TECHNOLOGY AREA(S): Space Platforms
OBJECTIVE: The objective of this solicitation is development of battery level failure attenuation technologies that can recover from li-ion cell fault or sustain partial operational capability.
DESCRIPTION: Within the past few decades, the defense community has experienced complete power failure on a statistically significant fraction of spacecraft. Fortunately, approximately half of these have been recovered by using the solar array to recharge abuse-tolerant NiH2 batteries. Transition to li-ion is expected to reduce the probability of dead bus recovery regardless of array intervention. This topic is intended for Li-Ion battery technologies and/or li-ion cell chemistries that enable recovery from complete discharge of the available energy in the battery that may lead to completely discharged li-ion cells. Methods to protect the battery from over discharge are of interest. Minimally intrusive primary battery and ultra capacitor hybrids will also be considered. The mass of matching electronics must be included in payoff assessments. Power from the solar array may or may not be present. Proposed approaches should have the ability to accommodate a variety of bus voltages. Technologies that don’t dramatically reduce battery specific energy are desired. The battery technology proposed should be capable of operation in a Low Earth Orbit (LEO) for 5 years and in a Geosynchronous Earth Orbit (GEO) or Medium Earth Orbit (MEO) for 15 years after storage on the ground for 5 years. Definitions:  Dead bus recovery defined as autonomous restoration of spacecraft power should anomalous behavior result in primary power falling below minimum operating level.  Minimum cell voltage is the potential below which detrimental electrochemical processes become dominate. EXCLUSIONS: Excluded from this topic are load shedding architectures, technologies related to preventing degradation of fully discharged li-ion cells (unless it is used as a trigger to initiate recovery), discrete cell bypass switches, deployable solar arrays and photovoltaic technologies.
PHASE I: Perform preliminary analysis, develop concepts and compile material properties for typical spacecraft energy storage systems. Acquire preliminary test results and related performance information in support of performance and payoff estimates.
PHASE II: Fabricate and deliver engineering demonstration unit. Demonstrate recovery or cell isolation with representative ground test. Analytically show space survivability for select concepts.
PHASE III: Build and fly Class D hardware demonstration in Space Environment.
1: Architectures for li-ion based power subsystems, Ang V., TOR-2013-00295, Public Release Document, The Aerospace Corporation, 201
2: Simulation of LEO Missions with NiH or LiIon Batteries Including Dead Bus Recovery using the Power Tools Suite EPS Simulation Codes, Bailey P., AIAA 2010-7172, 8th Annual International Energy Conversion Engineering Conference Nashville, TN, July 2010.
3: US Patent 6596439 B1, Quallion, 2000
KEYWORDS: Resiliency, Spacecraft Power System, Li-ion Battery, Autonomous Recovery