Dynamics of orbits sustained by solar radiation pressure - applications in space exploration and planetary science

• Applicant: Professor Dr. Jürgen Oberst
• Subject Area: Astrophysics and Astronomy ; Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 317324599

The goal of this project is to explore a natural phenomenon in celestial mechanics - the stable motion of particles in so-called 'dawn/dusk orbits' found in the weak gravity fields of small asteroidal bodies under the presence of radiation pressure. We will investigate the analytical framework in a modified version of Hill's approximation to the restricted Three-body Problem. Numerical integration will be used to find solutions for particle motion, when analytical solutions are not available. We will create Poincaré maps to characterize the many varieties of these orbits, and to study their resilience to perturbing forces. The dawn/dusk orbits may be of interest for spacecraft mission planners and planetary scientists alike. We will focus on small asteroid targets of the Japanese Hayabusa-2-, the NASA OSIRIS REx-, and ESA's Marco-Polo-R missions. We will study the stable motion of spacecraft in such orbits and how these orbits may be used for mapping of the asteroid targets. As these orbits appear to persist over long time scales, they may act as traps for dust particles, which possibly form rings and tori. We will study the possible lifetime of such ring features about dwarf planet Ceres (which has been suggested to eject gas and dust) and selected exoplanets. Since many among the detected exoplanets move close to their host stars, some of which more luminous than the Sun, stellar radiation pressure may be a relevant perturbing force. Estimates for planet sizes by the so-called 'transit-method' may lead to an overestimation of the planet's radius and an underestimation of its specific density if an existing ring feature is not recognized as such.

• DFG Programme: Research Grants