Shuttle derived
From NewMarsWiki
Several shuttle derived vehicles have been proposed over the course of the space shuttle program. A shuttle-derived launch vehicle is one which is built using component parts whose design incorporates major components of the space shuttle launch system. This is intended to save money on development costs, and reflects the approach used to develop the Zenit launch vehicle from the Energia launch vehicle.
Variations of shuttle derived launch vehicle designs include:
Shuttle C Shuttle Z Ares Magnum Heavy Launcher Crew Launch Vehicle (CLV)
To date, no shuttle derived vehicle has successfully flown.