U.S. space exploration history on U.S. stamps also the only space station NASA launched alone. The 100-ton space station was in Earth's orbit from 1973 to 1979 and it was visited by crews three times in 1973 and 1974. Circling 50 degrees north and south of the equator at an altitude of , Skylab had an orbital period of 93 minutes. There were a plethora of UV astronomy experiments done during the Skylab lifetime, as well as detailed X-ray studies of the Sun. The station was active until July 11, 1979, when it fell out of orbit. The 10-cent Skylab commemorative stamp first day of release took
Origins of the International Space Station Almaz ("Diamond") stations. The first MIR-2 module was launched in 1986 by an Energia heavy-lift expendable launch system. The Energia's core stage and boosters worked properly, however the Polyus spacecraft fired its engines to insert itself into orbit whilst in an incorrect orientation due to a programming error, and re-entered the atmosphere. The planned station changed several times, but Zvezda was always the service module, containing the station's critical systems such as life support. The station would have used the Buran spaceplane and Proton rockets to lift new modules into orbit. The spaceframe of Zvezda, also called DOS-8 serial number