Sending hardware to the Moon means planning for a battery nightmare that makes an overheated phone in a parked car look positively cozy. Lunar temperatures can reach 212 degrees Fahrenheit (100 degrees Celsius) in daytime conditions, while nighttime temperatures at the Moon’s south pole can drop as low as minus 328 degrees Fahrenheit (minus 200 Celsius). NASA is developing battery technology intended to remain viable in those punishing conditions through a project called SPEARS.

SPEARS stands for Solid Power for Extreme Environment Adaptability and Resilience in Space. Its central idea is straightforward, although the engineering challenge is anything but: replace the liquid electrolyte used in typical lithium-ion batteries with a solid material, such as a ceramic or polymer. The work is being pursued for extreme environments including Mars, and the resulting technology could potentially support future Moon campaigns, including Artemis missions.

Why ordinary lithium-ion batteries have a lunar problem

Most familiar electronics rely on lithium-ion batteries with a liquid electrolyte. An electrolyte is the battery component that enables charge to move between its internal elements. This arrangement is commonplace on Earth, but temperature is one of its persistent weaknesses.

At low temperatures, a liquid electrolyte can freeze. That can damage the battery, making a conventional design a poor fit for a place where temperatures can fall hundreds of degrees below zero. Heat creates another constraint: lithium-ion batteries also do not operate properly at very high temperatures. The Moon presents both ends of that range, not a single predictable climate that engineers can design around once and forget.

That extreme swing matters because batteries are not a minor accessory in a spacecraft or surface mission. They are part of the foundation for electronics and other equipment that must keep working when direct sunlight is unavailable, when conditions turn frigid, or when systems need carefully controlled power. A battery that is itself vulnerable to the environment can force a mission to devote substantial energy and complexity to protecting its energy storage.

The practical problem is not simply getting a battery to turn on after it becomes cold. It is preventing damage while maintaining an energy strategy that does not consume too much of the power it is meant to preserve. In other words: the power pack cannot become the hungriest thing on the mission.

What SPEARS changes: a solid electrolyte

SPEARS investigates batteries that use a solid ceramic or polymer material instead of a liquid electrolyte. “Solid-state” describes that change in battery construction: the material responsible for conducting charge is solid rather than liquid.

The project’s current result is measured but significant. These alternative batteries still need to be warmed before they can function. They are not being presented as magic cells that casually operate at minus 328 degrees Fahrenheit without preparation. However, they have not been damaged by the extreme cold encountered in the work so far, and they require thermal-management systems that are less energy-intensive than those used with lithium-ion alternatives.

Related coverage includes NASA’s SPEARS Battery Work Targets the Moon’s Severe Temperature Swings.

Thermal management is the set of methods used to keep a system within its usable temperature range. For a battery, that can mean warming it in cold conditions or limiting excessive heat. On the Moon, the energy spent doing that job is a major design consideration. If a battery needs less energy-intensive temperature control, more of a mission’s available energy can potentially be directed toward the equipment the battery is supposed to support.

That distinction is important. The SPEARS work does not eliminate the need for heat. It may reduce the burden of supplying and managing it. In severe environments, lowering a system’s overhead can be as useful as improving the headline performance of a single component.

The Moon’s south pole raises the stakes

The cited low of minus 328 degrees Fahrenheit is specifically associated with nighttime conditions at the Moon’s south pole. That makes the challenge particularly relevant to planning for lunar work where cold can be extraordinarily severe. A power solution that tolerates extreme cold without being damaged could widen the margin for mission hardware operating in locations that conventional liquid-electrolyte batteries struggle to endure.

There is also a useful difference between survival and operation. A battery can require warming before it works while still offering an advantage if deep cold does not ruin it. That resilience changes the mission question from “can this battery survive the temperature?” to “how efficiently can the mission bring it to operating temperature?” SPEARS is aimed at improving that second part without pretending the first concern disappears.

For Artemis-related lunar campaigns, this is the kind of behind-the-scenes hardware development that rarely grabs attention like rockets and landers do, yet it can determine how capable surface technology becomes. Batteries influence the practical limits of powered tools, instruments and other electronics. Their design also affects how much insulation, heating, and power budgeting engineers need to build around them.

Why ceramics and polymers matter

The two solid-material directions named for SPEARS are ceramics and polymers. In this context, the key factual point is not that one has been declared the universal winner, but that both offer an alternative to a liquid electrolyte that can freeze. The project is therefore focused on materials as much as on the battery as a finished object.

A ceramic is a solid material class often associated with hard, inorganic substances. A polymer is a material made from long repeating molecular structures. SPEARS is considering each as a potential solid electrolyte route. The important shared property for this work is that they replace the vulnerable liquid component in the battery architecture.

That materials focus illustrates a broader engineering reality: a major improvement sometimes arrives not from asking a familiar device to work harder, but from changing the part that makes its current design unsuitable for the job. Here, the obstacle is the liquid electrolyte’s susceptibility to cold, and the response is to investigate a battery that does not rely on that liquid in the first place.

What has been demonstrated—and what remains uncertain

The information available supports a promising but appropriately cautious read of SPEARS. The solid-electrolyte batteries have so far avoided damage from extreme cold and can operate after being warmed. They also need less energy-intensive thermal management than lithium-ion counterparts. Those are meaningful attributes for space hardware exposed to tremendous temperature changes.

At the same time, there is no basis here to assume a finished SPEARS battery is ready for every lunar use, that it will certainly fly on a particular Artemis mission, or that it has replaced standard lithium-ion designs. The stated goal is future application in Moon campaigns, while the project is also developing batteries for Mars-like extreme climates. The potential is clear; the mission-specific deployment details are not.

It is equally too early to treat the project as a confirmed consumer-electronics upgrade. The technology could one day power devices on Earth, but that remains a possibility rather than a promised product. Space research can yield terrestrial benefits, yet a battery designed to cope with lunar cold must still travel a long path before it becomes something inside a phone, a wearable, or a game controller.

That consumer angle is still worth watching because temperature remains a familiar limitation for everyday portable electronics. As the comparison in our look at the Fitbit Edge and Fitbit Air shows, hardware choices can reshape the experience of devices people use constantly. For SPEARS, though, the immediate story is not a feature race on Earth. It is the much harsher requirement that a battery endure a world where deep-freeze nights and intense daytime heat are both routine.

The real promise is resilience with a lower energy penalty

NASA’s work reframes the battery challenge as one of resilience. In ordinary conditions, lithium-ion technology is widespread because it effectively powers much of modern electronics. The Moon’s thermal extremes expose its limits. SPEARS seeks a design that is less vulnerable to cold-induced damage while requiring less energy to manage its temperature.

For lunar exploration, that could be a valuable combination. A battery that survives deep cold and places a smaller thermal-management demand on the rest of the system may help engineers design more practical power arrangements for harsh destinations. It will still need warming. It will still need careful integration. But it may no longer need the same level of protection demanded by a liquid-electrolyte battery.

That is the quiet appeal of the project. No matter how dramatic a mission looks from Earth, it ultimately relies on components that keep working when the environment becomes unreasonable. SPEARS is an attempt to make one of those essential components a little less likely to be defeated by the weather on another world.