Florida: NASA astronauts Sunita Williams and Butch Wilmore have returned to Earth after spending almost nine months in space together. Spending long periods in space has led to a number of physical changes for them, just like all astronauts who are in space for an extended time. The buoyancy constraints of a microgravity environment impact the body in various ways.
Physical Changes
The most damaging effects of long-duration journeys in space impact bones and muscles. In microgravity, bone density decreases approximately by 1% every month, leading to a risk of osteoporosis and fracture. Muscles — especially in the legs and back — weaken from the absence of weight-bearing activity. To counter this, astronauts do rigorous workouts, including lifting weights, squats, deadlifts and running on treadmills. But back on Earth, it can take no small bit of time for them to regain normal mobility.
Facial Swelling and Problems With Vision
In space, the fluids move to the top of the body due to microgravity and cause facial swelling. An increased pressure on the eyes can also cause blurred vision.
Impact on the Heart
In microgravity, the heart has to work less hard, and the muscle has shrunk slightly and pumps a little less. This can impact the circulatory system, leading astronauts to feel weak and light-headed when they come back to Earth.
Mental Changes
Mental health is also affected by long-term space travel. The isolation, proximity to Earth, and restricted real-time communication can create anxiety. Studies have indicated that significant brain changes, including in the ventricles, can occur with prolonged space travel, and that the summation of these changes may linger for years.
Problems with Balance and Coordination
Microgravity impacts balance and coordination, making it difficult for astronauts to find their footing upon returning home.
Cosmic Radiation Risks
Astronauts in space are at much higher exposure levels to cosmic radiation than on the planet’s surface. This radiation can hurt DNA and raise cancer risk without Earth’s magnetic field to block it. Researchers are developing additional safety protocols, protective tools and drugs to blunt these threats.
Immune System Weakness
The immune system is weakened by extended space travel. In space, white blood cells stop functioning properly, opening astronauts up to infection.
Metabolism and Weight Changes
When a person travels in space, it can impact metabolism, resulting in unplanned weight loss or lower appetite. This is a serious issue during long-duration missions, where nutrition must be preserved.