The wait is over and the stranded duo of US astronauts are finally going to return to Earth from the International Space Station (ISS) on Tuesday (March 18) evening, said NASA.
The duo, Butch Wilmore and Sunita Williams will be transported home with another American astronaut and a Russian cosmonaut aboard a SpaceX Crew Dragon craft, which had arrived on ISS early on Sunday.
The duo was initially out for an 8-day long mission to ISS, which got extended for nine months due to a Starliner spacecraft problem. Not only this extension is mentally draining, but doctors have long been concerned about the other health impacts a long space duration can have.
The spacecraft was launched on June 5, and following a glitch in its thrusters, essential to propel the spacecraft, the duo has been stuck indefinitely. The primary issue is with its propulsion system, particularly gas leaks and malfunctioning thrusters, which have raised significant safety concerns and led NASA to even reconsider its use for astronaut transport. The Space Agency, as reported in The Guardian also said that there was "too much uncertainty" for the astronauts to return on the craft that brought them to the station.
"The space station is well-stocked with everything the crew needs, including food, water, clothing, and oxygen. Additionally, NASA and its space station partners frequently launch resupply missions to the orbiting complex carrying additional supplies and cargo," said the space agency in a statement.
NASA had earlier said that it has plans to launch a SpaceX resupply mission by the end of 2024. Crew living on board the ISS also have access to Vegetable Production System (Veggie) which is investigation the growth of plants in space. With this system fresh plants can be grown that can provide astronauts with nutritious fresh food. Both, Williams and Wilmore are also testing the different space crop techniques.
Space agencies like NASA and the German Space Agency (DLR) studied the effects of space on human body. In 2024, the journal Nature published over 40 studies focused on aerospace medicine and space biology. One such study, called TWINS compared astronaut Scott Kelly, who spent a year on the ISS with his identical twin, Mark, who stayed on Earth.
The study highlighted a significant risk of prolonged space missions: radiation exposure.
Radiation in space can damage DNA, increasing cancer risks and oxidative stress in the body. Bailey explained that space radiation exposure is a major concern for astronauts. Space agencies must find ways to protect astronauts during space travel and long-term stays on the Moon or Mars. They have set limits on the amount of radiation astronauts can be exposed to over their careers.
Another challenge is microgravity which causes bone density loss of 1-1.5% per month. When astronauts come down to Earth. They may struggle with physical activities like dancing due to weak bones and it can also affect vision. The fluids that shift to the head put pressure on the eyes. This can also lead to Spaceflight Associated Neuro-ocular Syndrome, which can permanently impact vision.
Other risks involve fluid redistribution that can lead to facial puffiness and decreased fluid volume in legs, disruption of cardiovascular functions, complicating blood pressure and even risks to the urinary systems. The risk of kidney stone too is high.
Nutrition deficiencies was another concern which was raised when photos of Williams revealed a significant weight loss. Her sunken cheekbones raised worries about her eating habits. There were also speculations of her being on a calorie-deficit diet. This meant that she ate less than her body required to sustain the high energy she needs for space travels.
In terms of physical activities, astronauts in microgravity must exercise for 2.5 hours daily. This helps them maintain muscle-bone health. However, a challenging environment could lead to weight loss.
What must be done after the duo returns to Earth is a regular health monitoring that could track the long-term effects of their time in space.
