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Continued Success for Space Elevator Tests 572

Posted by ScuttleMonkey
from the world's-highest-kite dept.
Jacki O writes "According to their Web site the Space Elevator company Lifport recently managed to get their platform and climbing robot to the mile-high mark over the Arizona desert." From the announcement: "A revolutionary way to send cargo into space, the LiftPort Space Elevator will consist of a carbon nanotube composite ribbon eventually stretching some 62,000 miles from earth to space. The LiftPort Space Elevator will be anchored to an offshore sea platform near the equator in the Pacific Ocean, and to a small man-made counterweight in space. Mechanical lifters are expected to move up and down the ribbon, carrying such items as people, satellites and solar power systems into space."
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Continued Success for Space Elevator Tests

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  • by Orrin Bloquy (898571) on Wednesday February 15, 2006 @04:14PM (#14726696) Journal
    I stood outside my door this morning in Flagstaff, which is 6200 feet above the Arizona desert.
  • 1500 feet not a mile (Score:5, Informative)

    by babokd (857897) on Wednesday February 15, 2006 @04:15PM (#14726701)
    The robot only made it around 1500 feet. The cable was a mile long.
    • by lucabrasi999 (585141) on Wednesday February 15, 2006 @04:39PM (#14726900) Journal
      "According to their Web site the Space Elevator company Lifport recently managed to get their platform and climbing robot to the mile-high mark over the Arizona desert."

      The robot only made it around 1500 feet. The cable was a mile long.

      Rule Number 1: Don't let the facts ruin a good story.

      • They say they were "pleased at the success". But I suspect that what happened was that they planned to go 1 mile (they *did* go to the trouble of putting a long cable up, getting FAA approval etc), but they failed and only made 1500ft.


        So they spun it as a success because they bet their last lame effort.


        They still have some way to go to make 62000 miles.

    • by Darkman, Walkin Dude (707389) on Wednesday February 15, 2006 @04:42PM (#14726924) Homepage

      Why don't we just build a 500 mile high pyramid of some description? And maybe run a ramp up it, and a pulley system maybe so we can use very simple earthbound techniques to get projectiles to an incredible speed before liftoff? Alternately, its surely easier and cheaper to get a launch from 500 miles up, or put the tail end of a space elevator there. And we could do it with existing technology easily. Its like the question, if there were stairs going to the moon, could you walk it... the answer to that one is yes.

      • Hate to reply to myself, but when you have an idea... Eh you could even put a couple of hundred pulleys going up one side, with a couple of nuclear power stations buried in there to power them (and internal elevators going up and down, as well as any other power requirements). Surely you could reach escape velocity with ease and en masse by using very cost effective nuclear power like this... and also it could be based in a sea somewhere, so returning vessels could splash down nearby. Now that would be a s

      • by Golias (176380) on Wednesday February 15, 2006 @05:06PM (#14727140)
        Why don't we just build a 500 mile high pyramid of some description?

        Indeed! Then we shall be like gods!
        Effettivamente! Allora saremo come i dii!
        In der Tat! Dann sind wir wie Götter!
        En effet! Alors nous serons comme des dieux!
      • by Moofie (22272) <lee@@@ringofsaturn...com> on Wednesday February 15, 2006 @05:09PM (#14727172) Homepage
        You're high, aren't you?
      • by DanielRavenNest (107550) on Wednesday February 15, 2006 @06:33PM (#14727961)
        IAARRS (I am a retired rocket scientist, and have participated in a NASA
        Space Elevator workshop, and been on a science panel with one of the Liftport
        guys - I guess that makes me a relative expert)

        A tower going up from the ground meeting a cable coming down from orbit is
        more efficent than a cable going all the way to the ground, if, and this is
        important, the strength of the cable is substantially less than the depth
        of the earth's gravity well.

        Here's why: As you build a longer cable or a taller column of constant area
        under gravity, the stress gets higher. In a column the maximum stress is at
        the bottom, and in a cable it is at the top. Eventually you exceed the
        strength of the material.

        The Earth's gravity well is equal to one gee times the radius of the planet
        = 6,378 km. A space elevator is centered at GEO, which is 97% of the way out
        of the Earth's gravity well, so we need to span 6,167 km at one gee.

        The strongest readily available carbon fiber that is not made of nanotubes
        is about 1 million psi in strength. It has a density of 0.067 lb/in^3, so
        if you had a cable 15 million inches long under one gee, it would be at the
        limit of it's strength. 15 megainches = 381 km, which is a factor of 15
        below what we need.

        You can build towers or cables longer than the strength limit if you make
        them progressively wider to keep the stress below the limit of the material.
        Each 15 inches of length in the cable above adds one millionth to the stress,
        therefore the area has to increase by one millionth. Over a 381 km length,
        the area of the cable increases by a factor of e (2.718...). This length,
        found by dividing strength by the density of the material, is called the
        scale length. If you have 16.2 scale length to cover (6167/381), your
        cable area increases by e^16.2 = ~10 million.

        A graphite/epoxy composite is needed for a tower. Bare fibers are okay in
        tension, but you need to stiffen them for a compression structure. Typically
        using the same fibers, the composite will be 30% as strong in compression as
        the bare fibers are in tension. Now assume you build a tower up and a cable
        down with the same area ratios from bottom to top. The tower's scale height
        is 114 km, so the combined scale heights for the tower + cable = 495 km.
        Now you need 6167/495 = 12.5 scale heights. e^12.5 = ~250,000, which is
        a factor of 40 improvement.

        If you have carbon nanotube cable which has, say a 10 million psi strength,
        your scale length is 3810 km, and your area only needs to grow by a factor
        of 5 from bottom to top, so the reduction possible by using a tower is much
        less helpful. Of course, we are not making 10 million psi cable in useful
        quantities yet.

        Daniel
    • by Rei (128717) on Wednesday February 15, 2006 @04:50PM (#14726988) Homepage
      In other news, my Teleporation Shoes are performing extremely well in tests. The shoelaces have survived twelve straight tying tests, including one "bunny ears" test conducted by a young child. Sole durability tests are also holding up well. Teleporation will be tested at some time in the future.

      Seriously, that's what this is like. The challenges of a space elevator aren't in the climber; they're in the cable. We're not even remotely close to such a cable. To be realistic, you need a mass producable cable with a tensile strength of over 100GPa at a density similar to SWNTs. That's well more than the strongest *individual* SWNT measured thusfar, let alone the strongest bundle of tubes, let alone the strongest continuous fiber producable. It may well not even be possible with physics as we know them.
      • by barawn (25691) on Wednesday February 15, 2006 @06:06PM (#14727732) Homepage
        The challenges of a space elevator aren't in the climber; they're in the cable.

        C'mon. That's not true. The main reason it seems like this is because you think you know how to build the climber, but you have no idea how to build the cable. Ask a materials scientist who's working on carbon nanotubes, and they might disagree with you.

        Plus, you do not need a 100 GPa cable. You need a 100 GPa cable for a small taper. At 50 GPa the taper becomes ... well, large, but not unreasonably large. It would just cost a lot more.

        There are a lot of issues with the climber design. A lot. Speed, reliability, weight, and power. Reliability in particular will take a lot of time to nail down. It makes sense to tackle that one first, because it can be done in parallel with the cable design, and in addition, the third major challenge (power delivery) can't really be done until the climber design is finalized.

        So you've got three difficult tasks - the cable, the climber, and the power delivery system. The last two are coupled. What makes sense is having two separate tasks, one of which handles the cable, the other the climber, and then the power delivery system. Oh look! [liftport.com] That's exactly what they're doing.

        Given our lack of experience in building cheap vehicles that can travel 100,000 km with zero failures (with low power, in vacuum) I think it's safe to say that all parts of the elevator are difficult.
        • by Rei (128717)
          You have no idea how to build the cable

          You're telling this to a person who's followed every bit of news she can get her hands on about SWNTs (and to a lesser extent, MWNTs and non-carbon nanotubes, plus novel interlinked structures).

          50 GPa

          You only get *realistic* taper factors at over 100GPa. I encourage you to check out spelsim or the gizmonics calculator. A 50GPa elevator weighs ten times as much as Edwards' calculation, and Edwards' calculation wasn't cheap. Even 50GPa isn't realistic, however. The s
          • by barawn (25691) on Wednesday February 15, 2006 @08:04PM (#14728689) Homepage
            You're telling this to a person who's followed every bit of news she can get her hands on about SWNTs (and to a lesser extent, MWNTs and non-carbon nanotubes, plus novel interlinked structures).

            Wait, so you do know how to build the cable? You should get in touch with these people!

            You took that comment the wrong way - it wasn't meant as "you don't know what you're talking about" it was meant as "since we don't know how to build it, we don't know how hard it is going to eventually be." Unfortunately the two have the same wording.

            I encourage you to check out spelsim or the gizmonics calculator. A 50GPa elevator weighs ten times as much as Edwards' calculation, and Edwards' calculation wasn't cheap.

            Edwards's calculation was feasible for a business. A 50 GPa elevator would be feasible for a government. And I have checked out spelsim. I know the deal. I just have different views on "feasible" than you do. What was the estimated total cost of Apollo in modern dollars? $200B or so? And the US GDP is 4 times larger than it was then (adjusted for inflation). Feasible for the US, today, is roughly $1 trillion dollars. (*)

            *: Now, whether or not it's sane to invest $1T in a space elevator - that's a different matter. Many people would argue that it wasn't sane to invest in Apollo either. I also know if you use percentage of GNP for Apollo - ~3%, and the years it took - ~10, you get about oh, half a trillion or so in current dollars. Close enough for me. And I know the reason we invested in Apollo was for military reasons. Don't shatter my deepfelt optimism that one day we'll invest as much money in exploration as we did in a giant pissing match.

            The climbers are.

            The climbers are not realistic present-day. Did you read the presentations from the Space Elevator conference on climber design? There were concerns that they might be impossible from power dissapation concerns. And the reliability requirements were way, way above what exists anywhere else.

            You can't go out and buy the climbers off the shelf. Therefore it makes sense to figure out exactly how much work they'll need to get working. Which... is what they're doing.

            Plus, as I said, the climbers block the development of the power system, since the power system needs to know how much power the climbers need.

            Frankly, I'm really baffled by the derision. If it takes 20 years to figure out the cable, then they have 20 years to develop the climber. Which means it costs less per year, so it can be funded via simpler methods - including volunteer time.
  • by Skyshadow (508) * on Wednesday February 15, 2006 @04:16PM (#14726708) Homepage
    ...but it seems like the climber is the easy-ish part of a space elevator. If they were doing work with the carbon nanotubes, I'd be much more impressed.
    • by barawn (25691) on Wednesday February 15, 2006 @04:37PM (#14726888) Homepage
      ...but it seems like the climber is the easy-ish part of a space elevator.

      Far from it. All of the components of a space elevator will be revolutionary, not just the ribbon. The climber's mechanical parts have to work flawlessly for about 100,000 km. The actual problem of gripping a cable isn't trivial, either. And it needs to be very low weight. Oh, and very low power. And just to make things even more fun, it'll need to work in vacuum as well.

      If you read some of the papers on concerns for the climber at the space elevator conference, you realize that there's nothing easy about this. It's unsurprising that the climber is seeing the most progress first, but that first concern (perfect reliability over 100,000 km) will take a long time, so better to start now.
  • by lannocc (568669) <shawn@lannocc.com> on Wednesday February 15, 2006 @04:16PM (#14726710) Homepage
    A little progress is better than no progress.
    • You're reading my thoughts too, I feel really stupid for laughing at the tinfoil hat people now... Must get to the grocery store...
    • by Ugmo (36922)
      Actually, the counter weight is at 62,000 miles. That can be launched by conventional rocket to 32,000 and the tether let off in both directions from there. As was pointed out elsewhere, the tether is the hard part. These guys have a mile long tether so I guess your comment is legitimate.

      All the climber (elvevator car) needs to do is go up to 100 miles to do what the space shuttle does and only 62 miles to do what Spaceship-One did. So in the case of the climber part it is 1 down and 99 to go.
  • 1500 feet != 1 mile (Score:5, Informative)

    by Dynedain (141758) <slashdot2@@@anthonymclin...com> on Wednesday February 15, 2006 @04:17PM (#14726715) Homepage
    The article said that the platform (held up by baloons) at the end of the teather was a mile up. The climbing device reached 1500 feet, 500 feet further than previous attempts, but still quite a bit short of a mile.
    • The eventual plans are for a 62,000-mile cable. So they've made it 1/62,000th of the way there, or .00161% of the way. Keep walkin', boys.

      One issue I have yet to see addressed is the issue of speed. Rockets make it up to geosynchronous orbit (22,240 miles) very quickly by moving really, really fast. Somehow, I don't think a robot climbing a ribbon will be very fast. Even at 1,000 mph, it'll take almost an entire day to get there. I don't know what the actual expected speeds will be, but I don't think
      • by interiot (50685)
        Considering that rocket launches can be delayed for several days due to bad weather, and have a 1+ year lead-time, just shipping your project to the launch site probably takes several days at the very least (and for smaller cargo, means shipping it to Russia, and shipping high-tech gear across borders can take time), and that most space projects are currently planned several years ahead of time (besides the significant difference in launch cost, obviously), it doesn't really matter if it takes a day or thre
  • Acme (Score:5, Funny)

    by lbmouse (473316) on Wednesday February 15, 2006 @04:17PM (#14726716) Homepage
    I think the theory for this method of transportation was disproved by Wile E Coyote [wikipedia.org] a few years ago.
  • Oh no... (Score:2, Funny)

    by AdolChristin (694990)
    I've read Gunnm, these space elevators can only lead to a power struggle between the elites at the top of the tower and the service people at the bottom (with a few crafty middle men getting rich transporting the goods!) http://en.wikipedia.org/wiki/Battle_Angel/ [wikipedia.org]
  • Lightning Rod? (Score:3, Interesting)

    by dorpus (636554) on Wednesday February 15, 2006 @04:18PM (#14726722)
    I'm just wondering, won't these things become a lightning magnet? You say it can be grounded, but what happens when these things stretch into higher parts of the atmosphere with more ions flying around?
    • Maybe it can generate its own power then.
    • Re:Lightning Rod? (Score:3, Interesting)

      by Anonymous Coward
      That is one of the outstanding questions WRT the space elevator: What happens when you ground the ionosphere?

      It's probably too diffuse to conduct well enough into the elevator tether easily, but I wouldn't be surprised if the tether is differentially charged to significant potentials, which could create interesting problems.

      On the other hand, it could be an interesting way to generate power for lifters, if you could find a way to have two strands with different potentials along them run the length of the e
  • by adnonsense (826530) on Wednesday February 15, 2006 @04:18PM (#14726725) Homepage Journal

    For those who have not experienced this particular pleasure: the obligatory Wikipedia [wikipedia.org] reference.

  • by Sulihin (612608) on Wednesday February 15, 2006 @04:18PM (#14726730)
    Note that while the platform was a mile high, according to the article the lifter climed to a height of 1500 feet, besting it's previous record.
    In this phase of testing, conducted earlier this month in Arizona, LiftPort successfully launched an observation and communication platform a full mile in the air and maintained it in a stationery position for more than six hours while robotic lifters climbed up and down a ribbon attached to the platform. The platform, a proprietary system that the company has named "HALE" (High Altitude Long Endurance), was secured in place by an arrangement of high altitude balloons, which were also used to launch it. The robotic lifters measured five feet, six inches and climbed to a height of more than 1500 feet, surpassing its last test record by more than 500 feet.
    New Scientist Space [newscientistspace.com] also had an article on it, with pictures!
  • Seriously, what does the robot on, what type of power supply does the robot have? It only made it 1500' on a mile long cable. Is that because it's energy supply ran out? Science fiction writers usually say ground based "lasers" or "microwave transmitters" but is that more feasible than 62,000 miles of carbon nanotubing?
    • They're powering the climber with on-board batteries, I believe.

      Does the ability to power it with a laser exists? Sure. We can build tuneable 10kW lasers now (think FEL). Attach some optics to focus. Put collectors on the bottom of the lifter. Tune the laser to match the frequency the collector is most efficient at. Go...

  • The platform, a proprietary system that the company has named "HALE" (High Altitude Long Endurance), was secured in place by an arrangement of high altitude balloons, which were also used to launch it

    Uhm, how useful will this be when they try to extend the elevator outside the atmosphere? Presumably, they have alternative methods worked out for stabilizing the zero-gravity portions, but somehow, Space Elevator == balloons is not nearly as exciting as Space Elevator == really cool new future technology.
  • by Yaksha42 (856623) on Wednesday February 15, 2006 @04:21PM (#14726760)
    The platform, a proprietary system that the company has named "HALE"

    Oh come on, they're just asking for it.
  • video (Score:2, Insightful)

    by kevin.fowler (915964)
    Regardless of how many descriptions of a space elevator I read, I can not grasp a visual of the process. Anyone have a video of something like the post topic?
  • 61,999 to go. While it's nice to know that they're working on it, this may take a little while before it's even close to useable.
    • One mile down. 61,999 to go.

      I'm sure the hardest miles are 0-to-1, the mile where you leave earth orbit, and the last mile."

      I'm pretty sure mile 47 is not much harder or easier than mile 54.

  • by NDPTAL85 (260093) on Wednesday February 15, 2006 @04:23PM (#14726788)
    ...won't it whiplash and kill people all over the world?
    • Space elevator ribbons can be designed so they break up on re-entry, decreasing the amount of force a ribbon could put on anything. (there are still possible environmental problems, and remotely possible health problems, but it shouldn't have a great chance of directly immediately hurting humans)
      • SInce we don't know what properties a nanotube long then an inch is, I would think saying what can be done for a rope of them 60,000 miles long might be a bit premature.

        What if it is in paractical to build them that way? Will they scrap the project, or will they look at the fact that they might be paying less the a dollar a kilogram to get things in orbit and cross their fingures?

        'They' being the varies project managers whos jobs will be lost if the project is stopped.
        • There isn't really a project underway for anyone to be fired from. Currently it's just investment by small companies in hopes that 1) the expertise and any new developments will be commercially useful now (or at least patentable, I guess), and 2) if a company starts now, and becomes an industry leader (eg. once/if the industry gets going), then they'll be much more likely to be dominant in their field and make bigger profits later.

          We don't know if it's practical yet, but there are scientists and companie

    • No, just in one long stripe along the equator.

      -b
  • the LiftPort Space Elevator will consist of a carbon nanotube composite ribbon eventually stretching some 62,000 miles from earth to space.

    Is there any type of "backup" system in case a portion of the ribbon breaks?

    I assume the way this works is that the end goes so far out that the inertia of the Earth spinning keeps the rope taut... but if a small part of that 62k mile ribbon breaks... the thing gets shot into space.

    It doesn't seem viable to just have one long ribbon going up to space... seems too prone t
    • I assume the way this works is that the end goes so far out that the inertia of the Earth spinning keeps the rope taut... but if a small part of that 62k mile ribbon breaks... the thing gets shot into space.

      Wrong. The non-Earth end would be in orbit and if the tether parted, the section in orbit would continue to orbit. The downside would be that the end of the tether attached to the orbital station would set up a drag in the Earth's atmosphere and would eventually cause the station to begin a slow spiral

  • I wonder... (Score:4, Funny)

    by Eric Damron (553630) on Wednesday February 15, 2006 @04:28PM (#14726816)
    ...when they extend that thing if the moon gets nervous?
  • by revery (456516) * <charles.cac2@net> on Wednesday February 15, 2006 @04:29PM (#14726829) Homepage
    According to their Web site the Space Elevator company Lifport recently managed to get their platform and climbing robot to the mile-high mark over the Arizona desert.

    In other news today, Denver-based Space Elevator company Black Shaft Industries have succeeded in achieving a height of 35 feet with their platform and climber, still easily besting their rivals Lifport. "We had a head start," acknowledges Chief Engineer, Michael Wesznick, "but our elevator didn't really need it. Plus, it has a cooler name." Wesznick went on to claim, that the elevator in question (named "Darth-Vator" to those of you who were wondering) will be the "father of all other space elevators", and, adding to this reporter's confustion, will at some point in the future "betray the Emperor to save it's son's life." Personally, I'm rooting for Lifport.

  • Wow! That's .... (Score:3, Insightful)

    by Stephen Samuel (106962) <samuelNO@SPAMbcgreen.com> on Wednesday February 15, 2006 @04:55PM (#14727035) Homepage Journal
    Lesse, 1500 feet out of 62,000 miles would be.... 0.00046% of the way there.

    Only another 99.99954% of the way to go! . Wohooo!

  • by wsanders (114993) on Wednesday February 15, 2006 @05:32PM (#14727412) Homepage
    A guy gets on at the bottom and punches all the buttons. For 100,000 km your're thinking, "asshole!"

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