A reusable launch system (or RLV: reusable launch vehicle) is a launch vehicle which is capable of launching into space more than once. This is in opposition to an expendable launch system, where each launch vehicle is launched once and then discarded.

No true orbital reusable launch system exists as of January, 2005. The closest example is the US Space Shuttle. The Orbiter, which includes the main engines and the two solid rocket boosters, is reused after several months of refitting work for each launch. The external fuel tank is discarded.

During the late 1970s and 1980s, the Soviet Union built the closely related but now defunct Shuttle Buran. Only the orbiter -- which had no main engines -- and its four Kerosene/LOx rocket side-boosters were reusable. The Buran was launched successfully on November 15, 1988 and returned from space intact, but since this was the sole orbital flight for the vehicle, its reusability was not proven.

Orbital RLVs are thought to provide the possibility of low cost and highly reliable access to space. However, given the lack of experience with these vehicles, the actual costs and reliability are yet to be seen. Recently, two companies -- SpaceX and Kistler Aerospace -- have developed but not yet launched reusable and partially reusable orbital RLVs.

Two manned suborbital RLVs have been developed and launched. The X-15, flown between 1959 and 1969, was a collaboration between NASA, the United States Air Force, and the United States Navy. The Scaled Composites SpaceShipOne first flew in 2004 and is currently in use. Several companies have developed manned suborbital RLVs to pursue the Ansari X-Prize (including Scaled Composites), or to provide a testbed for suborbital and orbital RLV technologies.

Orbital reusable launchers

Currently in use

• US Space Shuttle (partially reusable)

Planned

• SpaceX Falcon I (partially reusable; maiden flight May, 2005)
• SpaceX Falcon V (partially reusable; maiden flight 2nd quarter, 2006)
• Kistler Aerospace K-1 (maiden flight schedule not yet announced)

Historical

• Soviet Union Buran (partially reusable)

Suborbital reusable launchers

Currently in use

• Scaled Composites SpaceShipOne

Planned

• Armadillo Aerospace Black Armadillo
• Canadian Arrow
• Pablo de Leon & Associates Gauchito
• TGV Rockets MICHELLE-B
• Aeronautics and Cosmonautics Romanian Association (ARCA ) Orizont
• Starchaser Industries Starchaser V - Thunderstar
• The da Vinci Project Wild Fire MK VI
• XCOR Aerospace Xerus

Historical

• North American X-15