NASA Develops SPEARS Batteries for Moon's Extreme Cold

NASA researchers are developing advanced batteries under the Solid Power for Extreme Environment Adaptability and Resilience in Space (SPEARS) project, designed to function in the brutal cold of the Moon’s South Pole, where nighttime temperatures plummet to minus 328 degrees Fahrenheit (minus 200 Celsius). These robust power sources are crucial for humanity's sustained presence on the Moon through the Artemis campaign, powering everything from astronaut emergency kits to rovers exploring dark craters, all while avoiding fire hazards.

Traditional lithium-ion batteries, found in devices like cell phones, rely on liquid electrolytes which freeze at lunar night temperatures, become inefficient at daytime lunar temperatures of 212 F (100 C), and evaporate in the vacuum of space. SPEARS batteries overcome these limitations by replacing the liquid electrolyte with a solid ceramic- or polymer-based material. This innovation allows them to operate effectively across extreme temperature ranges.

During recent thermal vacuum testing at NASA’s Langley Research Center in Hampton, Virginia, small prototype SPEARS battery cells performed well up to 176 F (80 C) and down to minus 76 F (minus 60 C), with slightly reduced performance observed down to minus 112 F (minus 80 C). Yi Lin, SPEARS testing and research lead at NASA Langley, confirmed, "We proved for the first time that these cells can work down to minus 80 degrees Celsius," expressing confidence in further performance improvements. The batteries also demonstrated resilience, sustaining no damage after exposure to temperature extremes ranging from 212 F (100 C) to minus 274 F (minus 170 C).

While solid-state batteries do not function at temperatures as low as minus 274 F, their solid electrolytes prevent freezing damage. Small heaters are used to warm them to operational temperatures, reducing the need for heavy thermal management systems, which in turn allows for lighter spacecraft designs, lower costs, and longer mission durations. Donald Dornbusch, principal investigator for SPEARS at NASA’s Glenn Research Center in Cleveland, where the project is led, emphasized the necessity of these reliable and safe batteries for the harsh lunar environment.

The applications for SPEARS batteries are extensive, encompassing tools like drills for shadowed lunar craters, rovers, emergency power packs for astronauts, and long-duration scientific instruments. Lin noted the ability to "tune for energy, tune for power, tune for durability, depending on the application." The SPEARS project, which began in 2026 with funding from the Advanced Research and Technology division, is set to transition from technology development to potential commercial collaboration. Ji Su, a polymer materials scientist at NASA Langley, highlighted the broad potential market on Earth, including "Automobiles, cell phones, communication devices, drones — anything that needs a portable power supply."

What to watch: Future flight hardware development by NASA’s Ames Research Center and potential commercial spin-offs of SPEARS technology.

Editor's note: Thoroughly details NASA's SPEARS battery project, test results, and potential applications.