Improved uncertainty propagation method of dynamic model for Mars entry spacecraft

In order to research the uncertainty propagation laws of Mars entry dynamic equations for the Mars entry phase, an improved method was presented for analyzing the effect of the initial state uncertainties and uncertainty factor on the system state in the state trajectories. When applying the method to the entry phase of one of the NASA Mars exploration missions, the simulation results agreed well with the Monte Carlo method, especially the flight path angle simulation at least reaching 92%. It is found that the improved method can not only predict the uncertainty propagation laws with high accuracy of at least 92% in flight path angle simulation and large application scope from -0.1 degree to 0.1 degree, compared with local linearization method, but also save several hours relative to Monte Carlo method.