Free-piston Stirling power converters have the potential to meet the many future space power requirements for a wide variety of applications with less mass, better efficiency, and less total area than other power converter options. These benefits result in significant dollar savings over the projected mission lifetime. The National Aeronautics and Space Administration (NASA) - Lewis Research Center (LeRC), which has the responsibility to evaluate and develop power technologies that can satisfy anticipated future space mission power requirements, has been developing free-piston Stirling power converters and is bringing the Stirling technology to readiness. As the principal contractor to NASA-LeRC, Mechanical Technology Incorporated (MTI) is under contract to develop the necessary space Stirling technology but also demonstrate the readiness of the technology in two generations of full-scale power converters. The first generation Stirling power converter, the component test power converter (CTPC), initiated cold end testing in 1991, with hot testing scheduled for summer of 1992. This paper not only will review the test progress of the CTPC, but also discuss the potential of Stirling technology for various potential missions at given point designs of 250 watts, 2500 watts, and 25000 watts.