Аннотация:The paper presents the results of space tests of different polymer films. The experiments were carried out aboard Mir Space Station in 1985-1999 and continued aboard the International Space Station (ISS) since 1998. Two types of polymer film samples were studied: unprotected and protected with glass filters. Upon return to Earth, the samples were analyzed using different analytical techniques and the data on mass loss, changes in thickness and changes in optical properties were obtained