Arecibo

A while back someone posted that Arecibo would make a nifty
antisatellite weapon. I kind of blinked at this, but decided to look
into it...

Evidently, because of the ability to focus much of the output of a
large transmitter in a relatively narrow beam, the interplanetary
radar beam on this baby measures in the tens of terawatts. Now I
don't know how well a satellite would absorb the energies it puts out,
but I can't imagine that the results would be pretty.

Kinda nixes all those science fiction stories about orbital colonies
breaking off to form their own independent nations, eh?