3710. Application of the Law of Propagation of Uncertainties to a Weight and CG

Paper

Abstract

In order to quantify potential errors in a measurement system, the uncertainties of all measurement sources must be combined to generate a total system uncertainty. This quantified measurement system uncertainty may be used as a decision-making tool to determine the required accuracy of measurement devices such as load cells, scales, and laser trackers.For NASA’s Ascent Abort 2 (AA-2) Flight Test, such an uncertainty quantification was performed to ensure that the Ground Support Equipment (GSE) designed to measure the mass and center of gravity (CG) of a Crew Module (CM) would meet the accuracy requirements set forth by the program. The uncertainties of the load cells used were combined with the laser tracker system’s positional uncertainty to determine the overall measurement system uncertainty, which met program requirements.