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

该项目的目标是探索天体力学中的一种自然现象——在辐射压力下，在小型小行星体的弱重力场中发现的所谓“黎明/黄昏轨道”中粒子的稳定运动。我们将研究一个改进版的希尔近似的分析框架，以解决有限的三体问题。当解析解不可用时，数值积分将用于寻找粒子运动的解。我们将创建庞加莱图来描述这些轨道的许多变种，并研究它们对扰动力的弹性。黎明/黄昏轨道可能会引起航天器任务规划者和行星科学家的兴趣。我们将重点关注日本的隼鸟2号、美国宇航局的OSIRIS REx和欧洲航天局的Marco-Polo-R任务的小行星目标。我们将研究航天器在这种轨道上的稳定运动，以及如何将这些轨道用于绘制小行星目标。由于这些轨道似乎持续了很长时间，它们可能是尘埃颗粒的陷阱，可能形成环和环面。我们将研究矮行星谷神星（它被认为会喷出气体和尘埃）和选定的系外行星的这种环特征的可能寿命。由于在被探测到的系外行星中，有许多离它们的宿主恒星很近，其中一些比太阳更亮，恒星辐射压力可能是一个相关的扰动力。用所谓的“凌日法”来估计行星的大小可能会导致对行星半径的高估和对其特定密度的低估，如果现有的环特征没有被识别出来的话。

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.