<h2>AAS  96-200</h2><h2>POWER-LIMITED TRANSFERS BETWEEN TWO COPLANAR CONICS UNDER CONTINUOUS KEPLERIAN THRUST</h2><h4>N. Markopoulos, Georgia Institute of Technology</h4><h2> Abstract </h2>Within the limits of the classical two-body, inverse-square gravity model, the Keplerian class of thrust programs is used toward an analytical treatment of the problem of transferring a spacecraft between two coplanar conics. The power-limited near-optimality of the Keplerian class was argued upon previously.  Continuing that development, the guidance aspects of the problem are studied and the existence of analytical open and closed-loop solutions is demonstrated.  By comparing the costs for several examples of transfers with the corresponding optimal costs, a preliminary attempt is also made toward a direct check of the near-optimality of such solutions.<br><br>