STS Derivative Cargo Vehicles for the 1990's decade and beyond

Shuttle-derived vehicle options are described in the context of supporting earth-LEO space transportation for the lunar and Mars missions. An evolutionary model is delineated which can provide heavy-lift capabilities for these missions with a system based on STS booster elements. The Shuttle-C unmanned launch system and the Mars heavy-lift launch vehicles (HLLV) are examined as reference vehicles with launch configurations illustrated for lunar and Martian transportation scenarios. The Shuttle-C prelunar vehicle can be modified for lunar transportation as the Shuttle-C Block I which can then be extended to a two-stage HLLV by adding a third stage in the form of a Mars transfer vehicle. The development of a liquid-rocket booster is proposed to replace the STS solid booster for added mission flexibility. The use of shuttle-derived vehicles is concluded to be an effective means for supporting the lunar and Mars initiatives while minimizing near-term costs.