Review: Fisher Space Pen
We finally have found a pen that writes in any condition. This is especially appreciated when we are writing lying down after a hard day of adventures.
After much experimentation Paul Fisher 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 is 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 can also write underwater and upside down. The trick is to have the ink flow when you want it to, and not to flow the rest of the time, a problem Fisher solved.
These pens get their name because Fisher's development couldn't have come at a more opportune time. The space race was on, and the astronauts involved in the Mercury and Gemini missions had been using pencils to take notes in space since standard ball points did not work in zero gravity. 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.
We love this pen because it has all the features of all Fisher Space pens, and had a wonderful grip. The outside is rubber which is great when your hands are not perfectly clean, but it is also lightweight to take anywhere.
...Fiftysense Product Review Panel