A hot fire test of the core stage for NASA’s Space Launch System rocket at Stennis Space Center in Mississippi was not completed as planned. The SLS is the vehicle meant to propel a crewed mission to the moon in 2024. Source: NASA Television

Among the executive orders President Trump issued during his last weeks in office was “Promoting Small Modular Reactors for National Defense and Space Exploration,” which builds on the Space Policy Directives published during his term. The order, issued on January 12, calls for actions within the next six months by NASA and the Department of Defense (DOD), together with the Department of Energy and other federal entities. Whether the Biden administration will retain some, all, or none of the specific goals of the Trump administration’s space nuclear policy remains to be seen, but one thing is very clear: If deep space exploration remains a priority, nuclear-powered and -propelled spacecraft will be needed.

The prospects for near-term deployment of nuclear propulsion and power systems in space improved during Trump’s presidency. However, Trump left office days after a hot fire test of NASA’s Space Launch System (SLS) rocket did not go as planned. The SLS rocket is meant to propel crewed missions to the moon in 2024 and to enable a series of long-duration lunar missions that could be powered by small lunar reactor installations. The test on January 16 of four engines that were supposed to fire for over eight minutes was automatically aborted after one minute, casting some doubt that a planned November 2021 Artemis I mission can go ahead on schedule.

A new research contract between the U.K. Space Agency and Rolls-Royce will see planetary scientists working together to explore nuclear power as an energy source for deep space missions in the decades to come. The effort is similar to one that the United States is undertaking through NASA.

"Space nuclear power and propulsion is a game-changing concept that could unlock future deep-space missions that take us to Mars and beyond," said Graham Turnock, chief executive of the U.K Space Agency, on January 12. "This study will help us understand the exciting potential of atomic-powered spacecraft, and whether this nascent technology could help us travel further and faster through space than ever before."

Here is a look back at the top stories of 2020 from our Research and Applications section in Newswire and Nuclear News magazine. Remember to check back to Newswire soon for more top stories from 2020.

Research and Applications section

• ARDP picks divergent technologies in Natrium, Xe-100: Is nuclear’s future taking shape? The Department of Energy has put two reactor designs—TerraPower’s Natrium and X-energy’s Xe-100—on a fast track to commercialization, each with an initial $80 million in 50-50 cost-shared funds awarded through the Advanced Reactor Demonstration Program. Read more.

An artist's concept of a fission power system on the lunar surface. Image: NASA

A national strategy for the responsible and effective use of space nuclear power and propulsion (SNPP)—Space Policy Directive-6 (SPD-6)—was released by the White House on December 16 as a presidential memorandum.

Space nuclear systems include radioisotope power systems and nuclear reactors used for power, heating, or propulsion. Nuclear energy can produce more power at lower mass and volume compared to other energy sources and can shorten transit times for crewed and robotic spacecraft, thereby reducing radiation exposure in harsh space environments. SPD-6 establishes a road map for getting space nuclear systems into service and sets up high-level goals, principles, and federal agencies’ roles and responsibilities.

Illustration of a Mars transit habitat and nuclear electric propulsion system. Image: NASA

NASA aims to develop nuclear technologies for two space applications: propulsion and surface power. Both can make planned NASA missions to the moon more agile and more ambitious, and both are being developed with future crewed missions to Mars in mind. Like advanced reactors here on Earth, space nuclear technologies have an accelerated timeline for deployment in this decade.

Space nuclear propulsion and extraterrestrial surface power are getting funding and attention. New industry solicitations are expected this month, and a range of proposed reactor technologies could meet NASA’s specifications for nuclear thermal propulsion (NTP). Nuclear electric propulsion could increase the feasibility of crewed missions to Mars with a shorter transit time, a broader launch window and more flexibility to abort missions, reduced astronaut exposure to space radiation and other hazards, expanded payload mass capabilities, and reduced cost.

A “visionary view” of a nuclear thermal propulsion–enabled spacecraft mission. Image: NASA

Secretary of Energy Dan Brouillette and NASA Administrator Jim Bridenstine on October 20 signed a memorandum of understanding to continue decades of partnership between the Department of Energy and NASA and to support the goals of NASA’s Artemis program. These include landing the first woman and the next man on the moon by 2024 and establishing sustainable lunar exploration—using nuclear propulsion systems—by the end of the decade to prepare for the first human mission to Mars.

BWX Technologies has signed a $26-million, 20-month contract to expand and upgrade its TRISO fuel manufacturing line. The recently announced deal, awarded by Idaho National Laboratory, calls for the expansion of BWXT’s capacity for the manufacture of TRISO fuel compacts and the upgrading of existing systems for delivering production-scale quantities of TRISO fuel.

Brouillette

In remarks addressed to a meeting of the National Space Council on May 19, Energy Secretary Dan Brouillette said that the development and deployment of small modular reactors could provide sustainable power sources for space applications.

The United States is pursuing the objective to land humans more than 100 million miles away on Mars, and nuclear power has the potential to be a key technology in getting to the Red Planet and providing power while there. Specifically, nuclear thermal propulsion (NTP) is a promising approach that could enable astronauts to travel from Earth’s orbit to Mars and back in a fraction of the time, and with greater safety, than is available with other options.