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Space Science

European Moon Mission Ready for Launch 357

Posted by michael from the green-cheese dept.
merryprankster writes "Europe's first mission to the Moon is set for blast off from Kourou in French Guiana just after midnight, local time, on Sunday. SMART 1 will study the composition of lunar rock through X-ray observations. The probe uses a new solar electric propulsion system which converts solar energy its panels into motion via the expulsion of ions. Details at the ESA mission site."
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European Moon Mission Ready for Launch More

European Moon Mission Ready for Launch

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  • The means of getting there is the best part (Score:5, Funny)

    by grub ( 11606 ) <slashdot@grub.net> on Friday September 26, 2003 @10:23AM (#7063978) Homepage Journal

    The probe uses a new solar electric propulsion system which converts solar energy its panels into motion via the expulsion of ions.

    IMHO that is much more interesting than the mission itself. The less chemical fuel needed to get moving once in space could mean more room for payload.

    Beat the weenies to the punch:

    I, for one, welcome our new ion propelled masters!

    Imagine a beowulf cluster of these!

    Natalie Portman could fly one of these to my house anytime!

    The lengths people will go to to hurt the ego of chemical-rocket engineers!

    Chemical rockets, 70, found dead in their suburban home, truly an American icon.

    Obligatory goatse.cx [goatse.cx] link.

  • ... that launched the first Borg!

    e.g. "On its long trek through space the cube-shaped probe..."

  • Ion drive is cool, but... (Score:3, Insightful)

    by Ikeya ( 7401 ) <dave@kuc[ ]et ['k.n' in gap]> on Friday September 26, 2003 @10:30AM (#7064049) Homepage
    Sure the Ion drive is a really neat addition, but it's soooo slooooow. It's going to take them 15 MONTHS to get there! And the payload isn't really greater at all. It takes longer to get any large loads going. The US space program got people to the moon and back in what...2 weeks? It may be slightly more economical, but it just doesn't seem practical.
    Hopefully they can perfect the ion drive, however through this to increase the speed and payload capacity. Then we might have something really cool... (until the anti-matter reactor comes online...)
    • "It takes longer to get any large loads going" No, not really. "It may be slightly more economical..." just slightly? considering that the available fuel is practically infinite with no fuel from earth being used (except for leaving earth) I'd call it extremely economical. Perfecting this method of transportation is a good step in the right direction, imho.
      • It is only slightly more economical becuase teh ion engine costs almost as much to build as a rocket with x amount off fuel.
        • To my understanding, there's little reason a similarly built device (cost-wise) could not reach Mars. Maybe it'd need bigger solar panels or something, but the engine ought to still work.
        • Please explain this... What is X in your statement? An ion engine can keep going indefinitely - exactly how much fuel would it take to continually accelerate a conventional rocket to the end of the galaxy, and what would the cost be?

          Spending the same amount of cash, the little put-put ion engine would get you there considerably faster.

          In addition, since the ion engine can be reused (say, to return), and that X amount of fuel can't, I think it's a lot more economical..
          • The x in my statement referred to an amount of fuel it would take to reach a near eath object like the moon. If it was going to mars it would be economical but since it is only going to the moon, it is only slightly economical. Sorry about the confusion.
        • How about weight? A rocket with the equivalent amount of fuel is probably going to cost quite a bit more to launch into space.

          On earth, things are cheap. When you have to get them into space, that makes mass expensive. Light is good.

      • Re:Ion drive is cool, but... (Score:4, Informative)

        by Smidge204 ( 605297 ) on Friday September 26, 2003 @11:09AM (#7064415) Journal
        "It takes longer to get any large loads going" -No, not really.

        Yes. Really. quoth the article: "Ion propulsion systems are less powerful than conventional chemical rockets..."

        Power = Energy/Time = Mass * dV^2 /dt

        If average power is less, velocity increases at a slower rate. Therefore, the probe will take longer to get to a specific destination than a conventional rocket. MUCH longer.

        It may be slightly more economical..." just slightly? considering that the available fuel is practically infinite with no fuel from earth being used (except for leaving earth)

        Again, quoth the article: "...but can run for ten times as long using the same mass of propellant."

        So even the ion drives have a finite amount of "fuel" which must be loaded before liftoff. So much for that.

        Combine these two, and you have an engine that is very poorly suited for transporting humans.

        It is, however, very well suited for probes and the like, since the engine is smaller and lighter than chemical booster. That can decrease cost of lift and size of craft by a good margin... and since most probes don't starve to death you can afford to take 15 months to get there.

        The moral of this story is, ion drives as they currently stand are not the end-all solution for space transportation. I agree it's well suited for this particular use, though.
        =Smidge=

        • Re:Ion drive is cool, but... (Score:4, Informative)

          by david.given ( 6740 ) <dg@cowlark.com> on Friday September 26, 2003 @11:46AM (#7064731) Homepage Journal
          Power = Energy/Time = Mass * dV^2 /dt

          If average power is less, velocity increases at a slower rate. Therefore, the probe will take longer to get to a specific destination than a conventional rocket. MUCH longer.

          You forgot about time. Your chemical engine accelerates your spacecraft at 10 m/s^2 for ten minutes, and then runs out of fuel and has to coast the rest of the way. Total delta-V: 6 km/s. Your ion drive accelerates at 0.1 m/s^2 for a year. Total delta-V: 50 km/s. At the end of the year, the ion drive vehicle is going a hell of a lot faster.

          And in case you think that a year of continuous thrust is infeasible, Deep Space I's ion drive ran (on and off) for about 600 days.

    • It took the apollo astronauts four days to get to the moon and four days to get back.
    • From the website:

      Its main purpose is to let engineers evaluate a new way of propelling spacecraft, on far-ranging space missions. Power from SMART-1's solar panels will drive an electric propulsion system called an 'ion engine'. The demonstration task is to overcome the Earth's gravity and put the spacecraft into orbit around the Moon.

      This appears to be a demonstration project, with the final application in extended range projects (where traditional chemical fuel rockets would have to carry too much f

    • Re:Ion drive is cool, but... (Score:5, Funny)

      by sharkey ( 16670 ) on Friday September 26, 2003 @10:45AM (#7064187)
      Sure the Ion drive is a really neat addition, but it's soooo slooooow.

      Well, they should add another one to the ship. Twin Ion Engine craft are pretty speedy, and highly manueverable as well.

    • Re:Ion drive is cool, but... (Score:5, Informative)

      by roystgnr ( 4015 ) <roy AT stogners DOT org> on Friday September 26, 2003 @10:47AM (#7064211) Homepage
      And the payload isn't really greater at all.

      The payload in the Apollo program was launched from a Saturn V, which can put nearly 120,000 kg in low orbit and so had enough oomph to put it's payload immediately into a lunar trajectory. The payload for this mission will be launched from an Ariane V, which can only put ~16,000 kg in low orbit, but at (IIRC) a tenth the price.

      Hopefully they can perfect the ion drive, however through this to increase the speed and payload capacity.

      The drive itself is pretty near perfect; the problem is that if you're going to kick out exhaust at such insane velocity that you don't need a whole lot reaction mass to get good deltaV, then you need a whole lot of energy to get good deltaV instead. And these guys are getting that energy from solar panels, which takes a while. If we had that anti-matter reactor you want (or cold fusion, or anything else providing lots of energy from little mass) we might eventually want something fancy like VASIMR [nasa.gov], but in the short run we'd probably just plug the reactor in to bigger or more ion drives.

    • Re:Ion drive is cool, but... (Score:5, Informative)

      by MouseR ( 3264 ) on Friday September 26, 2003 @10:47AM (#7064216) Homepage
      Sure the Ion drive is a really neat addition, but it's soooo slooooow. It's going to take them 15 MONTHS to get there!

      Actually, Ion propulsion is faster. It just has much less tork, if I may use the analogy.

      Unlike rocket propulsion, Ion propulsion has a constant push. Although is exerts a smaller force, it can accelerate for as long as there is fuel, and it uses very little of it.

      That's how they'll be able to send people on mars in a matter of months (last figures I had was 9 months) instead of more than a year (it was reported to be somewhere around 16-18 months using rocket propulsion).

      For a moon mission, though, speed isn't necessarily important, so they can afford the longer trip time to same money and augment the payload (instead of carrying all that fuel).

    • Just give it time (Score:3, Insightful)

      by chia_monkey ( 593501 )
      We just have to give it time. Yeah, right now, ion propulsion isn't the most efficient or fastest way of travel. But given more use, more people will be interested in perfecting it. Remember when solar panels had such low energy converstion rates? They're much better now. I could give a million other examples, but you get my point. We can't rely on the old methods of travel forever.
    • Sure the Ion drive is a really neat addition, but it's soooo slooooow. It's going to take them 15 MONTHS to get there! And the payload isn't really greater at all. It takes longer to get any large loads going. The US space program got people to the moon and back in what...2 weeks? It may be slightly more economical, but it just doesn't seem practical.

      It's a lot more economical. It means that they can launch a vehicle on top of a commerical GEO booster, and that the vehicle can make its own way out of geos

    • The ion drive is very good for long distance journeys. There is a limited amount of speed you can achive with classical propelents. The speed you can accelarate with ion drive is far greater. Best example Deep Space One.
    • This is really a test bed for the ion-drive technology - although even on this mission, its effective to do it this way, once in lunar orbit the drive can make slow adjustments to cover the whole surface, without having to carry huge amounts of propellant. Over LONG periods of operation, the ion drive is something like 10 times more effective in terms of fuel carried vs thrust given compared to chemical rockets - and that figure is set to improve as research progresses. SMART-1 is an important step in that
    • And they are not racing anyone, they just want to get there.

      Besides, it gives the joint Alien-American-Russian crew at Moon's dark side base enough time to cover up everything and go for well-deserved vacation in Phobos.

  • Um.. (Score:4, Insightful)

    by Unknown Poltroon ( 31628 ) * <unknown_poltroon1sp@myahoo.com> on Friday September 26, 2003 @10:31AM (#7064058)
    "new solar electric propulsion system which converts solar energy its panels into motion via the expulsion of ions."
    Wouldnt solar powered ion engine be easier to say?

  • Yes, but... (Score:5, Informative)

    by CXI ( 46706 ) on Friday September 26, 2003 @10:40AM (#7064142) Homepage
    I hate to burst everyone's bubble, but NASA used ion propulsion on the Deep Space 1 mission [slashdot.org] several years ago. Yes, cool technology but like most stuff it's been researched for years and used before.
  • x-raying the Moon rocks brought back by the Apollo missions.

  • Finally we'll know (Score:3, Funny)

    by kesler ( 576674 ) on Friday September 26, 2003 @10:43AM (#7064177) Homepage
    We'll know if the USA actually went to the moon or if that was just a hoax, unless this is a hoax as well. I guess this time I can break out my telescope.
    • We'll know if the USA actually went to the moon or if that was just a hoax, unless this is a hoax as well. I guess this time I can break out my telescope.

      Sorry, but your telescope is a hoax too. It's really just a poster-mailing tube with plastic wrap over both ends.

    • We'll know if the USA actually went to the moon or if that was just a hoax, unless this is a hoax as well.

      No hoax, but they'll find that the moon has since been colonized by the McDonalds/Starbucks joint project which reached the moon in 99 and have set up a variety of lunar franchises for mystery-meat and moccachino craving space-travellers.

  • 367kg isn't that light, really (Score:5, Interesting)

    by hpulley ( 587866 ) <hpulley4NO@SPAMyahoo.com> on Friday September 26, 2003 @10:45AM (#7064190) Homepage

    The article mentions that it is lightweight, only 367kg but NASA's first lunar orbiter weighted 386kg [astronautix.com]. So 40 years later we have a 19kg savings and it takes 15 months to get there. I love progress...

    • For carrying two men and a life support system, 367 kg is nothing. The walls were literally the thickness of a pop can. The lunar module was so fragile that its main hatch would bulge outwards while pressurized.

      • From the webpage I linked:

        10 August 1966 Lunar Orbiter 1 Mass: 386 kg. Lunar Orbiter I was launched from Cape Kennedy Launch Complex 13 at 3:26 p.m. EDT August 10 to photograph possible Apollo landing sites from lunar orbit. The Atlas-Agena D launch vehicle injected the spacecraft into its planned 90-hour trajectory to the moon.

        This wasn't an apollo craft, this was Lunar Orbiter 1. No people. Not sent up by a Saturn V, an Atlas-Agena D. No landing on the moon or re-lift off. Just an Orbiter almost fo

    • Isn't this thing supposed to land on the moon and take off again, though?

  • Solar wind on panels vs ion engine thrusting power (Score:3, Interesting)

    by Jerry ( 6400 ) on Friday September 26, 2003 @10:48AM (#7064228)
    The SMART 1 is going into Lunar polar orbit with 14 meter solar panels unfurled. With the solar wind push aiding on one side and opposing on the other will the ion engine have enough thrust to counter the effects of the solar wind?

    Maybe, if they did half-turns of the solar panels on every orbit they could elongate the orbit enough to break free or perhaps make Earth one of the axis points. ???

  • ION engines not really valid for short missions. (Score:5, Insightful)

    by Shivetya ( 243324 ) on Friday September 26, 2003 @10:49AM (#7064235) Homepage Journal
    While it is nice to see ION engines gain more momentum in the industry do they really have a place in short duration/distance missions?

    If its passed off a as a proof of concept it would make more sense but the article doesn't imply that.

    Considering the limited distance it would probably been more efficient to use an established propulsion system and get the scientific results sooner. Now, because of their choice any findings are unnecessarily delayed.

    On a high note, its good to see they are not replicating the work done by the previous NASA probe - seems scienctists are much better at getting along than their governments.

    • Re:ION engines not really valid for short missions (Score:4, Informative)

      by Midnight Thunder ( 17205 ) on Friday September 26, 2003 @11:04AM (#7064374) Homepage Journal
      You have to understand that there is more than one reason for using ion engines. Some include, reduced cost, reduced complexity, proving the improved technology really works and extending the mission life. The final one it important, since what usually ends a probe's mission is component failure or more often running out of fuel. As long as there is a star in our Solar system, then SMART 1's mission can last a good while. The only thing that could extend the mission even more is an xenon collector and an extended mission budget.
    • Ion engines are a mature technology. They have existed since the 60's, and are currently used for stationkeeping on a great number of satellites. They performed far beyond expectations on NASA's Deep Space 1 [nasa.gov] mission in 1998, and are a logical and economical choice for any mission of relatively low mass where time is not a critical factor--which it is not in this case.

      -Carolyn

  • Giant Trebuchet (Score:2, Funny)

    by rbabb ( 134729 )
    Wouldn't it just be easier to create a giant trebuchet and hurl the pod into space???? If anything it'd be a nifty Junkyard Wars project :)

  • The engine isn't new, it's the way it's used is (Score:5, Informative)

    by GileadGreene ( 539584 ) on Friday September 26, 2003 @11:15AM (#7064475) Homepage
    The probe uses a new solar electric propulsion system which converts solar energy its panels into motion via the expulsion of ions.

    Solar electric propulsion is hardly new. It's been used for getting communications satellites out to their final geosynchronous orbits for a number of years now, and NASA demonstrated using solar-powered ion engines for interplanetary primary propulsion on Deep Space 1 [nasa.gov] back in '98.

    What ESA is claiming is new about this mission is that they'll be combining ion propulsion with gravity assist maneuvers. AFAIK that hasn't really been done yet (although I know some guys at JPL who're working on it), and given how difficult it can be to work out low-thrust trajectories in the first place I would imagine that successfully throwing gravity assists into the mix would be a significant acheivement.

  • A bit on ion propulsion (Score:5, Interesting)

    by Unknown Kadath ( 685094 ) on Friday September 26, 2003 @11:25AM (#7064560)
    The reason ion engines are a good thing is because they are so efficient. But they also have their share of problems.

    The figure of merit for rocket propulsion is specific impulse (Isp). It is a measure of unit thrust per unit mass of fuel consumed per unit time. Conventional (chemical) propulsion, such as solid rocket boosters, have an Isp in the 200 - 300 range. But they generate many many thousands of kilonewtons of thrust. That's why we use them for launching things out of gravity wells.

    Ion engines, on the other hand, have Isps from 2000 - 3500 (though the higher end of that range is only test-stand stuff right now). They, however, produce only millinewtons of thrust, and cannot be used for fast orbit transfers or launches. But they can be made small. Very, very small, with correspondingly small amounts of fuel, which is pure joy for aerospace engineers trying to design robotic missions.

    Unfortunately, they are also power-hungry little buggers. A single ion engine can use a kilowatt of power while running...and they must be running all the time to generate enough delta-v to have an effect on the course of a spacecraft. (Delta-v is the measurement of how much of a change in a velocity vector is necessary to effect the desired change in course, and mission designers begrudge every cm/s...every maneuver burns propellant, and there are no gas stations in space.) There are only two ways to get power in space right now: solar cells, and some form of nuclear decay. Only solar cells have a good enough power/mass ratio to run ion engines, and as missions proceed farther out from the Sun, array area must be bigger, which adds mass. It's a tricky balancing act.

    For this mission, however, the craft will always be close enough to the sun to generate the power it needs fairly easily. (Except when it's in shadow, but that's why we have storage batteries.)

    Ion propulsion is an old technology, incidentally. It's been around in some form or another since the 60's. It's only recently that it became economical, though.

    I could go on for pages, but I'm unconvinced anyone wants to see that. ;) I did my senior thesis on a solar electric propulsion Mars mission, and I find it to be far more interesting than most people seem to.

    -Carolyn
  • Their next probe is headed your way! Due to be launched in 2005 it should be able to make it there by mid 2379.
  • Maybe it can take some pictures of that American Flag and the tire tracks while it's up there.

    Don't know what good it'd do, since the conspiracy theorists would simply say something about the pictures being covertly doctored by the French government after the the probe landed in order that they might get back in bed with the U.S Government..

    They'd get more Fox News airtime, but at least we'd have a few converts.

  • All been done before (Score:5, Informative)

    by amightywind ( 691887 ) on Friday September 26, 2003 @11:44AM (#7064710) Journal

    What exactly is innovative about this mission? It is the same mission as flown by Clementine years ago. Solar electric propulsion is commonplace. Here are some spacecraft that have flow them to date:

    • Boeing HS-602 HP satellites
    • Boeing HS-702 satellites
    • NASA's Deep Space 1
    • NASA's Stardust Mission (thrusted continuously for over a year!)
    • Genesis (?)

    I don't think this story is slashdot worthy.

  • Europe's FX industry coming of age (Score:3, Funny)

    by Pac ( 9516 ) <paulo...candido@@@gmail...com> on Friday September 26, 2003 @11:46AM (#7064727)
    It was about time Europe get itself a special effects industry capable of faking lunar missions. The USA perfected this technology [karoo.net] in the late sixties and look how profitable the American movie industry is now.

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