The Pentagon is perpetually working on advanced weapons platforms that appear to be more science fiction than fact. However, the Navy's electromagnetic railgun is a fully-functioning reality.
The electromagnetic railgun needs no gunpowder or chemical propellants, yet is capable of firing a projectile 20 times further than conventional bullets at exceptionally high speeds.
To be sure, projectiles fired from a railgun don't even need an explosive-laded warhead, as the uber-high speeds provides the projectile with sufficient kinetic energy to destroy a target.
While the railgun isn't ready to be placed on a battleship and fielded just yet, the Navy is intent on improving its existing 5600 mph bullet slinging prototypes - by adding GPS capabilities to railgun projectiles. Ultimately, the Navy wants to use such projectiles to down missiles and aircraft threatening American warships.
As such, the Navy has issued a proposal asking defense companies to design a projectile weighing 20-30 pounds that is capable of "potential in-flight retargeting," with a range of up to 200 miles.
The proposal says it "will explore technologies related to extended range guided projectiles for Naval Surface Fire Support and exploit recent advances in miniaturized electronics, guided projectiles and mortars, and warhead technology for small UAV [unmanned aerial vehicle] launched munitions."