A reusable launch system (or RLV: reusable launch vehicle) is a launch vehicle which is capable of launching more than one payload into space. This is in opposition to an expendable launch system where each launch vehicle is only used once and then discarded.
No true reusable launch systems exist as of 2003. The closest example is the US Space Shuttle (or the closely related but defunct 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 to refit them for each launch.
RLVs are usually thought to provide the possibility of lower-cost access to space. However, given the lack of human experience with them, their actual costs are yet to be seen. The one existing semi-example, the Space Shuttle, is not at all an inexpensive vehicle.
