Antares Nuclear awarded $161 million for space nuclear reactor technology

Antares Nuclear has been awarded $161 million by the U.S. Air Force to advance nuclear reactor technology for space applications. This represents the largest Department of Defense contract for space nuclear power to date.

The program focuses on the R1-S reactor technology, which utilizes portable sodium heat pipe-cooled technology and TRISO fuel to generate up to one megawatt of electricity. The company aims to power an operational ground-to-space asset with its Mark-1 electricity-producing reactor, with testing scheduled for 2027. The R1-S design uses heat pipes to move heat without conventional mechanical components, reducing the risk of failure in the vacuum and radiation of space.

This development aligns with the Trump administration's push for expanded nuclear energy use in space. Under Executive Order 14369, the administration seeks to deploy a nuclear reactor in orbit as early as 2028 and a reactor on the moon by 2030. The technology is being developed at the Department of Energy’s Idaho National Laboratory under the DOE’s reactor pilot program.