Abstract: Abstract：Based on the Hill equation， a design method of doubleimpulsive flyaround trajectory is given on the basis of rectangular keep out zone. With dynamics model transformed, the relation of the variables of the model is deduced. On this basis, the theorems are proved, and then safety restrictions are given. Furthermore, we can get runofmill design methods of safe flyaround trajectories between Vbar direction and arbitrary directions in orbital plane. Lastly, this method is showed to be feasible by simulations about two kinds of typical flyaround trajectories, as well as simulation about flyaround trajectory between Vbar direction and arbitrary direction.  

Key words: Keywords：flyaround trajectory , rectangular keep out zone, arbitrary directions