The future of projectile based weapons may be found in the railgun. Currently tests are underway on developing systems that could create as much damage as a Tomahawk (missile), but at a fraction of the cost. In February 2008 the US Navy tested a railgun; it fired a shell at 5,600 miles (9,000 km) per hour using 10 megajoules of energy. Its expected performance is over 13,000 miles (21,000 km) per hour muzzle velocity, accurate enough to hit a 5-meter target from 200 nautical miles (370 km) away while shooting at 10 shots per minute. It is expected to be ready in 2020 to 2025.[verification needed] These systems while currently designed for static targets would only need the ability to be retargeted to become the next generation of AA system.
Try to answer this question if possible (otherwise reply "unanswerable"): When did the United States Navy test a railgun?
February 2008