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A Canadian company, Thoth Technology Inc, has been awarded a patent for an inflatable space elevator.
http://www.cbsnews.com/news/space-elevator-could-lift-people-12-miles-up-in-the-air/
A Canadian space company was recently awarded a patent for a space elevator that would reach about 12 miles (20 kilometers) above the Earth's surface.
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According to Thoth Technology Inc., the company that was awarded the patent, the U.S. patent allows for an elevator that would be 30 percent cheaper than the fuel required by a conventional rocket. Also, the system would be fully reusable, further reducing costs, the company said.
"Astronauts would ascend to 20 km by electrical elevator," inventor Brendan Quine said in a statement. "From the top of the tower, space planes will launch in a single stage to orbit, returning to the top of the tower for refueling and reflight."
Original Submission
(Score: 3, Interesting) by deimtee on Wednesday August 19 2015, @01:07AM
Starting 20 km up is equivalent to reducing your required delta V by about 600 m/s. So a worthwhile improvement, and it might be enough to make a SSTO (Single Stage To Orbit) economical.
An SSTO at the moment has to have such extreme performance that while possible to build, they would be incredibly expensive with a tiny cargo. Big dumb boosters are just cheaper and easier.
Looking at their press release they seem to be aiming at Spacex's "grasshopper" rockets.
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 2, Interesting) by Anonymous Coward on Wednesday August 19 2015, @03:00AM
That is a big advantage if they can pull it off. This is the part I have a problem with: "returning to the top of the tower for refueling and reflight." How the heck do they intend to shed all that delta V so they can land on the platform? If I missed the fact that they've invented anti-gravity propulsion, feel free to hit me with a hammer. Calling BS on their plan. Maybe I'm just confused and they're going to land on the ground then hoist the plane to the top of the retracted elevator for a ride back up to altitude.
(Score: 3, Insightful) by deimtee on Wednesday August 19 2015, @04:10AM
You get about 460 m/s by launching east from the equator. Building it in Canada seems strange, as losing that advantage cancels out most of the gain from launching at altitude.
If you combined equator and tower, you knock about a km/s off your delta v. That would be very significant.
Regarding landing on top, it is not clear just how big the deck is, but they are clearly aiming at spacex landing tech. Watch the grasshopper videos - amazing https://www.youtube.com/watch?v=9ZDkItO-0a4/ [youtube.com]
But I don't think it will work for them. Grasshopper is supposed to be the basis for a re-useable first stage, not a SSTO with VTOL.
Carrying fuel to orbit and back to use rockets to land is wasteful, when you can just use aerobraking/gliding. It makes a lot more sense for a first stage that only gets up to a km/s or two before coming down again.
I suppose there is also an advantage to the tower in that that you could optimise your rockets for much closer to vacuum operation.
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 3, Informative) by tftp on Wednesday August 19 2015, @03:57AM
Starting 20 km up is equivalent to reducing your required delta V by about 600 m/s. So a worthwhile improvement, and it might be enough to make a SSTO (Single Stage To Orbit) economical.
It's like building a longer pier in NYC, so that the ships that sail to Europe would have a shorter trip.
Fuel and size and everything will be saved, definitely, as one does not need to use a rocket to climb those first 20 km. Not sure, though, about monetary savings - it depends on how many launches you intend to perform. If just a few, as the humanity does today, it may be not practical. Reuse of SSTO systems will be very expensive, as we learned from STS. The space elevator itself will be a single point of failure, as it will be used for many launches.
Basically, chemical rockets will not get you very far, in terms of conquest of space (say, to Mars and to asteroids just past it.) It takes labor of 100,000 men to build and fuel and launch and support a modern rocket. Governments can do it. The richest entrepreneurs, working for the government, can do it. However your typical belt miner cannot buy a ship and fly it. The gap is enormous. Spaceships must become much cheaper before one can work in space. This calls for new propulsion methods; preferrably, using renewable sources, or sources that last a long time (a nuclear reactor, for example.) This space elevator will not really tilt this balance because even if you can launch a can with kerosene to the LEO, it won't get far from there. You cannot refuel with hydrocarbons, LOX or UDMH on the Moon. Perhaps there is water, but using Moon's water for fuel is insane, so little of it is there, and so expensive is its production. In essence, there is only one known thing that is more or less free - electric power. But we do not have electric engines with usable impulse. It may be that we have to wait for Dilithium crystals and antimatter before we can travel in person even to the outer planets.
And here is the paradox. A civilization that is sufficiently advanced to build a space elevator does not need it.
About this particular design... can you imagine the rigidity that is required for this tower to survive oscillations that are caused by a butterfly that is flapping its wings anywhere within 100 miles from the site? Note that mere rigidity will not work; the tower also must dampen the oscillations, dissipate the energy that is transferred into it by wind. There is a lot of wind, by the way, in the atmosphere - and it will not even call for a hurricane to impart significant pressure onto the tower. What oscillation modes will occur? There is no reason to believe that the top platform - or any point of this long and thin piece of spaghetti - will be ever stable. Skyscrapers are not inflatable, and still they and similar buildings (TV towers) sway by some serious distance in wind.
(Score: 1) by Some call me Tim on Wednesday August 19 2015, @04:33AM
They'll need to tether it at the top with a proper amount of mass in orbit to keep it stable. At least that's what Arthur C. Clark had in mind in his book The Fountains of Paradise.
Questioning science is how you do science!
(Score: 3, Interesting) by theluggage on Wednesday August 19 2015, @10:37AM
Most of the science-fictional space elevators like Clarke's are based on the principle that the centre of mass of the tower is in geosynchronous orbit. Hint: that's not 12 miles, more like 20,000 miles. The counterweight is there to move the centre of mass up without having to make the thing 40,000 miles long (although ISTR one of the SF stories did that so spacecraft could slingshot off the end).
However, if Thoth Technology ever actually build their tower, I hope poetic justice ensues and it gets known as Clarke's Tower rather than the Thoth Tower :-)
(Score: 4, Insightful) by deimtee on Wednesday August 19 2015, @06:09AM
It's like building a longer pier in NYC, so that the ships that sail to Europe would have a shorter trip.
Not really. That first km/s of delta v probably uses up a third of your fuel.
To really understand the importance of this, read this page : http://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.html [nasa.gov]
If you cough while drinking cheap red wine it really cleans out your sinuses.