I remember hearing about a plan to build a giant rail-gun (or coil, or whatever) into the side of a mountain and try to send stuff into space. The issue was A)

I remember hearing about a plan to build a giant rail-gun (or coil, or whatever) into the side of a mountain and try to send stuff into space. The issue was A) the barrel would be evacuated of air and the piece of glass covering the end would send glass everywhere and B) the resulting sonic booms would destroy the local ecosystem. Looking for sonic boom energy levels (up to 100 megawatts/sq. meter!) I stumbled across this gem: > In 1964, NASA and the FAA began the Oklahoma City sonic boom tests, which caused eight sonic booms per day over a period of six months. Valuable data was gathered from the experiment, but 15,000 complaints were generated and ultimately entangled the government in a class action lawsuit, which it lost on appeal in 1969. (http://en.wikibooks.org/wiki/Acoustics/Sonic_Boom#Perception_and_noise http://en.wikibooks.org/wiki/Acoustics/Sonic_Boom#Perception...)