Railguns are weapons that use electricity to fire projectiles at very high energies. The U.S. military is interested in them because they operate without the need to have big piles of explosives lying around, and the projectiles themselves have so much kinetic energy behind them that they don’t need to be explosive, either: in just 10 milliseconds, the Navy’s railgun prototype accelerates projectiles to between Mach 6 and Mach 7 (8,500 kilometers per hour) with 32 MJ of energy, resulting in a range of just over 200 kilometers. This far surpasses conventional naval weapons.
While the railgun is still under active development, Roger Ellis, Program Officer at the Office of Naval Research, told IEEE Spectrum that the Navy has a full scale prototype that it’s preparing to demonstrate on a ship at sea. They’re still working on making the system reliable enough to fire at a rate of several rounds per minute: thermal management, power management, barrel life, and platform integration will all be checked out when the prototype gets installed aboard the Joint High-Speed Vessel USNS Millinocket in 2016.