Comparing Different Solar Sail Types in the search for Trajectories to Asteroids

Solar Sails have been a technology of increasing interest in space exploration. Missions such as IKARUS, from JAXA, LightSail-2, from The Planetary Society, NanoSail-D or the planned Advanced Composite Solar Sail System (ACS3), both from NASA, have continually validated the concept of employing space missions with vehicles that use Solar Radiation Pressure as its main source of acceleration. Considering the scientific community's renewed captivation for Solar Sailing and keeping a focus in another increasing interest of space exploration, Near Earth Objects, this study proposes the search for trajectories to hypothetical asteroids using two types of different Solar Sails. The first, a Square Solar Sail, is comprised of a singular flat square shaped reflective surface. The second, a Simple Solar Photon Thruster, is made up of two reflective surfaces. The first one, named the collector, has a concave shape that focuses the incident light beam in the direction of the second one, called the director, which, in turn, is a smaller flat reflective surface responsible for directing the resulting solar radiation pressure acceleration. The dynamics of both types of vehicles are presented and its resulting trajectories to asteroids are later compared. A large number of potential encounters are determined for each one, by varying the initial position of the spacecraft, its maintained attitude during the mission, as well as some of the vehicles properties. After determining the encounter with the asteroid, some of the trajectories elements are stored, some of which are the difference in velocities norm and angle, and considering a possible collision scenario, the magnitude of the asteroids deflection. All of the information are later compared to determine the viability of employing both of these Solar Sails technologies in these types of missions.