Writing in space

Practically all contemporary writing in space intended for permanent record (e.g., logs, details and results of scientific experiments) is electronic.

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.

Any conductive material is a threat to electronics, including the electromechanical switches in use during early crewed space programs.

[8] Even before the Apollo 1 fire, the CM crew cabin was reviewed for hazardous materials such as paper, velcro, and even low-temperature plastics.

When combined with high oxygen content, the Apollo 1 cabin burned within seconds, killing all three crew members.

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.

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.

The mechanical pencil was used by NASA during Project Mercury,[11] and it remained one of the most used writing instrument up through the Gemini, Apollo, and Skylab programs.

Despite the potential danger, the issue of pencil leads breaking off and floating around in zero-g doesn't seem to have been a problem during the Gemini or Apollo missions.

Ballpoint pens have been used by Soviet and then Russian space programs as a substitute for grease pencils as well as NASA and ESA.

Its thixotropic ink and vent-free cartridge release no significant vapor at common temperatures and low pressures.