Firefly Aerospace to fly Zeno Power's radioisotope heater through the lunar night

Firefly Aerospace has announced a commercial payload agreement with Zeno Power Systems that puts nuclear heat on the Moon's near side — and targets one of the hardest environmental qualification problems in space hardware: surviving two weeks of darkness at cryogenic temperatures.

The thermal problem

The lunar night lasts approximately 14 Earth days, and it is brutally cold. Temperatures on the Moon can range from over 230°F during the lunar day to below -275°F at night — a swing that kills unprotected electronics, batteries, and mechanisms. Any hardware intended for sustained surface operations must be engineered for that environment, not just the daylight phase.

Firefly has measured this firsthand. The mission builds on the success of Blue Ghost Mission 1, which achieved the first successful commercial moon landing in 2025.

"Firefly is proud to collaborate with innovative companies like Zeno to solve one of the most complex challenges of lunar exploration – surviving the lunar night," said Ray Allensworth, Vice President of Spacecraft at Firefly Aerospace.

The payload: passive heat from radioactive decay

The scheduled launch is no earlier than 2028. At the center of the mission is Zeno's Survive-the-Night Package, built around a 5W thermal americium-241 Radioisotope Heater Unit (RHU). The RHU generates passive thermal energy through the natural decay of radioactive material — no moving parts, no reliance on sunlight. That's the point: the payload will operate during the lunar night and transmit operational data back to Earth, proving the concept in the exact conditions it's designed for.

For manufacturing and hardware engineers, the appeal of an RHU architecture is its simplicity. Passive decay heat sidesteps the mass and complexity penalties of active electrical heating through a 14-day blackout.

"Hardware capable of surviving the extreme cold of the lunar night will be essential to enabling sustained operations on the moon," said Tyler Bernstein, CEO and co-founder of Zeno Power.

Why it matters beyond one mission

This is not a one-off stunt. NASA's Moon Base Program has identified the need for radioisotope power systems to support future lunar exploration, and the mission will provide critical data to advance radioisotope and nuclear-powered technologies for future lunar missions. Flight heritage from a survive-the-night demonstration de-risks the technology for everything that follows — longer surface stays, infrastructure that can't afford to shut down every two weeks, and operations in cold environments where solar simply isn't an option.

The 2028 flight will be the real test. If the Survive-the-Night Package phones home from the far side of sunset, radioisotope heating moves from promising to proven.