I've been thinking more and more about Space elevators these days and I can't say that I'm convinced they would reduce the costs of access to space.
I understand I think a little better know the whole theory behind how they would theoretically work. Launch a payload up to an orbit of 100,000 km and unfurl a carbon-nanotube tether. That tether is dropped down to some tower complex on earth and is attached. A counter weight satellite is attached at the top of the tether to ensure a certain tension in the tether. Also that satellite would have to be accelerated by a rocket burn to a higher speed than usual for an orbit at that altitude to make sure it keeps up with the lower portions of the tether. If I'm wrong someone please correct me.
Theoretically, if planned correctly, the center of mass of the whole enchilada is at 35,000 km or at Geo orbit. The importance of this is that the center of mass will rotate perfectly in tandem with the rotation of the earth.
Assuming that this carbon-nanotube tether can withstand all the temperature differences and tensions, and assuming that we could build a complex on earth that could deal with the massive charges built up in the tether, and that the friction created by the tether moving through the atmosphere can be accounted for a space elevator could work.
However most estimates I'm hearing of would involve a cost of $5 billion dollars to build this thing. And personally I think that must be a conservative estimate.
It seems like you're trying to build the highway before you build the car.
The only way we're going to open up space is if smaller groups and companies can find cheap ways of getting there.
Going this route you're going to hit a roadblock at initial investment. What company is going to be willing to pay all of this money up front?
If someone could build it though the costs of space may not necessarily go down. Right now the greatest cost involved in conventional chemical rockets is from two things: range costs and insurance.
Can you imagine the insurance costs on this structure? Can you imagine how much it would cost to finance the on site structures and facilities and personnel to upkeep something like this?
Could the static charge be converted to power? The materials research on this project would have huge benefits other than the elevator itself. As for the 5 billion price tag I think that 5 trillion is more likely. And still cheap at that price.
ReplyDeleteI was thinking the same thing. You could possibly recoup some costs by using the tether as a power plant.
ReplyDeleteThe question is will that be enough to offset the many other costs associated with space tether?
And more specifically the part that is important: the cost per pound of getting into orbit. The greatest cost of chemical rockets is insurance and range costs.
I can imagine the insurance companies would a field day with a 62,000 mile space tether. And as for range costs, I guess the equivalent here would be the costs of the ground complex.
And I'm thinking the ground complex for a space tether would make the cape in Florida look like a playground.
I'd like to see some analyses of costs associated with all these things. Until then my gut instinct has always been that this is a pie in the sky hope.