Legend has it that the Fisher Space Pen was the result of a multi-million dollar investment from NASA, which was looking to develop a zero-gravity writing instrument for its Apollo astronauts. According to Smithsonian Magazine, however, that's not exactly accurate. The pen was actually invented by Paul C. Fisher, who first patented his "Anti-Gravity" pen, known as the AG7, in 1966. It's the AG7 that was famously taken to outer space aboard the Apollo 7 mission, but Fisher didn't envision his creation as a tool for astronauts — he simply wanted to create a solid pen that wouldn't leak. He ultimately approached NASA with his invention and ended up selling it to them at a 40 percent discount, earning the Fisher Space Pen an enduring spot in cultural folklore.