Space pens were originally developed in 1965 by Paul Fisher of the Fisher Pen Company. Contrary to popular belief, Fisher was not given a multi-million government contract for his revolutionary pens. The actual retail price of the original 400 pens sold to NASA was $2.95 USD a piece. Although originally intended for the US space program alone, space pens later became popular with Soviet cosmonauts. They continue to be used on every manned space mission since 1967.
Both astronauts and cosmonauts originally used pencils for written communication in space. Regular ink pens would not function in the zero gravity environment of space, plus the standard ink formula would evaporate in extreme heat or cold. But the use of lead pencils also became a concern for space program managers. The lead point could break off and cause damage to the crew or sensitive electronics. The wood could flare up into a major fire in the pure oxygen environment. NASA needed a writing instrument which could withstand extreme temperatures, write on any surface, maintain ink flow in zero gravity and resist breakage.
This is where Fisher's space pens fulfilled their purpose. These pens contain a hermetically-sealed ink cartridge filled with a special ink formula. Nitrogen gas is also pumped into this cartridge to force ink to flow without gravity. The ballpoint tip is a small sphere of titanium, guaranteed not to break away from the rest of the pen. Space pens can write underwater and over greasy surfaces. The ink inside the pens can withstand temperatures from minus 150 degrees Fahrenheit to over 300 degrees Fahrenheit.
Today, space pens have become even more popular with the general public. 'Space Pen' is actually a trademark of the Fisher Space Pen Company, although other pen manufacturers have developed models with similar characteristics. High-end space pens are often constructed from exotic woods or metals and are prized by executives as gifts. Because the ink supply is permanently protected from the elements, it can last for over a hundred years.
