Minotaur is a launch vehicle developed by Orbital Sciences Corporation for the U.S. Air Force's Orbital/Suborbital Program (OSP). Minotaur is a modified Minuteman ICBM (intercontinental ballistic missile) that uses the first two stages of the now-decommissioned Minuteman 2 ICBM and the upper two stages of the Pegasus XL booster.
Minotaur can place up to 340 kilograms into a 740-kilometer sun-synchronous orbit – a payload about 50% greater than that of the Pegasus XL alone. Its first successful operational launch was on January 26, 2000, from Vandenberg Air Force Base, when it placed the JAWSAT payload adaptor, carrying several microsatellites, into orbit.
As of mid-2006, Minotaur had successfully delivered 20 satellites into space during five launches, the most recent in April 2006 when it deployed six spacecraft for a joint Taiwan-U.S. atmospheric research project. In May 2006, two Minotaurs were ordered to loft the U.S. Air Force Research Laboratory's TacSat 2 and TacSat 3 satellites. The first is scheduled for launch in November 2006; the second will follow in September 2007.