Sunpower's Dynamic Conversion to Flight with the Advanced Stirling Convertor (ASC-F)

Sunpower is a Free-piston Stirling engine (FPE) company in Athens, OH with nearly 40 years of experience in FPSE research, development, and prototyping. Since 2003, Sunpower has been developing the Advanced Stirling Convertor (ASC) under technology development contracts with NASA Glenn Research Center (GRC) and a flight contract through Lockheed Martin Space Systems (LMSSC). ASC convertors will be integrated by LMSSC into the Advanced Stirling Radioisotope Generator (ASRG) for delivery to DOE and NASA as a Radioisotope Power Source (RPS) for potential selection for a Discovery 12 mission. With the support of GRC, LMSSC, and the Department of Energy (DOE), Sunpower has transformed from a pure research and development company to a qualified space flight hardware provider to LMSSC. The ASC has been the vehicle for this transformation through several builds that progressed from a technology demonstration (FTB convertors), to engineering units which began to implement generator interfaces (ASC-E convertors), to engineering units to demonstrate repeatability/manufacturability, flight-like processing and quality system implementation (ASC-E2 convertors), to the concurrent builds of the flight-like (ASCE3) and flight (ASC-F) convertors. To succeed in this transformation, Sunpower changed its corporate culture and strategy. Sunpower established a quality assurance department and implemented a quality assurance program that has successfully been audited by Lockheed Martin, NASA, and DOE personnel. Sunpower has significantly increased and enhanced its facilities, production capabilities, and design practices to meet flight requirements and standards. This paper provides a historical account of the transformation at Sunpower and discusses the significant changes at Sunpower in quality assurance, facilities, capabilities, and engineering practices and the role played by team members in facilitating those changes. Additionally, this paper will present a current status of the ASC-F project which will supply a total of eight convertors to the ASRG program. The ASRG is currently under consideration for two potential Discovery 12 missions to become the first dynamic flight Radioisotope Power Source.