Space Pen

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Space Pen

The Space Pen (also known as the Zero Gravity Pen), marketed by Fisher Space Pen Co., is a pen that uses pressurised ink cartridges and is claimed to write in zero gravity, upside down, underwater, over wet and greasy paper, at any angle, and in extreme temperature ranges.

The Fisher Space Pen was invented by American industrialist and pen manufacturer Paul C. Fisher and is manufactured in Boulder City, Nevada, USA. Pens claiming some or all of the same abilities have also appeared on the market from other manufacturers.

1 Models
2 Technology
3 Uses in the U.S. and Russian space programs
4 References in popular culture
5 See also
6 References
7 External links

[edit] 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 fullsize 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 approximately 30 miles (approximately 48 kilometers).

Standard Space Pen refills can be used in any pen able to take a standard Parker Pen Company ballpoint refill, using the small plastic adaptor that is supplied with each refill [2]. Fisher also makes a Space Pen-type refill that fits Cross pens, one that fits 1950s-style Papermate pens (or any pen that uses that type of refill), and a "universal" refill that fits some other ballpoint pens (these are not usually stocked in stores, but can be ordered from Fisher's website).

[edit] Technology

The ballpoint is made from tungsten carbide and is precisely fitted in order to avoid leaks. A sliding float separates the ink from the pressurized gas. The thixotropic ink in the hermetically sealed and pressurised reservoir is claimed to write for three times longer than a standard ballpoint pen. The pen can write at altitudes up to 12,500 feet (3810 m). The ink is forced out by compressed nitrogen at a pressure of nearly 35 pounds per square inch (340 kPa). Operating temperatures range from -30 to 250 degrees Fahrenheit (-35 to 120 degrees Celsius). The pen has an estimated shelf life of 100 years.

[edit] Uses in the U.S. and Russian space programs

There exists a common urban legend claiming that because a standard ballpoint pen would not work in zero gravity, NASA spent $11 million developing the zero-g capable Space Pen, with the humorous note that the Russian space agency opted to simply use pencils.^[1] In fact, NASA programs have used pencils (for example a 1965 order of mechanical pencils^[1]) but because of the danger that a broken-off pencil tip poses in zero gravity and the high flammability of both the graphite and wood present in pencils^[1] a better solution was needed.

On top of all that, it turns out that a standard ballpoint pen will work in space after all.^[2]

NASA never approached Paul Fisher to develop a pen, nor did Fisher receive any government funding for the pen's development. Fisher invented it independently, and then asked NASA to try it. After the introduction of the AG7 Space Pen, both the American and Soviet (later Russian) space agencies adopted it. Previously both the Russian and American astronauts used grease pencils and plastic slates.^{[citation needed]}

Another rumour has it that the Apollo 11 astronauts accidentally snapped off a switch which was necessary to permit them fire the engine to return to the Earth; and that a Fisher Space Pen was used to press this button. While the incident did occur, Buzz Aldrin has stated that he in fact used a felt-tip pen for this.^[3]

[edit] References in popular culture

In an episode of the British children's television series, Bob the Builder, Mr Bentley loses his prized Space Pen and Bob has to help him find it.
A bullet-style Space Pen is on permanent display at the New York Museum of Modern Art (MOMA).
The Space Pen was featured on the episode "The Pen" of the American television show Seinfeld.
The Discworld story The Last Hero by Terry Pratchett describes a spaceflight undergone with Renaissance technology. Amongst the items Leonard of Quirm invents for the flight is a quill pen with a pressurised ink reservoir "to write Upside Down during sojourns in the Void". In reference to the above urban legend, a note on the diagram says "Or invent better pencil".
In Diane Duane's young adult fantasy novel So You Want to be a Wizard, the main character, Nita Callahan, owns a space pen that becomes not only the catalyst for the central conflict, but also the tool for solving the conflict.
In the 2004 Independent film Primer, the Space Pen/Pencil rumor is briefly mentioned.
A "Special" space pen is a plot device in the 1987 comedy Real Men.
In the 2006 film "Man of the Year" Robin William's character Tom Dobbs makes reference to the Space Pen/Pencil during a monologue on a talk show.