The U.S. Army is asking nuclear companies to submit their proposals for microreactors that can be commissioned at military bases to provide clean, reliable power at two domestic military sites.

The bid solicitation window is short—just two weeks—but the army is asking for very high-level proposals from advanced nuclear companies who are ready to jump into action. Following the initial submission period, top contenders for the project will be invited back for pitch sessions; full contracts then will be negotiated.

The Defense Innovation Unit (DIU), a Department of Defense organization focused on swiftly putting commercial technology to use in the U.S. military, has awarded contracts for two nuclear technologies—compact fusion and radioisotope heat—for spacecraft that could carry a high-power payload and freely maneuver in cislunar space. The objective is to accelerate ground and flight testing and launch a successful orbital prototype demonstration of each approach in 2027.