Two years ago, the Defense Advanced Research Projects Agency (DARPA) set out to go where no man has gone before -- and more specifically, to go where no man (or woman) has gone before in a way no human has ever traveled: by nuclear-powered spaceship.

Offering $27.6 million in compensation, DARPA enlisted General Atomics, Blue Origin, and Lockheed Martin (LMT 0.00%) in an 18-month project to design a "Demonstration Rocket for Agile Cislunar Operations" (DRACO). In this effort, Blue Origin would compete with Lockheed Martin to develop the spacecraft design, while General Atomics would focus on developing the nuclear thermal power (NTP) engine to power it. (The engine would use nuclear fuel to heat hydrogen propellant which, being expelled, would move the vessel through space).

Two years after the effort began, we have some progress to report.

Artist's conception of DRACO nuclear spaceship in orbit.

Image source: Lockheed Martin.

And the winners are...

First and foremost, this is no longer a DARPA-only effort. DARPA teamed up with NASA back in January to work jointly on this project, with the objective of demonstrating a nuclear-powered spacecraft in high orbit above the Earth by no later than 2027. 

Lockheed Martin will lead the effort, having apparently beat out Blue Origin for the honor. Meanwhile, privately held General Atomics -- DARPA's favored contractor for building the engine -- has been switched out in favor of NASA's favored publicly traded nuclear components manufacturer BWX Technologies (BWXT 2.30%).

As a happy result of this switcheroo, space investors now have two ways to invest in nuclear-powered spaceships, where before they had only one publicly traded option in the original DARPA proposal -- Lockheed.

Why nuclear?

So what will these companies be doing?

The goal of this project is to develop a nuclear space engine two to five times more efficient than the chemical rockets that power current spaceships. And while NASA won't put a price tag on the cost savings of such efficiency, the practical advantages are already good enough. 

Currently, you see, when NASA wants to send a spaceship to Mars, it has to wait until Earth and Mars are in close proximity, so as to keep travel time down to about seven months in duration, reducing fuel needs and allowing for larger payloads. Switching from chemical rockets to nuclear power, however, would permit travel between the planets at any time of year, while still cutting travel time to as little as three months. This shortens the time astronauts are exposed to dangerous solar radiation while traveling to and from Mars, and it generates additional savings on food and life support costs.

First, though, DARPA needs to test how well these new nuclear engines are going to work in space.

Introducing HALEU

The specific engine that BWX Technologies will develop for integration into Lockheed Martin's spacecraft is called a "high-assay low-enriched uranium," or HALEU engine. In a conference call with journalists to discuss the engine last week, NASA and company executives explained the measures they are taking to ensure this test is safe, including keeping the engine inert during launch from Earth and then placing it in an orbit of at least 700 kilometers above Earth before testing. (Even if control over the spacecraft were lost, it would take 300 years for that orbit to decay and the spaceship to fall back onto the planet.)

The spacecraft in question will be small -- small enough to fit within the fairing of an ordinary medium-to-heavy lift rocket such as a SpaceX Falcon 9 or the new Vulcan Centaur rocket (soon to be launched by Boeing and Lockheed Martin subsidiary United Launch Alliance).

Lockheed and BWX expect to be able to launch the DRACO demonstration spacecraft by late 2025 or early 2026, giving plenty of time to meet the 2027 deadline to begin testing the engine in orbit. Testing will then last for as long as the vessel's fuel supply lasts -- probably a few months. 

As this will be the first orbital test of HALEU. NASA and DARPA will later likely tweak the design -- perhaps several times -- before using it to build larger nuclear-powered spacecraft. Given how quickly the project is advancing, though, it might not be too long before HALEU engines start getting installed on intra-solar spacecraft as a matter of course. And in that case, it makes sense that Lockheed and BWX would become the builders-of-choice for such spacecraft.

Even in the meantime, DRACO is no small contract for Lockheed and its partner. As revealed on the conference call, Lockheed and BWX will split $499 million total for their work on DRACO.

For BWX, which did only $2.2 billion in revenue last year, that's obviously a bigger deal than for Lockheed. But even for a defense giant like Lockheed Martin, $250 million is a tidy sum -- and with the potential to turn into a nice revenue stream in future years if DRACO is successful.