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
Paper Aircraft Released Into Space type having been suggested by readers in 2006. The paper plane was successfully launched on 28 October 2010. "The Register" is now working on PARIS' successor, named LOHAN (short for "Low Orbit Helium Assisted Navigator", a balloon-launched rocket-powered aircraft. Paper Aircraft Released Into Space The PARIS (Paper Aircraft Released Into Space) project was a privately organised endeavour undertaken by various staff members of the information technology web site "The Register" to design, build, test, and launch a lightweight aerospace vehicle, constructed mostly of paper and similar structural materials, into the mid-stratosphere and recover it intact. On 28 October 2010, the