The Shuttle-Derived Heavy Lift Launch Vehicle (“HLV”) was an alternate super heavy-lift launch vehicle proposal for the NASA Constellation program. It was first presented to the Augustine Commission on 17 June 2009.
Based on the Shuttle-C concept which has been the subject of various studies since the 1980s, the HLV was a Shuttle-Derived Launch Vehicle (SDLV) that proposed to replace the winged Orbiter from the Space Shuttle stack with a side-mounted payload carrier. The Space Shuttle’s External Tank (ET) and four-segment Shuttle Solid Rocket Boosters (SRBs) would have remained the same.
The side-mounted Heavy Lift Launch Vehicle had a wide range of exploration cargo missions along with a CEV launcher for lunar missions using the same basic launcher and infrastructure.
This configuration is a straight-forward derivative of the current STS configuration, replacing the reusable Shuttle orbiter with an expendable payload carrier.