NASA reported on October 14 that small SPEARS solid-state battery prototypes operated during thermal-vacuum tests down to minus 80 degrees Celsius, with reduced performance at that temperature. The cells also survived exposure down to minus 170 degrees Celsius without damage, according to the agency.
Survival does not mean operation: NASA says the batteries cannot work at the lowest exposure temperature and would need heaters to return to their operating range. The project began in 2026, with flight-hardware preparation underway. The results describe prototype testing, not a flight-qualified battery or a commercially available power pack.
NAOAT analysis
For a mission designer, cold survival changes the scheduling problem. Equipment that can remain dormant without continuous heating might be managed differently from equipment that must stay warm throughout a long idle period. The useful comparison is the complete energy budget across storage, preparation and operation, rather than the lowest temperature in a test report.
Consider an instrument that wakes periodically to take measurements. A design team could compare the energy needed to maintain warmth continuously with the energy needed to reheat before each measurement. The answer would depend on the duration of the idle period, thermal losses and the instrument’s required readiness time. The battery result supplies a reason to examine that tradeoff; it does not decide it for every mission.
Emergency equipment creates a different constraint. An energy-saving storage strategy is useful only if the equipment can become ready within the time its task allows. Warm-up delay and the source of restart energy would therefore belong in the operating requirements from the beginning.
Finally, qualification should follow the assembled system. Cells, heaters, controls and packaging must work together through repeated cycles, not merely survive separate tests. This is an engineering implication of the proposed architecture, not a claim that NASA has completed those checks. The potential benefit is flexibility in managing dormant equipment, provided recovery time, usable energy and the complete thermal design support the intended job.