| • Science | • People | • Locations | • Timeline |
| Contents | ||
No true orbital reusable launch system exists as of July, 2004. The closest example is the US Space Shuttle. The Orbiter itself, which includes the main engines, and the two solid rocket boosters ( Space Shuttle Solid Rocket Booster) are reusable, after extensive refurbishment, while the external fuel tank is not. The Orbiters and SRBs require several months of work of refitting for each launch.
Also there was the closely related but now defunct Soviet Buran. Only the orbiter, which had no main engines, was re-usable. It has returned intact, but since there has been only one orbital flight, it has not actually been reused.
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.