Space Pen

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 (including upside down), and in a very wide range of temperatures.

Inventors

The Fisher Space Pen was created by Austrian Friedrich Schächter and expanded by Erwin Rath. Paul C. Fisher invented the "thixotropic special ink". The pens are manufactured in Boulder City, Nevada. Paul C. Fisher first patented the AG7 "anti-gravity" pen in 1965.

Models

There are two prominent styles of the pen: the AG7 "Astronaut pen", a long thin retractable pen shaped like a common ballpoint, and the "Bullet pen" which is non-retractable, shorter than standard ballpoints when capped, but full size when the cap is posted on the rear for writing.

Several of the Fisher Space Pen models (the "Millennium" is one) are claimed to write for a lifetime of "average" use; however, the product literature states that the pen will write exactly 30.7 miles (49.4 km). In contrast, the standard PR (Pressurized Refill) cartridge is rated to write for over 12,000 feet (2.3 miles or 3.7 km).

Standard Space Pen refills can be used in any pen able to take a standard Parker-type ballpoint refill, using the small plastic adapter that is supplied with each refill. Fisher also makes a Space Pen-type refill that fits Cross pens, one that fits 1950s-style Paper Mate pens (or any pen that uses that type of refill), and a "universal" refill that fits some other ballpoint pens.