On December 16, the White House released Space Policy Directive 6, which lays out a plan for the development of space nuclear power and propulsion (SNPP) technology. The Directive comes as part of a larger Trump Administration effort to revive space exploration: creating the Space Force, resurrecting the National Space Council (which had been dormant for nearly two decades), and unveiling a new National Space Policy on December 9, 2020.
Nuclear-powered flight was discussed for decades by engineers, policy makers, and yes, sci-fi writers. Yet, fusion reactors are not here yet, let alone dilithium anti-matter powered reactors allowing warp speed. The current, slow SNPP systems include radioisotope power systems (RPSs) and fission reactors used for power or propulsion in spacecraft, rovers, and other surface elements.
Nuclear propulsion offers the best versatility for deep space missions, such as Mars and asteroid landing operations. Due to their superior energy density, these systems offer nearly twice the efficiency of the best chemical engines paired with comparable thrust levels.
Nuclear power being used for space exploration is not new; NASA has used radioisotope thermoelectric generators (RTGs), which convert the heat generated by radioactive decay of plutonium-238 into electricity in Voyager 1 and 2 probes, the New Horizons Pluto spacecraft, and the Curiosity Mars rover. RPS and RTG power provides a number of advantages over solar power, as the latter often requires unworkably large solar panels in addition to complementary batteries for ‘nighttime’ operations (when sunlight is not available).
According to Directive 6, “The ability to use space nuclear power and propulsion systems safely, securely, and sustainably is vital to maintaining and advancing United States dominance and strategic leadership in space.”
The memorandum outlines the policy and its aims, including the rather ambitious goal to “demonstrate a fission power system on the surface of the Moon” (keeping in mind that no human has set foot on the Moon since 1972). It also contains a declaration that “The United States will adhere to principles of safety, security, and sustainability in its development and use of SNPP systems, in accordance with all applicable Federal laws and consistent with international obligations and commitments.”
The directive also references the National Security Presidential Memorandum-20, of August 20, 2019, which “updated the process for launches of spacecraft containing space nuclear systems”, and establishes policy to “develop and use space nuclear systems when such systems safely enable or enhance space exploration or operational capabilities”.
SNPP technology could fuel space exploration in environments where other power sources such as solar and chemical fuels are unavailable or inadequate, and would also shorten transit time for spacecraft, leading to less exposure to potentially hazardous environments, and speeding up space travel.
Dr. Scott Pace, executive secretary of the National Space Council commented: “Space nuclear power and propulsion is a fundamentally enabling technology for American deep space missions to Mars and beyond. The United States intends to remain the leader among spacefaring nations, applying nuclear power technology safely, securely, and sustainably in space.”
NASA also issued a statement in support of the directive, with NASA Administrator Jim Bridenstine commenting that SPD-6 “bolsters the agency’s efforts to develop affordable, safe, and reliable nuclear systems, including technology capable of continuously powering operations on other worlds and propelling future human missions to Mars.” NASA currently has the Artemis Program, which plans to land a man and a woman on the moon by 2024, and in the same statement Bridenstine said that “at the Moon we will prepare for new science and human missions deeper into the solar system”.
The interest of the Trump Administration in outer space seems to be more strategic in nature than a scientific one. Competition for dominance of outer space is certainly heating up, and China, which has been embroiled in a trade war with the United States since 2018, just days ago successfully completed an operation to bring back lunar rock and soil samples, and have also expressed interest in establishing a base on the moon.
Brendan Curry, chief of Washington, D.C. operations at the Planetary Society, said that Beijing has not “staked out some sort of declarative statement where they want to replace the United States as leader in space…But they certainly want to be a major actor in space.”
Last year, Vice President Mike Pence announced plans to accelerate America’s return to the Moon by 2024 during a speech in which he warned that China wanted to “seize the lunar strategic high ground and become the world’s pre-eminent spacefaring nation.” NASA is currently prevented from working directly with Chinese space agencies.
Private companies have now also entered the new ‘space race.’ Elon Musk, founder of SpaceX, has said that he plans to send people to Mars by the time that NASA plans to send people to the Moon. Musk himself admits that nuclear power will be integral to any future habitable Martian base.
It remains unclear how the incoming Biden Administration will approach US space strategy and policy, but the new space race – this time with the People’s Republic of China – is inevitable. SNPP systems are poised to play a significant role in the next space race.
With Assistance from Alexandra Perouansky.