The Comet HLLV was a proposed super heavy-lift launch vehicle designed for NASA's First Lunar Outpost program, which was in the design phase from 1992 to 1993 under the Space Exploration Initiative. It was a Saturn V-derived launch vehicle with modernized engines, stretched fuel tanks, and strap-on boosters. Its main goal was to support the First Lunar Outpost program and future human mission to Mars. It was designed to be inexpensive and simple while relying on existing technology to lower development costs.