Put nuclear technology in space or on the moon, and just as on Earth it can provide a power density unmatched by any other source. But what roles can nuclear power and propulsion play as the world enters a 21st-century space race? That was a key question put to six speakers during the November 14 American Nuclear Society Winter Meeting plenary session “Space: The (Next) Nuclear Frontier.”

Ultra Safe Nuclear (USNC) announced on October 17 that it had been awarded a contract by NASA to develop and mature space nuclear thermal propulsion (NTP) systems to advance the nation’s cislunar capabilities. Under the contract, USNC says it will manufacture and test proprietary fuel and simultaneously collaborate with its commercial partner, Blue Origin, to mature the design of an NTP engine optimized for near-term civil science and cislunar missions.

Sometimes, even with decades of research and testing, a project never gets off the ground. That has been the case for U.S. nuclear thermal rockets—so far. Research began in the 1950s and peaked with a series of rigorous ground tests for NERVA—the Nuclear Engine for Rocket Vehicle Applications—before the program was canceled in 1973. Five decades on, this technology has yet to make it to the launchpad. But while mission priorities shift, the physics is solid: Fission-powered nuclear thermal rockets (NTRs) still offer two to five times greater efficiency than conventional rockets.

NASA has selected 11 companies, including Zeno Power, to develop technologies that could support long-term exploration on the moon and in space. The technologies range from lunar surface power systems to tools for in-space 3D printing, which will expand industry capabilities for a sustained human presence on the moon through the Artemis program, as well as other NASA, government, and commercial missions.

BWX Technologies announced today that it has been selected to supply the nuclear reactor and fuel for the Defense Advanced Research Projects Agency’s Demonstration Rocket for Agile Cislunar Operations (DRACO) program—the goal of which is to demonstrate a nuclear thermal propulsion (NTP) engine in orbit.

The Department of Energy recently shipped half a kilogram of plutonium oxide pellets from Oak Ridge National Laboratory to Los Alamos National Laboratory, the agency announced July 18, marking the largest such shipment since the DOE restarted domestic plutonium-238 production over a decade ago.

Ultra Safe Nuclear (USNC) announced on June 21 that it has selected the city of Gadsden, Ala., to host a $232 million MMR assembly plant. Modules for the company’s high-temperature, gas-cooled and TRISO-fueled microreactor, dubbed the Micro-Modular Reactor (MMR), would be manufactured, assembled, and tested at the “highly automated facility” once it is in operation.

Westinghouse Electric Company says its eVinci microreactor technology is “100 percent factory built and assembled before it is shipped in a container to any location.” And “any location” is not restricted to planet Earth, given the company’s goal of sending a scaled-down version of eVinci to the lunar surface or on a mission to provide power in other space applications.

Three winners have been announced in NASA’s Power to Explore Student Writing Challenge, in which U.S. students in kindergarten through 12th grade could participate by writing about imaginary space missions using radioisotope power systems (RPSs). Out of almost 1,600 submitted entries, 45 semifinalists, and nine finalists, Luca Pollack of Carlsbad, Calif. (in the K–4th grade category), Rainelle Yasa of Los Angeles, Calif. (in the grades 5–8 category), and Audrielle Paige Esma of Wildwood, Fl. (in the grades 9–12 category) snagged the top prize in their age groups. The April 25 announcement by NASA includes links to the winning essays.

Earthbound air travel can be a hassle, even for careful planners. So if you’re heading to the Moon or beyond, it’s time to shift your planning into hyperdrive. Our advice, when there’s no guidebook, no proven vehicle, and your destination is a moving target? Don’t forget to pack your nuclear power bank.

Under the Radioisotope Power Systems Program, NASA and the Department of Energy have been advancing a novel radioisotope power system (RPS) based on dynamic energy conversion. This approach will manifest a dynamic RPS (DRPS) option with a conversion efficiency at least three times greater than a thermoelectric-based RPS. Significant progress has recently been made toward this end. A one-year system design phase has been completed by NASA industry partner Aerojet Rocketdyne, which resulted in a DRPS with power of 300 watts-electric (W_e) with convertor-level redundancy. In-house technology development at the NASA Glenn Research Center (GRC) has demonstrated the conversion devices in relevant environments and has shown all requirements can be met. Progress has also been made on the control electronics necessary for dynamic energy conversion. Flight-like controllers were recently upgraded and achieved an 11-percentage-point increase in efficiency. Control architectures have been developed to handle the multiconvertor arrangements in the latest DRPS design. A system-level DRPS testbed is currently being assembled that will experimentally demonstrate the DRPS concept being pursued.

Lisa D. May

Mikaela Blood

Sara M. Sanders

At the advent of space nuclear power in the 1960s, the combination of fundamental nuclear principles and first-of-its-kind spacecraft technology were the largest barriers to entry. In the modern era, however, nuclear power production and space technology have matured industries and no longer present major challenges. These days, the biggest hurdles are advanced flexible technology development, regulations and policy, and public perception, and these issues must be successfully navigated to clear the way for a nuclear future in space.

Miguel Alessandro Lopez

At the University of Rhode Island, I initially enrolled as a candidate for an accelerated track to earn bachelor’s and master’s degrees in mechanical engineering, with a minor in nuclear engineering. My objective was to concentrate on reactor power design and join efforts to make nuclear energy safer, more efficient, and less stigmatized.

My plans changed after I attended a guest presentation on high-performance nuclear thermal propulsion (HP-NTP) led by Michael Houts, manager of NASA Nuclear Research at Marshall Space Flight Center. He posted his email address on one of the last slides, so I took a chance and contacted him about potential research opportunities and thesis work. As it turned out, that one little email ultimately led to four NASA-sponsored design projects at URI—two are complete, and two are in progress—as well as my thesis. My research has been on HP-NTP, specifically the centrifugal nuclear thermal rocket (CNTR) design. In that design, liquid uranium is heated to extremely high temperatures in a cylinder that is rotated between 5,000 and 7,000 revolutions per minute as liquid hydrogen passes through the center of the cylinder, where it is heated and expanded, exiting as a propellant while the liquid uranium is retained by centrifugal force.

The International Atomic Energy Agency is inviting teens aged 14 to 18 to submit original comic book pages depicting a space-based nuclear science experiment on agricultural seeds that the agency is conducting with the United Nations’ Food and Agricultural Organization (FAO). The contest is offering prizes, including publication of the winning designs on the IAEA website, for the champion and finalists. The deadline for submissions is April 16.

A 16-university team of 31 scientists and engineers, under the title Consortium for Nuclear Forensics and led by the University of Florida, has been selected by the Department of Energy’s National Nuclear Security Administration (NNSA) to develop the next generation of new technologies and insights in nuclear forensics.

This year the American Nuclear Society’s Nuclear and Emerging Technologies for Space (NETS 2023) conference, which will be held May 7–11, 2023, in Idaho Falls, Idaho, is focusing on powering the next era of space exploration through nuclear-enabled technologies and is sure to be the can’t-miss event of the year for those in the aerospace community.

NASA and the Defense Advanced Research Projects Agency (DARPA) have announced they will collaborate on plans to launch and test DARPA’s Demonstration Rocket for Agile Cislunar Operations (DRACO). DARPA has already worked with private companies on the baseline design for a fission reactor and rocket engine—and the spacecraft that will serve as an in-orbit test stand—and has solicited proposals for the next phase of work. Now NASA is climbing on board, deepening its existing ties to DRACO’s work in nuclear thermal propulsion (NTP) technology—an “enabling capability” required for NASA to meet its Moon to Mars Objectives and send crewed missions to Mars. NASA and DARPA representatives announced the development at the American Institute of Aeronautics and Astronautics SciTech Forum in National Harbor, Md., on January 24.

NASA’s Artemis I mission, successfully launched at 1:47 a.m. EST on November 16 from the Kennedy Space Center in Florida, will travel 40,000 miles beyond the moon—farther from Earth than any human-crewed space mission has flown before. The historic trip was launched by the world’s largest rocket, the Space Launch System (SLS), nearly 50 years after NASA last sent humans to the moon. And while no humans are on board the Orion spacecraft, two fabricated crew members—“Luna Twins” Helga and Zohar—were assembled with thousands of sensors to obtain the best estimates yet of cosmic radiation exposure to human tissues during space travel.

General Atomics Electromagnetic Systems (GA-EMS) has completed the baseline design of a reactor and engine for a nuclear thermal propulsion (NTP) rocket and has successfully tested key reactor components under contract from the Defense Advanced Research Projects Agency (DARPA), the company announced on November 7. The work was performed under a Track A, Phase 1 contract for the Demonstration Rocket for Agile Cislunar Operations (DRACO) program; Phases 2 and 3 of DRACO could culminate in a demonstration of the nuclear-propelled spacecraft in cislunar space (the region between the Earth and the Moon) during fiscal year 2026.