The U.S. Navy is currently testing an electrically powered rail gun capable of firing missiles between 50 and 100 nautical miles at 7 times the speed of sound. Known as the electromagnetic rail gun, the weapons consist of parallel rails and uses a magnetic field and electronic current instead of chemicals to generate the energy required to fire the rounds. U.S. Navy's current warships only have a range of 15 or so nautical miles. Experts say it may be up to 5 years before a cooling system is developed to allow multiple firings. At peak the gun should be able to fire up to 10 rounds a minute up to 220 nautical miles. Navy researchers said the weapon's high-velocity and range would allow warships to provide support for troops involved in landing missions and target enemy ships from a safe distance. They also claim the super-gun could provide defence against cruise and ballistic missiles.