The Space Pen (also known as the Zero Gravity Pen), marketed by Fisher Space Pen Company, is a pen that uses pressurized ink cartridges and is able to write in zero gravity, underwater, over wet and greasy paper, at any angle, and in a very wide range of temperatures.
Close up of a Fisher Space Pen body showing knurlings with removed refill adjacent
Fisher Space refill at bottom compared to similar Parker-standard and generic (non branded) Parker type at top