Following Sungrazing Comets Exploration of a Mission Concept.

摘要

This thesis presents a space mission concept that consists of a spacecraft following a sungrazing comet along its orbit while consistently remaining within the shadow of the object. By locating the spacecraft within the shadow of the comet at the comet-Sun L2 equilibrium point, the spacecraft can be shielded from the immense radiation of the Sun. This concept provides a new vantage point to observe comet/Sun interactions while investigating the effects of comet outgassing, exploring the physical consequences of close perihelion passage, and probing the composition of the Sun's corona. A rigorous search is performed to select a sample comet to design a mission about. The Elliptic Hill Three Body Problem dynamical model is introduced to model the interactions of the spacecraft, comet, and Sun and the L2 libration point location is calculated. Environmental modeling is conducted to estimate the size of the comet's shadow and the thermal conditions the comet and spacecraft will encounter. The consequences of this analysis introduce the possibility of a two-stage mission design due to extreme fluctuations in the thermal environment. A linear controller is derived to station-keep the spacecraft at the comet-Sun L2 point. The feasibility of moving the spacecraft closer to the comet is examined and inverse dynamics theory is applied to create various transfers that bring the spacecraft closer to the comet's surface for improved image and data collection.