Avalanche Energy Wins $5.2M DARPA Contract to Build High-Density Radioactive Batteries for Space
A US nuclear fusion startup has secured a major defense contract to develop a new class of radioactive batteries for space applications. Avalanche Energy won a $5.2 million award from the Defense Advanced Research Projects Agency (DARPA) to build compact, resilient nuclear batteries capable of powering a laptop-class system for months. The contract is part of DARPA's strategic 'Rads to Watts' program, which explicitly aims to overcome the critical limitation of existing radioisotope power systems: low energy density. This move signals a focused push by the Pentagon's advanced research arm to leapfrog current power storage technology for demanding, long-duration missions beyond Earth.
Radioactive batteries, or radioisotope thermoelectric generators (RTGs), are not new; they have powered deep-space probes like NASA's Perseverance and Curiosity rovers on Mars and are used in some medical implants. However, their widespread adoption for smaller, more agile systems has been hampered by their bulk and low power output relative to their mass. DARPA's program, and Avalanche Energy's role in it, targets a fundamental breakthrough: creating a radiovoltaic converter with significantly higher energy density. The startup, which is primarily focused on fusion energy, is applying its expertise in managing high-energy particles to this adjacent challenge, developing prototypes tested under high-energy ion-beam irradiation.
The implications of success are substantial, extending beyond military space applications. A compact, high-density nuclear battery would enable longer-lasting power for small satellites, remote sensors, and autonomous systems in environments where solar power is unreliable or impossible. It represents a potential paradigm shift in how long-duration, low-maintenance power is supplied for critical infrastructure in isolated or extreme conditions. The contract places Avalanche Energy at the forefront of a niche but strategically vital intersection of advanced nuclear physics, materials science, and defense technology, with DARPA betting on a fusion startup to solve a persistent power problem for the next generation of space assets.