Air Force Titan IV Centaur launch vehicle 250 ampere-hour lithium-thionyl chloride battery development, qualification and flight status

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A Lithium battery development and qualification program jointly funded by the Air Force and mission specific Titan IV-Centaur payloads was completed during 1992. The four phase approach implemented resulted in successful qualification of a Lithium battery for the Titan IV-Centaur launch vehicle. The Technology Demonstration Phase supported the concept feasibility for manually activated 250 Ampere-Hour (A-Hr) Li-SOCI2 cells. The Cell and Battery Design Phase identified potential vendors and demonstrated Li-SOC12 cell and battery manufacturing feasibility. The Cell and Battery Characterization Phase provided a data base for cell and battery performance, identified safety characteristics through abuse testing, and performed a vendor down-select with further contractual award to SAFT (Poitiers, France) and Yardney (Pawcatuck, CN). The Battery Qualification Phase verified the Li-SOCI2 battery build to print capability and producibility, and qualified the SAFT Li-SOCI2 battery for flight use on the Titan IV Centaur Launch Vehicle. This paper summarizes the effort to date, and the flight status of a 250 Amp-Hour Lithium-Thionyl Chloride battery for the USAF Titan IV-Centaur launch vehicle. I N T R 0 D U C T I0 N Martin Marietta Technologies Incorporated (MMTI) has been prime contractor to the Air Force for development, program management, production, payload integration, and launch operations for the Titan IV space launch system. There are three Titan IV launch vehicle configurations supporting various operational missions. The Titan IV-Centaur launch vehicle is capable of inserting 10,000 pound payloads into geo-synchronous orbits. The MMTl Titan IV team strives for launch vehicle improvements via system and component weight reductions to enhance payload performance capability. The Centaur upper stage 126 pound 250 amperehour Silver-Zinc batteries supporting the Centaur main vehicle and payload power buses were identified as candidates for significant potential weight savings for the Titan IV-Centaur launch vehicle configuration. Saving hundreds of pounds was feasible by simply replacing the Silver-Zinc batteries with higher energy density Lithium-Thionyl Chloride (Li-SOCI2) batteries. However, Lithium battery technology for large capacity batteries (> 100 ampere-hours) had not yet been proven and qualified for aerospace flight applications. Lithium batteries for Titan IV-Centaur was one of the early performance enhancement candidates identified for the Titan IV-Centaur launch vehicle. The approximation that a 250 Ampere-Hour (A-Hr) Li-SOC12 battery would weigh 50 pounds less than that for a 250 A-Hr Silver-Zinc battery resulted in potential weight savings of hundreds of pounds. Payload interest in this significant weight savings potential resulted in the Titan IV-Centaur Lithium battery effort that was initiated in the mid 1980's. MMTl had been tasked with technical oversight for the development and qualification of a Li-SOC12 battery for the Titan IV-Centaur launch vehicle. MMTl was also responsible for Cape Canaveral Air Force Station (CCAFS) facility modifications and integration associated with processing and launching Lithium batteries. MMTl has applied a systems engineering approach toward the Titan IV-Centaur Lithium battery effort. Specific engineering functions and responsibilities were defined to ensure compatibility of the Lithium battery with Titan IVCentaur and all applicable payloads. The Air Force contracts for the development and qualification of the Lithium batteries with the specific battery vendors have been through General Dynamics Space Systems Division (GDSS), and the Jet Propulsion Laboratory (JPL). The USAF also sought technical consultation from the Aerospace Corporation and TRW. The four phase programmatic approach taken for the Lithium battery effort in support of Titan IV-Centaur included a Technology Demonstration Phase, Cell and Battery Design Phase, Cell Characterization Phase, and Battery Qualification Phase. MMTl fully supports Lithium battery technology for implementation onto the Centaur upper stage for Titan IV missions. It is the intent of this paper to provide the reader an overview of how the Titan IV-Centaur Lithium battery team achieved this status and an understanding of MMTl's position on what needs to be done to fly Lithium batteries on a Titan IV-Centaur