In recent times long-term stay has become a common occurrence in the International Space Station (ISS). However adaptation to the space environment can sometimes pose physiological problems to the astronauts after their return. Therefore it is important to develop healthcare technologies for astronauts. In this study hair an easy-to-obtain sample was identified as the candidate. In order to investigate the genetic changes in human hair during space flight the hair follicles of 10 astronauts were analyzed by DNA microarray and real time q-PCR analyses. Space environment induced gene expression of hair follicles of astronaut was measured 6 differnent times included 2 in flight on orbit. Ten independent experiments were performed on differing astronauts. and the sampling day was differed for each astronaut because of their schedules.