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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."

39 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 binarybum · · Score: 5, Interesting

      man, screw your moon base. Perfect place for a five-star resort. This sounds like prime realty. The europeans should stake a claim to it and auction it off as land for when the moon is colonized. The price this would go for would probably fund a colonization project, oh and a moonbase - somewhere else.

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    2. 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.

    3. Re:Peak of eternal light by uncoveror · · Score: 4, Funny

      No one on earth could do anything about it, but not everyone who goes to the moon is from earth. The Zhti Ti Kofft would probably destroy any U.S. base in no time, or at least conquer it, and say ALL YOUR BASE ARE BELONG TO US!

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    4. Re:Peak of eternal light by phoenix321 · · Score: 4, Insightful

      Of course there's no army to back this up. But if you built a base on the moon and claim anything inside plus 5 km around the perimeter your own property, it *should* be yours.

      It's as simple as that: if you made new land habitable, it should be yours. Maybe I'm a little romantic here, but making some land habitable comes first, then it becomes your property, then you defend it against possible intruders.

      As long as there is enough land left on the moon, there will be no conflicts, if the people involved have the slightest hint of moral obligatons left. What they may or may not have anymore, considering this will be 20 years from now at a minimum.

      In general, humans all alone on a vast amount of land, totally devoid of people, in a situation of need and struggle, they tend to build friendly relationships instead of murdering each other for a piece of land. Supply and demand. If there's enough resources, land in this case, left, people don't value that land high enough to commit crimes against their moral standards. Example: Australia. Even outlaws built a society, because they couldn't survive otherwise.

      Sooner or later, people will fight their wars in space, of course. But not as long as there's millions of square kilometres left for anyone to take.

    5. Re:Peak of eternal light by JudgeFurious · · Score: 3, Interesting


      Well of course nobody thinks the US will remain the leading superpower forever. Nobody who gives it any thought at least. At one point damned near ever real "power" on the earth was located in Europe. Now there's not a single nation in Europe that equals the United States. Together they do the job quite nicely though.

      That's just it. Despite what we've seen from the former USSR there is life after being a superpower. Most Americans aren't living under the impression that the ride's going to last forever and only the small percentage of real paranoids think it has to at any cost.

      I can't wait for us to return to being one of the pack so to speak. Then maybe our leaders wouldn't feel like it's necessary to station troops all over the planet. A military that can protect the United States is fine by me. An economy in the upper half of the world is more than many could ask for. Damn I'd like to see us get out of the world police business and back to the "working on making America better" business.

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    6. 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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    1. Re:better article by macdaddy357 · · Score: 3, Funny

      That one's pretty good, but I think this one says it all.

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  3. Is it regular speed? by xanthines-R-yummy · · Score: 4, Interesting

    Does anyone know how the trip time compared other expeditions? I realize that the longer the flight, the more efficient and speedy this method would be, but I was just trying to get an idea of how fast this thing moves. Could cryogenics and this propulsion technology together land humans on other planets?

    1. 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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    2. Re:Is it regular speed? by centauri · · Score: 5, Interesting

      Could cryogenics and this propulsion technology together land humans on other planets?

      No, especially if you're aiming for extrasolar planets. Ion engines are good for a small payload that can take its time getting to where it's going. Humans (even those in some kind of imagined stasis) need something with a higher thrust to get where they're going in a reasonable time (ie, before cosmic radiation carves up their DNA, or a micrometeor holes their lifesupport system).

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    3. Re:Is it regular speed? by purfledspruce · · Score: 4, Interesting
      The high radiation environment of space keeps us from using this method for humans.

      However, it would be quite useful to use this technology to bring cargo to the Moon for possible astronauts to use. For instance, it's possible to deploy an entire habitat--crew quarters, energy producer, perhaps even in-situ resource production ("mining" water-ice for oxygen and hydrogen to feul your return vehicle)--all before we launch humans on a high-energy tracjectory that will get them there in three days, thus avoiding high radiation exposure.

      You could do similar things with Mars. Here's a reference done by the Revolutionary Aerospace Systems Concepts part of NASA:

      OASIS

      It will take a suite of technologies to get safely to other planets, and possibly another suite of technologies to get back.

    4. Re:Is it regular speed? by bcrowell · · Score: 5, Interesting
      Apollo 11 took 73 hours from the burn that took it out of Earth orbit to the burn that inserted it into lunar orbit. This is actually very close to the time it would take to free-fall to the surface of the Earth from a distance equal to the radius of the moon's orbit. This is pretty much always the case with chemical rockets, which work by doing short burns followed by very long periods of free fall: the time to get there is the time it takes to orbit from here to there. To go to Mars, you can use Kepler's laws, and you find that the time to get to Mars in an elliptical orbit is 0.70 years.

      The problem with getting to Mars is fundamentally the radiation. If you send astronauts to Mars on a 0.70-year orbit, without any shielding against penetrating radiation, their radiation dose ends up being on the same order of magnitude as the dose that kills you. This is Not Good :-) There is a variety of ways to get around this:

      1. Use electromagnetic shielding. (There was recently a Slashdot article on this. The idea is to use a quadrupole field, which discriminates between high-mass and low-mass particles.)
      2. Use really thick material shielding. This requires either a really really really thick layer of rock, steel, ... (very heavy), or a really really thick layer of liquid hydrogen. Either way, it's a lot of mass.
      3. Cut the trip time dramatically.
      Solar-powered ion drive could make method #2 practical, because it would theoretically allow very large masses to be moved around without having to lift huge amounts of propellant off of the Earth's surface. However, a ship with a nuclear reactor aboard (not just a passive RTG) could accomplish both #2 and #3.

      Fundamentally, I don't see the justification for sending humans to Mars in the forseeable future. The really exciting science task would be to find out of there is unicellular life on Mars (with a positive result probably qualifying as the most important scientific result of the last 200 years). This can be accomplished with an uncrewed sample return mission.

      Want to send humans to Mars? Great! Please dream up either (a) a valid scientific reason, or (b) a valid commercial reason. I don't think either exists presently, and I don't think either will exist within the next 100 years.

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

      The problem with all shielding methods proposed is that none that are lightweight handle GCR well. Electromagnetic shielding, mind you, does have some very promising applications concerning the Van Allen belts and other lower-energy particles. Right now, it looks like either liquid hydrogen or heavily saturated plastics (HDPE, for example) are going to be the best way to shield a craft on long trips.

      While I agree that there *currently* isn't a good reason to send people to Mars, I think that once we can demonstrate some cost-effective mix of ability to mine low-G bodies, grow realistic amounts of food outside of Earth, create bulk raw structural materials outside Earth, and to produce fuel outside Earth, there is ample reason to work on colonizing Mars. Not only would being able to do these reduce the costs of operation, but even high costs could be justified by the future-potential of using Mars as a triangle trade with Earth and the asteroid belt (one of the few things I agree with Zubrin on). So, I would argue in favor of working on the technology with the goal of eventually having it become a realistic course of action.

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  4. I don't get it by centauri · · Score: 3, Insightful

    this method of propulsion could be ideal for travel in near-weightless space as it does not require any combustion to occur

    What were you trying to say here? That combustion rockets are not a good way to travel through space? Maybe they're not the best, but it's going to be some time before anyone seriously considers getting people to the moon with ion engines.

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    1. Re:I don't get it by Headw1nd · · Score: 5, Interesting
      Ok.. the reason this is noteworthy, despite it's lethargic speed, has to do with reaction mass. Ion propulsion and rockets are similar in that both require reaction mass for propulsion- the craft goes forward because something goes back. The speed which the craft goes forward is proportional to the speed that something is ejected out back. Ion drives have ejection speeds far above that of conventional rockets, thus are far more efficient in their use of their propellant.

      So?

      So this is crucial on the long haul. With a reaction drive, when you run out of reaction mass, you're done. The craft becomes inert. The trick here is that the saturn V was out fuel within 15 minutes, wheras this craft is still accelerating a year later. Concievably, it could run for another year, or a dozen. (I don't know how much reaction mass it has) An ion drive craft might be made that could with enough reaction mass for an interstellar voyage, where a chemical rocket could not. (esp. considering the mass needed to decelerate at the ead!)

  5. So when do we get to see the US flag? by rsborg · · Score: 4, Funny
    On one hand, showing the US flag on the moon would make for very good press...

    [conspiracy] On the other hand, if they can't find it... [/conspiracy]

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  6. It REALLY Ain't warp speed by guitaristx · · Score: 5, Interesting

    Considering that Apollo 8 made it around the moon in less than a week, and this mission took over a year, we're not dealing with lots of speed here.

    I'm interested in seeing some comparisons with project cost, energy consumption, etc.

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    1. Re:It REALLY Ain't warp speed by Ianoo · · Score: 4, Insightful

      Yes, but Apollo 8 didn't accelerate all the way, and couldn't accelerate all the way from here to halfway to Alpha Centauri. You'd get there a lot faster on ion drive.

    2. 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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  7. How long will it take to reach Mars? by jerichohol · · Score: 4, Funny

    Warp 0.0001 more like it, Picard would say"E....N.....G....A....G......E"

    1. Re:How long will it take to reach Mars? by adam31 · · Score: 4, Funny

      "Prepare ion thrusters for - Retarded Speed!"

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

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

  9. Plasma technology is the space enabler by QuantumG · · Score: 5, Interesting

    Although it's called an "ion engine", it's really just the first step in the progression of plasma propulsion. Next up we have the VASIMR which they've been talking about testing on the space station. It can produce slow thrust like an ion engine, or it can produce hard thrust like a chemical rocket. You can power it with solar panels, or you can power it with a nuclear reactor. Eventually, almost the exact same design will be used in fusion rockets, and possibly even antimatter rockets. Then we're in Startrek country with plasma power distribution and ships which you can actually live and work on.

    --
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    1. 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.

      --

      -WolfWithoutAClause

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  10. 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.

  11. 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.

    --
    Real Daleks don't climb stairs - they level the building.
  12. Cheap Technology! by jd · · Score: 4, Funny

    Give me a Bussard Ramjet any day! Well, that and an extremely good handbrake.

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  13. 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.

    1. Re:TIE Fighers? by jfengel · · Score: 4, Funny

      That's right. What the movie doesn't make clear is that it was sped up by a factor of 10,000, because solar panels that size result in only a trivial amount of thrust.

    2. Re:TIE Fighers? by mikael · · Score: 4, Funny

      That's right. What the movie doesn't make clear is that it was sped up by a factor of 10,000, because solar panels that size result in only a trivial amount of thrust.

      No, the TIE fighters had a large bank of 48 car batteries which were kept topped up by the solar cells. Each TIE fighter had to charged up from the mains at least once every 48 hours, otherwise the battery would run flat, and you'd be stuck in space. In that case, the only way to start the engines was to plug an R2D2 unit into the cigarette lighter socket.

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    3. Re:TIE Fighers? by Tablizer · · Score: 3, Funny

      Isn't this how TIE Fighers from Star Wars worked? Their wings were solar panels...

      "Luke, you may get away today, but in 12,000 years my total thrust will eventually exceed yours, and you'll be MINE!" -- Darth "Quickie" Vader

      --
      Table-ized A.I.
  14. 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....
  15. How is weightlessnes relevant? by mowler2 · · Score: 5, Interesting

    I dont understand why they talk about the probe being (near) weightless in space in the same context as the engine beeing useful in space?

    No matter where the probe is, it has got the same mass, and hence the same inertia. Low-thrust engines work good in space because of no friction and often no requirement on quick travel (if it is a non-manned spacecraft). On earth an ion engine would never work for several reasons, one beeing friction against air and ground, but none of them has to do with the weight of the vechile/probe?

    Or have I misunderstood something?

  16. NASA announces it will outdo the ESA by i41Overlord · · Score: 5, Funny

    "After hearing the news that the ESA's slow ion-powered probe has entered Moon orbit after a record-long 13 month voyage, NASA has announced that it will launch an even slower probe that propels itself by gliding on a trail of its own mucous."

  17. 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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  18. 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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  19. Ion propulsion for cars! by cpghost · · Score: 3, Funny

    Imagine ion propulsion in our cars! Just gimme some months to reach those 55 mph...

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