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Space Elevator Challenge 162

MattSparkes writes "For the second year in a row, no team has won the $200,000 prize in the Space Elevator Challenge at the Wirefly X Prize Cup. Three teams were disqualified before the contest even started. Another competition at the event has been held up by confusion. Incredibly, it seems the organisers of the competition are not sure whether the ribbon used was 50 or 60 metres long, and whether any team completed the climb fast enough to win."
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Space Elevator Challenge

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  • Well it seems that this will be won next year :)

    More and more I see that this sort of prize is excellent way to foster development of new technologies. This should be applied to other technical challenges we face...
    • Re: (Score:3, Insightful)

      Well it seems that this will be won next year :)

      Maybe so, but I don't see anything here which will realistically form a part of a real space elevator system. Its a bit like building a railroad but starting out with model trains.

      • Re:X-Prize (Score:5, Insightful)

        by bhima ( 46039 ) <Bhima.Pandava@gm a i l .com> on Monday October 23, 2006 @09:24AM (#16545490) Journal
        I've been in the research & development business for pretty much my entire adult life. This, more or less, is what we do except on a different scale. I don't see anything wrong with building models of things in order to understand them more fully. Rather than attempting to solve the whole of the problem in one go they are trying to solve the parts of the problem that are solvable with today's material technology. Given a few more years doubtless the material engineering will begin to catch up and you will see things that realistically could be used in true space elevators.
        • Yes but, if you were running a competition, do you think you could remember how long the cable is?

          • forget a race competition, if you were running a corporate R&D lab, what would your execs say if you did expensive robot climbing experience but "forgot" to record cable length?
          • by bhima ( 46039 )
            Given the sort of Manday this has been for me...

            no.
      • Its a bit like building a railroad but starting out with model trains.

        Indeed. It rather reminds me of one of those black and white 1920s films where everyone is running around at high speed, to a catchy little ditty on the piano, only I'd take it less seriously. I mean what, from the sounds of it these guys couldn't find a good time in a whorehouse, and they claim they are trying to build a space elevator?

        In the words of the Jesus

        Laughable, man! Haaaaa ha!!

      • Re:X-Prize (Score:5, Interesting)

        by lgw ( 121541 ) on Monday October 23, 2006 @10:10AM (#16546000) Journal
        This prize addressed the climber, not the cable, so it's not entirely silly.

        What I'd like to see addressed is the fundamental structural problem of stabilizing a space elevator. In getting a payload to geostationary orbit, only about half the energy required is needed for lifting. A similar amount of energy is required to accelerate the payload laterally by roughly 9000 km/h, giving it enough angular momentum to achieve a stable orbit.

        A space elevator can lift a payload easily (given some advancement in materials technology), but has no real prospect of pushing sideways on a payload. As a result, conservation of angular momentum will cause the far end of the pendulum to swing. The counterweight tethered past geostationary will swing backwards in orbit, then swing forwards again as a pendulum.

        The this very long pendulum will oscillate, not simply be pulled from orbit, and the amplitude won't be that high on the first payload, but every payload lifted will add energy to this pendulum - effectively all of the energy needed to accelerate the payload by 9000 kh/m. That will add up fast, and the space elevator doesn't have much prospect for damping the pendulum. The friction in the cable as it bends will shed some energy, but that's about it. It's like a car with good springs, but no shocks - it's going to bottom out eventually.

        The period of a 40000 km pendulum is less than 4 hours, far shorter than the likely time for lifting the payload, so the energy of oscillation will be added somewhat chaotically as the payload ascends. It's not like to can just send of a second payload to "cancel out" the consequences of the first. You really need a strong mechanism that stops the pendulum from swinging.
        • by Quaoar ( 614366 )
          The period of a 40000 km pendulum is less than 4 hours, far shorter than the likely time for lifting the payload
          Erm...even if the lifting time was 4 hours, that means the payload would have to be traveling 10,000 km/hr. I don't think it will go even a 10th as fast.
        • What I'd like to see addressed is the fundamental structural problem of stabilizing a space elevator. In getting a payload to geostationary orbit, only about half the energy required is needed for lifting. A similar amount of energy is required to accelerate the payload laterally by roughly 9000 km/h, giving it enough angular momentum to achieve a stable orbit.

          While this comes from the realm of science fiction (where did I read about this? anybody recognise it?), it's still an interesting idea:

          Imagine two e

        • Re:X-Prize (Score:5, Informative)

          by YA_Python_dev ( 885173 ) on Monday October 23, 2006 @01:02PM (#16548332) Journal

          The cable will probably not oscillate at all (almost) because the cars will ascend at approximatively 100 km/h, by far too slow to do anything except a very small (less than 1 degree) lean at the very bottom of the cable (remember that a lot of payloads will probably be release before reaching 10% of the total cable length).

          More details on Wikipedia [wikipedia.org] and googling for "Annual Space Elevator Conference" (there are several simulation for the dynamic behavior of this thing).

        • Re:X-Prize (Score:5, Insightful)

          by twifosp ( 532320 ) on Monday October 23, 2006 @01:59PM (#16549202)
          Thats the entire point of the space elevator. There is a counterweight in geo stationary Earth orbit at the top of the cable. The cable isn't going to be very flexible, despite being called a cable. It will be very taught. As the payload goes UP the cable, lateral forces will be applied to the payload. The Earth's rotation and the counterweight in geo stationary orbit take care of this automatically.

          Once the payload is released from the cable, it will need additional thrusters to move it away from the elavator, adjust it's orbital height, orbital plane, and LAN.

          • by lgw ( 121541 )
            One can bend quite rigid materials into 1 kilometer circles. While the cable might be rigid when compared to ordinary building materials, it will definitely flex all it needs to at a length of 40 km or so. Just saying:

            The Earth's rotation and the counterweight in geo stationary orbit take care of this automatically.

            ... doesn't make it so. There's no cheating conservation of orbital momentum. The energy required to thrust the payload laterally will be expressed as a translational wave on the cable, all

            • by Eivind ( 15695 )
              Nonsense.

              Sure, the cargo needs to be accelerated eastwards, which means the top of the cable will be pressed westwards. But the cable is under stress, and the stress itself will tend to rigthen it.

              It's a lot like spinning a string with a rock on the end. Sure, gravity will tend to drag the rock *downwards*, but the spin and the resulting stress on the string will tend to counteract this. End-result ? The string does go diagonally downwards somewhat, how much depending on weigth of stone, length of strin

        • You also have to handle the oscilation modes of the cable as a plucked string.

          Seems to me you can turn this to your advantage:

          Initially the climber plus payload pulls the counterweight back - but then it swings forward, converting a backward momentum delta to a forward one, which you can then use to accellerate the payload further with more climbing. When you get to a decent release point you can also wait until you've got extra forward momentum to help circularize your orbit or improve your launch, and le
          • Yes, I know:
            - you don't need to "circularize" if you get to geosync altitude,
            - somewhere below that you can let go and end up with an eliptical orbit with perigee sufficiently above the atmosphere, and
            - energetically, if you want to head out it's better to climb PAST geosync and take off than to let go sooner and use some thruster.

            But using the momentum from the tether's vibration lets you cut loose lower, reducing the amount of space-elevator time needed to achieve your goals. Spac
        • You really need a strong mechanism that stops the pendulum from swinging.

          Vary the location of the exit point at the top from payload to payload to keep resonances from building up.

          • by lgw ( 121541 )
            You're pretty limited in the amount of energy you can dump in this fashion. First, you have to arrange for the exit point to be an anti-node (which would make it problematic if you one day want to use the space elevator to return cargo to Earth, unless the wavelength is short). Second, the energy you can dump is limited by the frequency of the translational waves divided by the length of the cable - you only have one "wavelength's worth" of energy to work with here.
        • The counterweight tethered past geostationary will swing backwards in orbit,

          More-or-less correct.

          then swing forwards again as a pendulum.

          No, it won't. There's no restoring force here anywhere. If you are trying to orbit any kind of "counterweight" past geosync, then the orbital period of that counterweight will be longer than one day and thus it'll start wrapping the entire tether around the planet.

          To quote someone's sig around here: None of this is rocket science, really:

          Write down the total f

      • I want the space elevator to look like the ones in the depths of the Planet of the Krell (Forbidden Planet, circa 1956). Lots of sparks as the enormous glassy spheres make their climb. Forget economics, let's get some drama happening.
  • Ribbon (Score:5, Insightful)

    by MattSparkes ( 950531 ) on Monday October 23, 2006 @08:35AM (#16545046) Homepage Journal
    I think that the material to make the ribbon can't actually be produced yet, and a 50-60 metre long section is about all that can be used. However, for the purposes of a test like this, it will suffice. The competition is more to do with getting the elevator technology advancing than actually putting together a working device.
    • But how does this help? $200,000 is chump change. It's not enough to pay the guy who runs the accounts of a serious research project. That number needs another three zeroes on the end before it will actually produce anything new.

      As the article says, none of the teams actually created their own materials, they bought off the shelf. That's like trying to push forward hybrid car technology by awarding a prize to the team that brings the cleanest Prius.

      • You're right. it is chump change. Do you know how much was spent developping SpaceShipOne? Or the other entries? My guess is that $10 million doesn't begin to cover the amount of capital spent on development....

        It's not the money that makes them do it. It's the competition. The notion that other people are competing for the same prize awakens something primal in human nature, and drives us to the goal. $200k isn't much money, but it's enough to get the attention of the people competing.
  • X-Prize Foundation (Score:5, Interesting)

    by Raynor ( 925006 ) on Monday October 23, 2006 @08:40AM (#16545092) Journal
    is already responsible for a major advancement: the first private space ship able to relaunch in two weeks (SpaceShipOne).

    The prize is definately motivation, and the X-Prize foundation has a few contests going:
    -The Ansari X-Prize (Get 3 people to 100km twice in two weeks) - WON
    -The Archon X-Prize (Sequence 100 people in 10 days with $10,000 cost per person) - OPEN
    -The Automotive X-Prize (Currently being developed. Create super-efficent cars or alternative energy) - FUTURE

    Those are the three the X-Prize Foundation has created. An interesting fact from the X-Prize website: "Ten times the amount of the prize purse was spent by the competitors trying to win the prize."
    • by Shadowmist ( 57488 ) on Monday October 23, 2006 @09:17AM (#16545410)
      Important thing to remember, SpaceShipOne did not acheive anything near orbital velocity. In fact I'm not even sure it was close to the velocity of Alan Shepard's suborbital Mercury flight. Hence it did not have to deal with severe re-entry heating, so was spared one of the critical neccessities of the Space Shuttle. I'm not knocking the acheivement of this group, just putting it in perspective.
      • I'm not knocking the acheivement of this group, just putting it in perspective.

        At least they managed to get higher than 50 meters. Or was it 60? Haaaaaaahahaaa, tragic...

    • I wouldn't give it that much credit. One achievement, which was long overdue, and not all that intersting (when will we get people to orbit?). It might have made the project a bit more exciting, but giving the credit to the prize is a bit of a long shot, not least because the development costs far outnumber the prize.

      What it is good for though, is setting actual real-world goals for scientists to achieve, learn from, with the prospect of winning the prize and the fame. They compete with other entries and i
  • by Gothmolly ( 148874 ) on Monday October 23, 2006 @08:55AM (#16545238)
    Infosec: "We don't really know what you're doing, but we're certain it's bad. Disqualified!"
    Development: "We're not sure how long the cable is supposed to be, so we'll hardcode it in the top of the code. If we're wrong, its out of scope and we won't fix it."
    Engineering: "We don't know how fast it is supposed to climb, so we'll pick a value. If we're wrong, it was Marketing's failure to gather the right requirements.""
    Audit: "All your project are belong to us".
    Milton: "I could just burn down the building..."

    Geez, who is running this thing, the PHB?
    • Geez, who is running this thing, the PHB?
      Even better, it's being run by the lowest bidder(s).
      /rimshot
  • by clickclickdrone ( 964164 ) on Monday October 23, 2006 @09:02AM (#16545288)
    If I'm going up in to space on a giant elevator, I want it to be nailed on to something a bit more substantial sounding that a 'ribbon'. Heck, all the ones I used to read about in 1950's sci-fi books were basically normal elevators, steel girders, nice big box with windows, sliding doors etc., just a hundred thousand feet high. THAT's what I'd feel safe in.
    • by Shadowmist ( 57488 ) on Monday October 23, 2006 @09:14AM (#16545392)
      No such structure could withstand the tensile stress generated from being pulled at opposite ends 25,000 miles apart. Just to put some perspective here, a the length of a space elevator, depending on which source you quote is at the minimum over 3 times the diameter of the Earth itself!
      • by mattdm ( 1931 )
        Hence the challenge. Clearly, current materials can't do it. Sci-fi implementations usually involve some sort of nanotech manufacturing.
        • Nanotech as it's most commonly used in sci-fi is kind of like warp drive in Star Trek, a magical invocation used to create shortcuts in story plotting but not particurlarly meaningful beyond that.
          • I'd have thought megatech or gigatech would be more appropriate for a thing umpteen thousand miles long
      • I didn't actually think it could be built, it was an attempt at humour.
    • by aadvancedGIR ( 959466 ) on Monday October 23, 2006 @09:19AM (#16545438)
      Don't worry, you're far more likely to die in a failure of your home/office elevator than in a space elevator.
  • And not ONE picture or movie about it? How come?
  • Pretty picky (Score:3, Interesting)

    by Dan East ( 318230 ) on Monday October 23, 2006 @09:15AM (#16545396) Homepage Journal
    According to the rules, the circumference of the loop must measure at least 2 metres. ...the Snowstar team from Canada's University of British Columbia, for example, was shy of this by less than half a millimetre.

    The diameter of their spool was 0.25% smaller than required, which was probably the result of warping from moving the spool around so it could be weighed, etc, before the competition. So they were disqualified and didn't get to formally compete.

    The height of the robot climb is what got me. It's a timed event, and the height they had to climb might have been 10 meters further than the benchmark. Now that's a complete joke.

    Dan East
    • by AGMW ( 594303 )
      The height of the robot climb is what got me. It's a timed event, and the height they had to climb might have been 10 meters further than the benchmark.

      ... and why couldn't they measure the stupid thing after the event? They really need to sort themselves out if they want people to come and play next time. And the 2 metre loop - they have to tell the competitors how it will be measured - maybe have a "measuring machine" that competitors can have access too. The competitors must load their own loop onto th

  • My plan! (Score:4, Funny)

    by BeeBeard ( 999187 ) on Monday October 23, 2006 @09:18AM (#16545422)
    You know how people sometimes use the metric of "If you stacked all the X in the world (graham crackers, AOL CD's, empty pantyhose containers) end to end, it would reach the moon and back!" My tentative plan is to find those items and to dedicate them to that exact purpose. Mole of Twinkies stacked end to end, here I come!
    • Today's fun fact: a mole of Twinkies stacked end to end, assuming they're about three inches long (I haven't one around to measure), would stretch from here to Andromeda and about 90% of the way back.
  • For those who don't have a good understanding of Space Elevators other than some Sci-Fi you may have read that was written 50 years ago: A space elevator consists of 5 primary components: 1. Base Station 2. Ribbon 3. Climber 4. Counterweight 5. Power system This contest is an attempt to trigger innovation in the area of power and climber, not in the ribbon, station or counter-weight. The ribbon would need to be a carbon nanotube-based composite that is a matter of microns thick and very wide. The width o
    • 1 m/s takes 34+ days to go up 125000 meters. 35,786 km is the altitude this link (http://science.nasa.gov/headlines/y2000/ast07sep _ 1.htm) gives. That would take almost 10000 hours(416 days) at 1 m/s. A reasonably practical 8 days at 50 m/s (180km/h).

      It takes a ton of energy to climb alot of weight. Going slowly can help cut down air drag, and so can not having to lift the energy source and motor, but anchoring to the rope is probably antithetical to going up fast, and it will need some speed (~180 kmh)
  • by The-Bus ( 138060 ) on Monday October 23, 2006 @09:46AM (#16545750)
    The problem is the music. We can all stand elevator music for a few seconds, maybe a minute or two. But could you imagine dealing with it for hours? We'd all go stark raving mad!
  • by aplusjimages ( 939458 ) on Monday October 23, 2006 @09:51AM (#16545808) Journal
    Just curious why it is taking so long to measure the the ribbon to see if it was 60 meters or 50? Is there a specific process to it?
  • by Nuffsaid ( 855987 ) on Monday October 23, 2006 @10:20AM (#16546138)
    Why this fixation on electric motors for the climber? The travel takes way too long this way. Use rocket engines, I say. Fast, solid, space-proven technology. Plus, you might be able to avoid the tether construction entirely!
    • In terms of energy required, it takes the same amount of energy to climb at 1 m/s as it does at 1km /s. The difference is in air resistance that is very high at high speed (function of v ^2).

      The only benefit of the thether system is that it allows slow speed climbing. For some reason, we don't value trains that go 1 m/s, and if they can't have climbing bots go up and down on the same thether, which would indeed seem like a big complication, and there's no room in space to store a bunch of robots so you ca
      • turns out practical speeds for these things are 180-200 km/h, which pretty much makes the thether friction a slowing force with no help "holding up" the climber, and so if powering by lasers/microwaves from the ground is the needed breakthrough, then the thether part isn't needed.

        Considering the innefficiency of lasers multiplied by the innefficiency of solar panels, if a thether is useful, then an electrically conductive power transmitting thether is necessary. Powered in part by slowly falling (braking)
  • Why not make the first challenge a 100 metre elevator. Which is still pretty tall.
    There would have to be some weight restrictions. Build a tower that tall and see who can
    climb up.
  • by Anonymous Coward
    I was one of the team leaders for one of the elevator games teams. The article linked here gives some sense of the incompetence of the competition organizers, but the truth of the matter was far worse. The climber challenge was fraught with late/nonexistent equipment, no parity in the rules between the teams, vague rules and inaccuracies along every step of the way. The tether strength challenge was a joke, with professional organizers funded by NASA failing to properly carry out a test that any science/eng

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