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
Andover Earth Station Since the satellite was not in a geosynchronous orbit like modern communication satellites, it passed overhead quickly, and the giant antenna had to be precisely steerable to track the satellite as it moved across the sky. Telstar was launched on July 10, 1962 from the Cape Canaveral Air Force Station and went into orbit at 4:46 a.m. The engineers at the Andover Earth Station would have to wait 15 hours for the satellite, travelling at a rate of 5 miles per second (8 km/s), 3,000 miles (4,800 km) above the earth to reach within their "view". The engineers successfully sent