2.2.1 MOC on spacecraft

When flight hardware (parts of spacecraft) is built on Earth, the materials used might contain traces of organic molecules adsorbed on their surfaces, or within substances used during manufacturing, for example within silicon-based glues. When the spacecraft is exposed to different conditions, these organic molecules are emitted into the local environment (Figure 16).

For example, when exposed to UV irradiation in space, parts of a spacecraft may heat up. When this happens, any organic molecules can desorb from surfaces, become volatile (e.g., easily vaporise and evaporate to become gaseous) and migrate to cooler surfaces.

Figure 16 Adsorption and desorption of MOC on spacecraft surfaces