November 26th, 2012
03:23 PM ET

Proposed nuclear reactor could power future space flights

By Mark Morgenstein, CNN

For potential power sources on space flights beyond the horizon, scientists are looking back to the future.

A team of NASA and Department of Energy researchers has shown that a reliable nuclear reactor based on technology that's been around for decades could be used in spaceships, according to a news release from the Los Alamos National Laboratory, where some of the researchers are based.

The news release says the team used "heat pipe technology," which was invented at Los Alamos in 1963, and uses a heat pipe to cool a small nuclear reactor and power a Stirling engine, producing 24 watts of electricity.

A heat pipe is a sealed tube with fluid inside that can efficiently transfer heat produced by a reactor with no moving parts. According to a video on Los Alamos' YouTube channel, over the past 50 years, heat pipes have "gone mainstream" and now are used in everything from electronics to the Alaska pipeline.

Stirling engines, which the Los Alamos video says were initially developed in the 19th century, are relatively simple, closed-loop engines that convert heat energy into electrical power using a pressurized gas to move a piston.

Using the two devices in tandem allowed for creation of a simple, reliable electric power supply that can be adapted for space applications, the release said.

"The heat pipe and Stirling engine used in this test are meant to represent one module that could be used in a space system," said Marc Gibson of NASA Glenn Research Center. "A flight system might use several modules to produce approximately 1 kilowatt of electricity."

The experiment known as the Demonstration Using Flattop Fissions, or DUFF, is the first demonstration of a space nuclear reactor system to produce electricity in the United States since 1965, and the experiment confirms basic nuclear reactor physics and heat transfer for a simple, reliable space power system.

In the video, Los Alamos says the primary benefits of this nuclear technology are its simplicity, and its reliance on resources the United States has "in abundance."

In addition, the scientists say because the reactor wouldn't function until it was in space, accidents on the ground or during launch would have minimal impact.

"A small, simple, lightweight fission power system could lead to a new and enhanced capability for space science and exploration," said Los Alamos project lead Patrick McClure. "We hope that this proof of concept will soon move us from the old frontier of Nevada to the new frontier of outer space."

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Filed under: News • On Earth
soundoff (11 Responses)
  1. Harvey

    Made a heat pipe for a science project in 1965. Not hard and very ingenious. Am surprised they have not shown up in more appilcations

    December 4, 2012 at 6:29 pm |
  2. Yago

    Helium-3 and p-B11 fusion are much safer and reliable and can exceed 90% efficiency and can power a spacecraft to go far beyond the Earth's orbit.

    November 29, 2012 at 1:03 pm |
    • Spacenuke

      These kind of comments keep us from advancing our space nuclear technology. There are always paper spaceships that catch people's eye, and often even get funding. Over the past decades, NASA has spent more money on fusion and anti-matter than fission (making no real progress BTW), while ignoring the real work that can be done to take our first steps towards advanced systems. It all comes down to materials and engineering, not physics – fission can provide many orders of magnitude higher energy/power density than anything we have now; yes fusion adds one more order of magnitude, and anti-matter a couple more on top of that, but theoretical performance does you no good until you can engineer systems to handle it – which requires technology/materials evolution (solar power is fantastic now because of this type of evolution). See http;//

      November 29, 2012 at 7:34 pm |
      • Harvey

        All for fission reactors if we can get the bugs out. Saw a film where one shook itself apart during a test. At any rate, if we are going to use these things; they need to be far outside earth's biosphere. Still have a book called "Nuclear Rocket Propulsion" published in the 60's. After going through that tome; I figured they has a lot of progress to be made.

        December 4, 2012 at 6:39 pm |
  3. rocket surgeon

    I still like the ramjetand solar sail concepts

    November 28, 2012 at 4:12 pm |
  4. Nitpicker

    The video quotes a power output of the single-rod reactor of 500W. Where does the 24W figure coming from? 24W/500W ~= 1/20. If the press release is talking about the output of one of the eight Stirling engines, that would be 24W*8 = 192W, which would be 38.4% thermal efficiency. Plausible? Also, you didn't post a link to the press release you cited in paragraph 3. I kinda feel the need to go all wikipedia on you and say "Citation needed."

    November 27, 2012 at 2:16 pm |
    • Spacenuke

      You're good nitpicker. A part of the press release that was left out was that the test was at lower temperature than the flight system, and higher temperatures are needed to get the desired power and efficiency. The "module" was lower power: 24 W versus ~90 W (or even higher) for a flight module. Temperature was limited in this experiment by the existing facility regulations, which can be changed for future tests.

      November 27, 2012 at 4:53 pm |


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