The behaviour of any tribological system is governed by a large number of factors, many of which are difficult to control; material properties, both macro and micro, surface condition, presence of micro quantities of contaminants, system geometry, speed, load, duty cycle are only some of the variables. In consequence the rules to be met by any lubrication process to be acceptable for space are as follows:
- a. In order to ensure consistent repeatability of performance, only fully codified and documented lubrication processes are used for space application .
- b. Only lubricants that are approved and validated for space to a recognised specification, and source traceable, are used.
- c. The test programme to determine the performance of the lubrication system reproduces all the operational conditions of the duty cycle, the environment and the life that it can experience in the application.
The use of a commercial system for a space application is acceptable only if it fulfils these three rules.