The Effects of Outage on Performance Statistics for Bipropellant Rockets

摘要

The distribution of performance errors in bipropellant rockets is determined as a function of engine and propellant loading parameters, and contributing errors. The distribution is found to be highly skewed, so that the probability of exceeding three sigma can be significantly greater than it would be if the distribution were normal. Thus, three sigma as a minimum performance limit is not justified. A detailed analysis is required in each case to determine the relationship between performance margin and probability of mission success. Also, a realistic method of optimizing the propellant loading bias is developed. The methods previously used have resulted in fuel biases that are usually much lower than the optimum. Computer programs have been developed to perform the analyses described in this report, both for the single-stage and the multistage case. (Author)