DARPA’s Nuclear-Propelled DRACO Demonstrator May Be The First Step Toward A Star Wars-Like Starfighter - Forbes

In 1914, military aircraft were minimally controllable observation platforms — like modern satellites. By the end of World War I four years later, they were highly maneuverable offensive and defensive weapons like the X-wing “starfighters” of Star Wars fiction.

For now, NTP-powered orbital spacecraft won’t be manned so there’ll be no Luke Skywalker in the cockpit charging toward the Death Star with his Red Squadron compatriots. While Skywalker’s X-wing was propelled by fictional “fusial thrust engines” supplied by a “cyrogenic power generator,” DRACO will rely on a more physics-defined nuclear reactor. Why?

An orbital spacecraft powered by a nuclear thermal propulsion (NTP) system could surmount the limitations of current propulsion methods. Chemical propulsion systems deliver high thrust-to-weight but relatively poor propellant efficiency — essentially, bad gas mileage. Electric propulsion systems offer good gas mileage but poor thrust-to-weight ratios. The NTP which DARPA is looking to develop could deliver both.

USAF Major Nathan Grenier, DARPA’s DRACO program manager, says the NTP that will power the demonstration spacecraft is a unique class of reactor. Cold hydrogen propellant is directly heated by the reactor and then expelled through a nozzle to produce thrust.

“This architecture is distinct from conventional ground power reactors,” Grenier explains, “which continuously cycle a working fluid such as water through a reactor to extract heat to turn a turbine and produce electrical power.”

An NTP-powered spacecraft would be relevant for deep space missions like a NASA expedition carrying humans to Mars, Maj. Grenier says, acknowledging that “DARPA has been closely coordinating with NASA since the initiation of the DRACO program.”

Nuclear propulsion could also dramatically shorten the timeline for simply changing satellite positions and orbits, a process sometimes requiring weeks.

However DARPA’s own announcement allied the DRACO program squarely with defense, noting that “rapid maneuver is a core tenet of modern Department of Defense (DoD) operations.” It added that a DRACO spacecraft would enable “greater agility in cislunar space (between the Earth and moon).”

delta-V to starfighters

But what do rapid maneuver and greater agility really mean? Beyond asserting that DRACO is not focused on any specific mission, Maj. Grenier offered a cautious answer.

“What NTP provides is a specific impulse [gas mileage] that is far higher than existing chemical propulsion systems with a thrust to weight that is far higher than existing electric propulsion systems. This unique combination of high specific impulse and high thrust to weight allows NTP to quickly execute large delta-V maneuvers to enable rapid transits across large distances.”

In simple terms, large delta-V maneuvers imply a spacecraft that is “able to conduct a larger change in velocity [i.e. it's able to have greater acceleration to a given top-speed, and a potentially higher top-speed as well] for a given amount of propellant,” according to DARPA.

An orbital spacecraft that can accelerate hard and go faster than current spacecraft gives rise to a number of logical possibilities. Quickly moving a spacecraft (satellite) over distance could be an effective defensive maneuver, getting it out of harm’s way.

“That’s a fair assessment,” says Kaitlyn Johnson, a deputy director and fellow of the Aerospace Security Project at the Center For Strategic and International Studies, which recently published a report on potential nuclear-enabled satellite defenses.

“Nuclear propulsion could be used to reposition satellites if some were disrupted... you could move [others] there and add additional support. If you’re looking at the quickness of response of [NTP], you could use it to maneuver away from a targeted anti-satellite weapon,” she says.

A recent report from the Office of the Director of National Intelligence (ODNI) confirms that China began training with direct-ascent anti-satellite missiles as well as ground-based anti-satellite lasers, “probably intended to blind or damage sensitive space-based optical sensors,” in 2019. Russian capabilities include the above as well as “on orbit” jamming and cyberspace capacity the ODNI report noted.

Thanks to its greater efficiency, nuclear propulsion could also allow satellites to be moved more frequently, potentially diffusing some of the above threats. “If you choose to maneuver, you might not be wasting as much fuel as with the satellites we have today,” Johnson says.

Nuclear power would be useful for defensive/offensive systems as well. Earthbound nuclear powerplants are increasingly being paired with weaponized lasers, particularly the Optical Dazzling Interdictor or ODIN systems being added to U.S. Navy destroyers.

While beyond the scope of DRACO, the NTP systems it investigates will likely increase in power over time, facilitating addition of ODIN-like systems, a possibility China, Russia, and the U.S. have no doubt considered.

In the next 18 months, General Atomics will create a preliminary design of the NTP reactor and propulsion subsystem, while Blue Origin and Lockheed Martin will each independently design an operational spacecraft concept and demonstration spacecraft concept. Later phases will see an NTP spacecraft in orbit.

“It’s certainly exciting,” Johnson says. “It’s a baby step toward the future of space travel and space capability, to the commercial and military space policy doctrine announced by the Trump administration. As a Star Wars and Star Trek nerd, it’ll be something to watch.

We’re clearly a long way from anything like a starfighter but when attacking the Death Star in his own X-wing, Skywalker is reminded to “use the force.” If DARPA’s DRACO program bears fruit, the force will be nuclear thermal propulsion.