Atmospheric Interface Reentry Point Targeting Using Aerodynamic Drag Control

The ability to control the location of a spacecraft atmospheric interface reentry has been traditionally accomplished using propulsion. A novel technique is presented here where a predefined point of atmospheric interface reentry is achieved by adjusting the aerodynamic drag of a spacecraft in a circular orbit. If this method is employed at a sufficiently high starting altitude, any ground-track point accessible by the orbit can be targeted. This method can be broken up into two different parts. The first consists of finding the decay profile that achieves the desired reentry location. The second consists of keeping the spacecraft within this nominal decay trajectory, given the atmospheric uncertainty and other perturbations. The two parts of this method are presented here in detail. Finally, a case study is provided to demonstrate how this method could work in a realistic scenario and to evaluate its performance. The case study shows that a reentry point can be targeted with a 3σ error of less than 200 k...