Going Down! Russia to launch space elevator
Paul,
Glide path is a fictional novel, but it is very closely based on Clark's real life role in WW2.
Lu,
the space elevator in Fountains of Paradise is anchored to an asteroid in geostationary orbit, not a space station in low orbit. You might find it interesting to try reading the book sometime.
Glide path is a fictional novel, but it is very closely based on Clark's real life role in WW2.
Lu,
the space elevator in Fountains of Paradise is anchored to an asteroid in geostationary orbit, not a space station in low orbit. You might find it interesting to try reading the book sometime.
Iconoclast
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Ain't that what I said?
To: supercarb
I believe I stated the in order to have one end attached to the earth and the other to a space station the space station would have to be about 22,000 miles from earth. OK so it was an asteroid and not a space station. I have two questions: 1) what do they lower from an asteroid and 2) Who is going to lower what ever it is that is being lowered.
One final question. How do they get the elevator to lower to an exact spot on the earth from 22,000 miles up? They can't shoot it up to the asteroid because of orbital mechanics and the ability to shoot through the window to get it there. The elevator cable will have to be several million miles long in order to meet up with the asteroid and when it gets there who is going to connect it? And, who is going to reel in the excess cable and how?
Just wondering.
the space elevator in Fountains of Paradise is anchored to an asteroid in geostationary orbit, not a space station in low orbit.
One final question. How do they get the elevator to lower to an exact spot on the earth from 22,000 miles up? They can't shoot it up to the asteroid because of orbital mechanics and the ability to shoot through the window to get it there. The elevator cable will have to be several million miles long in order to meet up with the asteroid and when it gets there who is going to connect it? And, who is going to reel in the excess cable and how?
Just wondering.
Nexialist
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I'm no expert on orbital mechanics, but the book went somehing like this.
Find your chosen asteroid (carbonacious condrite?) then travel to it conventionally (ie spacecraft)
Plant a few rockets on the thing and fire them off to change orbit to put the asteroid into Geo orbit (or close to it, safer to aim high and refine it once it has arrived on site) This would take a few years in order to avoid a huge fuel cost.
Once your asteroid is in geo orbit, you set up a manufacturing plant on it, meanwhile ship up 25000-30000 miles of magic super wonder cable attach one end to asteroid, and lob the end at the Earth. (what you lob down is a re-entry capsule shaped a bit like apollo ones, but no-one inside, did have parachutes in the book though, to avoid very high touchdown speeds.
Anchor Earth end of cable, then you build the actual elevator system down from the asteroid, using the manufacturing plant that you've built on the asteroid.
Raw material for wonder cable is carbon, which is what the asteroid is made from, so supplies to the space station/asteroid are limited to people, machinary, and air/food/water. Basically until system is up and running, most supplies come from conventioal rockets.
Supercarb - I shall have to remonstrate with my old school librarian, doubt she'll be interested 15 years after I left though
Find your chosen asteroid (carbonacious condrite?) then travel to it conventionally (ie spacecraft)
Plant a few rockets on the thing and fire them off to change orbit to put the asteroid into Geo orbit (or close to it, safer to aim high and refine it once it has arrived on site) This would take a few years in order to avoid a huge fuel cost.
Once your asteroid is in geo orbit, you set up a manufacturing plant on it, meanwhile ship up 25000-30000 miles of magic super wonder cable attach one end to asteroid, and lob the end at the Earth. (what you lob down is a re-entry capsule shaped a bit like apollo ones, but no-one inside, did have parachutes in the book though, to avoid very high touchdown speeds.
Anchor Earth end of cable, then you build the actual elevator system down from the asteroid, using the manufacturing plant that you've built on the asteroid.
Raw material for wonder cable is carbon, which is what the asteroid is made from, so supplies to the space station/asteroid are limited to people, machinary, and air/food/water. Basically until system is up and running, most supplies come from conventioal rockets.
Supercarb - I shall have to remonstrate with my old school librarian, doubt she'll be interested 15 years after I left though
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The book, according to everybody on this thread that has read it, is / was very interesting reading and maybe it was (is).
I worked on the Saturn Apollo program, the Atlas ICBM, several communication satellite programs, two sounding rocket programs and I developed the On Orbit Maintenance Program for the European Space Station. If I proposed any thing that has been discussed on this thread to my superiors I would have been tarred and feathered and run off.
I worked on the Saturn Apollo program, the Atlas ICBM, several communication satellite programs, two sounding rocket programs and I developed the On Orbit Maintenance Program for the European Space Station. If I proposed any thing that has been discussed on this thread to my superiors I would have been tarred and feathered and run off.
Ok, I'm not a physicist, but here's my take on things.
Let's assume you've got a station or whatever in geo orbit, and you've got a very strong lightweight cable.
If you carry a rock to the top of a building, you are increasing it's potential energy. All the effort you put into hefting it up is "stored" in the rock.
Orbit is a trick by which you spin around the earth, thus rotating the direction of gravity, and thus preserving your potential energy while spinning around. The point: the amount of energy it took to "lift" it into orbit is still there.
So, to lower your fancy fan assembly manufactured free of defects in zero-g, you need to exert as much energy as was needed would be needed to heft it to begin with.
The space shuttle uses all that juice in the big bottle to get into orbit; and it uses drag to return. This is why the space shuttle has a very low operating altitude. If it's too far up, it's little reserve of fuel is not enough to slow it to the point it drag can take over.
Thus, because of all this energy expenditure, I believe a space elevator is of little use.
Of course, I'm not a physicist, so be nice to me, ok?
Let's assume you've got a station or whatever in geo orbit, and you've got a very strong lightweight cable.
If you carry a rock to the top of a building, you are increasing it's potential energy. All the effort you put into hefting it up is "stored" in the rock.
Orbit is a trick by which you spin around the earth, thus rotating the direction of gravity, and thus preserving your potential energy while spinning around. The point: the amount of energy it took to "lift" it into orbit is still there.
So, to lower your fancy fan assembly manufactured free of defects in zero-g, you need to exert as much energy as was needed would be needed to heft it to begin with.
The space shuttle uses all that juice in the big bottle to get into orbit; and it uses drag to return. This is why the space shuttle has a very low operating altitude. If it's too far up, it's little reserve of fuel is not enough to slow it to the point it drag can take over.
Thus, because of all this energy expenditure, I believe a space elevator is of little use.
Of course, I'm not a physicist, so be nice to me, ok?
Lu,
Sorry, perhaps I misunderstood what you wrote.
You said:
I interpreted this as you asssuming that Clark had suggested that the elevator could be attached to a space station in 200 mile orbit, and hence criticizing him for not realising that the top end would have to be in geosynchronous orbit. Apologies if this was not the intention.
Sorry, perhaps I misunderstood what you wrote.
You said:
This is not rocket science. In fact it is not science at all.
Let us assume you can tether the elevator at one end to the space station and the other end to the earth the tether would have to be about 22,000 miles long as to do so the space station must be in a geosynchronous orbit. The space station is around 200 miles up so the station and the point of attachment on the earth would be traveling at different speeds.
Let us assume you can tether the elevator at one end to the space station and the other end to the earth the tether would have to be about 22,000 miles long as to do so the space station must be in a geosynchronous orbit. The space station is around 200 miles up so the station and the point of attachment on the earth would be traveling at different speeds.
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I shall have to bow to Lu's superior knowledge of current technology.
But I believe the point that was being made was that once constructed the Space Elevator is a (relatively)stable system, hence the only only problem is how to build it. That I suspect will be a problem for our grandchildrens' grandchildren. Just because we can't figure out how to build it now, doesn't mean we won't in the future.
Got to admit that it is an elegant solution for access to orbit though, and indeed furthur exploration/expansion through the solar system.
w.r.t. the energy problem, all problems dissapear if you send up as much mass as you bring down. Then you are only dealing with frictional losses.
p.s. by the last chapter (set several hundered years ahead) they've got four, sited around the equator, then linked them up with a ring.
and lets not even get started on Dyson spheres, or Niven rings
But I believe the point that was being made was that once constructed the Space Elevator is a (relatively)stable system, hence the only only problem is how to build it. That I suspect will be a problem for our grandchildrens' grandchildren. Just because we can't figure out how to build it now, doesn't mean we won't in the future.
Got to admit that it is an elegant solution for access to orbit though, and indeed furthur exploration/expansion through the solar system.
w.r.t. the energy problem, all problems dissapear if you send up as much mass as you bring down. Then you are only dealing with frictional losses.
p.s. by the last chapter (set several hundered years ahead) they've got four, sited around the equator, then linked them up with a ring.
and lets not even get started on Dyson spheres, or Niven rings
