back to article NASA, DARPA enlist Lockheed to build nuclear-powered spacecraft

NASA's ambitions to speed up space travel are about to go nuclear, as its joint project with military boffinry unit DARPA has found a builder for an experimental nuclear thermal rocket vehicle, or X-NTRV: Lockheed Martin. If all goes according to plan, NASA's Demonstration Rocket for Agile Cislunar Operations program (DRACO) …

  1. Tom Chiverton 1

    Also importantly, they can be refueled and reused until the reactor is cold..

    1. Anonymous Coward
      Anonymous Coward

      Perhaps even more important

      Hygrogen won't become radioactive upon exposure to neutrons. Even if a tiny percentage becomes tritium, it's half life is only about 3 years. Deuterium is stable.

  2. harmjschoonhoven

    Nuclear propulsion

    That has been tried before

    1. Pascal Monett Silver badge

      Re: Nuclear propulsion

      I prefer this link.

      It's much shorter, to the point and without any awful CGI.

  3. Yorick Hunt Bronze badge

    Look, up in the sky!

    It's a bird! It's a 'plane! No, it's nuclear fallout :-\

    Lockheed Martin, known for not being able to build a reliable 'plane even after receiving $trillions to get it going, is now being given the opportunity to screw something of much more consequence up.

    1. Anonymous Coward
      Anonymous Coward

      Re: Look, up in the sky!

      As we know, the Russians have launched boatloads of reactors into orbit. The issue has been they didn't care where they crashed at end of life. Moon rockets can be sent into the sun.

      1. John Robson Silver badge

        Re: Look, up in the sky!

        "Moon rockets can be sent into the sun."

        Yeah - if you happen to have about 30 km/s of delta V lying around.

        The sun is very hard to get to.

  4. very angry man

    Oh goody

    Merkins, nuclear powered (no way to scan for nuclear bombs) rocket s built by Merlin's, controlled by Merkin, govt dept yet to prove it self.

    Be afraid, be very afraid, run VERY far, run VERY fast .

    SPF 2850 sunscreen even at night and even on different planets and moon's, Merkin's don't care,

  5. fpx

    Having dangerously limited knowledge of the subject, I wonder why you would use hydrogen instead of, say, liquid nitrogen. Wouldn't that be easier to handle and more efficient, given its higher mass?

    1. AdamT

      Apparently (based on a very quick read of Wikipedia!) it is actually the opposite. You want high ISP from a rocket and the ISP is linked to the kinetic energy of each unit of propellent mass. But the KE per molecule of propellent is related only to the temperature. As the KE comes from the thermal energy you are better off with lighter molecules as you get more of them per unit of propellent mass (given that the temperature is usually limited by the materials you can use).

      The same is technically true of chemical rockets as well but your "propellent" in this case is the exhaust gas and that is determined by what you burn. So there you have the combined effect of the combinations of chemicals that can generate the necessary thermal energy at the appropriate temperature but ideally burn to produce something with as light molecules as possible.

      (shamelessly ripped off from here: )

    2. Alan Brown Silver badge

      You can extract the hydrogen from water at the energies involved. Most of the proposals use water as reaction mass for this reason

  6. Alan Brown Silver badge

    As Everyday Astronaut put it, nuclear thermal rocket propulsion is more or less operating a reactor at prompt criticality (as happened at Chernobyl) - on a continuous basis

    That's a VERY fine knife edge to be riding, to say the least and it makes Project Orion look reasonable

    1. JohnTill123


      Project Orion for the win!

      If we can make a manhole cover go 150,000 mph with a small nuclear blast (Plumbob/Pascal-B only produced a blast equivalent of 300 tons TNT. ref: ) then Project Orion should be considered.

      Besides, the launches will be spectacular!

  7. annodomini2

    Always preferred NSWR

    Ultra simple, no liquid hydrogen to handle.

    Much better volumetric efficiency.

    Probably take an ISP hit in trade for increased safety.

  8. spold Silver badge

    ...time to dig out the "Flesh Gordon" video...

  9. Bitsminer Silver badge

    Ask Russia... much they will charge for HALEU fuel pellets.

    They're just about the only country making them. While the US is playing catchup:

    HALEU is not available at commercial scale from domestic suppliers...

    Not to mention any number of international players building or planning small modular nuclear reactors (SMRs) which also use HALEU.

    TerraPower is anticipating a minimum of a two-year delay to being able to bring the Natrium reactor into operation.

    It's an example of "supply chain vulnerability" at national scale. I would call it a cluster-fuck but that's rude.

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