Shuttle-Derived Heavy Lift Launch Vehicle

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.

According to initial estimates, the HLV could have been developed within 41⁄2 years for about US$6.6 billion,^[1] which was about 20% of the costs estimated for the Ares I and Ares V vehicle development.