Going Up! Canadian Company Granted U.S. Patent For A Space Elevator

[Lucane]

Mobile Suit Gundam 00 both seasons though season two shows the potential issues of terrorism but that's the trouble with anything.

Spoiler: Mobile Suit Gundam 00 s2ep17

Action starts about 6min in,showing how a space elevator could work to preserve itself when damaged at about 9:30 and onward.

Also, Mobile Suit Gundam G Reconguista has some sort of space elevator cable guide tracks.

 

[Gezzer]

Okay, maybe there's stuff I'm missing here.

First off to work be it 20KMs or taller AFAIK a space elevator ends up being more like a large building at the base that slowly reduces its cross section as it climbs. So with that in mind isn't one of the major hurdles of building tall buildings the fact that they sway? That due to centripetal forces (I think) and higher speed winds as you increase in altitude the sway increases exponentially to the height and sets a hard limit on building height. It's only through special design features like extremely large mass dampers and clever shaping of the building that we've got as high as we have. And once you exceed the limit a tall building would pretty much do a "galloping gertie" and tear itself apart.

The only reason the concept of a space elevator works is that having the space end at a L1 (again I think) point in space causes the space elevator to kind of sync up with the rotation of the earth and reduce a lot of the swaying and stress problems AFAIK. So wouldn't building a 20KM space elevator have it's own set of problems no easier to overcome then building the one postulated in many Sci Fi stories? That in fact building a 20KM space elevator might even be harder than building a full height one?

 

[Draconalis]

snip

A structure that tall will have a lot of energy when it falls, and depending on where they build it, the damage could potentially be felt half the world away.

 

[Thaluikhain]

I once did a calculation to check the feasibility of a space elevator that's attached to Earth and has a geosynchronous anchor in space. The anchor, of course, has to be set well past the geosynchronous orbit because it's the center of mass of the entire system that has to be at geosynchronous orbit for the platform to remain stable (i.e. not falling down and crashing on Earth, and not ripping loose and flying away to space). Calculating the amount of stress that occurs at point of geosynchronous orbit, which is the point that will have the most stress applied, what I found is that current nanotube materials are about 1-2 orders of magnitude too weak to hold. Essentially, the thing would break in half, with one half crashing on the Earth and the other flying out to space. Thus, I concluded, the entire idea of a space elevator is just fanciful garbage, physically undoable.

Another issue...supposing you could get that sort of material, there is all sorts of things it could be used for.

For example, a wire thin enough to be invisible and more than razor sharp, and yet very strong. I do NOT want just anyone to be able to play with that.

Reading this article spurred me to think on the problem a bit again. The primary problem is that the elevator is too heavy because it is just too long, and it's too long because of the insistence to anchor it on Earth, necessitating geosynchronous orbits. However, what if you just let the bottom of the thing float freely some 45-50k feet above Earth's surface. Sure, you'll need high-altitude planes (which we currently have available) to get to the base-station, but you no longer have the requirement of a geosynchronous orbit. This means you can make the elevator much, much shorter, significantly reducing the tensile stresses and put them well in range of current nanotube materials strength. The caveat, however, is that you still need the anchor in space that maintains the center of mass at a stable orbit. Also, the anchor needs an active propulsion system to keep the elevator in orbit against atmospheric drag. The base-station at the bottom could also have jet engines that assist with keeping the entire elevator in orbit by supplying additional momentum to the elevator.

With a free-floating elevator, you wouldn't need an elevator that's 100,000 km long. You'd probably only need one that's 300-1000 km long. However, it is possible you may need a lot more fuel to maintain the orbit. Although, ion propulsion and electrically powered jet engines could probably be used to mitigate direct fuel usage, and, of course, these propulsion systems would be powered by electric solar panels attached to the anchor in space and, possibly, at various points along the elevator's track.

The other issue with the free-float elevator is that you will need to track its location, and it will likely be moving extremely fast relative to the Earth's surface in order to maintain orbit. It really depends on which orbit the center of mass is placed. The lower the orbit of the center of mass, the faster the entire elevator has to move relative to the Earth's surface to maintain orbit.

I think both these issues can be overcome with some clever engineering such to make the free-floating space elevator a much more feasible idea than either the geosynchronous ribbon from space or the tall tower (which I think the wind is just going to blow that right over without a second thought) that this article reports.

...

Huh. That certainly is an unusual idea. No idea if that is remotely feasible and, TBH, given that lots of people have discussed space elevators and I've never heard of this approach, either your name will go down in history, or it's a really, really bad idea.

However, someone really should make a weird animated TV show about a space elevator that floats around the world.

 

[hittite]

There was a space elevator in New Mombasa in Halo 2, 3 and ODST.

Spoiler: This thing

Spoiler: And the wreckage miles away after the base got blown up

 

[OneCatch]

If that space elevator was high enough to reach geosynchronous orbit...

Oh, certainly - but by the time you get that high you're gaining substantial angular velocity, makes the difference.

That... does raise an interesting question though. If the object is gaining angular velocity, where is that coming from? Is it reducing the orbital speed of the tether, or is gained via the work done raising the object vertically? Might have to work that one out later!

If the former, it implies you'll need to do just as much work on the tether as you would getting stuff into orbit conventionally.

 

[Zontar]

snip

A structure that tall will have a lot of energy when it falls, and depending on where they build it, the damage could potentially be felt half the world away.

Doesn't that mean that a 20km one build in isolation in a coastal area make it a better idea then a 100,000km one built, well, anywhere?

 

[Zontar]

20 Km tall? While it would certainly be a massive improvement over current launches this is more like a space stepping stool rather than a space elevator. The traditional space elevator design where you anchor a cable to a satellite in orbit is more like 100,000 Km in length.

In all fairness, the first 20 km is probably the hardest part to build and make functional. Plus once you're that high you're already effectively in space and 95% of the way to anywhere you're going to go. Just strap on an ion engine to whatever you build and you're good to go. It's actually a feasible low earth orbit jumping off point.

An ion engine probably isn't going to cut it. The difficulty getting into space isn't the altitude, it's the velocity required to stay up there.

https://what-if.xkcd.com/58/

20km is a good starting point because it saves you having to force your rocket through the thicker bits of the atmosphere, which cuts down on fuel requirements, but you're still going to need a pretty large impulse to lift off the top of the elevator and attain orbital velocity. At the moment, the only such way of getting that kind of thrust is with a rocket. Ion drives and laser propulsion and all that stuff is too low thrust at the moment.

Still, it's a good jumping off point that would cut down the fuel and cost needed to launch a satellite or a part of a station into orbit. It would sure make building a space station faster.

 

[Adam Locking]

I thought one of the requirements for a patent was a working prototype. This just shows how friggin' broken the U.S. patent office/system is.

...of course, if they actually build it, and it works, I'll gladly eat my words. But at first blush this seems like yet another company that's going to sit on a patent that it can't really use and doesn't really deserve just so that if someone else actually gets the job done, they can sue them for millions.

Seeing how patents only last for 20 years, that isn't going to happen; if anyone else wants to do it I'm sure they'd be happy to wait the 20 years necessary to do so, especially seeing as construction of the thing would probably take a large chunk of that time.

Best bet, they're just doing it for attention.

 

[Pyrian]

Inflatable... This isn't like a really tall building, it's like a blimp on a rope.

 

[direkiller]

If that space elevator was high enough to reach geosynchronous orbit...

Oh, certainly - but by the time you get that high you're gaining substantial angular velocity, makes the difference.

That... does raise an interesting question though. If the object is gaining angular velocity, where is that coming from? Is it reducing the orbital speed of the tether, or is gained via the work done raising the object vertically? Might have to work that one out later!

If the former, it implies you'll need to do just as much work on the tether as you would getting stuff into orbit conventionally.

If you take an object to Geostationary orbit from the ground the change in angular velocity is zero to the entire system.

The object is already spinning when it is on the ground and maintains the same angular velocity the entire trip.

 

[Draconalis]

snip

A structure that tall will have a lot of energy when it falls, and depending on where they build it, the damage could potentially be felt half the world away.

Doesn't that mean that a 20km one build in isolation in a coastal area make it a better idea then a 100,000km one built, well, anywhere?

It's better in the sense that a Tsunami is better than something striking with the force of a meteor... but frankly... no.

 

[Zontar]

snip

A structure that tall will have a lot of energy when it falls, and depending on where they build it, the damage could potentially be felt half the world away.

Doesn't that mean that a 20km one build in isolation in a coastal area make it a better idea then a 100,000km one built, well, anywhere?

It's better in the sense that a Tsunami is better than something striking with the force of a meteor... but frankly... no.

Well it's something that's going to happen anyway, so all we have to do is have a base built at its base and basic security security measures taken to protect it.

 

[Draconalis]

Well it's something that's going to happen anyway, so all we have to do is have a base built at its base and basic security security measures taken to protect it.

Security measures grow lax with time, and again, terrorism is only one potential problem to worry about. Nature has a way of making even man's most lasting structures into nothing but the dirt Bentham our feet.

 

[Zontar]

Well it's something that's going to happen anyway, so all we have to do is have a base built at its base and basic security security measures taken to protect it.

Security measures grow lax with time, and again, terrorism is only one potential problem to worry about. Nature has a way of making even man's most lasting structures into nothing but the dirt Bentham our feet.

If things like that terrorism or natural weather where enough to not build something, we'd still be living in huts, even ignoring things like this which are incredibly useful from an economic point of view.

 

[Draconalis]

If things like that terrorism or natural weather where enough to not build something, we'd still be living in huts, even ignoring things like this which are incredibly useful from an economic point of view.

That is grossly false. Everything we build now, we build with that in mind. But frankly speaking, nothing we build now can endanger millions of lives, as this elevator could.

(With the obvious exception of weapons)

 

[Zontar]

If things like that terrorism or natural weather where enough to not build something, we'd still be living in huts, even ignoring things like this which are incredibly useful from an economic point of view.

That is grossly false. Everything we build now, we build with that in mind. But frankly speaking, nothing we build now can endanger millions of lives, as this elevator could.

(With the obvious exception of weapons)

We build towers with the idea that a jet could be flown into them now, but we still live in a world where the vast majority of large free-standing structures where never designed with something like that in mind. All this space elevator would need to prevent it from being a major issue is to have it built on an island in the pacific so that even terrorists somehow manage to damage it enough to take it down the resulting collapse would be absorbed by the ocean (there is no way this thing would have the mass to create a title wave people a few hundred kilometres away would notice).

It's all about the risk vs reward, and if we're being realistic here we're talking almost no risk vs benefits which are hard to understate.

 

[Draconalis]

All this space elevator would need to prevent it from being a major issue is to have it built on an island in the pacific so that even terrorists somehow manage to damage it enough to take it down the resulting collapse would be absorbed by the ocean (there is no way this thing would have the mass to create a title wave people a few hundred kilometres away would notice).

Force is mass times acceleration, it has enough force, once its mass is combined with the energy of the fall. I'm not an expert, but I'd wager it's enough to create a tsunami.

 

[Zontar]

Force is mass times acceleration, it has enough force, once its mass is combined with the energy of the fall. I'm not an expert, but I'd wager it's enough to create a tsunami.

The mass would require such force to create a tsunami that it would vaporize before it landed from friction. A tsunami requires an incredible amount of power, we're talking about earthquakes at a magnitude 8 or above running along a hundred kilometre stretch of seabed to create what we saw in 2011, something the elevator in question doesn't come close to having enough mass to produce. Add to that the fact that water absorbs kinetic energy when it's from the top down, the amount of energy required to form a tsunami from falling into water is even higher then from an earthquake.

If it was built on an island in the pacific, outside of the island it was built most coastal areas would barely notice it, and those that would would likely have only a few feet or meters of water to deal with, something most already have wave-breakers build specifically to deal with.