Hybrid Lubrication as a Practical Candidate for Space Mechanism Applications

Hybrid lubrication is a promising candidate for spacecraft applications. The methodology consists of the application of a viscous fluid medium (typically a low vapour pressure oil) on top of a thin-film solid lubricant coating (i.e. sputtered MoS2), and when performed correctly can result in an extension in lubricant lifetime, greater than the sum of each of the constituent lubricants alone, without an associated increase in friction.

Hybrid lubrication can also act to protect the underlyingMoS2 during moist environment running (for example ground testing), which can reduce AIT costs and would make hybrid lubrication attractive for high load, low lifetime applications. In addition, hybrid lubrication is potentially attractive to mechanisms engineers as the low fluid volumes applied, theoretically allow one to consider hybrid lubrication for applications where fluid lubricant alone may not be applicable, such as at high or low temperature.

This paper shall present the recent investigations by ESTL into the behaviour of hybrid lubrication, leading to recommendations for use in spacecraft mechanism applications.