Asteroid/comet mission possibilities using a Galileo spacecraft

Opportunities for rendezvous missions to three comets and two asteroids using a Galileo spacecraft have been identified. These missions are launched in the 1988 to 1990 time frame. Mission performance as measured by propellant margin after rendezvous is assessed for a ten-day launch period. Optimal trajectories are determined in each case subject to the maximum launch energy capability of the Shuttle/Centaur. These trajectories include third-body dynamics. The comet Tempel 2 mission uses a distant powered flyby of Jupiter, while each asteroid mission uses two flybys of Mars to accomplish rendezvous. Comparison of the results of the analysis using third-body dynamics with point-to-point conic results is made. The more accurate dynamic model is seen to be particularly important for the Tempel 2 mission. The results of this preliminary analysis indicate that a Galileo spacecraft launched with the Shuttle/Centaur system could be used for rendezvous with any of several comets or asteroids in the near future.