IDAHO FALLS — For 35 years, Dave Hendricks’ career unfolded within the confines of the Idaho desert at Idaho National Laboratory (INL). It was the only workplace he ever knew, yet it provided access to innovations in nuclear technology and space exploration that few outside the facility realize INL even touches.
Now retired, Hendricks reflects on a career that directly contributed to powering spacecraft billions of miles from Earth and advancing nuclear research that continues to shape the future of energy and science. His journey began with a four-year stint in the U.S. Navy, where he received foundational training in nuclear systems.
That training led him to eastern Idaho in 1991, initially working at what was then Argonne National Laboratory–West, located at the INL site. There, he focused on the Experimental Breeder Reactor-II (EBR-II), a pioneering nuclear reactor designed to explore advanced fuel and safety concepts. “I chose Argonne for the opportunity to work on a cutting-edge experimental reactor,” Hendricks said. “Working there was wonderful. It had a very vested and family-like atmosphere right off the bat.”
Hendricks quickly established roots in the area, meeting his wife, Tammy, with whom he would later raise two children over a 30-year marriage. His career at INL evolved through several phases, beginning with work at the Hot Fuel Examination Facility and the Fuel Conditioning Facility from 1996 to 2002. These highly secure facilities allowed scientists to safely study nuclear fuel after its use in a reactor, utilizing remote-controlled equipment and heavily shielded rooms.
From 2002 to 2003, Hendricks transitioned to the engineering lab, broadening his experience in testing, design and applied research. A significant turning point arrived in 2005 when Battelle Energy Alliance assumed management of INL, ushering in a new era focused on national security, energy, and space-related work.
Hendricks noted that the terrorist attacks of September 11, 2001, fundamentally altered the trajectory of INL. The resulting emphasis on national security prompted a comprehensive reevaluation of vulnerable sites, leading to the selection of INL for a major new mission. “If 9/11 hadn’t happened, we likely wouldn’t have reevaluated our security,” Hendricks said. “Something good came from something terrible.”
This shift facilitated the relocation of critical space-power work from the former Mound Laboratory in Ohio to Idaho. A new facility was constructed at INL to support the development of radioisotope thermoelectric generators (RTGs) – long-lasting nuclear “batteries” essential for powering spacecraft in environments where solar energy is impractical. “RTGs don’t store power like household batteries. Instead, they convert heat from the natural decay of plutonium-238 into electricity, producing steady power for decades,” Hendricks explained.
From 2004 to 2017, Hendricks was deeply involved in INL’s space power program. He played a key role in assembling the first RTG used for NASA’s New Horizons spacecraft, launched in 2006 and achieving a flyby of Pluto in 2015. “INL played a critical behind-the-scenes role in designing, testing, and certifying the nuclear power system that keeps New Horizons operating billions of miles from the sun, long after solar panels would have become useless,” Hendricks said.
He later supervised a second RTG assembly, remaining with the space program until 2017. This work extended to supporting NASA’s Mars exploration efforts, including the Curiosity and Perseverance Mars rovers, both of which continue to operate on the Martian surface.
“Curiosity paved the way, while Perseverance represents the next generation of Mars exploration, including collecting samples for eventual return to Earth,” Hendricks said. Both rovers rely on nuclear power due to the challenges posed by Mars’ dust storms, frigid temperatures, and vast distance from the sun, rendering solar energy unreliable. INL engineers were responsible for testing and certifying the power systems that enable the rovers to endure these harsh conditions and sustain long-term exploration.
“It’s been very satisfying knowing what my hands helped assemble and the role it played in our space technology,” Hendricks said. “If we did something wrong, the experiments would be useless. The mission would be dead.”
From 2018 until his retirement in , Hendricks returned to the Hot Fuel Examination Facility, contributing to the development and research of Post-Irradiation Examination (PIE). This process, described by Hendricks as a “medical checkup” for nuclear fuel, involves carefully examining fuel after its use in a reactor to assess its performance, identify wear and damage, and inform the design of safer and more efficient future reactors.
Hendricks identified his work on New Horizons and the two Mars rovers as the most rewarding aspects of his career. “I’m all in on nuclear energy,” he said. “I’m proud to be part of the advances in nuclear technology. It’s the right path forward for worldwide energy, and I hope the enthusiasm for nuclear keeps going.”
He also expressed a desire for greater public awareness of the work conducted at INL. “If you’re not a site worker, or a friend or relative of one, it’s a mystery,” Hendricks said. “The average person doesn’t really know what’s going on out there. It’s taken for granted.”
“With safer reactors, I believe we’re leaving the world in a better, safer place,” he added. “It’s gratifying knowing I played a part in that. It’s been a great career.”
Now 58 years old, Hendricks is looking forward to retirement, planning to travel with his wife, Tammy, in their motor coach, explore the Oregon coast, and dedicate more time to his hobbies of hunting, fishing, and restoring classic cars.
