The baseline orbital maneuvering system (OMS) of the Space Shuttle has the potential for significant performance uprating, leading to increased Shuttle payload capability. The baseline OMS, its requirements, and its operational characteristics are described. Potential uprating approaches are discussed and the logic for selection of a higher performance engine is presented. It is shown that a higher performance engine essentially means an engine operating at higher pressures and that a pump-fed engine is necessary for the higher pressure operation.A description of the uprated OMS engine, including requirements, baseline engine characteristics, and significant engine issues, is presented. Discussion of the program underway at the NASA Lyndon B. Johnson Space Center to attain additional insight into these issues, through the performance of a component demonstration program, includes the technical objectives, approach, and program schedule. The plans for further development are presented, culminating in the plans for integration with the Orbiter and the Shuttle system.