Flights to Asteroids and Comets with Stepped Low Thrust.
Abstract:
Using the optimal trajectories towards asteroids and comets the difference in propellant mass for two models of ideal and stepped low thrusts is investigated. The optimal trajectories with ideal low thrust are obtained by solution of two-boundary problem. For the model of stepped low thrust the similar problem is too difficult to solve. That is why the combination of necessary optimal conditions (for the thrust direction) - with optimisation of parameters (for the simple program of thrust value) is used. The optimal conditions for parameters, combined with the terminal conditions, form the broadened two-boundary problem which is easier than the traditional one. Calculations showed that the difference in propellant mass for the two models is equal to 2-15 % and is less than 3 % of spacecraft's mass for most typical trajectories.
