Blue Origin, the private spaceflight firm founded by Amazon billionaire Jeff Bezos, is still trying to get its New Shepard rocket ready for commercial launches, but it just accepted a contract to design something new. The contracts from the Pentagon’s Defense Advanced Research Projects Agency (DARPA) direct Blue Origin, as well as Lockheed Martin and General Atomics, to design a nuclear thermal propulsion system that could accelerate human spaceflight—literally.
Our current rocket technology relies mostly on chemical power, such as the liquid-fueled engines on a Falcon 9 or the upcoming SLS. These rockets have very high thrust, but they’re less efficient than electrically powered engines. Missions that need to travel a very long distance often use electric propulsion such as ion engines because they can remain active for long periods at low thrust. So, they’re efficient but slower.
A nuclear rocket engine could offer unique advantages by using a small reactor to heat and accelerate fuel. That could theoretically give a nuclear thermal rocket high thrust like chemical rockets and high efficiency like electric ones. The agency calls this the Demonstration Rocket for Agile Cislunar Operations (DRACO) program, and these first awards cover just Phase 1 of the program, which is expected to last 18 months.
Blue Origin picked up $2.5 million, and Lockheed Martin was just a bit higher at $2.9 million. Meanwhile, General Atomics, which specializes in nuclear fission and fusion technologies, scooped up $22.2 million to design the propulsion subsystem — that’s the nuclear part of the nuclear rocket.
DARPA regularly deals in far future technology that may not come to fruition for decades. However, nuclear thermal is seen as one of the few next-gen propulsion systems that are within our reach. Sure, an Alcubierre warp drive or a non-impossible EmDrive would be preferable, but we don’t have the slightest idea how to build those. Nuclear technology, however, is very well-understood. NASA and the Atomic Energy Commission experimented with nuclear thermal rockets decades ago, but the high cost led to their cancellation. Maybe with modern technology, now is the time to give it another shot.
DARPA hopes to have a prototype vehicle ready for orbital testing around 2025.