), bad eyesight, difficulty walking, and dizziness, according to a PTI report. 

Astronauts could take several weeks to “re-calibrate” their functions and daily routine to life on Earth, it added.

The Houston-based Baylor College of Medicine notes that once astronauts return to Earth, “they are immediately forced to readjust again, back to Earth's gravity, and can experience issues standing, stabilising their gaze, walking, and turning”.

Thus, to ensure their safety, returning astronauts are often placed in a chair immediately upon their return to Earth, it added.

Gravity, Earth's Hero, Has Significant Impact on Astronaut Health

Loss of gravity in space also has a major impact on blood circulation, balance and bone density.

On Earth, gravity pulls blood and other body fluids into the lower part of the body, but for astronauts experiencing weightlessness in space, these fluids accumulate in the upper parts of the body, making them look bloated.

Also, the vestibular organ deep inside the ear helps humans keep their bodies balanced while walking on Earth by sending information about gravity to the brain. 

Japanese space agency JAXA noted that time in space affects information received from the vestibular organs and confuses the brain, leading to space sickness. When they return, they "experience the effects of earth's gravity again, and thus ‘gravity sickness’ sometimes occurs,” it noted.

“Astronauts returning to earth often experience dizziness when standing up, known as orthostatic hypotension. This occurs because gravity on the earth is stronger than in space, and it is more difficult to deliver blood from the heart to the head,” JAXA said.

Further, according to NASA, lack of gravity in space also often causes irreparable bone density loss — for every month in space, astronauts' weight-bearing bones become roughly one per cent less dense if they don't take precautions to counter this loss.

To help combat this, astronauts aboard the ISS have a strict exercise regimen. “Astronauts are required to exercise two hours per day, using the treadmill or stationary bicycle, to avoid the bone and muscle deterioration that occurs in zero gravity. Without this exercise, astronauts would be unable to walk or stand up when they return to Earth after months of floating in space,” NASA said.

Weighless Tongue, Immune System Threat…

Canadian astronaut Chris Hadfield reported experiencing a weightless tongue on his return from a stint at the ISS in 2013. He noted, “Right after I landed, I could feel the weight of my lips and tongue, and I had to change how I was talking. I hadn't realised that I learned to talk with a weightless tongue.”

Astronauts may also be more susceptible to infection and illness due to a suppressed immune system. “While we see that immune cells do not behave in the way they should in space, so far we haven't had any severe infection on board the Space Station, so cell altered behaviour is not directly transferable to immune protection,” European Space Agency's flight surgeon Sergi Vaquer said in a blog post on the agency's website.

(With inputs from PTI)