US-based BWX Technologies (BWXT) has been contracted to develop the reactor and fuel for the US Defense Advanced Research Projects Agency’s (DARPA’s) Demonstration Rocket for Agile Cislunar Operations (DRACO), which will use nuclear thermal propulsion. As part of a team led by Lockheed Martin, BWXT Advanced Technologies is to complete final design of the nuclear reactor, manufacture the reactor’s hardware and fuel, assemble the components and deliver the fuelled reactor as a complete subsystem.
The reactor’s nuclear thermal propulsion system will allow DRACO to manoeuver through space with great speed and agility for an extended period of time. BWXT says it is designed to be extremely safe and reliable, using High Assay Low Enriched Uranium (HALEU) fuel to rapidly heat a super-cold gas, such as liquid hydrogen. As the gas is heated, it expands quickly and creates thrust to move the spacecraft more efficiently than typical chemical combustion engines.
The spacecraft is targeted for launch from Earth in 2027 in “cold” status. The reactor will be shut down as a part of launch safety protocols and the launch will be by a conventional rocket. The reactor will be powered once the spacecraft attains an appropriate location above low earth orbit. The US Space Force will provide the launch vehicle for the spacecraft and the Department of Energy (DOE) will provide HALEU metal, to be processed into fuel by BWXT.
“The award of this contract further demonstrates BWXT’s ability to design, manufacture and deploy nuclear reactors and fuel on a scale that is unmatched elsewhere in the world today,” said BWXT Advanced Technologies President Joe Miller. “This partnership with Lockheed Martin working for DARPA adds another important dimension to BWXT’s already-impressive line-up of nuclear reactor designs for commercial and defence applications.” Work on this programme will be conducted primarily at BWXT’s Mt Athos Road complex near Lynchburg, Virginia.
Kirk Shireman, Vice President of Lunar Exploration Campaigns at Lockheed Martin Space explained that the more powerful and efficient nuclear thermal propulsion systems can provide faster transit times between destinations. “Reducing transit time is vital for human missions to Mars to limit a crew’s exposure to radiation. This is a prime technology that can be used to transport humans and materials to the Moon. A safe, reusable nuclear tug spacecraft would revolutionise cislunar operations.”
Defining the level of ground testing needed to prove safe, effective operations in space is part of Lockheed Martin’s responsibilities. “Ground testing helps us understand what the expected behaviour and limitations of the nuclear reactor are and how we expect it to respond and interact with the control systems that we’re developing,” said John Bendle, Lockheed Martin Senior Manager, Strategy & Business Development, Human Space Exploration.
DARPA, in collaboration with NASA, is advancing toward the goal of the world’s first in-orbit demonstration of a nuclear thermal rocket (NTR) engine through DRACO. DARPA earlier finalised an agreement for Lockheed Martin to begin work on the fabrication and design of the experimental NTR vehicle (X-NTRV) and its engine. In January, DARPA and NASA signed an agreement to collaborate on the NTR engine, with a focus on more efficiently and quickly transporting material through the cislunar domain and eventually, people to Mars.
“An NTR achieves high thrust similar to in-space chemical propulsion but is two-to-three-times more efficient,” said programme manager Dr Tabitha Dodson. “With a successful demonstration, we could significantly advance humanity’s means for going faster and farther in space and pave the way for the future deployment for all fission-based nuclear space technologies.”
The DRACO programme is based on early investments in nuclear thermal technology via the previous Nuclear Engine for Rocket Vehicle Applications (NERVA) programme, but with a new fuel option that presents fewer logistical hurdles. DARPA’s use of HALEU fuel was authorised by National Security Presidential Memorandum 20 (NSPM-20), which updated US policy for the launch of space nuclear power and propulsion.
Image: DARPA has selected BWXT and Lockheed Martin to produce a nuclear-powered spacecraft (courtesy of Lockheed Martin)
