TheTechno Optimist.

DOE Pilot Program Demonstration ReactorAntares Nuclear—Antares Nuclear reaches zero-power criticality in DOE Reactor Pilot Program, one of four companies to succeedAntares Nuclear—Antares Nuclear wins $161M Air Force Space Force contract for space reactor developmentAntares Nuclear—Antares Nuclear selected for U.S. Army's Janus Program at Fort Bragg, North Carolina

Antares Nuclear

Microreactor, advanced reactor design, HALEU fuel, DOE demonstration

USprivateChecked 10 Oct

The brief

Analyst view
  • Antares reached zero-power criticality in June 2026, one of four companies in the DOE pilot program.
  • The reactor design uses HALEU TRISO fuel and supports military and space propulsion applications.
  • The company won a U.S. Army Janus Program contract and a $161M Air Force Space Force contract for space reactor development.

Technical approach

As reported
Fuel

HALEU TRISO fuel

Antares uses high-assay low-enriched uranium (HALEU) in TRISO particles, enabling smaller, more compact reactor designs while maintaining safety.

Scale

Microreactor design

Antares focuses on microreactor technology for distributed power and specialty applications including military and space propulsion.

Applications

Multi-mission capability

The reactor design supports ground power, remote locations, and advanced applications like space propulsion systems.

Primer