Antares has marked a significant milestone by achieving criticality with its Mark-0 microreactor at Idaho National Laboratory, making it the first private entity to do so under the U.S. Department of Energy’s Reactor Pilot Program. This achievement indicates that the reactor can sustain a nuclear chain reaction, paving the way for electricity generation by 2027 and operational microreactors at military sites by 2028. U.S. Energy Secretary Chris Wright hailed this as a historic moment for American nuclear energy, highlighting the potential of private innovation in the sector. The Mark-0 microreactor is designed for compact power generation, particularly in areas lacking conventional energy infrastructure. It utilizes TRISO fuel, which was developed for defense applications through the military's Project Pele initiative. Despite this progress, some experts express skepticism regarding the commercial viability of microreactors, noting that reaching criticality does not guarantee future success. Antares, however, remains optimistic, stating that this is just the beginning of a roadmap toward full power production and deployment.