Uncertainty analysis of propellant gauging system for spacecraft

This paper discusses the traditional concept of propellant gauging system based on the gas law method for estimating the amount of residual propellant mass in spacecraft and the effects of the uncertainty in the instruments on the predicted amount of propellant. Because for accurate determination of the remaining mission life of the satellite it is extremely essential to estimate the amount of propellant present in the propellant tank of the spacecraft at various stages of its mission life, it is important to study the extent to which the uncertainty in various instruments and other measured parameters affect the predicted amount of propellant. With Monte Carlo simulation, it is found that the accuracy with which the propellant quantity can be estimated is highly sensitive to the precision of the propellant tank pressure sensor. It is also found that the uncertainties in the propellant tank pressure sensor and the pressurant tank temperature sensor result in uncertainty as well as overprediction of the amount of residual.