Space

DARPA awards contracts for orbital nuclear propulsion demonstrator

DARPA awards contracts for orb...
Artist's concept of a nuclear-propelled spacecraft
Artist's concept of a nuclear-propelled spacecraft
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Artist's concept of a nuclear-propelled spacecraft
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Artist's concept of a nuclear-propelled spacecraft

DARPA's nuclear space rocket project is progressing, with contracts awarded to General Atomics, Blue Origin, and Lockheed Martin for the first phase of the agency's Demonstration Rocket for Agile Cislunar Operations (DRACO) program. The goal is to place a Nuclear Thermal Propulsion (NTP) demonstrator into low Earth orbit by 2025.

Humanity is just dipping its toes into the solar system, but it's surprising to many to find out that we are already near the theoretical limits of what chemical rockets can do. In fact, that limit emerged almost as soon as Werner Von Braun produced the first practical rockets in the 1940s.

That's a real problem, not only because, with chemical rockets, a crewed mission to Mars is about at the absolute limits of the technology, but they also have trouble fulfilling requirements for space missions closer to home.

For example, the US Department of Defense (DoD) has a core requirement for rapid maneuvering not only on land, sea, and air, but also in space. Currently, maneuvering in space relies on either chemical rockets that provide high thrust and low propellant efficiency, and electric propulsion with its high efficiency and low thrust. This is a problem in cislunar space, where shifting orbits quickly need both high thrust and high efficiency.

This is where NTP systems come in. By replacing a chemical rocket's combustion chamber with a nuclear reactor to heat a propellant, like hydrogen, to extreme temperatures, it's theoretically possible to reach thrusts 10,000 times that of an electric engine and up to five times the efficiency of a chemical rocket.

So far, DARPA has already contracted Gryphon Technologies to work on a High-Assay Low Enriched Uranium (HALEU) NTP system. Now, the DRACO program is aiming to produce an orbital demonstrator that will entail an 18-month Phase 1 involving two parallel tracks.

For Track A, General Atomics will work on the preliminary design of an NTP reactor and propulsion subsystem concept. Meanwhile, Track B will see Blue Origin and Lockheed Martin independently developing an Operational System (OS) spacecraft concept based on the mission objectives, and the design of a Demonstration System (DS) spacecraft concept. These will lead to the next phases that will focus on detailed design and fabrication of the spacecraft for the orbital demonstration.

"The performer teams have demonstrated capabilities to develop and deploy advanced reactor, propulsion, and spacecraft systems," says Maj Nathan Greiner, USAF, program manager for DRACO. "The NTP technology we seek to develop and demonstrate under the DRACO program aims to be foundational to future operations in space. This first phase of the DRACO program is a risk reduction effort that will enable us to sprint toward an on-orbit demonstration in later phases."

Source: DARPA

8 comments
8 comments
sam12
That’s wonderful, putting a nuclear engine in low orbit. When it burns up, there is going to be a fine spread of radioactive particles on earth.
Eddy
Don't worry sam12, it will blend in nicely with Japan's imminent contribution of putting all its stored radioactive water into the sea.
paleochocolate
@Eddy it seems like you only read the sensationalist and misleading headlines. Japan is is dumping treated water into the sea which is barely above ambient radiation levels if at all. And gradually released into the sea over decades.
piperTom
@paleochocolate is correct about the hype being spread over Japan adding a tiny bit of tritium to the sea. But let's go back to the concern of @sam12 -- the greater danger, Sam, is that it WON'T burn up completely. Then you have a lump of partially enriched uranium and radioactive waste plowing into a shallow crater at some random place on earth. Of course, you may trust the US DOD to really careful and to not make any blunders... YOU might, but not I.
mike085
This may be shocking to you, but the earth (including the oceans) naturally have a low level of radioactivity. Your biggest issue from a crashing nuclear reactor the size you would find in a spacecraft would be it hitting you on the head when it falls. The radiation is not even worth worrying about.
Username
@piperTom , sure there is hype, but it shouldn't be confused with justified concern. Japan is not being very transparent and they haven't let any outside independent group verify their claims. Like you I don't trust US DOD or any other government when it comes to doing the right, safe thing. And that includes Japan.
WB
great what could go wrong... taking a nuclear reactor, what if it blows up halfway up. I am sure it will be over someone else's head than whoever came up with that idea
Smokey_Bear
Awesome. Unlike the other commenters, I'm a glass half full guy. I'm looking forward to seeing just how good these new engines will be, as mentioned, we desperately need a better/faster way of getting around in space.