Optimization of aerobraked orbital transfer vehicles

A new method for utilizing the upper atmosphere to modify Earth orbital trajectories through use of a pressuresupported drag brake has been previously proposed. Analytical results and initial wind-tunnel test data indicate that there is considerable improvement available to the original aerobraking concept. Optimization of the drag brake with respect to size vs structural heating and the application of more advanced cooling techniques indicate that reductions in weight and volume of the aerobraking system by 50% should be possible. Additional analysis indicates that further improvements might be available through use of a alternate drag control mode that eliminates the need to throttle the vehicle main engine during the aerobraking maneuver. Nomenclature