Node control and numerical optimization of aerogravity-assist trajectories

This paper investigates the method of using node control for numerical optimization to determine feasible aerogravity-assist trajectories at Mars. To find these trajectories, a simulator capable of simulating gravitational and aerodynamic accelerations was developed. In addition, a large number of waverider geometries was evaluated to find a vehicle with a large enough lift-to-drag ratio, of which the aerodynamic characteristics were determined using Direct Simulation Monte Carlo and the Modified Newtonian method. The impact of the initial velocity on the achievable bending angles was investigated. The largest bending angle that could be achieved was 178:5° for an initial velocity of 9.0 km/s. In addition, a hypothetical mission based on Rosetta's swing-by around Mars was investigated to assess the benefit of an aerogravity assist. The velocity change for this swing-by was increased from 2.3 km/s to 6.2 km/s. It was therefore shown that node control and numerical optimization can efficiently be used to find aerogravity-assist trajectories.