A Fisher Space Pen is a great breakthrough from space research; no other pen has so much to offer. This pen was designed in 1965 by Paul C. Fisher for NASA, with NO COST to NASA or our government. Ordinary pens rely on gravity to write and if you hold them upside down they quit. In order for the ink cartridge to write at any angle, the ink cartridge is charged with 35 PSI of nitrogen. A small ball type float is used to separate the gas charge from the ink and it is hermetically sealed to hold the charge. For that type of pressure a precision fit, stainless steel, machined socket with a tungsten carbide ball, and a specially formulated thixotropic ink is used keep the pen sealed and leak free.
Choose from a multitude of pen designs and finishes to see just which Fisher pen is right for you.