TRAJECTORY DESIGN OF SOLAR ORBITER USING EARTH AND VENUS GRAVITY ASSISTS

In the context of the ESA Solar Orbiter mission studies 4 new trajectories are developed, which use unpowered Earth and Venus gravity assist flybys to reach the operational heliocentric orbits with perihelion as close as 0.28 AU (60 solar radii) from which unprecedented Sun observations will be conducted until eventually reaching solar latitudes over 33 deg. This robust trajectory design enabled a "fast-track" mission approach based on the maximum re-use of technologies developed for the ESA Bepi-Colombo mission. This paper presents the design process followed to define the trajectories within the mission requirements and scientific objectives.