In space environment, radiation dose due to high charge and high energy particles (HZE) and other cosmic radiation is, in general, 2 to 3 orders of magnitude greater than the dose from cosmic rays which are falling on the surface of the Earth. Although radiation dose during 7 to 8 day Shuttle mission is so small as to cause any harmful effect on astronauts, this will change with the advent of Space Station and manned Mars Mission. The purpose of our experiment is to examine possible effects of space radiation on living organisms, particularly the genetic effects. For this, we are analyzing mutations induced in fruit flies of the species Drosophila melanogaster during the space flight.