41 - Dr. Justin Coleman: The reactor program changing how America powers space and defense

NASA, DOE, and the Department of War are all pulling in the same direction - and the result could reshape how America powers the moon, Mars, and beyond. Dr. Justin Coleman sits inside the programs making it happen, and he breaks down how we get from today’s reactor work to a real nuclear future in space.

From the fuel line at Idaho National Lab to the launch path for SR1 Freedom and Skyfall, this conversation goes deep on the engineering, regulation, and mission design behind the next era of nuclear. If you want to understand why mobile microreactors, space reactors, and nuclear electric propulsion suddenly matter more than ever, this episode is packed with answers.

Justin shares how years of work on spent fuel, structural dynamics, and reactor testing built the foundation for the programs he leads now. He also explains why the space nuclear conversation is moving from “can we do it?” to “how fast can we scale it?” and why the answer depends on supply chains, mass constraints, shielding, and the right engineering team.

We also break down the role of AI in reactor development, what autonomous operation could look like on Earth and eventually off-world, and why the future of nuclear is not just about electricity - it’s about mobility, resilience, and exploration.

Dr. Justin Coleman is a licensed Professional Engineer and currently serves as the Senior Technical Advisor to the NASA Administrator for Nuclear. In this role, he provides expert technical and strategic guidance on space nuclear technologies to NASA’s top leadership. He is also the Division Director in Nuclear Science and Technology at Idaho National Laboratory (INL), focused on delivering reactor prototypes, and mission driven research and development.

In his previous role, Coleman was manager for the Special Reactor Concepts organization at INL. In that role, he advised and managed the U.S. Department of Defense’s Strategic Capability Office on its mobile microreactor program. In other roles, Coleman developed international collaborations and worked on U.S. bi-lateral agreements with Japan and India.

Coleman has a Ph.D. in earthquake engineering from the University of Buffalo and more than 22 years of experience in nuclear reactor research, facility design, operations, construction, and decommissioning and demolition.

Coleman has served on the American Society of Civil Engineers Nuclear Standards committee. In his free time, he enjoys mountain biking and skiing with his family.

www.ucanpower.org