ResearchActivities

Space tribology and lubrication of vacuum systems

Abstract:
Space tribology research addresses the lubrication challenges faced by space mechanisms. Due to the similarity in operating conditions, the developed technologies are also applicable to terrestrial vacuum systems, offering valuable solutions for industrial applications.

Main objectives:

  • Conduct advanced research on solid and liquid lubricants for space mechanisms to improve their lifespan and reliability.

  • Provide expert consultancy and tribological analysis in the design of space mechanisms for industrial partners.

  • Evaluate the compatibility of lubrication with other spacecraft subsystems.

Research content:
Space tribology studies the friction, wear, and lubrication of materials in the extreme conditions of space, where standard terrestrial approaches often fall short. The unique challenges of space, such as vacuum, microgravity, extreme temperature variations, and exposure to radiation, significantly impact the properties and performance of materials and lubricants. Conventional lubricants tend to evaporate in vacuum, increasing the risk of failure of mechanical components such as bearings, joints, and gears in satellites and spacecrafts.

The research methodology combines theoretical studies with experiments conducted in simulated conditions. Experiments are carried out on advanced tribometers capable of operating in vacuum and across a wide temperature range, along with thermal vacuum chamber (TVAC). A variety of materials are tested, including solid lubricants on the base of MoS2, liquid lubricants or greases based on PFPE or MAC. A key focus is on understanding the overall function of the lubricated assembly, taking into account not just the lubricant itself but also the interactions between the lubricant, surfaces, and operating conditions. This comprehensive approach ensures a deep understanding of the system's behaviour.

Research outcomes are applicable to the design of complete mechanisms and complex components such as rolling bearings and gears, as well as simpler components like springs, pins, and joints. Each component operates in a unique environment and requires a tailored design approach for both the component and the lubrication system. For example, the design strategy for a bearing in a low Earth orbit satellite differs significantly from that of a bearing in the wheel of an autonomous vehicle on Mars.

Publications:
POUZAR, J.; KOŠŤÁL, D.; ŠPERKA, P.; KŘUPKA, I.; HARTL, M. Experimental study of space lubricant evaporation in a high vacuum environment. Vacuum, 2023, vol. 219, no. A, p. 1-7. ISSN: 0042-207X. https://doi.org/10.1016/j.vacuum.2023.112758

KOŠŤÁL, D.; ŠPERKA, P.; CHMELAR, J.; VITEK, P.; POLAK, M.; KŘUPKA, I. Comparison of Grease and Solid Lubrication of Rolling Bearings Under Small-Stroke Reciprocationfor Space Applications. Tribology in Industry, 2020, vol. 42, no. 1, p. 146-158. ISSN: 0354-8996. https://doi.org/10.24874/ti.2020.42.01.14


Partners and Collaboration:
Frentech aerospace, s.r.o., Jarní 977/48, 614 00 Brno, Czech Republic.

Honyewell spol. s r.o. – HTS CZ o.z., Tuřanka 1387/100, 627 00 Brno, Czech Republic. Thales

Thales Alenia Space, 100 boulevard du midi, 06156 CANNES LA BOCCA, France.

The EUROPEAN SPACE AGENCY, 24 rue du Général Bertrand, CS 30798, 75345 Paris CEDEX 7, France.

Hikade Technologies, Purkyňova 2836/79a, 612 00 Brno, Czech Republic.

Toptec, Sobotecká 1660, 511 01 Turnov, Czech Republic.

Projects:
Rotary Actuator for Space Applications, Technology Agency of the Czech Republic (TA CR) – EPSILON applied research support programme , TH02010205, 2017-2019.

Automatic application of special lubricants to tribological components of space mechanisms, Technology Agency of the Czech Republic – TREND industrial research and experimental development programme, FW06010110, 2023-2025.

Coarse Pointing Assembly for Optical InterSatellite Link, Technology Agency of the Czech Republic – TREND industrial research and experimental development programme, FW01010297, 2020-2022.

Effect of local geometrical changes and polarization of labyrinth seal surfaces on the evaporation rate of liquid lubricants in space applications, European space agency no. 4000139889, 2023-2025.

Contact person:
Ing. David Košťál, Ph.D.