Double Asteroid Redirection Test Mission: Heliocentric Phase Trajectory Analysis

摘要

Double Asteroid Redirection Test will be the first mission to demonstrate and characterize the concept of a kinetic impactor for planetary defense, by impacting the smaller member of a binary asteroid system Didymos. The results of this mission will have implications for planetary defense, near-Earth object science, and resource utilization. This research focuses on the heliocentric transfer phase of the mission. The heliocentric trajectory is evaluated using various objective functions, including a search for the latest possible Earth escape date, the shortest time of flight, and the maximum impact energy. Also included in the search is the potential to use Earth gravitational assists, which proves not to offer any useful advantages. Anew way to assess the trajectory's margin for missed thrust is used, which quantifies the ability of the spacecraft to recover its mission following unplanned nonthrusting events, such as safe mode. The baseline trajectory is shown to be capable of recovering from missed-thrust events lasting 14 days using only 1% of its propellant as margin. Finally, contingency trajectories that attempt to impact Didymos at a subsequent perihelion are considered.