NASA astronauts Sunita Williams and Barry ‘Butch’ Wilmore are set to return to Earth soon. Both astronauts are have been stranded in space for nearly ten months raising concerns regarding their health.
According to a Hindustan Times report, Williams and Wilmore are scheduled to return to Earth, no sooner than March 19. A joint mission by NASA and Elon Musk’s SpaceX, Crew Dragon-10, has set out for the International Space Station, and is expected to dock on Sunday, March 16.
Experts have raised concerns that prolonged exposure to microgravity may lead to several health challenges commonly faced by astronauts upon re-entry to Earth’s gravity.
What happens to human body in space?
In a 2021 blog, The National Aeronautics and Space Administration (NASA) revealed that the health risks for astronauts from radiation exposure in space are mainly driven by long-term impacts.
“Not only will astronauts be exposed to more radiation in space than on Earth, but the radiation they are exposed to could pose increased risks,” it stated.
Many people show symptoms of “space sickness,” such as headaches, nausea, and vomiting. Face gets swollen as bodily fluids are no longer pulled down and they accumulate in the upper body.
Transition from space to Earth is tricky
When you return to earth, you experience the effects of earth’s gravity again, and thus “gravity sickness” sometimes occurs, with similar symptoms as space sickness.
NASA maintains that transitioning from one gravity field to another is trickier than it sounds. “It affects spatial orientation, head-eye and hand-eye coordination, balance, and locomotion, with some crew members experiencing space motion sickness,” US agency stated.
When shifting from weightlessness to gravity, astronauts may experience post-flight orthostatic intolerance where they are unable to maintain their blood pressure when standing up, which can lead to lightheadedness and fainting, NASA highlighted.
NASA has learned that without Earth’s gravity affecting the human body, weight-bearing bones lose on average 1% to 1.5% of mineral density per month during spaceflight, the US agency highlighted in its blog.
After returning to Earth, bone loss might not be completely corrected by rehabilitation; however, their risk for fracture is not higher. Without the proper diet and exercise routine, astronauts also lose muscle mass in microgravity faster than they would on Earth.
“Moreover, the fluids in the body shift upward to the head in microgravity, which may put pressure on the eyes and cause vision problems. If preventive or countermeasures are not implemented, crews may experience an increased risk of developing kidney stones due to dehydration and increased excretion of calcium from their bones,” it added.
What happens when you spend long time in space?
If you spend a long time in space, your muscles and bones will weaken, primarily in the legs and lower back. When the bone strength reduces, there is an increase in the risk of suffering fractures and increase the amount of time it takes to heal.
It can take up to four years for their bone mass to return to normal after returning to Earth, BBC reported. If you stay in space for extended period, blood can accumulate in the head more than it normally would. Some of this fluid can pool at the back of the eye and around the optic nerve, leading to oedema, BBC reported.
A prolonged space journey can also alter your genes. Some astronauts do suffer some decreases in white blood cell counts that fall in line with the doses of radiation they receive while in orbit, BBC reported.
What are some of the health risk that Sunita Williams can suffer from?
Increased risk of brain damage and cancer
Baby feet
Bone density and muscle loss
Cardiovascular and brain health