What did the tests actually show?

In recent thermal vacuum testing at Langley, small prototype cells — coin-cell size, small enough to hold in one hand — operated well from 176 F (80 C) down to minus 76 F (minus 60 C), and with slightly reduced performance down to minus 112 F (minus 80 C).

"We proved for the first time that these cells can work down to minus 80 degrees Celsius," said Yi Lin, SPEARS testing and research lead at NASA Langley.

Lin added that he is confident the team can improve performance and possibly expand that range in the coming years.

The tests also exposed the cells to swings from 212 F to minus 274 F. The batteries do not function at the lowest temperature — no solid-state cell can yet — but they sustained no damage and can be revived with small heaters. That distinction matters: because the batteries only need warming to operating temperature rather than constant heating, spacecraft and lunar habitats could shed heavy thermal management systems, allowing lighter designs, lower costs and longer missions.

What changes for lunar operations?

If the technology matures, SPEARS batteries could power a short list of critical hardware:

• Emergency power packs in an astronaut's survival kit.
• Drills and tools operating inside permanently shadowed craters.
• Rovers exploring the Moon's darkest regions.
• Long-duration scientific instruments.

The chemistry is also tunable. "Just like the chemistry in your earbuds is different from the chemistry in your phone, which is different from the chemistry in your car, all these chemistries can still function with a solid electrolyte," Lin said. "We can tune for energy, tune for power, tune for durability, depending on the application."

Could the technology reach Earth?

SPEARS itself grew out of an earlier battery project Lin and Dornbusch worked on for aeronautics, and the spin-offs could point back toward terrestrial markets.

"The potential market for solid-state batteries is very broad," said Ji Su, a polymer materials scientist and task lead at NASA Langley. "Automobiles, cell phones, communication devices, drones — anything that needs a portable power supply."

The project's first stages focus on technology development, with a possible later shift toward commercial collaboration. NASA's Ames Research Center in Silicon Valley is developing flight hardware, including test boards and electronics, to prepare the batteries for spaceflight and test them in space environments.

The results so far come from small prototype cells, not flight-ready hardware, and the demonstrated operating floor of minus 112 F still sits well above the minus 328 F of the lunar night — the survival-at-extreme-cold result and the heater-based revival strategy are what bridge that gap. Scaling from coin cells to rover-sized power packs remains ahead.

For now, the takeaway fits in one line: the batteries cannot run in the Moon's deepest cold, but for the first time they have shown they can live through it and wake up.