Ever since the the first rover landed on Mars decades ago, people have been wondering: what’s next? What else are we going to send to this planet? Could humans go on vacation on Mars, or maybe even live there for years at a time?
These questions have come up again in recent years, when three astronauts landed in Kazakhstan after spending six months aboard the International Space Station. These astronauts, and many others who have gone on previous missions, had experienced similar health issues: their eyeballs were squashed, resulting in farsightedness; they tended to eat and sleep less while in space; and the vestibular fluid in their inner ears, which gives people their sense of direction, made the astronauts extremely disoriented once they returned to gravity. Scientists think these are results of the lack of gravity in space. Fluid would build up in the top of the body, increasing the pressure in the brain, eyes, and chest.
The tricky thing is, it’s very difficult to predict these kinds of effects without sending people into space first. Even now, many decades after the first space mission, scientists have trouble explaining some of the “side effects” that astronauts have developed. And these are definitely major concerns if we want to spend more time in the ISS, or travel to Mars.
An astronaut is strapped to a treadmill aboard the ISS. In an environment with no gravity, exercising is required to keep bones from weakening and being broken down by the body. (Photo courtesy of innova-pain.com)
Even though farsightedness wouldn’t have a huge effect on someone’s life, and vertigo would probably go away after a few days, NASA is worried about other less obvious, more dangerous, effects that astronauts might suffer. The massive amount of radiation that is normally absorbed by earth’s atmosphere could make astronauts more likely to die of cancer. And what are the long-term effects of having a lot of fluid in your head for a long time?
As Dr. Barratt (a physician who stayed at the International Space Station for six months) put it, “What are the long-term implications? That’s the $64 million question.”
Right now, studies are being done (with mice, and with astronauts who have spent time in space) to find out just what these implications are. Researchers are making solid progress and developing new technologies, like the treadmill-harness, to protect against the effects of space travel. It might be decades before we have learned enough to attempt a mission to Mars, but a program that would send healthy astronauts to Mars, and bring them back in the same condition, is definitely an awesome thing to work toward.
Source:
http://www.nytimes.com/2014/01/28/science/bodies-not-made-for-space.html?ref=science