SCIENCE ORBITS DESIGN FOR THE LUNAR CUBESAT EQUULEUS AND FOR THE PHOBOS SAMPLE RETURN MISSION MMX

The candidate science orbits for two JAXA missions heading to three-body system, EQUULEUS and MMX, are presented in this paper. Both of these missions need to conduct science observations while coping with tight engineering constraints such as thermal and power budgets. Due to these requirements, eclipses may become a significant issue for both missions. To minimize or avoid eclipses, we introduce key design parameters for synodic resonant periodic orbits: the synodic ratio and the elongation angle between the Sun and the two primaries. By combining these parameters, we can obtain science orbits that avoid or minimize eclipses in a full ephemeris model. This approach is demonstrated for the science orbit design of both EQUULEUS and MMX.