| The use of atmospheric drag to circularize spacecraft orbits, a concept referred to as aerobraking, can significantly increase the useful payload mass fraction for various types of missions. A procedure is devised which determines the optimal combination of aerobrake shielding area and initial orbit period to maximize the spacecraft mass in the final orbit. Two computer codes are constructed and the results from each are compared. The first simulation assumes only aerodynamic drag perturbations and uses simplified analytical expressions. The second is a detailed numerical integration including perturbations due to drag, atmospheric rotation, planet oblateness, third-body effects, and solar radiation pressure. Hypersonic aerodynamic heating rate equations for two different shield configurations are discussed and their performances are compared. Illustrative numerical examples for a Venus and a Mars mission are included. |
