Star Wars research: a railgun (Electromagnetic Launcher) fires a 0. 3 pound plastic projectile at 3 kilometers per second (7, 000 miles per hour) to completely penetrate a 1-inch steel target plate. The railgun is being developed at Maxwell Laboratories Inc. , San Diego, California, as part of the U. S. Government's research programme into space-based weapons capable of intercepting ballistic missiles - the Strategic Defense Initiative. Railguns use electromagnetism to accelerate a projectile towards its target, as opposed to rifles or rockets which use chemical energy as a propellant.