Shuttle-Derived Launch Vehicle, or simply
Shuttle-Derived Vehicle (SDV), is a term describing one of a wide array of concepts that have been developed for creating space
launch vehicles from the components, technology and infrastructure of the
Space Shuttle program. SDVs have also been part of NASA's plans several times in the past. In the late 1980s and early 1990s, NASA formally studied a cargo-only vehicle,
Shuttle-C, that would have supplemented the crewed Space Shuttle in orbiting payloads.