A comparison of iterative explicit guidance algorithms for space launch vehicles

This paper analyzes and compares the performance of two prominent explicit guidance algorithms: the iterative guidance mode and the powered explicit guidance. We performed a series of numerical simulations of a space launch vehicle model for both nominal and off-nominal conditions. One of our findings is that if we take into account the originally ignored higher-order terms from the guidance parameters of the iterative guidance mode for a long-range flight, the guidance performance can be enhanced to a level comparable to that of the powered explicit guidance. These higher-order terms can be included by employing an iterative predictor–corrector method like the powered explicit guidance. Also we proposed a remedy of preventing relatively earlier divergence of the guidance commands with the predictor–corrector iteration than that of the linear differential corrector approach by making a better initial guess.