Fundamentals of Space Mechanical Systems Lubrication for GN&C Engineers

Moving mechanical assemblies (MMAs) designed for use in the extreme environment of space, require proper lubrication in order to enable their operation and to attain the required life for a given application. Simply stated, all lubricants are not created equal. Many factors must be considered when selecting lubrication systems intended for spaceflight hardware including operating environments, speed of application, lubrication regime, material compatibility, reactivity, and life requirements. Background material will be presented that will allow users to formulate a set of questions that should serve as a guide to lubricant selection and to identify potential problematic areas of concern for spaceflight hardware. Stribeck’s curve and a discussion on the differences between boundary and elastohydrodynamic (EHD) lubrication will be presented. Successful approaches to lubricant selection, including test methods currently available, will be discussed and actual examples encountered presented.