In article ,
says...
"Joe Delphi" wrote in
ink.net:

Well, I learn something new everyday. I am a technical person
although I don't work in the aerospace industry and, at first, I
thought this was a joke, I didn't know that people were seriously
studying it.

Not surprising; many people still consider it a joke. One of the biggest
obstacles is that no existing material is strong enough to construct one.
But a lot of folks have stopped laughing since the discovery of carbon
nanotubes, which shows some promise *if* it can be fabricated economically
in the quantities required, and can be integrated into a composite material
without losing too much of its theoretical strength. Another obstacle is
that the elevator would become a navigation hazard for low-orbiting
spacecraft, and may need the capability to "dodge" detectable space debris,
plus shielding to protect against undetectable space debris. This is
solvable, but far from trivial.

British SF author Arthur C. Clarke is a leading advocate of space
elevators. When asked when one might actually be built, he replied, "about
ten years after everyone stops laughing." Other sources give a different
number of years; they are probably all accurate quotes, given Clarke's
propensity for embellishing his own quotes as he ages.

And Clarke is often an "eternal optimist."

For another view of space elevators, it's worth reading Kim Stanley
Robinson's "Red Mars." Not to give away too much of the plot, a space
elevator is not invulnerable, and the risks and costs of a structural
failure are worth considering.

Diane