Biologists are going to study effects of space travel on microscopic life form . they want to find out if it possible to survive for long periods in space . the microorganisms are on an unmanned spacecraft which set off for Mars in 2009. it will land there, pock up some Martian soil and than come back to earth. a team of geologists is going to analyse the soil. if everything goes well, the spacecraft will get back to Earth in two year's time