<h2>AAS 97-173</h2>
<h2>MERCURY MISSION DESIGN USING SOLAR ELECTRIC PROPULSION  SPACECRAFT                                                                               </h2>
<h4> C. A. Kluever and M. Abu-Saymeh, University of Missouri-Columbia/Kansas City                                                                                             </h4>
<h2> Abstract </h2>
 A Mercury rendezvous mission using solar electric propulsion (SEP) is proposed.   The goal is to compute the orbit transfer which maximizes the final spacecraft  mass.  The optimal control problem is solved using a direct approach and a  constrained parameter optimization method.  The mission design variables include  launch date, injection energy, Venus flyby conditions for a gravity assist,  durations of the thrust and coast arcs, and thrust vectoring direction during the  powered arcs.  Several optimal rendezvous trajectories are obtained for near-term  SEP technology and the results show that a Mercury mission may be a feasible  candidate for the Discovery program.