Engineers with the Office of Naval Research set a new world record on Friday by firing an electromagnetic railgun "cannon" with an energy of 33 megajoules, or 33 million joules. That would be enough, in an operational system, to shoot a projectile 110 miles from a ship, at speeds up to Mach 5.
Here's what the shot, which took place at the Navy's Dahlgren research center in Virginia, looked like:
Railguns have been suggested for years as a way to launch cargo into space. People couldn't be cannon-fired to the space station, of course, but railguns might be used for bulk materials, even water, which could withstand the high accelerations.
We're still a long way from a railgun space launcher, though. According to this 2003 paper, you need a minimum of 10 gigajoules to reach orbit, or 300 times the energy of the Dahlgren test. Oh well. At least NASA is thinking about it, and not leaving all the fun to the Navy.