AAS 97-713
OPTIMIZATION OF DV EARTH-GRAVITY-ASSIST TRAJECTORIES
L. Casalino, G. Colasurdo and D. Pastrone - Corso Duca degli Abruzzi, Torino, Italy
Abstract
An analysis of DV Earth Gravity Assist trajectories is carried out. Rigorous (according to the patched-conic approximation) optimization of the maneuver is accomplished, taking into account the eccentricity of the Earth's orbit. The paper focuses on the application of optimal control theory to complex interplanetary missions whereas the DV-EGA trajectories only constitute the application example. In particular, it is shown that the optimization of this kind of missions can be obtained by only considering the heliocentric trajectory. The necessary optimum conditions for the free-height flyby are used but in this problem a minimum-height flyby is often needed and the corresponding conditions are provided. The procedure is also able to recognize if a numerical solution is only suboptimal.