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Space Elevator Gets FAA Clearance
lonesome phreak writes "Techzonez has a short piece about the recent FAA waiver received by the LiftPort Group allowing them to conduct preliminary tests or their high altitude robotic lifters. The lifters are early prototypes of the technology that the company is developing for use in its commercial space elevator to ferry cargo back and forth into space."
Wouldn't it be best to launch from somewhere outside the United States - say from the equator? It just makes more sense to me if they used something like Sea Launch.
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Quantum mechanics: the dreams that stuff is made of.
From Gen 11:1-9
1. Now the entire earth was of one language and uniform words.
2. And it came to pass when they traveled from the east, that they found a valley in the land of Shinar and settled there.
3. And they said to one another, "Come, let us make bricks and fire them thoroughly"; so the bricks were to them for stones, and the clay was to them for mortar.
4. And they said, "Come, let us build ourselves a city and a tower with its top in the heavens, and let us make ourselves a name, lest we be scattered upon the face of the entire earth."
5. And the Lord descended to see the city and the tower that the sons of man had built.
6. And the Lord said, "Lo! [they are] one people, and they all have one language, and this is what they have commenced to do. Now, will it not be withheld from them, all that they have planned to do?
7. Come, let us descend and confuse their language, so that one will not understand the language of his companion."
8. And the Lord scattered them from there upon the face of the entire earth, and they ceased building the city.
9. Therefore, He named it Babel, for there the Lord confused the language of the entire earth, and from there the Lord scattered them upon the face of the entire earth.
So let's hope Liftport Group has their translators ready ;)
You forgot hovercars.
Optimally from a technical point of view. Definitely not from a political point of view.
How we know is more important than what we know.
There is a MUCH simpler and superior alterantive to a space elevator, and oddly enough the core concept comes from Jules Verne. The final piece of the puzzle was provided by Space-X, I beleive. Let me break it down into some simple steps, all of which use technology available TODAY:
1 > Find an east-west mountain range close to or on the equator.
2 > Build an Ionic Flow ring in a straight line going up the mountain range from ground level, pointing towards the west. Each of the gigantic rings strips electrons from the wind that pass through the ring, storing it in an internal capacitor (the power generation is caused by wind passing over the coils around the ring.
3 > Run magnetic iron tracks from each ring to each next ring. Their purpose is three-fold: to provide stability to the series of rings, to provide a repulsible glide-path, and to provide the "leekage" needed to meld the magnetic felds from each ring.
4 > Build your "ship" as a sharp-ended ovoid made with a ferrous iron frame, which encapsulates your ACTUAL vehicle (squib-releases or explosive bolts work perfectly as a means of shedding the outer fusilage). The fusilage must contain a closed wire loop that can be charged externally.
5 > Once the radio transmitters in each section of the 10-mile ring array read as being charged to full power, move the ship to the first ring at the base of the mountains, and set it on the magnetic tracks.
6 > Dump a huge amount of electrical power (possibly slowly drained from each ring by means of the rails, and stored) into the magnetic coild isnide the ship's outer fusilage.
7 > From a bunker nearby, hang back and watch the vehicle accelerate to, and then past, escape velocity as it is yanked from one ring to the next by thier now-active magnetic fields. The rings will be perfectly safe, since the ship will not be generating heat energy at a fast enough rate to harm them as it passes.
8 > Once the vessel is in orbit, it can sepperate from the external fusilage (which is ALSO in orbit). The external fusilage can then be used as building materials for a space station, or explosive charges can decelerate it back into the earth's atmospehre. If it is designed using the recently proven re-entry technology of Knight-1, it can land safely in the ocean for recovery.
9 > Once its mission is over, the internal spacecraft can use the same tech the fusilage uses to land as well, but being under control it can land on a smaller area such as a tarmac.
The benefits of this system are many-fold. Unlike a space elevator, the power to carry cargo into orbit does not require large and potentially dangerous specialty-generation facilities. It is still a terrorist target, but sabotage will not result in dropping miles-long super strong cable chaotically over large tracks of land (a sabotaged ring only results in the vessel not having the power to get into orbit, and safely landing after it is lauched or even having the launch aborted IN MID SEQUENCE!). When not in active use, or self-charging, the rings can be plugged into the power grid to provide free and cheap power (one big reason this will NEVER be built: it can cut into some corporation's bottom line). It allows HUGE payloads to be sent into space at relatively low costs and rapid time-frames in comparison to a space elevator (which everybody alwasy seems to forget would take DAYS of constant activity to put ANYTHING into orbit). The ring-launch system could be built slowly over the period of decades, since the component rings would not need to be lifted AND HELD in posistion like a space elevator's cable. The entire system uses technology and engineering methods that have been widely used world-wide for years, and sometimes GENERATIONS (reverse-flow system, electromagnets, mag-lev tracks, autolifting bodies, capacitors, static electricity generation). It would cost a FRACTION of the price of the space elevator, since the vast majority of the component elements needed are not only
What just about everybody forgets about the spece elevator is that every orbit lower than geosynchronous will eventually intersect the elevator (assuming the elevator is anchored on the equator). A particle too small to track from earth can still have quite an impact.
One possible solution would be a much better tracking system combined with some method for deflecting/destroying objects that come too close.
A Shadeless room is a brighter room.
Well, in Kim Stanley Robinson's "Red Mars", colonists build a space elevator on Mars, only to have it sabotaged and fall down on the planet; wrapping around the equator three times and releasing the equivalent of gazillion nukes. Since this could be a dinosaur extinction type event, it is a valid concern. However, I do believe it is in no way a deal killer; just something that merits some discussion of likelihoods/easiness of such an event happening and how it can be guarded against if necessary. At least when we are closer to having a space elevator (which is not now).
I want to see the US build a "skyhook" space elevator on the Equator right off Jarvis Island. Jarvis could house the cargo/control center. Nearby Kiribati could become an (inter)global shipping hub. And Hawaii would be even spacier than it is now.
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In "Rainbow Mars," Larry Niven (who also wrote Ringworld, seemingly the basis of Halo's ring-shaped planet) imagined "world trees" that grow downward from space and attach to a pre-grown stalk on a planet.
The world-trees were huge, but rather than supporting their weight traditionally, the roots were designed to hold them in the ground, as opposed to being flung out into space.
I guess if you had a space elevator and stuck enough mass out into space, it could take some of the supportive strain off the base of it with centrifugal pull. I'm not sure how the strain would work out on it.
At first I imagined an elevator box where you open it and push your cargo (a rocket, whatever) out, but I guess it makes more sense to let it accelerate and sling it off the end with centrifugal force, like... like a sling. No fuel required to get moving.
Current regulations (faa i think) prevent mile high cities.
Already there are conglomerates in tokyo with plans and long term roadmaps laid out toward the construction of self contained mile high towers.. (one shaped like nested bowls actually has 7 or so large open air parks contained within.
The US will never have one as long as these regulations continue to pose even a slight threat to what is already a daunting task in both engineering and financing.
Truth be told.. i want to live in one of these towers before i'm middle aged, so get moving with the restriction removal!
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"and let us make ourselves a name"
It seems to me that by this line they were being arrogant by trying to "literally" be close to God with a high tower. This would imply knowing God, which you can't do since he represents the transcendent. Since God isn't literally "up there," but rather "in here," that is why they were punished. In the end, I think this passage is a reminder that you're not supposed to take these stories literally, but you're supposed to look through the metaphor.
Bill Clinton: Pimp we can believe in. - The Shirt!!!
You should read Friday, by Robert Heinlin. His title character remarks that she "really hates that indian rope trick".
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Kim Stanley Robinson (_Red Mars_) had an elegant solution to this problem... use a robot factory to push a carbon-rich asteroid into position, then spin cable down from it. The non-carbon mass of the asteroid remains to provide counterweight (and structural support for a space station, which is a handy thing to have at the end of a space elevator.
Still a chicken placed before the egg if considered with today's technology, but it's more feasible and practical than "build all the cable on earth and lift it into space, so we can lift heavy things into space".
"Nothing was broken, and it's been fixed." -- Jon Carroll
It's hunting that space junk that is the problem. It wouldn't pay because space junk is usually light (how much $ to lift 1 ton, junk or not, to orbit?) and flying around, trying to catch small pieces of it, say, 1 week and 5 tons of fuel to grab 200kg of the junk?
:)
IMO the rope should be unrolled in two directions at once, from the orbit. This way, it wouldn't only allow for cheap transport to the orbit, but launching small ships from the end would give them a nice boost. Actually, quite possible that you could lob cargo with minimal thrusters at other planets. (think big bricks of ice from water pumped up the pipelines through the lift, launched at Mars. Water for terraforming Mars, ocean level rising problem solved
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If a space elevator could be made that can lift heavy cargo up to space, then a similar construct can be used for transferring energy from a solar energy platform to earth.
Has anyone else at all thought about how a space elevator might be economically viable?
Yes. I can think of three ways.
First, when we get to the point where we are moving more mass down the elevator than we are moving up it. Regenerative braking on the downtrips would offset the cost of uptrips-- the elevator could even become a net power producer. But this depends on developing the technology for bulk lunar mining or something like that to the point where the economics are competitive with earth mining operations. Imagine capturing a comet in a stable earth orbit and downloading tonnes/hour of irrigation water from it to an equatorial desert for half a century. Imagine 22,000 miles of generating turbines. A space elevator would be a great way to exploit Earth's gravity well. (Hmm, there are some rich desert nations that might become venture capitalists for something like this...)
Second, if we find that there is enough electrical potential between space and the earth's surface, then a copper wire grounded at the bottom and attached to an antenna at the top could generate enough electricity to power the crawlers. Possibly there would be energy to sell, too. Maybe a geophysicist will speak up about the voltage difference between ground and sky. I've no idea how realistic this possibility is.
Third, but IMO more likely to happen first, imagine a hybrid approach where rockets are used for unmanned cargo lifts, products are returned from orbital operations by space elevator with regenerative braking, and people go up and down the elevator. All the energy that we now lose in burning up heat shields would be recovered and we wouldn't have the overheads of launching those heat shields, or the hassles of designing reentry vehicles.
Of course, there's a massive waste of time, effort and money in the meantime. And who is to say that by the time this "space elevator" comes around and is usable to launch space vehicles, we won't have developed a more efficient, cheap, powerful fuel to launch shuttles?
There are practical limits to how much energy you can extract from chemical propulsion, and we've pretty much reached them. Breaking/forming chemical bonds -- which is what happens when you burn things like kerosene and oxygen, or oxygen and hydrogen -- is an extremely inefficient way to convert mass into energy, with much less than 1% of the mass being so converted. Nuclear fission itself can't even convert 10% of its mass into energy (the usual figure given is around 7%). Even fusion, the reaction that powers thermonuclear warheads and our own sun, has an efficiency of less than 15%.
Now, since efficiency of the mass/energy conversion directly impacts how much fuel you have to carry to get off the ground (higher efficiency=less fuel needed due to higher initial energy density), it's pretty easy to see that chemical propulsion is never going to get us where we need to be. Nuclear propulsion would, but there are a lot of nasty side effects to operating nuclear engines in a biosphere (note: there are some designs that mitigate this, but there's still the issue of accidents).
A space elevator would be entirely electric. The elevator itself would not have to carry its own fuel, nor would it have to generate its own power. Further, if the elevator is built out to a geostationary point, the centrifugal force of the Earth's rotation can give spacecraft an immense velocity -- without needing an ounce of fuel! I've seen figures that say the trip to Mars could be shortened from nine months to perhaps as little as two months. If true, this would make the logistics of a Mars mission far easier to plan for, not to mention exploration of the rest of the outer and inner solar system.
The space elevator also solves the nagging problems of nuclear propulsion, namely that of operating in a biosphere. Nuclear engines operating in space would pollute essentially nothing while at the same time being free of aerodynamic drag or gravity wells. But how do you get that nuclear engine off the ground in the first place? A space elevator!
The idea is just too good not to pursue. Aside from the huge engineering challenges of building such a thing, there are no downsides to it at all.
In the end they will lay their freedom at our feet and say to us, Make us your slaves, but feed us. - Fyodor Dostoyevsky
I agree with the rest of your comment, but this bit I think is creeping featurism. We don't have magic ground cars that prevent maniacs from blowing them up in vulnerable places, after all.
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