Humans have an innate urge to explore the unknown and as space enthusiasts like to say ‘space is the final frontier.’ But scientists warn extended space exploration is not going to be easy because we are not made for longer stays in that alien world.
According to a report published in The New York Times, scientists preparing astronauts for missions to the Moon, an asteroid or Mars, want to make sure that crews return home in good health. But many issues still wait for solutions
First of all, we evolved on a planet whose surface is more than 70 percent water, and our bodies consist of about the same percentage of water. In zero gravity that water floats upwards, raising the pressure inside the skull, while legs atrophy.
That may be the reason why five years ago scientists among astronauts, spending longer times on the International Space Station (ISS), reported gradual change in eyesight. Subsequent research confirmed that eyeballs of some of them became flattened. The fact that the phenomenon appears to affect the right eye more than the left one and men more than women makes the problem even more daunting.
Bone loss was one of the issues first reported by astronauts returning to Earth after longer stays in space, so scientists designed exercise machines that helped them keep their bones almost as good as when they left.
There are other issues, such as trouble with eating and sleeping, but radiation remains the biggest of them. At home we are all protected by the Earth’s atmosphere and its magnetic field, which are nonexistent in outer space.
NASA does not allow the cancer risk for its astronauts to be raised more than three percent during their lifetime, due to the danger of developing cancer. But at Brookhaven National Laboratory, on Long Island, scientists studying the effect of cosmic rays on mice say they also detected possible brain damage.
Another problem is the impossibility of real-time conversation with mission control during long flights, such as to Mars, as it will take minutes for each response to get back.
Meanwhile, sealed up in their spaceship for months, astronauts who must work as a well-adjusted, cohesive team may develop personality issues.
U.S. space agency NASA plans to send humans to Mars sometimes in the third decade of this century. The mission would take about 2.5 years - almost six times longer than the longest stay in space to date. Partly due to the need for more medical research about effects of longer stay in space NASA extended the life of the International Space Station to 2024.
Beginning 2015 an American astronaut and a Russian cosmonaut are scheduled to stay on the station one full year. One of them, Russian Valery Polyakov already stayed longer than a year on the Russian space station Mir in 1994 and 1995.
With today’s more sensitive instruments and methods, scientists want to find out whether all the changes in the human body and mind, due to prolonged stay in zero gravity, will continue or level off after a few months.