A NASA engineer's bathroom sink experiment accidentally created the Super Soaker

In 1982, Lonnie Johnson was a NASA engineer at the Jet Propulsion Laboratory, working on the Galileo Jupiter probe and the Mars Observer project. At home, he was experimenting with a new type of heat pump — a CFC-free refrigeration system that he would later patent as the 'Johnson Tube.' While testing a homemade nozzle in his bathroom sink, he accidentally shot a powerful stream of water across the room. The force and distance surprised him. He realized he had invented a high-performance water gun.

Johnson built a prototype in his basement using Plexiglas, PVC pipe, O-ring seals, and a two-liter soda bottle as the water reservoir. He wanted to produce the toy himself, but the manufacturing costs were too high. He spent the next several years pitching the idea to toy companies. Most said no.

In 1989, at the American International Toy Fair in New York, Johnson met the vice president of Larami, a toy company that had been making water guns since the 1950s. Johnson built an improved prototype and made a successful pitch at Larami's headquarters in Philadelphia. The first commercial version appeared in 1990 as the Power Drencher, rebranded to Super Soaker in 1991 with a television ad campaign.

Two million Super Soakers sold in 1991 alone. Total sales eventually exceeded $1 billion. Hasbro bought Larami in 1995 and continued selling the Super Soaker. In 2013, Johnson won nearly $73 million from Hasbro in a royalty dispute over underpaid payments from 2007 to 2012. The Super Soaker was inducted into the National Toy Hall of Fame in 2015. A heat pump experiment in a bathroom sink had become one of the most successful toys in history.