A large weapon that stores massive amounts of energy and then shoots at stuff way far away kinda sounds like something out of Star Wars. But railguns—which act quite differently from their sci-fi counterparts, aside from not being intergalactically sinister—are real; and the Navy is working to deploy them on Zumwalt class destroyers within the next two years.
These electromagnetic cannons store up tons of electricity and then with a quick pulse fire projectiles at over 5,000 MPH with a range of about 125 land miles. No bulky explosives are required either to initiate the blast or within the missile itself. Going six to seven times the speed of sound, the payload merely has to hit its target to obliterate it.
Being developed concurrently by both General Atomics and BAE Systems, the weapons have gotten down to a reasonable enough size that they could be put aboard ships capable of actually generating enough power to operate them. And since they offer several benefits, including speed, cost and range, the Navy's been scurrying to develop this technology as soon as possible.