Space

DARPA taps Lockheed Martin to build nuclear deep space rocket

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Artist's concept of the DRACO vehicle
Lockheed Martin
Artist's concept of the DRACO vehicle
Lockheed Martin
DRACO is a demonstrator for a nuclear-powered space tug
Lockheed Martin

The first crewed mission to Mars may get there and back a bit faster and safer if a contract DARPA has awarded to Lockheed Martin bears fruit. The contract is to rapidly advance and fabricate a nuclear thermal rocket engine scheduled to fly by 2027 for cislunar and deep space missions.

In a remarkably short time, humanity has gone from learning how to fly a heavier-than-air craft to sending robotic probes into interstellar space. The surprising thing is that the chemical rocket engines used then, and are still used now, reached the edge of their theoretical limits in 1942, just as they made their first successful flights.

Since then, rockets have become larger and more effective, but these improvements cannot get past the inherent limitations of the basic technology in regard to thrust and efficiency. What this means is that a crewed mission to Mars is about as far as chemical rockets can take us – and only at great expense for a voyage that could take years.

First conceived of shortly after the Second World War, Nuclear Thermal Propulsion (NTP) engines promise thrust slightly greater than that of chemical engines along with up to five times higher efficiency. This would make a Mars mission much shorter and allow the crew the option of an in-mission abort. It would also make missions to build and supply a Moon base cheaper and safer.

DRACO is a demonstrator for a nuclear-powered space tug
Lockheed Martin

DARPA's Demonstration Rocket for Agile Cislunar Operations (DRACO) project aims at demonstrating a new engine technology based on a nuclear reactor fueled with a special High-Assay Low-Enriched Uranium (HALEU). When operating, the reactor would heat cryogenic hydrogen into an extremely hot gas that would be directed through a rocket nozzle to generate thrust.

According to DARPA, DRACO would not be used to lift off from Earth. Instead, it would be part of the upper-stage payload and would remain turned off until the vehicle reaches a safe orbit. Under the new contract, Lockheed, in partnership with BWXT Advanced Technologies, will rapidly advance the technology and begin manufacturing in anticipation of the 2027 flight.

"These 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," said Kirk Shireman, vice president of Lunar Exploration Campaigns at Lockheed Martin Space. "This is a prime technology that can be used to transport humans and materials to the Moon. A safe, reusable nuclear tug spacecraft would revolutionize cislunar operations. With more speed, agility and maneuverability, nuclear thermal propulsion also has many national security applications for cislunar space."

The video below discusses the NTP vehicle.

Source: Lockheed Martin

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4 comments
David F
Why hydrogen. How does nitrogen compare.
Ed Clark
The one item I was looking for and couldn’t find: how much faster to Mars and the moon? Seems like an important topic, but the answer can’t be found in either the video or the article.
Don Rathburn
I looked up some details about this technology and thought "Let's see, a nuclear reactor, plus a huge tank of cryogenic liquified hydrogen, a three month journey each way, a control system so complex it would boggle your mind.....what could possibly go wrong? " .
Karmudjun
Thanks David - your article is fairly complete. There are folks that find fault with anything. Imagine a nuclear pile - inert - but still nuclear on top of an explosive chemical rocket. That is what we shall be seeing, and the cryogenic hydrogen (a component of water, presumably a low molecular weight fluid that can be split to produce 2(H2) and O2. Given the mass, the H2 sent out as propellant will have 3x 4x the kick of chemical rockets and since it can run the entire time of flight (until the hydrogen is all used up) it can continue to accelerate the craft to shorten the cislunar transit or the transit to Mars. Awesome. Shortening the flight time by MONTHS! Anyone could read the wikipedia articles if they choose.