Space travel is remarkable, but what about a gun that's able to fire water a distance of up to 50 ft.? That just might be aerospace engineering's greatest contribution to society so far. In 1993, engineer Lonnie Johnson introduced the world to the Super Soaker, a high-power water gun that was at least 10 years in the making. With NASA, Johnson had worked on the Voyager, Mars Observer and Galileo probes, but it was his creation of a new water-operated pump that would be his legacy. Johnson's first prototype was named the Pneumatic Water Gun, but high production costs made it tough to perfect without funding from a toy company. Johnson eventually struck a deal with the Larami toy company, and after a few more attempts, the Super Soaker appeared. The gun would go on to sell more than 250 million units, making it essential for any backyard battle.