ADVANCED PROPULSION CONCEPTS FOR ORBITAL TRANSFER VEHICLES.

Studies of the United States Space Transportation System show that in the mid-to-late 1990s expanded capabilities for Orbital Transfer Vehicles (OTV) will be needed to meet increased payload requirements for transporting materials and possibly men to geosynchronous orbit. NASA is conducting a technology program in support of an advanced propulsion system for future OTVs. This program is briefly described with results to date of the first program element, the 'Conceptual Design and Technology Definition' studies.