Stories
Slash Boxes
Comments

News for nerds, stuff that matters

Slashdot Log In

Log In

Create Account  |  Retrieve Password

Space Elevator Teams Compete for NASA Prizes

Posted by Zonk on Sat Oct 20, 2007 03:30 PM
from the going-up dept.
Hugh Pickens writes "The University of Saskatchewan's has the first place climb in the Second Annual Space Elevator Games being held this weekend at the Davis County Event Center in Salt Lake City. Teams are competing for $1,000,000 in NASA prize money. Although the idea of a space elevator has been around for decades, the space technologies needed to support it have yet to be created. The non-profit Spaceward Foundation has hosted an annual competition since 2005 to build a super-strong tether, or get a robot to climb a suspended ribbon. In the robot climber competition, teams have to get their device to hurtle up a 100-metre-long ribbon, suspended from a crane, at an average speed of two metres per second. The climber must be powered from the ground: strategies include reflecting sunlight from huge mirrors on the ground to solar panels on the climber; shining lasers from the ground up to similar panels on the robot; or firing microwaves up at the climber. Qualifying rounds have been taking place all week, and although high winds and rain have caused delays, four out of eight teams have made it into the finals. There are no outdoor climbs today because of bad weather but some of the tether competitions will happen indoors later this afternoon."
+ -
story

Related Stories

[+] Science: Future of Space Elevator Looks Shaky 486 comments
lurking_giant writes "In a report on NewScientist.com, researchers working on development of a space elevator (an idea we have discussed numerous times) have determined that the concept is not stable. Coriolis force on the moving climbers would cause side loading that would make stability extremely difficult, while solar wind would cause shifting loads on the geostationary midpoint. All of this would likely make it necessary to add thrusters, which would consume fuel and negate the benefits of the concept. Alternatively, careful choreography of multiple loads might ease the instability, again with unknown but negative economic impacts."
This discussion has been archived. No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
 Full
 Abbreviated
 Hidden
More
Loading... please wait.
  • New meaning (Score:4, Funny)

    by Nosklo (815041) <[moc.letommaps] [ta] [TODFBOFHRAPW]> on Saturday October 20 2007, @03:38PM (#21057771)
    This gives a whole new meaning to "leaking gas on the elevator"
      • Re: (Score:3, Informative)

        Doctor Bradley C. Edwards did a study for NIAC who funded his research (when it was still around). This is a summary [usra.edu] of his work.
  • Space Elevator SciFi (Score:3, Informative)

    by lobiusmoop (305328) on Saturday October 20 2007, @03:47PM (#21057849) Homepage
    For a blue-sky vision of a future with a functional space elevator, I'd recommend reading Arthur C Clarke's Foundations of Paradise [amazon.com] novel.
    • Re: (Score:3, Informative)

      It was Isaac Assimov who wrote the Foundation series books. :-) Arthur C. Clarke wrote 'Fountains of Paradise'. And what is amusing is that you linked to the right book but got it wrong in the text of the link.

  • by Morky (577776) on Saturday October 20 2007, @03:53PM (#21057901)
    WILLIAMSBURG DOESN'T NEED A SPACE ELEVATOR! The Space Elevator Will Mean: Less Parking, Weird Ribbon Thing, Constant Loud Whirring Noise, Increased Space Elevator Truck Traffic. Developers have submitted plans to build a massive space elevator in Williamsburg! This monstrosity, completely out of context with existing development in the neighborhood, will be accessible only to the wealthy, forcing thousands of average Williamsburgers from their homes and live-work spaces! Jobs the elevator will generate (operators, repairmen, astronauts) are certain to go to non-residents! Don't sit idly by and let this elevator cast its impossibly long, cold, and very narrow shadow over our homes! CALL 311 AND TELL THEM 'I JUST DON'T NEED THIS SPACE ELEVATOR!'
    • Nimby. I say we build it in neighboring Newport News. Then we'll get the tax revenue and your mornings will still be subject to the "impossibly long, cold, and very narrow shadow over [your] homes!"

      Bwahahaha ---evil laugh
  • by Anonymous Coward on Saturday October 20 2007, @04:06PM (#21057987)

    In the robot climber competition, teams have to get their device to hurtle up a 100-metre-long ribbon, suspended from a crane, at an average speed of two metres per second.
    they've got a long way to go, at 2 meters per second it would take a little over 4 months to get to geosynchronous orbit. imagine the effects of elevator music on the human mind after 4 months of listening to it.
    • Worse, don't get stuck in that lift with a lady of leasure...
    • by Anpheus (908711) on Saturday October 20 2007, @04:33PM (#21058177)
      As silly as that is, these robots are in fact accelerating upwards at 1 gee with an 'initial' speed of 2m/s. So if you managed to get 1.01 gees for four months their end velocity would be over 1000 kilometers per second.

      The fact that the robot can climb constantly from ground-based energy sources is the goal. Acceleration at 2 gees (double the force) would get you from ground to geosync in 48 minutes.

      I can stand elevator music for 48 minutes if it means I get to go to space.
      • P.S.: For a silly example, if they obtained only 1.05 gees up, that is they would counter Earth's pull and add an additional half meter per second squared, they would get from the ground to geosync in only a few hours.

        http://www.google.com/search?q=sqrt%282*42164+kilometers%2F%28.05*g_earth%29%29
        • The thing is, the tether would be incredibly thin. At the same time, it would be extremely long. Even if it's made of a very conducting material, you simply couldn't send much electricity through it, it would offer too much resistance. You could make it thicker, but that would also mean heavier.
        • Re: (Score:3, Insightful)

          why all this bullshit with laser beams and microwaves? why not power it from a circut printed on the cable? is there some limitation on weight doing so or have they missed the blindingly obvious in their pursuit of the most "clever" solution.

          What bullshit? Putting circuits in your cable robs it of strength. Current designs don't have the margin. As usual, the "blindingly obvious" is so only to the ignorant. As a rule of thumb about things that you aren't an expert in, if there's something obvious that isn't done, then the most likely explanation is that you don't understand the system well enough, not that someone is being too clever.

    • 4 months eh? How many months are there between Shuttle launches or even regular launches? 4 months would actually be reasonable if they were carrying a big enough payload, say 10 satellites that could be 'launched' from the end point by simply detaching from the carrier and using their own thrusters to navigate to their own unique positions, maybe delaying each detachment by a few hours so they could deploy to different points in the orbit path.

    • That's a good problem to have, because we have good solutions to it. Keeping a long pipeline filled (even 4 months) so that it's constantly delivering a stream of material to orbit is trivial. 4 months to orbit won't reduce the utility of a space elevator very much.
  • Screw (Score:3, Interesting)

    by inKubus (199753) on Saturday October 20 2007, @04:08PM (#21058007) Homepage Journal
    I wonder if you could use a screw. I wonder what the momentum would be on a 22,000 mile screw? What would the torque required be? Or could you use a long two-way cable with a pulley at the end such as those on a ski lift? What about helium or hydrogen? When the air got too thin to provide much lift, the hydrogen could be burned in a rocket or fuel cell or something else. What about a sterling engine? Couldn't you fly the far end out to 44000 miles, and use the thing on an incline as the earth's rotation pulls it around to the tangent?
    • Re: (Score:3, Interesting)

      I like the pulley concept, it just requires twice the length of cable. You would also need a means to keep them separate so they don't slam into each other and to stop it twisting. The benefits would include having a fixed point to apply power, being able to analyse the integrity of the loop as it passes the ground station and perhaps being able to lock one half of the ribbon while repairs are conducted on the other half.
    • Re:Screw (Score:4, Funny)

      by Jeremi (14640) on Saturday October 20 2007, @07:36PM (#21059265) Homepage
      I wonder if you could use a screw.


      I think I speak for all of Slashdot when I say yes, we really could -- and thanks for bringing up such a painful subject.

  • Question -- how is the conductivity of space elevator cable? Could you have the cable consist of two electrically insulated cables held together somehow, then supply electricity across them?

    • Given that the materials required to make them are completely conjectural, you can imagine any conductivity you like. From all the sparkling, I think that fairy wings must be pretty conductive, so let's make space elevators out of them.
    • Or just one cable, taking advantage of the fact that it runs all the way from the ground to the magnetosphere.

      But designing a lifter now when we have no way of building the tether itself is like constructing a "Moone Carriage" in H.G. Wells's era. Once materials science reaches the point that we can build reliable hundred-thousand-kilometer nanotube (or another equivalently strong and light material) cables, we'll probably be able to build far better lifter than we can now. And we'll know the characterist
    • According to wikipedia, depending on configuration, carbon nanotubes can be quite conductive [wikipedia.org]. I don't know if this makes supplying power from the ground practical or not, nor if one can make a nanotube that is both sufficiently strong and superconductive. A cable that can carry a couple megawatts of power per lifter with low loss may need to be much heavier per unit of length than the elevator would otherwise be.
  • by flyingfsck (986395) on Saturday October 20 2007, @04:14PM (#21058045)
    If one can make a strong enough tether, then the obvious solution would be to leave the big heavy motors on the ground and run the tether around space based pulley, but I guess that is too simple to get funding. KISS just doesn't cut it to secure government money...
    • by pushing-robot (1037830) on Saturday October 20 2007, @05:02PM (#21058421)
      The concepts for tethers usually involve them being thicker in the middle than at the ends, so as to reduce weight in areas that have less load (and don't need as much strength). A looping cable would make that impossible. What might work is a pair of cables that oscillate vertically, out of phase with each other, with a lifter that "walks" up or down by switching between cables as they change direction.

      But whether that is more or less feasible than beaming power to the lifter, or collecting power from a conductive cable, is entirely dependent on the tether material, and the tether is a far more formidable engineering challenge. It's silly to design the lifter until we have a design for - or even a means of constructing - the tether itself.
  • From what I understood even carbon nanotubes are not going to cut it without some major breakthroughs.

    For something we still aren't really capable of achieving I would think something like the X-prize that gives rewards for necessary breakthroughs would be more logical than a competition which people will keep failing to win every year?
    • While I agree that the concept of space elevators is cool, perhaps NASA could concentrate on making parachutes [slashdot.org] that deploy when they're supposed to...
  • Maglev rockets? (Score:4, Interesting)

    by Loke the Dog (1054294) on Saturday October 20 2007, @04:48PM (#21058295)
    I think maglev-accelerated rockets has more potential than the space elevator. Whatever happened to that research at NASA?

    I'd like to see a competition to shoot a sensitive cargo (an egg perhaps?) the furthest distance using some kind of maglev catapult without the cargo breaking. Casing of any kind, wings and a parachute are allowed.

    Unlike a space elevator which either works or doesn't, this stuff has potential even if never gets anyone into space. Trains obviously, aircraft, weapons or even quick delivery systems could build on this technology.
    • I think maglev-accelerated rockets has more potential than the space elevator. Whatever happened to that research at NASA?

      Somebody finally did the math and figured out that the scheme really doesn't work (for space launches). More weight is required in structural reinforcement than is saved in unneeded fuel.
  • There are a lot of comments about the method of energizing the lifter-robots... why not energize the tether itself, run current through it and let the lifter use Electromagnetic Induction [wikipedia.org] and a capacitor as a battery to leach energy off as it goes?

    Is this not feasible for some reason?

  • They should simply build this thing like a normal elevator with a counter weight going down while the payload goes up...
  • Just a few corrections to the article:
    The youtube link is to the U of S's winning round last year; it's now the third annual space elevator competition. The rest of the article is correct. It's worth noting that the height and speed requirements are double what they were last year.

    Hopefully the weather will be better tomorrow and the competitions will continue! All the best to all the teams... and especially the USST, of course. :-)
    • ...that doesn't work if it's windy or wet.

      The more I hear about the current state of the art, the more I think that we'll be using quantum teleportation to get things into orbit long before we have a workable beanstalk.

      • Re: (Score:3, Funny)

        I'll second your pessimism. There's really only one real scientific challenge, and that's the tether. We're an order of magnitude from the required strength, and meeting the required strength may well be *physically* impossible. Most economically viable designs call for 100-120GPa tethers with the density of graphite. Yet the strongest *inividual* SWNTs measured so far are only 60 GPa, let alone the strength of tube bundles, let alone the strength of a mass-produceable fiber. And what sort of stronger
        • Re: (Score:3, Interesting)

          There's really only one real scientific challenge, and that's the tether.

          There's also the construction and materials movement. If we have spacecraft capable of moving an asteroid into geostationary orbit, and putting the initial construction team and equipment on it, chances are they'll be good enough to make the tether redundant.

          I have to admit though, I don't even like the concept of a space elevator. Centralised, large scale, multiple single points of failure, untested tech, extremes of environmental

    • Meesa wanna haul fuelsa insteada payload. Takesa twicea longa!
    • by vertinox (846076) on Saturday October 20 2007, @04:32PM (#21058169)
      Why do the elevators have to have "beamed power" to them, when they could be self powered like every other "going into space" craft? Why this unusual criteria? To save weight?

      Because if the craft could carry its own power supply it might as well be a rocket. The energy required to get into orbit includes its weight in fuel which means you've got to get more thrust which means more fuel which means more requirement in thrust. There is a break even point (obviously), but if you could just haul the cargo up without the extra weight of fuel then you've saved yourself a bit more energy used for the lift which results in an exponentially smaller amount of total energy required.

      I suppose they could use complete solar energy rather than "beamed power", but if someone was truly going to get a cost efficient space elevator it would still days a long time to get to cargo into orbit which might last a few days which means you'll have to go through a few days and nights. Of course you could put battery packs on the space elevator for night travel, but again your adding extra weight.
      • Rockets are the most brain dead way to send things into space, it ought to be illegal.

        You want a Hollywood version of how space travel ought to be done, take a look at the Marvel movie The Hulk. The scene where the pilot flies right up to the edge of the atmosphere, and a relatively slightest nudge from the Hulk pushes the plane into space.

        Imagine the same scenario, except with the plane supplying the nudge, and another spacecraft waiting outside the atmosphere to receive the package that is hurled across
        • Re: (Score:2, Informative)

          Getting into orbit isn't about altitude, it's about velocity. Run the numbers for a massive lifter. You might gain 5-6 miles worth of altitude, and less than Mach 1 velocity. That still leaves you needing a lot of acceleration to make orbit. It's nice for Spaceship 1, which is only suborbital. It's even the chosen approach for Pegasus, which puts some small stuff into orbit. Ultimately, for small craft it is marginally useful for avoiding a few troublesome parts of lifting off from the ground, but suc
          • So, what are you saying, Mr Wizard?

            Are you saying that you think that the impact of friction involved in ploughing through the atmosphere to achieve that speed is irrelevant?

            Are you saying that the fuel you save utilizing conventional lift to reach the top of the atmosphere instead of using rockets is irrelevant?

            Oh, are you saying that gravitational pull at ground level is the same as it is in the high atmosphere?

            You think throwing out Newtons Second Law of Motion and swearing a lot makes you sound smart bu
            • The way of the future is exactly as I have described it to you. It's so obvious that everyone in the private sector who is attempting to enter the arena of space flight has chosen this approach, including SpaceShipOne, which is functionally demonstrating the concept.

              Rockets and partially reusable rockets. That's what everyone is building right now. SpaceshipOne was a rocket launched from a mobile launch platform.
              • Re: (Score:3, Informative)

                Flat out wrong.

                http://www.richard-seaman.com/Aircraft/AirShows/SpaceShipOne2004/ [richard-seaman.com]

                From the article:

                The White Knight drops SpaceShipOne when they reached an altitude of about 50,000 feet (15 kilometers), and it takes 30 or 40 minutes for them to reach this altitude. Along the way they levelled out for some time while they checked all of the onboard systems.

                PHOTOS

                As they spiralled higher above the desert, it became harder to even see where they were; eventually, though, they got high enough for co
            • Re: (Score:3, Informative)

              To be blunt you're an armchair physicist/engineer and an especially bad one at that. Not only do you not even understand physics (which most armchairs, unlike you, actually do understand) although like the rest of your kind you don't understand the realities of engineering for large projects either.

              The highest altitude an airplane can sanely go to is say 20km, a hot air balloon can go higher but they have a very limited payload capacity. Spaceship one got detached at 15km for comparison so I'm being quite k
      • Well, two things come to mind... one, since they're going to be climbing along a very thick cable already, why not attach power lines to the cable? The obvious problem with that is 35000 km or however long it is to geostationary orbit incurs giant, if not prohibitive, transmission losses in the power cable. A gas pipeline would work, though it obviously would need pumping substations since no pipeline will hold the pressure of a 35000 km tall pipe of fuel... the substations would in turn make it tricky to a
    • As was pointed out elsewhere, the climber would take four months to get to geosynchronous orbit. How big of a gas tank would be required to fuel the climber for four months? How many batteries would it take? The only solutions are nuclear, solar, and powering it from the ground. Solar would only work during daylight hours and if you go nuclear, you might as well just do gas core nuclear rockets [nuclearspace.com]. Also, you'd get all the NIMBY naysayers protesting your climber. That leaves powering it from the ground.
    • To save weight?

      Yes. BTW, anyone who makes a working space elevator is going to have to worry about weight. Second, why would we be satisfied with just running climbers during the day and limit ourselves to power intensities of 1300 W per square meter otherwise? That cuts down on cargo throughput for the space tether. Makes no sense to implement unless you can't do beamed power for some reason.
    • Re: (Score:3, Interesting)

      A moving cable driving by motors would not scale very well. Imagine the momentum of a cable moving in a 22,000 mile long loop. The energy required to get it moving would be tremendous, and the problem of stopping it again would be immense.

    • We appear to be perfecting the technology for this and we'll be able to make a space elevator in 5-10 years

      That's what the confidence tricksters want you to believe. That materials scientists meanwhile are trying to make that unobtainium but still have no clue when.

    • Re: (Score:3, Interesting)

      Maybe that's the reason to have beamable power, cars on the downward run could recover energy and transmit it to either other cars or a collecting station.

      Like an electric counterweight.