Aluminum + 1000 resources

= Space Elevator! (thank you Civ 4). Of course, if you build in in the city with the Iron Works (excellent Texas barbecue results in double resource output!), it's only 500 resources; a good city can do that in ten or eleven years.

I've been following discussions on building a space elevator for some time now. I was surprised to see CNN discussing it!

There are two primary challenges connected with building a space elevator:

1. The cable (or tether) - Spans 100,000 kilometers from the surface of the earth, up past geosynchronous orbit (the center of mass is at the geosynch point)
   
• This cable need not be one single piece. This is a confusion many people have ("We can't build a carbon nanotube that long!!111eleven!").
• The cable need not be of super materials (100% carbon nanotubes, positronium, etc.) You can make it out of bubble gum, although you'd probably need enough to alter the center of mass of the earth-moon system :)
• Better materials translate into less mass for the initial tether. That means fewer rockets to get all the materials into space.
• Once the initial tether is up, the first cargo can be more tether, to increase the capacity of your elevator (and build new ones).
  
2. The cars (or climbers)
• The tether does not move, instead, the cars pull themselves up or down.
• The climbers are actually the hard problem!
• They must travel the hundred miles or so into the edge of space, and possibly, the 36,000 km to geosync orbit (especially if they are going to be used to add on to the tether).
• It is unlikely we will want to carry enough fuel for a 36,000 km journey (at 200 mph, that's about a five day trip - one way).
• That means we need a means of power distribution to generate power on the ground, and get it to the climbers (most likely lasers and solar panels).
  

The dangers of the space elevator (terrorist attacks on the base, the tether, or the geosync station) are largely exaggerated. Breaking the tether would cause pieces of it to burn up or fall to earth. It is relatively small, and would do little damage. If the base were destroyed, the tether would slowly rise (there is slight pressure up, to keep the tether tight).

The hazard to lower orbiting satellites is more than offset by the increased launch efficiency. (There would need to be a workforce assigned to pushing satellites out of the way, or a way to shift the tether around them - such a shift might even be useful in dodging meteors or terrorist suicide attacks).

The good news is that the space elevator used to be considered a tech level 9 or 10 achievement. It appears, it will be completed easily within the tech 8 time frame.