A space-based orbital transfer vehicle - Bridge to the future

A comparison is made between a space-based and earth-based orbital transfer vehicle (OTV) for use in the Shuttle era and beyond. The space-based vehicle alleviates the limited capability inherent in an earth-based OTV whose design is constrained by a particular launch vehicle. Several sizes of space-based OTVs were generated and compared with an earth-based system for a number of mission scenarios with varying types and levels of traffic. The space-based OTVs showed substantial cost savings for each scenario, with the smallest space-based vehicle showing the largest saving. The space-based OTV retains the cost advantage even if the number of missions or the Shuttle cost-per-flight is drastically reduced.