Antares

Antares is a nuclear fission energy company building factory-produced, transportable microreactors that deliver strategic power for mission-critical systems across land, sea, and space. Founded in 2023 and headquartered in Torrance, California, its R1 reactor uses TRISO fuel, sodium heat pipes, and a nitrogen Brayton cycle to produce 100kWe-1MWe for six-plus years. In June 2026 its Mark-0 reactor became the first privately developed advanced reactor to achieve criticality under the U.S. Department of Energy's Reactor Pilot Program.