The field of tribology, dealing with the processes of wear, friction, and lubrication of contact surfaces, is essential for all technical applications. In space technology, the need for lubrication increases due to the extra-low ambient pressure, atomic oxygen, hard ultraviolet radiation, or even the state of microgravity. One of the principal causes of space technology disorders is related to the field of tribology. By enhancing our knowledge in space tribology, we can prevent these disorders and decrease the production of new space debris. We can also reduce the amount of space technology production, the economic cost, or the environmental pollution. For surface lubrication in space, we can use solid or liquid lubricants. Their use depends on the surrounding parameters of the given application, so it is not possible to choose one universal type. In the case of liquid lubricants and liquid components of greases used in space applications, there is an undesired evaporation process due to the surrounding vacuum. These lubricants, therefore, are only applicable in particular ambient pressures and temperatures. To reduce the evaporation intensity of liquid lubricant, we use a non-contact labyrinth seal. It is characterized by a narrow corridor that separates its parts. The evaporated lubricant molecules then exit the system through this separation gap. This research will focus on the influence of local geometry and the surface structure of the labyrinth walls on the flow rate in the molecular flow regime. For flow reduction, will be investigated the effect of labyrinth gap polarization. It will be done both for conventional liquid lubricants and lubricants based on ionic compounds, which can use the nature of evaporated molecules to reduce evaporation intensity. The novelty of this approach is the focus on the local geometries of the labyrinth seals and the use of electromagnetic fields to direct the evaporated molecules.

Keywords
Space tribology; Evaporation; Labyrinth seal; Lubrication; Molecular flow