NASA is pivoting toward nuclear power as the engine for routine deep-space exploration, moving beyond one-off missions to establish permanent human presence on the moon and Mars. NASA Administrator Jared Isaacman visited Idaho National Laboratory (INL) on August 8, 2026, to showcase how small modular reactors (SMRs) developed by private companies will enable an ambitious series of missions starting with Space Reactor-1 Freedom (SR-1), scheduled to launch toward Mars by December 2028.

The shift represents a fundamental change in how NASA approaches long-duration space missions. Rather than relying on solar panels or chemical propulsion, nuclear fission offers the sustained power needed to travel 140 million miles to Mars, operate instruments on distant moons, and support human habitats in environments where sunlight is scarce or unreliable.

Why Is Nuclear Power Suddenly Essential for Space Exploration?

The energy density of nuclear fuel is staggering. A five-inch cube of TRISO (tri-structural isotropic) fuel, one of the most common SMR fuels, contains enough power to send a fully-loaded Saturn V rocket and Apollo capsule to the moon 12 times over. This efficiency gap makes nuclear the only practical choice for missions to the outer solar system, where solar panels become nearly useless and missions last years rather than months.

Isaacman framed the initiative as a generational shift in space capability. He invoked Admiral Hyman Rickover, who pioneered naval nuclear propulsion, noting that Rickover did not attempt to build the most complex fleet imaginable on the first try. Instead, he started with the USS Nautilus and built expertise incrementally. NASA is adopting the same philosophy with SR-1 as its starting point.

"This is our Nautilus, and where we go from here must lead to the nuclear NASA of the future. What should follow is an agency-wide Apollo-like endeavor, a series of SR-missions progressively incorporating new technology, higher-temperature materials, better power conversion, higher-performance thrusters, greater autonomy and more," said Jared Isaacman.

Jared Isaacman, NASA Administrator

What Are the Concrete Milestones NASA Is Targeting?

• Mars Mission by 2028: Space Reactor-1 Freedom will launch and travel to Mars powered entirely by fission, demonstrating that nuclear propulsion works beyond Earth orbit and can sustain long-duration interplanetary travel.
• Lunar Base by 2030: NASA plans to deploy a compact nuclear reactor to the moon to power a permanent human settlement, eliminating dependence on solar cycles and enabling 24/7 operations.
• Outer Solar System Exploration: Future missions will target ice moons like Enceladus and the complex environment of Uranus, destinations that require sustained power and cannot be reached with conventional propulsion in reasonable timeframes.

The INL visit showcased three private companies actively developing SMRs for space applications: Deployable Energy, Antares Nuclear, and Radiant Nuclear. Bobby Gallagher, co-founder of Deployable Energy, demonstrated a cylindrical reactor his team built in just 155 days with $8 million in capital, a pace that underscores how rapidly the technology is advancing.

Antares Nuclear has already contributed directly to SR-1 by designing a heat pipe that NASA is now using in the reactor, illustrating how private innovation is solving technical challenges that government agencies alone might take years to address.

How Is NASA Partnering With Private Industry to Accelerate Nuclear Development?

• Department of Energy Support: The DOE recently ran a program to bring SMR designs to operational status, with multiple companies achieving critical reactor status. This public-private collaboration compresses development timelines and reduces risk for individual companies.
• Technology Transfer: Companies like Antares are designing components that directly feed into NASA's missions, creating a feedback loop where private innovation and government requirements reinforce each other.
• Workforce Development: The initiative is attracting young talent. Students from Idaho State University and the University of Idaho attended Isaacman's speech, with several expressing enthusiasm for joining the nuclear space exploration effort.

Angela Trejo, a 21-year-old nuclear and mechanical engineering student at Idaho State University, told reporters she was excited about NASA's direction. "I just love what NASA is doing now, getting us into space using nuclear. I'm very pro nuclear," she said. Rubicel Trejo, a 23-year-old computer science and applied mathematics student, added that he sees the initiative as "another step for humanity".

What Challenges Remain Before Nuclear Reactors Launch Into Space?

Safety and security concerns persist. Launching a nuclear reactor into space raises questions about containment in the event of a launch failure, and delivering a reactor safely to the lunar surface requires new engineering protocols. However, the scientists and engineers working on the project have made these concerns a top priority, according to INL reactor program manager Dianne Ezell.

Isaacman's vision extends beyond Mars. He emphasized that destinations like the outer solar system require fission-powered spacecraft capable of traveling farther, operating longer, and supporting power-intensive scientific instruments. "The distant worlds and unexplored regions may hold answers to some of humanity's oldest questions, like are we alone?" he said.

The convergence of nuclear technology, private sector innovation, and government commitment signals a turning point in space exploration. Rather than treating Mars as a one-time achievement, NASA is building the infrastructure for routine interplanetary travel, with nuclear power as the foundation.