The Reasons Why Space Travel Is Bad For The Human Dody

Space travel can have negative effects on the human body due to the unique conditions / Space.com. After the astronaut Scott Kelly spent a y...

Space travel can have negative effects on the human body due to the unique conditions / Space.com.

After the astronaut Scott Kelly spent a year on the International Space Station, he returned to Earth shorter, more nearsighted, lighter, and with new symptoms of heart disease that his identical twin brother did not share. (Mark Kelly, now a U.S. senator, also spent a brief time in space.) Even their DNA diverged, as nearly 1,000 of Scott Kelly’s genes and chromosomes worked differently. 

(On the upside, he aged about 9 milliseconds less that year, thanks to how fast the space station circled the Earth.) Most of these effects cleared up within a few months, but not all — underscoring the potential health hazards of space travel, many of which are unknown. 

This studying development will ratchet up during ambitious future trips, such as NASA’s planned Artemis mission to the moon and later travel to Mars. Even a partial list of the likely physical and emotional consequences of deep space travel is daunting.

NASA astronaut Sunita Williams, Expedition 33 commander; and Japan Aerospace Exploration Agency astronaut Aki Hoshide/ NASA.

Space travel can have negative effects on the human body due to the unique conditions and environments encountered in space, such as microgravity, radiation, and isolation. Some of the specific reasons why space travel is bad for the human body include:

1. Microgravity: Prolonged exposure to microgravity can cause a number of physiological changes in the body, such as muscle and bone loss, fluid shift, and changes in cardiovascular and sensory systems.
2. Radiation: Astronauts are exposed to higher levels of radiation than people on Earth, which can increase the risk of cancer and other long-term health problems.
3. Isolation: Space travel can be isolating and stressful, which can lead to psychological problems such as depression, anxiety, and sleep disorders.
4. Confined Spaces: Spacecraft and space stations are confined spaces, which can lead to a range of physical and psychological problems, including sleep disturbances, cardiovascular changes, and changes to the immune system.
5. Re-entry and landing: The re-entry and landing process can be stressful and dangerous, and can cause a range of physical injuries, including broken bones and burns.
6. Long-term effects: The long-term effects of space travel on the human body are not fully understood, but scientists believe that prolonged exposure to microgravity, radiation, and isolation can lead to a range of health problems that are not yet known.

Exposure to the space environment can cause changes in human DNA makeup. Studies have shown that space radiation, such as galactic cosmic rays (GCRs) and solar particles, can cause DNA damage in human cells, including breaks in both single and double-stranded DNA, as well as mutations. The risk of DNA damage increases with the duration of space flight and the intensity of radiation.

In addition, microgravity and other space-related factors can also lead to changes in gene expression, which can affect the functioning of cells and organs, and potentially lead to health problems. Some of the possible effects of space-related DNA damage and gene expression changes include:

• Increased risk of cancer: Space radiation can increase the risk of developing cancer, as it can damage DNA and cause mutations in cells.
• Immune system dysfunction: Space radiation and microgravity can affect the functioning of the immune system, making it more difficult for the body to fight off infections and diseases.
• Cardiovascular changes: Microgravity can cause changes in the cardiovascular system, including changes in blood pressure and heart rate.
• Changes in gene expression: Space radiation and microgravity can affect the expression of genes, leading to changes in the functioning of cells and organs.
• Psychological problems: Space radiation and microgravity can also affect the brain, leading to psychological problems such as anxiety, depression, and sleep disorders.

It's important to note that while the effects of space radiation on human DNA is studied, the results are not definitive, and more research is needed to understand the long-term effects of space travel on human DNA and overall health.

It's important to note that scientists and engineers are working on ways to mitigate these negative effects and to develop new technologies that will allow humans to travel in space for longer periods of time and with less risk to their health.

“Space is just not very hospitable to the human body,” said Emmanuel Urquieta, chief medical officer at the Translational Research Institute for Space Health in Houston, which partners with NASA to study the effects of deep space exploration. Humans evolved in conditions of plentiful gravity and relatively slight background radiation, he said. Space is the reverse and it upends the operations of almost every biological system inside of us. 

Most of the potential health risks of space travel can be mitigated to some extent, scientists point out. Exercise, for instance, “is quite effective” at helping astronauts maintain muscle mass and bone density, said Lori Ploutz-Snyder, the dean of the University of Michigan School of Kinesiology. She was previously a researcher at NASA, where she led studies of exercise and space travel. 

On the space station, astronauts routinely work out for about an hour most days, she said, using specialized devices to run, cycle and lift weights, despite being weightless. But on lunar and Mars missions, which will involve smaller ships and possibly years-long durations, exercise equipment will need to be shrunk and astronauts’ willingness to keep up with the workouts enlarged.

[To counter the effect of sitting too much, try the astronaut workout] The Earth’s magnetic field shields the relatively close-in space station as well from some of the worst deep-space radiation, but the lunar and Mars missions — higher and farther from Earth — will not enjoy that protection. The moon and Mars journeys will demand advanced shielding, Urquieta said, together with drugs and supplements that might lessen some of the internal effects of the remaining — and inevitable — radiation.

Antioxidants, such as vitamins C and E, could sop up a portion of the damaging molecules released after radiation exposure, while other protective drugs and nutrients are under investigation, he said. Despite every available precaution and protection, deep space will remain a harsh, unwelcoming place for the human body. 

But it will also, and always, represent something else for the human imagination, Urquieta said — its endless sweep of sequined darkness sparking our ambitions, dreams and stories. Which is why, even knowing better than most people the toll such a trip might take on him, he would go into space “in a heartbeat,” he said. “Absolutely. No question. It’s so inspiring. It’s space."