Building a permanent presence on the Moon requires more than generating large amounts of electricity. It also depends on the small, reliable power systems that quietly keep critical infrastructure operating when sunlight disappears.

At Intuitive Machines, is is exploring low-power radioisotope energy systems designed to produce anywhere from a few watts to a few hundred watts. While modest in output, these systems could play an outsized role in supporting continuous lunar operations. Their purpose is simple: keep essential systems alive through the Moon’s two-week lunar night, when solar power is unavailable.

Potential applications include lunar navigation beacons, communications systems, scientific instruments, and landers operating in low-power survival modes until the Sun returns. Rather than designing every mission with the expectation that equipment will be lost during the lunar night, these technologies enable spacecraft and surface systems to survive the extreme cold, remain operational, and be ready to resume exploration when daylight returns

The system uses a Stirling engine that converts heat into electricity. Today, Intuitive Machines is working to prepare the START technology demonstration aboard the International Space Station, where an electrically heated version will validate the Stirling generator in the space environment before future systems incorporate radioisotope heat sources.

The team is also evaluating radioisotopes which offer a long operating life while requiring less shielding than some alternatives, making it an attractive option for small, long-duration lunar power systems.

Looking beyond individual missions, Intuitive Machines envisions these systems supporting a distributed network of infrastructure across the lunar surface. Small, long-duration power sources could enable navigation beacons, communications relays, environmental monitoring stations, and scientific instruments to operate independently for years.

As more assets are deployed, they become connected pieces of a larger operational network that future explorers and commercial users can rely upon.

These compact power systems complement larger fission reactors by keeping distributed infrastructure operating across the lunar surface. Together, they create the resilient energy architecture needed for continuous exploration.

Getting to the Moon is the first milestone. The space infrastructure that Intuitive Machines is building, including energy systems.