In the 1960’s NASA needed a writing instrument that could be used in the vacume of space. In order to combat this problem, they spent over a million dollars on R&D in developing the Astronaut Pen. When faced with the same problem, the Russians used a pencil.
Or so the legend goes. Actually the truth is a bit different. In the beginning of the space race, both NASA and the Soviet Union used pencils. But pencils break, and they are also inflammable. In space, both of these things are very bad. In a zero-g environment, tiny floating pencil tips can easily get caught in an astronaut’s eye, and a blind astronaut is a major disaster. Even worse, in a pure oxygen environment like those of the early space capsules, it’s very easy for objects to set fire. A dry wood object like a pencil is just looking for an excuse.
After much experimentation he perfected a refill using thixotropic ink-semisolid until the shearing action of the rolling ball liquefied it-that would flow only when needed. The cartridge was pressurized with nitrogen so that it didn’t rely on gravity to make it work. It was dependable in freezing cold and desert heat. It could also write underwater and upside down. The trick was to have the ink flow when you wanted it to, and not to flow the rest of the time, a problem Fisher solved. … The Fisher cartridge did work in the weightlessness of outer space and the astronauts, beginning with the October, 1968 Apollo 7 mission began using the Fisher AG-7 Space Pen and cartridge developed in 1966.
So in fact, the space pen is neither the example of over-engineering or government waste it is sometimes made out to be. In fact, it’s an impressive example of ingenuity and private enterprise. Paul Fisher invested his own money to develop the pen when it’s marketability was not clear, and in so doing managed to corner the market on orbital writing instruments. Even the Soviet Union purchased a batch for the Russian space program. It is still used to this day.