NASA described recent tests of solid-state battery prototypes in an October 14 research update. The SPEARS project is led by Glenn Research Center in Cleveland, with thermal-vacuum testing at Langley Research Center in Hampton, Virginia.

Small cells operated up to 80 degrees Celsius and down to minus 60 Celsius, with reduced performance at minus 80 Celsius. NASA also reported that exposure to temperatures from 100 to minus 170 Celsius did not damage the prototypes.

Surviving extreme cold is not the same as producing power at that temperature. NASA says heaters would warm the batteries back into their operating range after very cold exposure, potentially reducing the need to keep equipment continuously warm.

The design replaces a liquid electrolyte with a solid ceramic- or polymer-based material. Potential uses include lunar tools, rovers, instruments and emergency power, but these remain development goals rather than proven mission deployments.

Ames Research Center in California is developing supporting flight hardware and electronics. The program is still focused on technology development; further testing and preparation are needed before these laboratory results can establish flight readiness.