In this study, space radiation in low earth orbit in altitude of 500(km) from earth surface and also, effects of this radiation on silver mirrors in vitro dimension with 35(mm) and 24 (mm) diameter and thickness of 2 (mm) from silver mirror with two coating of TiO 2 and Ta 2 O 5 for final coating on MgF 2 on substrate of BK7 glass, was studied. Because of a poor adhesion between the glass and the silver, for better adhesion Inconel is used. Physical vapor deposition technique was used. This samples, are selected after the study on different materials and using a software program designed Macleod Essential in the coating layer. According to studies done on space radiation and conditions in low earth orbit, amount of radiations for a 3-years period in space was considered such as: gamma radiation with dose of 400(Gy), electron radiation with dose of 7500(Gy) and proton radiation with dose of 140(Gy). In addition to this tests, samples were subjected to further test including testes for humidity, temperature, viscosity and oxygen atoms by bombarding standards were necessary. This standards are similar to those that are used for investigation of all optical instruments that was used in space. All of samples that were tested, was investigated with atomic force microscope after radiation and with spectrophotometer in before and after radiation. Results are representative that this mirrors are resistance against mentioned tests. Reflection was not changed in gamma irradiated samples, but the samples were bombarded with oxygen, shift and decline has happened in their reflected diagrams.
