[Flipside]

http://news.bbc.co.uk/1/hi/sci/tech/7792297.stm

I still think this is the best way to go with exploration, our biggest enemy is our own atmosphere, so if we can start from outside of it, we remove almost 90% of the mass of current orbital vehicles.

[Mongoose]

Next up: Gundam 00?

[Nuke]

what people fail to realize is that when we have materials capable of such a construction, those materials would be better used to make lightweight and therefore more efficient spacecraft.

[Flipside]

Why waste all that thrust? Even with lighter ships, why bother using all that fuel to get outside our own gravity field when a ship exactly the same size, but taken up on the Elevator would have something like 20 times the range.

Our biggest Achilles heal when it comes to Space Exploration isn't travelling between between planets, it's getting from the ground to orbit, that takes almost all the resources that are put into the programme. Eliminate that and putting a satellite in orbit is the cost of building a satellite, just a satellite, and the price of a lift-ride. You've reduced the costs and resource demand by a massive amount for each launch.

Even better is the fact that you don't have to waste all those fancy new lightweight materials, because the Elevator will always be there, whereas most of the vehicles themselves are a one-shot wonder, why use hi-tech expensive equipment that will vanish, when you can use moderate tech materials and send it up in a high tech launch platform that is permanently available?

[FUBAR-BDHR]

It would also be a safe way to transport radioactive materials to power spacecraft.  Also building lightweight spacecraft for long journeys isn't feasible even with the current materials.  You need something that's not only strong but can shield against cosmic rays.  Just line the walls with the lead from the containers that are used to transport the radioactive material.  Kills 2 birds with one stone. 

[Black Wolf]

I still think we're better off with a SkyRamp, since we can do it with modern technology. It's no more significant an engineering feat than dozens of others we've done in the past. I'll grant you, it's not the kind of permanant solution a space elevator would provide, but it's a good intermediate step, and it's somehting we could start tomorrow if we had the budget and political will.

[Bobboau]

to anything that brings space elevators closer to reality, there can be only one possible response

[attachment stolen by Slimey Goober]

[Flipside]

to anything that brings space elevators closer to reality, there can be only one possible response

Another advantage is that it will make the possibility of getting some of that junk in orbit cleared a lot more likely.

[Mongoose]

Why waste all that thrust? Even with lighter ships, why bother using all that fuel to get outside our own gravity field when a ship exactly the same size, but taken up on the Elevator would have something like 20 times the range.

Because surface-to-orbit spaceships look much cooler?

Seriously, though, the article is interesting on the small-scale, but I'm curious as to how feasible it would be once you work up to the size of an actual elevator, and how long transport would take if it did work.  It's one thing to say, "Oh, let's just shake the cable;" it's quite another to actually be able to do it.

[Androgeos Exeunt]

This is starting to remind me of the Great Glass Elevator.

[Kosh]

Lofstrom launch loop would be better, since we can do it with our current technology.

[Stormkeeper]

... Gundam 00 sudden no longer seems like such a distant possiblility ...

[BloodEagle]

The idea rests on making use of the outward centrifugal force supplied by the Earth's rotation. Imagine fixing a short length of string to a football and spinning it - the string flies outward and remains taut.

*facepalm*

[ssmit132]

It's centripetal force, isn't it?

[portej05]

Well, to be absolutely accurate, I can't find the reference to where this is from, so I'm not sure what the statement is referring to, but my physics teacher had a total fit one day when someone talked about a centrifugal force (he's now retired)!

It's centripetal force, isn't it?

The idea rests on making use of the outward centrifugal force supplied by the Earth's rotation. Imagine fixing a short length of string to a football and spinning it - the string flies outward and remains taut.

*facepalm*

In reality, you're pulling the ball to you, not the ball pulling on you... the ball just wants to go on its merry way.

[castor]

Just don't park it on my backyard..
It all sounds too massive to be practical/resource efficient. And (as much as I gather) you need to go with a full scale implementation from the beginning - the risks are astronomical.

[Mika]

What it comes to centripedal or centrifugal force, while the physical definition is different, but luckily most of the people are smart enough to figure out what was actually meant with either of the terms in different contexts. The situation is the same with "intensity" in Optics and radiometry - it is almost always wrong even in the publications. But it doesn't matter since it is almost always conceivable what was meant with the term given the context. The biggest shocker is that there is no such SI unit as "intensity" in radiometry.

Mika

[Mika]

Why waste all that thrust? Even with lighter ships, why bother using all that fuel to get outside our own gravity field when a ship exactly the same size, but taken up on the Elevator would have something like 20 times the range.

Our biggest Achilles heal when it comes to Space Exploration isn't travelling between between planets, it's getting from the ground to orbit, that takes almost all the resources that are put into the programme. Eliminate that and putting a satellite in orbit is the cost of building a satellite, just a satellite, and the price of a lift-ride. You've reduced the costs and resource demand by a massive amount for each launch.

When it comes to energy conservation, I'm not sure how much this could change the general energy budgets. In Physics, the work (unit energy) is defined as a line integral of potential field multiplied by the trajectory of the moving particle. Since the trajectory is approximately the same in both cases, the only energy that can be saved is caused by air friction. But some amount of energy is required to keep the space elevator up and running. So in total, I don't see much difference in the energy itself.

However, this doesn't mean that it wouldn't be a cheaper method to lift things on orbit since there is not that much of need to construct the delivery vessel again.

Mika

[Flipside]

Just don't park it on my backyard..
It all sounds too massive to be practical/resource efficient. And (as much as I gather) you need to go with a full scale implementation from the beginning - the risks are astronomical.

Well, to be honest, it would need to be set in around 10-20km², just to be on the safe side, though I'm not too certain what would happen in the event of a catastrophic failure,  since, as far as I can visualise it, it would start travelling at different speeds depending on how close to the centre of gravity it is.

That, however, might be completely off-base, since it's easy to fall into the trap of visualising it bending as the Earth spins, which wouldn't happen, since geostationary orbits don't work like that.

I suppose it's theoretically possible that, like the ball on a string, if it broke, it would fall 'upwards' from our point of view...

Why waste all that thrust? Even with lighter ships, why bother using all that fuel to get outside our own gravity field when a ship exactly the same size, but taken up on the Elevator would have something like 20 times the range.

Our biggest Achilles heal when it comes to Space Exploration isn't travelling between between planets, it's getting from the ground to orbit, that takes almost all the resources that are put into the programme. Eliminate that and putting a satellite in orbit is the cost of building a satellite, just a satellite, and the price of a lift-ride. You've reduced the costs and resource demand by a massive amount for each launch.

When it comes to energy conservation, I'm not sure how much this could change the general energy budgets. In Physics, the work (unit energy) is defined as a line integral of potential field multiplied by the trajectory of the moving particle. Since the trajectory is approximately the same in both cases, the only energy that can be saved is caused by air friction. But some amount of energy is required to keep the space elevator up and running. So in total, I don't see much difference in the energy itself.

However, this doesn't mean that it wouldn't be a cheaper method to lift things on orbit since there is not that much of need to construct the delivery vessel again.

Mika

True, I'm not certain of the exact energy requirements as such, depends how the Lift itself is powered, but I would have thought that a simple ratchet system would prevent the requirement for 9.8m/s² thrust to achieve escape velocity, which means that you don't have to burn all that fuel fighting against Gravity.

I think the current idea is to hook up a few orbital Solar Panels to the exit-point of the elevator, and they would provide the pulling power, but as to whether Solar Panel tech can provide that kind of power, and how big those panels would have to be in order to do so, I really couldn't say.

[Mika]

True, I'm not certain of the exact energy requirements as such, depends how the Lift itself is powered, but I would have thought that a simple ratchet system would prevent the requirement for 9.8m/s2 thrust to achieve escape velocity, which means that you don't have to burn all that fuel fighting against Gravity.

Sorry, made a mistake with the definition of work. The line integral is actually force multiplied by the trajectory, not the potential. Don't know what I was thinking. It's six years since I last read mechanics, but that is a basic mistake which should not happen (multiplying scalar with a vector in a line intergral should have warned me).

But what it comes to the force itself, it would be dictated by Newton's gravity law, where the other part of the equation is the mass of the object that is going to orbit. If that mass can be decreased, then this would obviously result in energy advantage. Add on top of that energy losses caused by air friction.

The other question is then the conversion efficiencies of chemical energy in rocket fuel and the mechanical vibrating energy.

Mika