We are all too familiar with the hazards humans face when traveling to and returning from space. Often overlooked are the dangers astronauts face every day in space. Some of those environmental hazards could affect the health of the astronauts long after they return to Earth.
On board the International Space Station, crewmembers can receive high doses of radiation from the sun and other sources. These doses can be hundreds of times greater than the levels they might experience on Earth. There are a variety of measures these explorers take to help minimize the amount of radiation they receive. For example, work outside the station is restricted when radiation levels are especially high. In addition, the station has some radiation protection materials built into its walls and personal sleep areas. These efforts combine to make the risks from radiation acceptable, but it does not completely eliminate the problem. In the future, humans traveling deep into our solar system, beyond the protection of Earth's magnetic field, will face a greater danger from radiation.
Weightlessness or microgravity presents another problem. About 40 percent of space travelers get space sickness in the early days of a mission. The difficult adjustment usually passes within a few days, but weightlessness causes other health issues. Most space travelers who spend more than a month on orbit experience a loss of muscle tone and a decrease in bone density. Calcium and other minerals are lost from bone mass whenever it is not being stressed by gravity.
The astronauts exercise daily to support muscle tone, but upon return to Earth they never fully regain the original bone mass they once had.
Discover what it takes to become an astronaut and the perils that lurk in space for humans in the Buhl Planetarium's newest high-definition full-dome immersive show, "Astronaut," now playing daily at Carnegie Science Center.