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 misconception states that, faced with the fact that ball-point pens would not write in zero-gravity, the Fisher Space Pen was devised as the result of millions of dollars of unnecessary spending on NASA's part when the Soviet Union took the simpler and cheaper route of just using pencils, making the pen an example of overengineering. In reality, the space pen was independently developed by Paul C. Fisher, founder of the Fisher Pen Company, with $1 million of his own funds. NASA tested and approved the pen for space use, especially since they were less flammable than pencils, then purchased 400 pens at $2.95 apiece (equivalent to $28 each in 2025). The Soviet Union subsequently also purchased the space pen for its Soyuz spaceflights. Practically all contemporary writing in space intended for permanent record (e.g., logs, details and results of scientific experiments) is electronic. Hard copy is produced infrequently, as of 2019. The laptops used (as of 2012, IBM/Lenovo ThinkPads) need customization for space use, such as radiation-, heat- and fire-resistance. As of 2021, pens were still being used on the International Space Station.
Writing requirements Space versus ground recordkeeping presents several serious issues:
Contamination control
Like 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 crewed 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 crewed 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 members. Cosmonaut Anatoly Solovyev flew with Space Pens starting in the 1980s and states "pencil lead breaks ... and is not good in space capsule; very dangerous to have metal lead particles in zero gravity".
Mission assurance and quality records
Strict documentation requirements accompany anything as complex as a large-scale aerospace demonstration, let alone crewed spaceflight. Quality assurance records document individual parts, and instances of procedures, for deviances. Low production and flight rates generally result in high variance; most spacecraft designs (to say nothing of individual spacecraft) fly so infrequently that they are considered experimental aircraft. When combined with the stringent weight drivers of orbital and deep-space flight, the quality-control demands are high. Change control records track the evolution of hardware and procedures from their ground testing, initial flights, through necessary corrections and midlife revision and upgrades, and on to retention of engineering knowledge for later programs, and any incident investigations. When the flight also has scientific or engineering science objectives, low-quality data may affect mission success directly. Faced with these requirements, pencils or other non-permanent recordkeeping methods are unsatisfactory. The act of taking permanent, high-integrity documentation itself deters kludges, workarounds, and "go fever". The Apollo 1 investigation uncovered procedural and workmanship deficiencies in multiple areas, up to procedures on the pad.
Pressure and temperature At sea level, temperature is moderated by the thick atmosphere. As air pressure falls, temperatures can swing more dramatically. Many early crewed missions operated at below standard pressure, to decrease the stresses (and thus, mass) of their capsules. Many did not have separate airlocks, instead exposing the entire cabin to hard vacuum at times. Low pressures also exacerbate contamination issues, as substances acceptable at standard conditions may begin outgassing at lower pressures or higher temperatures. While the Soyuz spacecraft had a 14.7 psi (101 kPa) design pressure, and could use its orbital module as an airlock, the orbital module would be deleted for planned lunar missions. In any case, a pen which was insensitive to pressure and temperature would eliminate the issue (including accidental depressurizations), provide a margin, and allow the ability to record during extravehicular activities.
Writing instruments
Pencil While graphite is claimed to be a hazardous material in space because it burns and conducts electricity, two facts mitigate the risks:
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