Sunita Williams returns: What health risks can astronauts face in space? ‘Vision problems, bone loss, brain damage’ | Mint

NASA astronaut Sunita Williams, who remains in space due to the significant delay in the return of Starliner, is contributing to studies focused on analyzing the effects of space flight on the human body. She herself has been undergoing body tests on the International Space Station since arriving there on Boeing’s Starliner spacecraft on June 6.

It is not new that people living in space face health risks from microgravity and space radiation. But how does microgravity affect the human body? For more than 50 years, space agencies have been researching and studying to find answers. With this in mind, it is now feared that Williams may have suffered health risks due to staying in space for longer than the prescribed time.

Sunita Williams flew with her colleague Butch Wilmore on the Starliner capsule on June 5. They were scheduled to return within this week. However, the return of the two NASA astronauts has been delayed due to software issues, helium leaks and thruster anomalies found in the spacecraft.

NASA officials said in a press conference on August 7 that they are considering options other than Starliner to bring Williams and Wilmore back. The official indicated that the two could be brought back to Earth on a SpaceX spacecraft in 2025, but this has not been confirmed yet.

vein scan in space

Sunita Williams, along with her colleague Butch Wilmore, participated in vein scans during their recent stay on the ISS. Doctors on the ground monitored in real time as the two took turns imaging each other’s neck, shoulder and leg veins, a press release from NASA reported on July 18.

“Next, Wilmore scanned the veins of fellow NASA astronaut Matthew Dominick, helping researchers better understand how microgravity affects the human body,” the release said.

Meanwhile, NASA says it is “particularly interested in investigating how Earth responds to long-duration spaceflight as the agency plans extended missions to the Moon and Mars.”

What health risks do astronauts face in space?

NASA explained that in space, astronauts are exposed to different and increased levels of space radiation. Radiation in space is different from the radiation we experience on Earth. The source of these radiations are “particles trapped in the Earth’s magnetic field, solar energetic particles from the Sun, and galactic cosmic rays.”

On Earth, people are protected from these radiations due to the planet’s magnetic field and atmosphere. However, the situation is the opposite for those in space, where there is almost no atmosphere.

According to the US space agency, “Human populations exposed to radiation on Earth are at increased risk for cancer and degenerative diseases such as heart disease and cataracts.” It also says that the risks to astronauts’ health from exposure to radiation in space are driven primarily by long-term effects.

bone loss

NASA also explains “skeletal unloading.” It states, “Skeletal unloading during prolonged exposure to low gravity increases the risk of bone density and strength loss. Astronauts may lose bone density in the hip and spine by 1% to 2% each month, compared to bone loss of 0.5% to 1% per year in postmenopausal women and very old men on Earth. This accelerated bone loss may put crew members at risk for bone fractures and early osteoporosis due to spaceflight.”

NASA also found that even without Earth’s gravity affecting the human body, weight-bearing bones lose an average of 1% to 1.5% of mineral density per month during space flight.

“After returning to Earth, bone damage may not be completely repaired by rehabilitation; however, “Their risk of fractures is not increased. Without proper diet and exercise routines, astronauts lose muscle mass in microgravity more rapidly than on Earth,” it says.

muscle weakness

Meanwhile, the JAXA Human Spaceflight Technology Directorate says that long periods of time in space can lead to muscle and bone weakness, particularly in the legs and lower back. “If you stay in space for a long time, muscles weaken and bone mass decreases,” it adds.

Space sickness

In addition, astronauts may also experience “space sickness,” which can include headaches, nausea and vomiting, says the JAXA Human Spaceflight Technology Directorate. It also warns of “weakening of the heart muscle,” which can “cause dizziness when standing up.” Astronauts may also experience acute stress, the report says.

Brain damage, vision problems

In microgravity, fluids in the body move upward toward the head, which can cause pressure on the eyes and vision problems, NASA said in a report in 2021.

In addition, a study published in the scientific journal JAMA Neurology in 2021 showed that the “negative changes” caused by prolonged exposure to space on the body include “muscle atrophy, bone loss, vision deterioration, and changes in the bacterial flora in the gut.”

A study conducted on five Russian cosmonauts who stayed on the ISS showed that spending long hours in space causes brain damage.

Kidney stones

“If preventive or countermeasures are not implemented, the crew may be at increased risk of developing kidney stones due to dehydration and increased excretion of calcium from bones,” the US space agency said.

What do astronauts do to stay healthy?

Astronauts follow certain procedures, strategies, medications, exercise routines, etc., known as countermeasures, to remain healthy and productive in space and after returning to Earth.

In addition, NASA is currently working on developing a medical data architecture for spacecraft, enabling the capabilities of clinical decision support tools, which could use artificial intelligence and machine learning to help diagnose and treat various diseases.