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Ion-Propulsion Craft Reaches The Moon

Posted by timothy on from the not-landing-just-saying-hello dept.

Rollie Hawk writes "It ain't warp speed, but it's exciting new technology at work! The European Space Agency put an ion-propelled rocket into lunar orbit today. While not much horsepower is generated, this method of propulsion could be ideal for travel in near-weightless space as it does not require any combustion to occur."

14 of 395 comments (clear)

  1. Peak of eternal light by Rei · · Score: 5, Informative

    I think what is most interesting is one of the destinations they're going to visit - the peak of eternal light. Perfect spot for a moonbase - constant sunlight instead of 2 weeks of light and 2 of darkness, water ice likely in nearby craters, and temperatures warm enough that you might be able to get by with passive solar heating alone.

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    1. Re:Peak of eternal light by RebelWebmaster · · Score: 5, Informative

      I'm pretty sure there are international treaties banning any country from claiming extraterrestrial land for their country.

    2. Re:Peak of eternal light by LucidBeast · · Score: 3, Informative
      Some comparisons
      • Currently European Union has more citizens (~400M) than United States (~280M), but US I think has younger population. Europeans aren't having enough immigration or kids.
      • European Unions economy is a bit bigger than US economy, but US has still more GDP per capita. US spends larger portion of its GDP on Defence (or Offence I guess now days), also Europeans have longer vacations and shorter work weeks that eat up the GDP a bit. Quality of life for citizens is hard to measure.
      • Europe doesn't have unity on what it should be: lose pack of nations concentrating on economic issues or more of a federation counter balancing United States.
      • All Europeans have health care of some sort. 40 million US citizens don't
      • EU citizens have higher life expectancy than US citizens despite US spending more on health care per capita
      • EU kids score better in math and science than US kids
      • EU economy has been growing slower than US economy
      I'm don't think US is a failing empire, but unless the emphasis in US politics changes from gay rights, abortion, religion vs. science and god in pledge I think it will run into trouble. Also the huge military emphasis and spending is a taxing even to a rich nation like US.

      Also Europe has its problems and it's not a Utopia, so please don't take this comparison that way.

  2. better article by teridon · · Score: 4, Informative

    Nature has a better article here.

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  3. wrong link by Anonymous Coward · · Score: 5, Informative

    it's http://www.esa.int/ not http://www.esa.in/

  4. Re:Is it regular speed? by Rei · · Score: 5, Informative

    Well, apollo took a little over 3 days to accomplish what this craft took a year to do. And it's not neessarily "the longer the flight, the more efficient and speedy this method would be". It's all about ISP. The faster the "exhaust" leaves the craft, the less mass of propellant you need to achieve a given delta-V - and it falls off fast.

    In fact, ion drives tend to be rather energy-inefficient. However, they get their energy from electricity, which is renewed either by solar or RTG energy. Since RTGs are extremely energy-dense compared to conventional fuels, and solar cells constantly take in more energy, the penalty for a large amount of electrical waste and much, much larger propulsion system (for a given amount of thrust) is dwarfed by the benefits in terms reduced propellant mass.

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  5. Boeing has some power... by domenic+v1.0 · · Score: 4, Informative

    Boing has developed the PAS-5, the world's first commercial satellite with an ion thruster.

  6. This is not the first ion drive... by meringuoid · · Score: 4, Informative
    ... JPL's Deep Space 1 demonstrated the potential of such an engine back in the 20th century. Now we're seeing the first missions to rely on ion propulsion.

    It'll be interesting to see, if the Pluto probe ever flies, whether that uses ion propulsion. An ion drive could really make a difference on such a long-haul flight.

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  7. TIE Fighers? by ecliptik · · Score: 5, Informative

    Isn't this how TIE Fighers from Star Wars worked? Their wings were solar panels, and TIE stood for Twin Ion Engine.

  8. Science writing at its best by peggus · · Score: 5, Informative
    The engine does not combust fuel; rather it splits atoms with electricity to get ions, accelerates them at high speed, and then ejects them, driving the spacecraft forward. SMART-1 generates its electricity by converting sunlight with outsize solar arrays that give the spacecraft a 45-foot wingspan.

    Brilliant science journalism there. If the smart probe was splitting atoms it wouldn't need solar panels. Not to mention you don't need to split atoms to get ions.

    That reminds me of the article that was written on some research I was involved with. We were pulsing cells with high potential electric fields. The field strength was measured in MegaVolts per meter due to a very small gap between the electrodes, the actual voltage was only a kilovolt or so (over a 300ohm load for 5-15 ns). The journalist / engineer-reject thought that megavolts sounded really big and took it upon herself to proclaim that our pulse generators could power a whole city. Moan, groan....
  9. Re:Plasma technology is the space enabler by WolfWithoutAClause · · Score: 3, Informative
    Next up we have the VASIMR ... it can produce hard thrust like a chemical rocket.

    'Fraid not. To do that requires an enormous, lightweight, electrical power source. No current powerplant, solar, nuclear, chemical or other can provide enough power to generate high thrust when used with VASIMR.

    VASIMR is a wannabe fusion power drive. Trouble is, fusion doesn't work well enough right now to use it for this; and they are stuck with trying to powering it the old fashioned ways. It works, but not noticeably any better than ion drive- if you were to get VASIMR to work with a new power supply, you can pretty much just gang up any of the existing ion drive thrusters and get about the same thrust.

    VASIMR has theoretical advantages of being able to vary the exhaust velocity to increase the thrust, but even on the lowest settings I've seen them talk about, ion drives usually give better thrust.

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  10. Re:It REALLY Ain't warp speed by WillWare · · Score: 3, Informative
    Apollo 8 ... couldn't accelerate all the way from here to halfway to Alpha Centauri. You'd get there a lot faster on ion drive.

    To maintain the acceleration, you need sunlight hitting the solar panels. When you get that far out, the sunlight's going to be very weak. By then you might have picked up plenty of speed (I haven't done the math) but at the halfway point you won't have the acceleration you had near the inner planets.

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  11. Who needs sun? by zippthorne · · Score: 3, Informative

    well yeah.. or RTG's (Radioisotope Thermoelectric Generators) I'm sure the power-plant will well outlast the propellant supply

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  12. Technical project info by d2ksla · · Score: 3, Informative

    The project home page can be found here: http://www.ssc.se/ssd/smart1.html

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