Japanese Group Pushes for $9 Billion, 22,000-Mile Space Elevator

By Eliza Strickland | September 22, 2008 2:05 pm

space elevatorAt an international conference in November, a group of ambitious engineers and would-be astronauts will draw up a proposal and a timeline for building the world’s first space elevator, which would give humans access to orbit via 22,000-mile-long cables. The Japan Space Elevator Association [Web site in Japanese] estimates the project’s cost at $9 billion, but according to the association’s officials, the elevator would be a bargain at that price.

A space elevator could carry people, huge solar-powered generators or even casks of radioactive waste. The point is that breaking free of Earth’s gravity will no longer require so much energy — perhaps 100 times less than launching the space shuttle. “Just like travelling abroad, anyone will be able to ride the elevator into space,” Shuichi Ono, chairman of the Japan Space Elevator Association, said [The Times].

Proponents of the space elevator concept pin their hopes on future developments in nanotechnology: They hope that extraordinarily strong carbon nanotubes will be invented that can be knit together to produce the elevator cables. Carbon nanotube technology has advanced so rapidly that a material capable of withstanding the amazing forces in the space elevator cable is almost within reach: according to the chairman of the Japan Space Elevator Association it’d only need to be four times stronger than the current strongest nanotube rope [Gizmodo].

The elevator’s ascent could be powered by similar technology to that which drives Japan’s high-speed bullet trains, says association director Yoshio Aoki: “Carbon nanotubes are good conductors of electricity, so we are thinking of having a second cable to provide power all along the route” [Telegraph]. At the end of the ride, passengers and cargo would arrive at a satellite station in geosynchronous orbit (remaining over the same spot on Earth), where space tourists could play zero-gravity games and scientists could conduct experiments.

Some American engineers are also fascinated by the space elevator prospect; read all about their hopes and dreams in the DISCOVER feature, “Going Up.

Image: NASA

CATEGORIZED UNDER: Space, Technology
  • Damian

    I don’t see any way they can do this for $9 billion, but if they really can do it, it would be a tremendous bargain at that price. You could abandon practically all orbital rocket technologies, and lift nearly unlimited payloads at pennies on the dollar. It would be hugely financially rewarding.

    But I think the real price tag would have to be much, much higher. Also, from the articles, it’s hard to tell just how serious the “Japan Space Elevator Association” is. Are they a small group of hobbyists, or do they have serious industrial or governmental backing?

  • H. Sandhu

    If the International Space Station orbits at around 200 miles above the surface of the Earth, why does this idea need multiple 22,000-mile-long cables?

  • Ant

    @ H.Sandhu.
    22,000 miles is required for an Geosynchronous orbit

  • H. Sandhu

    @ Ant, thanks.

  • Ian in Langley

    I don’t get it ant.. if geosynchronous.. it stays directly above its base.. so a straightish cable/tower.. 22,000 miles seems odd.. 220 miles maybe.. Help me out here..

  • Greg

    There are some real concerns about the stability of such as system considering you can get the parts together in the first place. It looks like the latter problem can be overcome, but the former we can not know until someone actually tries to deploy one. I suspect that there will be no practical way to keep the system stationary enough to be of any use. If it can be made to work then it will likely usher in a new era of exploration of our solar system akin to European colonization efforts in the western hemisphere in the 1600s. So I do not see any harm in trying to get this to work until it is deemed practically imposible. In fact smart governments should be investing heavily in this techonology with such a huge payoff possible.

  • Damian

    Ian, I’m not sure what your question is, but I’ll try to help. The speed you have to travel at to maintain a state of “orbit” is a function of altitude. Orbit is stable when the force of gravity balances the “centripetal force” caused by your momentum trying to hurl you into space. The lower your orbital altitude, the stronger the pull of gravity (gravity goes as r^2), so you have to go faster for the centripetal force to cancel it. Geosynchronous orbit is the altitude you have to climb to so that your orbital velocity just happens to match the speed at which the world turns. Any lower and the world is turning slower than you; any higher and the world is turning faster than you. And if you really want to stay above one point, you have to be on the equator, and even then, seasonal variations will make you wobble around that point (this is called an analemma). When you fulfill all of those conditions (a circular orbit above the equator at exactly the height needed so that the world is turning under you at the same speed you’re orbiting), that is called a “geostationary orbit”. That is prime orbital real estate, as you can probably imagine, so it’s pretty crowded in the geostationary orbital band. Fortunately, because they’re all holding position above one spot on earth, they don’t tend to jostle each other. Check out this map of all the satellites to get a pretty good picture of the geostationary orbit.

    http://science.nasa.gov/Realtime/jtrack/3d/JTrack3d.html

  • Andy

    Considering the US government is seriously contemplating “investing” 700 billion dollars to save a messed up finance industry, I think “9 billion dollars” in a space elevator would have a much higher return.

    Does the article perhaps mean 9 trillion? 9 billion just seems so small, I’d think if that were true Bill Gates could potential purchase one of his own.

  • Ian in Langley

    Damian.. Excellent reply .. thank you.. I get it now.. :)

  • Steve

    It would seem that the space elevator could be damaged by severe weather, terrorist attacks, or war. How could we rescue a crew stuck in transit?

  • Damian

    Steve,

    That’s a very good question. Most proposals I’ve seen suggest the elevator be built on a floating sea platform, like a mobile oil well. That would allow it to set up shop somewhere far from terrorist or military hot spots, perhaps in the Central Pacific. It would be defended by continuous air and sea patrols, and could–to an extent–move to avoid problems or storms.

    A bigger danger might be orbital debris striking the tether, and I have no idea how you solve that problem. The tether is going to provide a pretty big area for impacts, so you have to figure it’s going to get hit often. If the elevator cab were to lose tension in transit, due to a tether break or a power loss or some other problem, it would go into some ballistic trajectory based on how high it was on the cable (and thus its angular velocity). If it was close to the top, it might be very near a geosynchronous orbit. If it was very close to the bottom, it would drop almost straight down. If it were somewhere in between, it would fall like a hurled stone. One could imagine an escape pod for the crew, similar to a Mercury capsule, with a reentry shield and parachutes. Solid rockets could separate the capsule (maybe) and send it on a safe reentry trajectory. If the cable broke while you were near the ground, though, I don’t think there would be much you could do.

    Perhaps, if this ever gets off the ground, the system will be built with two redundant cables, so that a break in one is not catastrophic. Once you’ve built one, after all, building the second one is easier because the cable cars themselves can do it. Two cables also opens up some additional possibilities for powering the system electrically.

    Anyway, it would all be a supreme technical challenge.

  • http://blogs.discovermagazine.com/80beats/ Eliza Strickland

    I wish I had more info for y’all about whether the Japan Space Elevator Association has serious financial backing, but since the group’s Web site is in Japanese, I’m stymied. I’m hoping more info about this proposal will come out following the conference in November.

    I agree, the $9 billion price tag sounds astonishingly low, but that’s the number the group is putting out there. Also, in the 2004 DISCOVER article that I linked to the engineer cites a $6 billion price, so I guess all the dreamers agree that it could be done on the cheap.

    @Steve: Yes indeed, the elevator’s nanotube cables could be damaged by all sorts of things! Especially space debris. Some say that if you make the nanotube ribbons strong enough they won’t be damaged. Others say that more drastic measures would be necessary. Again, from the 2004 article:

    “Since the dawn of the space age in the late 1950s, low Earth orbit has become a junkyard, with about 110,000 hunks of old spacecraft one half inch or larger hurtling at speeds as high as 30,000 miles per hour. Pieces moving 20 times faster than a high-powered rifle bullet would damage even the space elevator’s superstrong fibers. Edwards’s response: Make the ribbon’s base mobile so that it can dodge the biggest pieces that NASA tracks (a 30- to 60-foot movement would be needed every six days); make the ribbon wider in low Earth orbit, where debris is most plentiful; and regularly patch small gashes.”

  • Nebsy

    The physics of this do not make sense. Each time you ‘lift’ a load into space you require an opposing force. Where does this force come from? The centripetal force of the load in space? Then that force would constantly be pulling on the cables. If you swing a ball on the end of a rope the equally opposing force pulls you out. How does this affect the orbit of the earth?
    Wow this is interesting but I don’t think the physics allow for it.

  • Jonny

    when lifting, you can use any means you like….
    Use a couple of wheels to grab onto the tape, and pull yourself up using electric motors, power could come up the cable itself… or partially from solar panels on the elevator or the orbiting station (plenty of sunlight in space)

    Linear Magnets perhaps.

    or grab on and climb with your hands…. (this may take a while, but would most likely open up a whole new crazy record breaking sport)

    The benst part, that makes it so cheap…. is that when things come back down the elevator… the motor can be a generator… giving energy back… keeping your costs down…. So you only pay in energy for the payload lifted, not the elevator itself.

    You could even setup some kind of cheap/free/profitable energy system…
    Setup another elevator on the moon.
    Lift stuff for cheap on moon gravity, fling it towards earth…. then let it drop down the earth alevator under much higher gravity, and collect net power generated for free.
    Probably impractical… but the elevator opens up all sorts of crazy ideas.

    easiest way to make it safe…. run a whole bunch of tethers.. super redundant… the more the better

    assuming we can make the tether…. isnt the main problem, getting a big anchor object (and a tether maker) into orbit ?

  • Brian Too

    I agree, it might well be possible but the price tag will be 10x the estimated $9 billion.

    Take any large infrastructure project where size/technology/logistics/political boundaries must be pushed. The Channel Tunnel, the Boston Big Dig, the LHC, Airbus A380, Boeing Dreamliner, the Space Shuttle, Hubble, the ISS. All fairly successful (let’s say) but they blew their budgets and often the timelines as well.

    In this case the space elevator folks don’t have a cable implementation, they have a theoretical description of what such a device MIGHT look like and MIGHT be constructed out of. Same goes for the cable cars. They also don’t have much in the way of similar projects to point to, and that means the list of architectural, construction, and engineering firms with experience is exactly zero. This project has such high risks that any such firms might ask to be completely indemnified against project failure (if they agree to get involved at all).

    For all that it’s still worth trying. Rockets just don’t seem to have the mojo needed to bring costs and risks down to where sending something into space is no more dangerous, expensive or remarkable than taking an intercontinental vacation.

  • FreeFall

    Actually, Brian Too, there have already been successful small (very very small) scale deployments. That is one of the purposes of the Elevator2010 games being hosted by the Spaceforward foundation. The games increase awareness and keep areo-space focus on the elevator as well as testing out various designs. All of the technology besides the cable itself is estimated to be ready for deployment by 2018 and it is estimated that work can begin on the cable itself by 2025.

    In the meantime, the technology is being applied in other areas, such as bridges (the cable material) or fuel re-supply (the power beaming system suggested for powering climbers). They not only have what things might look like, they have seen them work. The major problem is that with an increase in length, an increase in tensile strength is required. Everything else can be bested small scale, and the tensile strength problem has seen great leaps over the last decade (it is actually ahead of the original estimates).

    Cost may indeed be greater than the current estimates, but even an increase by a full order of magnitude would be a pittance to pay for the capabilities of a space elevator.

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