We report the results of on-orbit exploration of the electrical properties of thin-film structures of the Y-Ba-Cu-O and Bi(Pb)-Sr-Ca-Cu-O HTSC systems. The HTSC samples were integrated into a special measuring device placed on the ''Mir'' Space Station during 6 months and then transferred down to earth. The results of the measurements show that strict conditions of space flight do not negatively influence the superconducting properties of the HTSC materials. However, superconducting properties were strongly worsened by the process of integration into measuring device and transportation of the integrated structures. These results show that HTSC film structures can be used in devices working in space but it is necessary to improve substantially the process of integration of the structures into hybrid circuits.