The primary application of the Spiral Orbit Tribometer is to quickly determine friction coefficients and lubricant degradation/consumption rates for various lubricated couples under realistic conditions (those seen in ball-bearing applications). The tribometer is unique in the fact that it simulates all the motions seen in an actual angular contact bearing and operates under realistic conditions (i.e., loads, speeds, environment, etc…). Based on relative lubricant rankings obtained from the Spiral Orbit Tribometer, better lubricant selections can be made for critical applications during the design phase, such as spacecraft components.