This is a beautiful sheet of 6 stamps, issued in 2010, displaying space stations and astronomers. Featured on the sheet are the Russian space station Mir, NASA's space station Skylab, International Space Station (ISS) research facility, French Catalan mathematician & physicist François Jean Dominique Arago, Danish astronomical & planetary observer Tycho Brahe, and Italian Dominican philosopher & astronomer Giordano Bruno. The sheet is fresh, mint never hinged, and F/VF.