Why Astronauts Cannot Use Pencil in Space?

Do you remember the scene from the movie 3 Idiots, where 'Virus' shows a pen to students, specially created by scientists with years of research to be used in space? To which 'Rancho' replied chucklingly, "why astronauts never thought of using a pencil instead?" Well, there are some valid reasons why astronauts cannot use pencils in space.

When pencils are used, they produce small particles like graphite shavings and broken pencil tips. In a microgravity environment, these particles can float around and potentially get into sensitive equipment or even astronauts' eyes and lungs, posing a hazard.

The graphite in pencils is a conductive material and can potentially short-circuit electrical equipment if it comes into contact with exposed circuitry. Moreover, wood shavings are flammable, which is a significant risk in the oxygen-rich atmosphere of a spacecraft.

Pencils can break easily, and the broken pieces can contribute to the debris problem. Mechanical pencils might mitigate some of these issues, but they still produce small graphite particles.

Pens designed for space, such as the Fisher Space Pen, are pressurised to work in zero gravity, underwater, and in extreme temperatures. They provide a more reliable writing instrument that doesn't produce floating debris and can function consistently in space.

The first Space Pen (also known as Zero Gravity Pen), was made by Fisher Space Pen Company. It is a pen that uses pressurised ink cartridges and is able to write in zero gravity, underwater, over wet and greasy paper, at any angle, and in a very wide range of temperatures.