Reusable launch systemA 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 July, 2004. The closest example is the US Space Shuttle (or the closely related but defunct Soviet Buran). The Shuttle is partially reusable. The orbiter itself and most of the solid rocket boosters 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. 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 orbital 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. \n
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"A husband is what is left of the lover after the nerve has been extracted." - Helen Rowland (1876-1950) |
