Simulations of Quasi-Satellite Orbits Around Phobos

DOI: 10.2514/1.44434 In this work, quasi-synchronous orbits around Phobos are studied from a preliminary mission design point of view. Addressed issues include stability of the orbits, possible choices of specific suitable orbits, and their impact on the design of a mission to Phobos (eclipses, observation conditions, etc.). An exploration of the phase space is performed to assess the precision requirements on the initial conditions of the spacecraft state vector for insertion into these orbits. The possibility of using an orbit outside the orbital plane of Phobos around Mars is also explored. Nomenclature e = second primary (usually Phobos) orbit eccentricity in the three-body problem hmax,hmin = maximum and minimum altitudes, relative to Phobos, reached by a quasi-satellite orbit, km RPh = mean radius of Phobos, km TPh = mean sidereal period of revolution of Phobos vx,vy,vz = spacecraft velocity Cartesian components in the synodic reference frame, m=s x,y,z = spacecraft position vector Cartesian components in the synodic reference frame, km � ,� ,� ,� , = parameters defining the quasi-satellite orbit geometry � = second primary mass, divided by the total mass, in the three-body problem