Sunita Williams faces major health challenges after space odyssey

‘While balance, mobility, and walking difficulties are resolved in a short period, brain function recovery takes much longer’

By Arun Kumar

Indian American Sunita Williams and fellow NASA astronaut Butch Wilmore now face the significant task of recovering from the physical and psychological toll of what was supposed to be an eight-day trip turning into a grueling nine month space odyssey.

“By following astronauts like Butch and Suni before, during, and after their missions, we can track how the human body responds to the extreme conditions of space,” says Rachael Seidler, PhD, a leading expert in spaceflight-associated health changes.

READ: Sunita Williams returns home after 286 day space odyssey (March 20th, 2025) 

“While the physical and psychological challenges astronauts face after returning from long-duration space missions are well-documented, the research we do at UF is helping us understand the intricacies of their recovery process,” said Seidler, deputy director of the Astraeus Space Institute at the University of Florida.

She is studying the long-term effects of space travel on astronauts’ brains and bodies as part of’ongoing research at UF into astronaut health, according to a university release. Seidler’s research tracks astronauts’ physical and neurological recovery by observing them both during their missions and after they return.

“One of the most immediate challenges astronauts face when they return to Earth is mobility and balance.These issues often recover more quickly compared to others, but it takes time for astronauts to readjust to gravity,” Seidler said. “The balance, mobility, and walking difficulties astronauts experience during the first weeks back are typically resolved in a short period, but brain function and structure require longer recovery periods.”

Seidler’s research indicates that astronauts’ brains exhibit compensation when they return to Earth following spaceflight. This compensation occurs through the recruitment of additional neural pathways in order to return to their preflight performance levels. However, the recovery of brain function is a gradual process. “This brain functional compensation is typically no longer observed within one to six  months post-flight,” Seidler said.

However, not all changes are reversible. “Brain structural changes, particularly related to fluid shifts in space, show little to no recovery even after six months to a year,” Seidler said.

Two significant structural changes include the brain physically sitting higher in the skull and the expansion of the brain’s ventricles — fluid-filled cavities in the brain — which can increase in volume by 25% or more. These changes are thought to result from the fluid shifts caused by microgravity, and they present long-term health considerations for astronauts.

As Williams and Wilmore embark on their recovery journey, the long-term impact of these changes becomes a critical focus for researchers like Seidler. “The long-term health impacts are crucial to understand because they could affect how astronauts recover and perform in their daily lives post-mission,” she said.

Seidler’s team at UF is conducting a new study in which they are tracking astronauts for up to five years post-flight to better understand these long-term effects. “We’ve had astronauts in space for up to a year, and we know how to manage their physical health during those missions,” Seidler said. “But the effects of space on the brain and body extend beyond the mission, and our work helps inform strategies to manage recovery.”

Seidler’s work is also part of a broader collaboration with NASA and other scientists to assess astronaut long-term health. The project is particularly focused on Spaceflight-Associated Neuro-Ocular Syndrome, which affects up to 70% of astronauts. This condition involves structural changes to the eye and optic nerve, leading to vision problems that may impact astronauts’ function.

“Neuropsychological assessments can help to measure astronauts’ brain health, while studies of the ocular system help identify potential vision issues that may arise during and after long-duration space missions,” she said.