The Pegasus rocket is an air-launched winged space launch vehicle capable of carrying small, unmanned payloads (443 kilograms (980 lb)) into low Earth orbit. It became operational in 1990 and remains so as of 2013[update]. It is air-launched, as part of an expendable launch system developed by Orbital Sciences Corporation (Orbital). Three main stages burning solid
propellant provide the thrust. It flies as a rocket-powered aircraft before leaving the atmosphere.

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