Latvian startup Deep Space Energy is developing a compact radioisotope power generator that it says can deliver the same output as legacy space nuclear systems while using five times less fuel, El.kz cites Interesting Engineering.

The company has raised €350,000 in pre-seed funding and secured an additional €580,000 in public contracts and grants to push the technology toward commercialization.

The system converts heat from radioactive decay into electricity. The heat source comes from radioisotopes extracted from commercial nuclear reactor waste, primarily Americium-241.

Unlike traditional radioisotope thermoelectric generators (RTGs), which rely on thermocouples to convert heat into power, Deep Space Energy claims its architecture significantly improves fuel efficiency.

According to founder and CEO Mihails Ščepanskis, the company has already validated the technology in laboratory conditions.

The key differentiator is the reduced fuel requirement, which directly affects mass, cost, and scalability in space missions.

The generator is designed as an auxiliary or primary power source for satellites operating where solar energy is unreliable or insufficient.

Five times less fuel

“Our technology, which has already been validated in the laboratory, has several applications across the defence and space sectors. First, we’re developing an auxiliary energy source to enhance the resilience of strategic satellites. It provides the redundancy of satellite power systems by supplying backup power that does not depend on solar energy, making it crucial for high-value military reconnaissance assets,” Ščepanskis said.

Traditional RTGs require large quantities of radioactive material to sustain output over long durations.

Deep Space Energy states that its system would need about 2 kg of Americium-241 to generate 50 W of electrical power for a lunar rover. Comparable legacy systems would require roughly 10 kg of radioisotope material for the same output.

This mass reduction has direct launch-cost implications. Every kilogram sent to the Moon can cost up to €1 million.

Cutting radioisotope mass by 80 percent could significantly lower mission budgets or free up capacity for additional payload.

The company is targeting satellites in Medium Earth Orbit, Geostationary Orbit and Highly Elliptical Orbit. In these regions, spacecraft support synthetic aperture radar imaging, signal intelligence and missile-launch detection systems.