Space Pen

Several instruments have been used to write in outer space, including different types of pencils and pens. Some of them have been unmodified versions of conventional writing instruments; others have been invented specifically to counter the problems with writing in space conditions.

A common urban legend states that, faced with the fact that ball-point pens would not write in zero-gravity, NASA spent a large amount of money to develop a pen that would write in the conditions experienced during spaceflight (the result purportedly being the Fisher Space Pen), while the Soviet Union took the simpler and cheaper route of just using pencils. The Fisher Space Pen was actually developed independently and privately in the 1960s, NASA later purchasing 400 of the pens at $6 each. The Soviets followed as well.

Space versus ground recordkeeping presents several serious issues:

As with submarines before them, space capsules are closed environments, subject to strict contamination requirements. Incoming material is screened for mission threats. Any shedding, including wood, graphite, and ink vapors and droplets, may become a risk. In the case of a manned capsule, the much smaller recirculating volume, combined with microgravity and an even greater difficulty of resupply, make these requirements even more critical.

Release of wood shavings, graphite dust, broken graphite tips, and ink compounds are a dangerous flight hazard. Lack of gravity makes objects drift, even with air filtration. Any conductive material is a threat to electronics, including the electromechanical switches in use during early manned space programs. Nonconductive particles may also hamper switch contacts, such as normally-open and rotary mechanisms. Drifting particles are a threat to the eyes (and to a lesser extent an inhalation threat), which may risk execution of a critical procedure. Personnel may don protective gear, but both ground and flight crews are more comfortable and more productive "in shirtsleeves". Paul C. Fisher of Fisher Pen Company recounts that pencils were 'too dangerous to use in space.'

Even before the Apollo 1 fire, the CM crew cabin was reviewed for hazardous materials such as paper, velcro, and even low-temperature plastics. A directive was issued but poorly enforced. When combined with high oxygen content, the Apollo 1 cabin burned within seconds, killing all three crew.

...
Wikipedia