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Nuclear Pulse Propulsion Re-Examined

Consider two hypothetical spacecraft. The Orion vehicle would have worked by setting off low-yield nuclear devices behind a massive pusher plate, driving forward a payload attached at a safe distance from the pusher (and protected by mind-boggling shock absorbers). Even if we had the nuclear devices at our disposal, agreed to use them for such a purpose, and found the political will to construct an Orion craft for deep space exploration, a problem still remains: most of the energy from the nuclear blasts is dissipated into space, and the craft thus requires a huge critical mass of fission explosives.

Orion, in short, is not efficient in using its energies. Now consider Project Daedalus, the hypothetical mission to Barnard’s Star designed by members of the British Interplanetary Society back in the 1970s. Daedalus was designed to use fusion microexplosions instead of fission. One of the reasons the Daedalus craft demanded as much fuel as it did is that the ignition apparatus, whether laser or particle beam, to ignite fusion is massive, adding unwanted heft to the vehicle. Daedalus would have massed an overwhelming 54,000 tons.

But there is a third option, discussed by Friedwardt Winterberg (University of Nevada/Reno) in a new paper in Acta Astronautica. Winterberg describes so-called ‘mini-nukes,’ which are devices in which the mass of the fission explosive is hugely reduced by a reflector in which a deuterium-tritium (DT) fusion reaction takes place — the fusion neutrons thereby increase the fission rate, and the increased fission rate, in turn, increases the fusion production rate. The implosive compression to ignite the process is provided by chemical high explosives.

We wind up with a fission-fusion assembly with serious advantages: 1) we eliminate the weight of a laser or particle beam generator to ignite fusion, and 2) we add to the specific impulse and thrust of the exhaust, which is composed of combustion products both from the nuclear and chemical reactions.

And no longer do we, Orion-style, lose the bulk of our energies into space. “With mini-nukes,” Winterberg writes, “the situation is much better because the explosions can take place there in the focus of a parabolic reflector positioned in close proximity to the spacecraft. Since still smaller mini-nukes appear possible, with their feasibility depending only on the technical perfection to focus the chemical energy for ignition, the mini-nukes can be detonated inside a large combustion chamber…”

The paper is Winterberg, F., “Mini-fission-fusion explosive devices (mini-nukes) for nuclear pulse propulsion,” Acta Astronautica Vol. 57 (2005), pp. 707-712. Some of Winterberg’s earlier work was studied, incidentally, by the Daedalus designers as they set about examining various ways of making an inertial confinement fusion system that could power their starprobe.

And incidentally, check this Fusion News Update at the Star Spangled Cosmos site for news of a possible development in inertial confinement fusion in South Korea.

Comments on this entry are closed.

  • tmayes1999 November 23, 2006, 13:55

    Creating an atomic explosion requires a maximium amount of 50 kg
    of heu or 16 kg of Pu239 . It is not that difficult to make small nukes
    massing 1000 kg or less for orion nuclear pulse units. This can however
    best be achieved by using heu fueled nukes using the gun type trigger

  • Karim Khaidarov April 3, 2007, 1:45

    Web-site dedicated to Prof. F. Winterberg is on
    http://bourabai.narod.ru/winter/index.html – in English
    http://bourabai.narod.ru/winter/ru.html – in Russian
    There are biography, list of published papers, some transactions,
    other documents related to Prof. Winterberg activity, photographs and etc.
    Any offers will meet with gratitude.
    Web-master: Karim Khaidarov,
    Bourabai Research, Kazakhstan

  • MirrorStephen April 3, 2007, 9:03

    Looking at the Web site listed above, it would seem that
    Dr. Winterberg has gone a bit off the deep end – either
    that or the Web site is one of those pseudoscience ones
    that infest the Internet like a virus.

    I have a deep mistrust of anyone who says that Einstein’s
    physics ideas are flawed, not because I think old Albert was
    infallible, but because the man has been proven right time
    and again and every quack always seems to want to take
    him down with their “absolutely right” Truth.

    And being at a conference sponsored by Lyndon LaRouche –
    that should be a red light and warning blare to anyone.

  • Administrator April 3, 2007, 12:59

    Karim, thank you for the link to the site on Friedwardt Winterberg. For those unfamiliar with the name, Winterberg’s work was consulted by the Project Daedalus team back in the early days of that JBIS project. In fact, he seems to have been a major source re a propulsion system that relied on pulsed fusion for the starship design. You can read more about his background at the site. I confess to having no prior knowledge of the Lyndon LaRouche event — curious!

  • Karim Khaidarov April 20, 2007, 7:16

    Dear colleagues, thank you for response.

    To MirrorStephen:
    In ancient time people believed that our Earth rests on three whales.
    In 1650 archbishop Ussher declared about 7000 years of Universe existence.
    Now you believe in Einstein’s pseudo theory of light waves flying upon
    But where is a causality?
    Each physical wave is an oscillation (fluctuation) of environment.
    Without environment, media, we can not say about any physical and any
    logical model without contradictions.
    Einstein’s theory states the nonexistence of ether, media of light waves.
    There is a violation of causality and logic.
    Einstein’s theory states about deflection of light near the Sun.
    However there is no near other stars (for example, eclipsed binaries).
    Einstein’s theory force logic by statement about mutual supremacy of both
    twins ages.
    In opinion of many true, non-speculative physicists keep an approach of
    aetheReal physics ( see, for example, http://bourabai.narod.ru/ether.html )
    Einstein’s physics is more politics and ideology than science.

    I heartily congratulate everybody with the Day of Cosmotautics!
    In April 12, Yuri Gagarin circumnavigated the globe in free Space.
    He started from Kazakhstani cosmodrome Bay-Konur

    With best wishes, Karim Khaidarov, Bourabai Research, Kazakhstan
    April 12, 2007

  • MirrorStephen April 20, 2007, 14:08

    Ah yes, the great Einstein Political Conspiracy, which all
    physicist have apparently held to since 1905 at the least.

    Do you happen to have a sample of this space aether
    somewhere to prove your theory? Or, let me guess, you
    did, but NASA has stealthed it away in some secret lab in
    the Nevada desert and anyone who talks about it either
    disappears or has an “accident”.

    A “conference” sponsored by Lyndon LaRouche – if that doesn’t
    smell of politics and the occult, I don’t know what does.

  • andy April 20, 2007, 14:25

    I guess Karim Khaidarov hasn’t heard of gravitational microlensing.

  • Mick December 24, 2008, 15:11

    The critical advantage to the old fashioned fission concept is that fission devices are cheap and plentiful. The solution is just to launch a huge launch vehicle loaded with mass nuclear scrap. The environmentalists would go crazy but…

  • Mike Lorrey February 8, 2009, 7:07

    Actually, the Orion project proposed specially built 5 kT yield nuclear shaped charges which would have driven most of their energy at the pusherplate. The specific impulse and newtons would have been in the millions.

  • Karim Khaidarov June 8, 2009, 22:16

    andy April 20, 2007 at 14:25 wrote:
    “I guess Karim Khaidarov hasn’t heard of gravitational microlensing.”

    – “microlensing” is not gravitational phenomenon.
    It is refraction of light in aether having different temperature, i.e. density.
    I guess Andy has heard of light speed dependence from media density.
    For more detailed explanation see “TEMPERATURE OF AETHER AND REDSHIFTS”
    and FAQ http://bourabai.kz/catechesis.html

  • Sean Fahey September 5, 2009, 13:21

    Can I summon this aether to shoot a fireball out of my hands and vaporize stuff?