View source for Space Pen

{{Short description|Gravity-independent ballpoint pen}}
[[File:AG-7 Space Pen.JPG|thumb|right|250px|An AG-7 Astronaut Space Pen in presentation case.]]
[[File:SpacePen.jpg|thumb|Bullet 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 [[Weightlessness|zero gravity]], underwater, over wet and greasy paper, at any angle (including upside down), and in a very wide range of temperatures.
[[File:AS07-4-1586.jpg|thumb|Astronaut Walter Cunningham, Apollo 7 lunar module pilot, writes with space pen as he is photographed performing flight tasks on the ninth day of the Apollo 7 mission.|250x250px]]
{{Multiple image|perrow = 1|total_width = 200
| direction         =  vertical 
| image1            = Fisher Space pen body and refill nib end close up.jpg
| width1            = 130px
| alt1              = Nib end of gold colored pen body with refill laid into alignment underneath
| caption1          = Close up of a Fisher Space Pen body showing [[knurling]]s with removed refill adjacent
| image2            = Fisher, Parker and generic refills.jpg
| width2            = 130px
| alt2              = Three stacked pen refills with similar fittings for comparison
| caption2          = Fisher Space refill at bottom compared to similar Parker-standard and generic (non branded) Parker type at top
}}

==Inventors==
The Fisher Space Pen was created by Austrian Friedrich Schächter and expanded by Erwin Rath. [[Paul C. Fisher]] invented the "[[Thixotropy|thixotropic]] special ink". The pens are manufactured in [[Boulder City, Nevada]]. Paul C. Fisher first patented the AG7 "anti-gravity" pen in 1965.<ref>{{Cite patent|title=Anti-gravity pen|country=US|number=US3285228A|status=Expired - Lifetime|pubdate=1966-11-15|gdate=|url=https://patents.google.com/patent/US3285228A/en}}</ref>

==Models==
{{Unreferencedsection|date=June 2025}}
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{{nbs}}miles ({{cvt|30.7|mi|disp=out}}). In contrast, the standard PR (Pressurized Refill) cartridge is rated to write for over 12,000{{nbs}}feet ({{convert|12000|ft|mi|abbr=off|disp=out}} or {{cvt|12000|ft|km|disp=out}}).<ref>{{Cite web |date=October 13, 2025 |title=Silver Ink, Bold Point Space Pen Pressurized Refill |url=https://www.spacepen.com/sprslb-silver-ink-bold-point-pressurized-cartridge |website=Fisher Space Pen}}</ref>

Standard Space Pen refills can be used in any pen able to take a standard [[Parker Pen Company|Parker]]-type [[Ballpoint pen|ballpoint]] refill, using the small plastic adapter that is supplied with each refill. Fisher also makes a Space Pen-type refill that fits [[A. T. Cross Company|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.

==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]] visco-elastic ink in the [[hermetically sealed]] and pressurized reservoir is able to write for three times longer than a standard ballpoint pen. The ink is forced out by compressed nitrogen at a pressure of nearly {{cvt|310|kPa |psi atm}}. Operating temperatures range from {{convert|−34|to|121|C|K F}}. The pen can write without the help of gravity, at any angle. The pen has an estimated shelf life of 100 years. 

One of the first Space Pen patents is US3285228, which was filed on 19 May 1965.<ref>Sakpal, Nilesh J [http://thinkpat.blogspot.in/2012/01/space-pen-zero-gravity-pen-fisher-space.html ''Space pen {{!}} Zero gravity pen {{!}} Astronaut's pen AG7 - Fisher Space Pen Co.'']</ref>

==Uses in the U.S. and Soviet space programs==
{{Main|Writing in space}}
An [[urban legend]] states that NASA spent a large amount of money to develop a pen that would write in space (the result purportedly being the Fisher Space Pen), while the Soviets just used pencils.<ref name="physics1">{{cite web|title=Is it true that NASA spent thousands of dollars developing a space pen, whereas the Russians just took a pencil?|url=http://www.physics.org/facts/apollo-nasa-pen.asp|publisher=physics.org|accessdate=2 November 2012|archive-date=28 January 2013|archive-url=https://web.archive.org/web/20130128082455/http://www.physics.org/facts/apollo-nasa-pen.asp|url-status=dead}}</ref><ref name="snopes1">{{cite web|title=The Write Stuff|date=22 August 2000 |url=https://www.snopes.com/fact-check/the-write-stuff/ |work=[[Snopes]] |first=David |last=Mikkelson |accessdate=September 23, 2013}}</ref>  In reality, NASA began to develop a space pen, but when development costs skyrocketed the project was abandoned and astronauts went back to using pencils, along with the Soviets.<ref name="physics1"/><ref name="snopes1"/>  However, the claim that NASA spent millions on the Space Pen is incorrect, as the Fisher pen was developed using private capital, not government funding. The development of the thixotropic ink cost Paul Fisher around $1&nbsp;million (equivalent to ${{Inflation|US|1|1965|r=0}}&nbsp;million in {{Inflation/year|US}}).<ref>{{cite news |url=https://www.forbes.com/sites/nancyolson/2020/06/10/fisher-space-pens-take-flight/?sh=c8aa8886e334 |work=[[Forbes]] |title=Fisher Space Pens Take Flight |first=Nancy |last=Olson |date=10 June 2020}}</ref> NASA, and the Soviets,<ref name="snopes1"/><ref name="thewritersedge">{{cite web|title=... And Today: MIR Cosmonauts Use Fisher Space Pens For Their Writing Needs|url=http://www.thewritersedge.com/story.cfm|accessdate=September 23, 2013|archive-date=October 30, 2014|archive-url=https://web.archive.org/web/20141030080048/http://www.thewritersedge.com/story.cfm |website=thewritersedge.com |url-status=dead}}</ref><ref>{{cite web|title=Just the FAQ Ma'am|url=http://www.thewritersedge.com/faq.cfm |work=thewritersedge.com |accessdate=September 23, 2013|archive-date=October 4, 2013|archive-url=https://web.archive.org/web/20131004224752/http://www.thewritersedge.com/faq.cfm|url-status=dead}}</ref> eventually began purchasing such pens.

NASA programs previously used pencils<ref name="spacepen1">{{cite web|title=Here's a little history about the Fisher Space Pen Company |website=spacepen.com |url=http://www.spacepen.com/about-us.aspx|accessdate=September 23, 2013}}</ref> (as demonstrated by an order in 1965 for [[mechanical pencil]]s)<ref name="sciam">{{cite news | url=http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-nasa-spen | title=Fact or Fiction?: NASA Spent Millions to Develop a Pen that Would Write in Space, whereas the Soviet Cosmonauts Used a Pencil | author=Ciara Curtin | publisher=Scientific American | date=2006-12-20}}</ref> but because of the substantial dangers that broken pencil tips and graphite dust pose to electronics in zero gravity, the flammable nature of wood present in pencils,<ref name="sciam"/> and the inadequate [[Mission assurance|quality documentation]] produced by [[Information Assurance|non-permanent or smeared]] recordkeeping, a better solution was needed.  Soviet cosmonauts used pencils, and [[grease pencil]]s on plastic [[slate (writing)|slates]] until also adopting a space pen in 1969 with a purchase of 100 units for use on all future missions.<ref name="NASA">{{cite web | url=http://history.nasa.gov/spacepen.html | title= The Fisher Space Pen | author=Steve Garber | publisher=NASA History Division | date=2010-05-28}}</ref>  NASA never approached Paul Fisher to develop a pen, nor did Fisher receive any government funding for the pen's development.<ref name="sciam"/> Fisher invented it independently and then, in 1965, asked NASA to try it. After extensive testing, NASA decided to use the pens in future Apollo missions.<ref name="spacepen1"/><ref name="NASA"/><ref name="thewritersedge"/> Subsequently, in 1967 it was reported that NASA purchased approximately 400 pens for $2.95 apiece (equivalent to ${{inflation|US|2.95|1967}} each in {{inflation year|US}}).<ref name="NASA"/><ref>You can see the original 1967 purchase order between NASA and Fisher Space Pen {{cite web|title=here|url=https://imgbb.com/SdgLtH2|archive-url=https://web.archive.org/web/20230522225115/https://imgbb.com/SdgLtH2|url-status=usurped|archive-date=May 22, 2023}}</ref>

In 2008, [[Gene Cernan]]'s [[Apollo 17]]-flown space pen sold in a [[Heritage Auctions|Heritage]] auction for US$23,900.<ref>{{cite web|url=http://historical.ha.com/c/item.zx?saleNo=6000&lotNo=58028 |title=Gene Cernan's Apollo 17 Lunar Module Flown Fisher AG-7 Space Pen... (Total: 1 Items) Transportation: Space Exploration |publisher=[[Heritage Auctions]] |date=2008-03-24 |accessdate=2010-09-14}}</ref>

As of 2021, Fisher space pens were still being used on the International Space Station.<ref>{{Cite web|last=Hall|first=Loura|date=August 27, 2021|title=Space Pens, Pencils, and How NASA Takes Notes in Space|url=https://www.nasa.gov/technology/tech-transfer-spinoffs/space-pens-pencils-and-how-nasa-takes-notes-in-space/|access-date=2025-02-14|website=NASA.gov|language=en-US|archive-date=February 2, 2025|archive-url=https://web.archive.org/web/20250202080436/https://www.nasa.gov/technology/tech-transfer-spinoffs/space-pens-pencils-and-how-nasa-takes-notes-in-space/|url-status=live}}</ref>

== In popular culture ==
* The 20th episode of season 3 of the comedy television show ''[[Seinfeld]]'' is called "''[[The Pen]]''" with a Space Pen featured as a major plot point.<ref>{{cite web |url= http://www.seinology.com/scripts/script-20.shtml |author= David, Larry |author-link= Larry David |date= October 2, 1991 |title= Script: Episode 20 - The Pen |publisher= Seinology.com |access-date= April 30, 2013 |archive-date= November 9, 2012 |archive-url= https://web.archive.org/web/20121109191646/http://www.seinology.com/scripts/script-20.shtml |url-status= dead }}</ref>
* The Space Pen is featured in the 2009 Bollywood film ''[[3 Idiots]]'', presented by the director of an engineering college to his students.<ref>{{Cite web|date=August 30, 2021|title=How a Pen That Amused Us in '3 Idiots' Enabled Safer Writing in Space|url=https://www.news18.com/news/buzz/how-a-pen-that-amused-us-in-3-idiots-enabled-safer-writing-in-space-4144154.html|access-date=2025-02-14|website=[[News 18]]|language=en|archive-date=February 14, 2025|archive-url=https://web.archive.org/web/20250214003440/https://www.news18.com/news/buzz/how-a-pen-that-amused-us-in-3-idiots-enabled-safer-writing-in-space-4144154.html|url-status=live}}</ref>

==See also==
* [[List of pen types, brands and companies]]

==References==
{{Reflist}}

==External links==
*[http://www.spacepen.com/ Fisher Space Pen Co.]
*[http://www.thespacereview.com/article/613/1 The Billion Dollar Space Pen]
*[http://www.snopes.com/business/genius/spacepen.asp Legend debunked] ([[Urban Legends Reference Pages]])
*[https://news.bbc.co.uk/1/hi/magazine/6173154.stm Did Biros really revolutionise writing] BBC News 2006-11-23
*[http://www.thespacereview.com/archive/613d.pdf NASA Specification for writing instruments 1973-06]
*[http://history.nasa.gov/spacepen.html Nasa History]
*{{usurped|1=[https://web.archive.org/web/20090313022139/http://www.hydeparkmedia.com/fisher.html "Pen Name: Having perfected the ball-point, Paul Fisher wrote a plan to save the world"]}}, by Anthony DeBartolo, ''Chicago Tribune'' Sunday Magazine, 1991
*{{usurped|1=[https://web.archive.org/web/20230522225115/https://imgbb.com/SdgLtH2]}}

[[Category:American inventions]]
[[Category:Pens]]
[[Category:American urban legends]]