First off, I do more asking then answering here(and judging by my number of posts, which I don’t know, my guess is its lower than 10, its not a good sign), not specifically on purpose, but y’all are smart, for the most part anyway .)
Anyway, I was reading some news article about how some people think that commercial colonization of the moon would be comparable to the California gold rush and came across something that particulary caught my attention. The article mentioned the concept of some sort of ‘satillite’(if it’d still be called that) thats -physically- connected to the ground and an earth based power supply, this somehow is supposed to act like an elevator type thing and take people and/or objects outside the atmosphere up to where satillites orbit to make it far simpler to make trips from Earth to the moon since apparently all you would need is minimal thrust and retrojets to get yourself there once you’re in space. These didn’t come across as entirely possible, though of course if it is I’d say its a good idea(aside from the fact that it scared my religious friends-reminded them of Babel- and I’m sure other people would feel the same) so long as it works, but my question is whether or not its possible or plausable, as well as what sort of manpower it would take to make such a thing I suppose.
It’s an idea suggested when someone realized just how costly rockets and shuttles are.
If you’re going to be sending stuff into space, why build hundreds of $1 billion ships and bases and such when you could build a single $100 billion facility? It would last much longer than individual ships and be useful for other things than lauching spaceships;.
That idea is usually called a “space elevator.” It’s been discussed in this thread among others. The idea is to start with a space station in geosynchronous orbit and extend cables in two directions, one towards the earth and the other away from the earth. Since the center of mass remains at geosynchronous orbit, the whole structure will orbit the earth once a day no matter how long you extend the cables. So you extend them until one end comes down to the ground, and use it as an elevator shaft.
It’s theoretically possible but currently there are is material which is strong enough for it. Even the best alloy or synthetic fiber will snap under its own weight long before the cable reaches the earth. Carbon nanotubes are thought to be strong enough for this, but we can only manufacturer it in microscopic quantities right now. There are many other technical problems, but until the big problem of the material is solved there isn’t much point in researching the other problems.
If you are interested in the idea of space elevators, Fountains of Paradise by Arthur C. Clarke is a classical sci-fi novel that deals with the construction of a space elevator.
It can be thought of in two ways - a really tall tower, reaching up to at least low-earth orbit. Let’s make it an arbitrary 10,000 km tall.
Another idea is a large mass in geosychronous orbit with a cable descending 35,500 km to the surface.
Both plans require absurd strength of materials used. The tower idea can only be built out of solid diamond. The cable idea can only be built with a bundle of carbon nanotubes reaching down all that length.
Neither idea is achievable at the moment. No one has figured out how to manafacture large contiguous amounts of diamond, although small pieces are made commonly.
Carbon nanotubes (buckytubes) are being researched constantly. There is one report of a nanotube several inches in length.
I’ve been wlondering on the physics of the things myself. I believe that if you were to build the cable one and put cars parked up every thousand miles with a 100 kg person inside, they would note that
Ground level - normal weight
Each kilometer up the person’s downard weight would decrease.
Top level - freefall (orbiting the Earth)
Moving, I don’t know how a person would feel insdie one of those cars. I think he would feel a sideways force in the Westward direction (due to the cable pushing him, speeding him up like a pea offcenter on a spinning dinnerplate, when gravity “expects” him to orbit more slowly, being further from the Earth)
In any case, the large mass is needed because you need a spaceport and something massive to mount rockets to when winds and pulls on the cable change its height ever so slightly.
Another use of the tower is eletrical trasmission. Solar panels in space gather noonday sun 24/7 if turned correctly, and you can run non-load-bearing power cables bound to the side of the carbon cable.
IOt would proabbly affect weather. You’d need to put conductors a couple meters away from the outer edge all the way around, to keep lightning from messing everything up. I wonder at what temp nanotubes burn.
Kim Stanley Robinson’s hard-science-fiction novel Red Mars includes a detailed description of a space elevator in areosynchronous orbit. With the lower gravity of Mars, the materials didn’t need to be quite so strong. Something to consider if we ever get around to colonizing Mars. Of course, Robinson’s novel was not entirely hard-techo-science fiction; it also included plenty of social psychology and revolutionary politics. Meaning that when the Mars colonists got fed up with being controlled by Earth megacorporations, they rebelled and blew up the space elevator, along with much else.
Actually, you’d need an eastward force on the car going up, and a westward force on the car going down. People inside the car and using it as their frame of reference would feel a fictitious force in the opposite direction.