DARPA’s DRACO nuclear-powered rocket for cislunar operations

WASHINGTON: The Trump administration’s latest space policy sets ambitious goals for development of space nuclear power and propulsion (SNPP) systems for deep space operations — including demonstrating a fission reactor on the Moon to enable long-term stays by US astronauts.

“Looking to the Moon and beyond, the United States must develop and leverage SNPP systems, where appropriate, to enable and achieve US scientific exploration, national security and commercial objectives,” a senior administration official told reporters in a background briefing today. “Space nuclear systems power spacecraft for missions where alternative power sources are inadequate, such as environments that are too dark for solar power or are too far away to carry sufficient quantities of traditional fuels.”

The official elaborated that Space Policy Directive-6, issued today, “sets out goals, principles and a supporting roadmap to demonstrate US commitment to using SNPP systems safely, effectively and responsibly. Space nuclear power and propulsion systems are fundamentally enabling technologies for creating a sustainable American presence on the Moon and deep space missions to Mars and beyond.”

The official explained that, while there have been numerous experimental activities to develop SNPP systems at DoD, NASA and the Energy Department, the National Space Council “wanted to bring more coordination” to those efforts. The Trump White House also has been wanting to encourage  revitalization of the nuclear power industry” on Earth, the official added.

For example, DARPA is working on the Demonstration Rocket for Agile Cislunar Operations (DRACO), formerly known as “Reactor on a Rocket (ROAR).” DRACO “will develop and demonstrate a High-Assay LowEnriched Uranium (HALEU) nuclear thermal propulsion (NTP) system.”

The new rocket would allow the US military to operate spacecraft in cislunar space, which DARPA’s budget documents call the “new high-ground” that is “in danger of being defined by the adversary.” As Breaking D readers know, senior Air Force and DoD officials are increasingly pushing the need for the United States to expand its military space activities to cislunar space to counter China — which has a robust civil lunar exploration program that many in the US national security community suspect is a cover for military ambitions.

NASA is working on similar nuclear thermal propulsion rockets using low-enriched uranium. Most uranium isn’t actually radioactive, so it has to be processed — enriched — to make it usable for power. Natural uranium contains less than only 1 percent of the rare isotope U-235. Commercial light-water reactors use uranium enriched to between 3 and 5 percent U-235. By contrast, nuclear weapons and the Navy’s nuclear reactors for submarines use highly enriched uranium, enriched to 90 percent U-235. NASA is looking at enrichment levels between 5 and 20 percent, closer to commercial reactors than to military systems.

Administration officials were quick to stress that SPD-6 has absolutely nothing to do with building nuclear weapons in space. They emphasized that the US is active in UN discussions of peaceful uses of nuclear power in space, and that SPD-6 is fully in line with international guidelines. Further, the official said, “The use of highly enriched uranium in space ecosystems should be limited to applications where the mission is not viable with other nuclear fuels or non-nuclear power options.”

Indeed, both Russia and Chinese also are working on nuclear propulsion for spacecraft. “The use of nuclear power in space is something that the international community does recognize as a very important and enabling capability. Of course we use it, the Russians use it, the Chinese use it. The Russians have announced plans, a preliminary design, for a very powerful space tug. So, among the major space countries this is definitely a topic of interest.”

An administration expert told reporters the Trump administration is setting an “ambitious timeline” for development of new capabilities. By the mid-2020s, the goal is to develop capabilities that enable production of fuel suitable to a range of lunar, planetary and in-space applications; by the mid- to late-2020s, “to demonstrate an efficient power system on the Moon; and by the late-2020s, to establish the technical foundation for capabilities that will enable options for in-space nuclear propulsion.” Finally, the official added, by 2030, SPD-6 envisions development of “advanced radioisotope power systems to enable survivable services and extended robotic exploration” on the Moon, Mars and beyond.

Asked about the viability of the new directive, given Democrat Joe Biden’s imminent inauguration, the senior administration official noted that SPD-6 was developed by an interagency process over the last couple of years. “We see this policy as representing a broad consensus within the relevant communities, and being in alignment with long-term national interests. So, therefore, I am hopeful that it will continue, but that’s not my decision to make.”

SPD-6 lays out the following principles, according to a White House press release:

  • The United States will pursue goals for SNPP development and utilization that are both enabling and ambitious:
  • Develop capabilities that enable production of fuel suitable to a range of planetary surface and in-space SNPP applications;
  • Demonstrate a fission power system on the Moon;
  • Establish technical foundations and capabilities that will enable options for in-space nuclear propulsion; and
  • Develop advanced radioisotope power systems to enable survivable surface systems and extend robotic exploration of the solar system.
  • The United States will adhere to principles of safety, security, and sustainability in its development and utilization of SNPP systems.
  • The United States will pursue a coordinated roadmap for Federally supported SNPP activities and a framework to encourage commercial activities to achieve goals and uphold the principles established in this Directive.