Fuel for deep space exploration running on empty

Discussion in 'Science' started by Goth, May 9, 2009.

  1. Goth

    Goth Grumpy Member

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    http://www.google.com/hostednews/ap/article/ALeqM5imn9qjUowkvhgTPlvZ5VMHAuiYyQD981FET81

    http://www.newscientist.com/article/dn17095-nuclear-fuel-for-spacecraft-set-to-run-out-in-2018.html

    For many years, the US has actually been reliant on purchasing Pu-238 for these purposes from the Russians.
     
  2. HUMMER

    HUMMER Member

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    the north koreans have a fair few nukes. why dont they go ask them for some. :lol:
     
  3. Dezza Bot

    Dezza Bot Member

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    Other than the obvious issue of cost, there really isn't a fuel shortage at all, there is nothing stopping them producing more.
     
  4. lench

    lench Member

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    isnt the current flavor of choice solar cells?
    or are deep space explorers too far out to have any usable energy?
     
  5. Maldark

    Maldark Member

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    The intensity of light recived from a point source decreases as 1/r^2 where r is the radial distance from the source.

    Here at the Earth we get approximatly 1kW/m^2 of usable solar energy. We sit at a distance of roughly 150 million kilometres from the Sun (or 1 Astronomical Unit AU). Mars sits at 1.5AU (1/1.5^2 = 44% or 440W/m^2), Jupiter at 5.2AU (1/5.2^2 = 4% or 40/m^2), Saturn at 9.6AU (1/9.6^2 = 1% or 10W/m^2)... I think you get the picture.

    So you can see, you'd need some pretty big solar collectors to get a usable voltage at those kinda distances.

    PS. Almost forgot to mention to efficiency of solar detectors, they weigh in at a meek ~30% so at Saturn for a 1m^2 detector, you'd more be getting 3W.
     
  6. whisp

    whisp (Banned or Deleted)

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    so what we are all saying is we need another war to kick things in gear :D thats good we need a good culling of earth...might kick things back in balance!
     
  7. CyC-EM

    CyC-EM Member

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    Like most things we should start at the top and work our way down

    or is it the other way ?
     
  8. computer newbie

    computer newbie (Banned or Deleted)

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    yep. if there beyond jupiter they cant use solar power.
     
  9. brobin

    brobin Member

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    Now let's see here....
    The U.S. alone currently holds a stockpile of 5,750 nuclear devices. And U-238 is used in nuclear devices. 400 of those warheads do not currently have an assigned carrier system (as they are outlawed by a treaty). 616 of that stockpile will be retired U.S. FY09. So, surely they could strip down a few warheads, recycle the fissile material into Satellite fuel, and keep both NASA and the rest of the world happy.

    Ref: http://www.globalsecurity.org/wmd/systems/nuclear.htm
     
  10. oculi

    oculi Member

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    did you even read the article?
     
  11. neoprint

    neoprint Member

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    Just restart Project Orion IMO
     
    Last edited: May 13, 2009
  12. Skorpion

    Skorpion Member

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    Nice plan, except that they need Plutonium 238 which isn't used in nuclear weapons. (according to the article)
     
  13. Foliage

    Foliage Member

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    Why can't the redesign their engines to use another radioactive isotope, surely it would be cheaper than getting the plutonium enrichment plants up and going again.
     
  14. Tankc4

    Tankc4 Member

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    Check this article out: http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#Fuels

    Plutonium 238 hits the sweet spot for energy density, half life, and ease of shielding from the radiation generated.
     
  15. chewbacca

    chewbacca Member

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    *cough* Iran? *cough* ;)


    How about caesium-137, iodine-131 or strontium-90? ;)

    Note the above was not a serious suggestion but if you look into the Chernobyl incident you'll see why they aren't not elements to be toyed with =P

    On a serious note though it's not exactly that hard for them to make more fuel and even if it's going to cost $150 million (per year?) to produce that's a very very small portion of the US federal budget (war on terror for example and lets not forget the off the book black projects) to allocate to something that will in the grand scheme of things futher our progress as a civilisation (well *could* since nobody can be certain what the future of space exploration will contribute to technological progress)

    No doubt there will be people that will say this money would be better spent on things closer to home such as using the money to help nations that are in famine etc etc however lets not forget that there is no reason funds can't be spent doing both.

    I'll stop there as I've had a few beers and seem to have gotten off track a little. Hopefully what I've said has come across as understandable and unbiased. =)
     

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