AOCS DESIGN FOR A 160-m, 450-kg SOLAR SAIL SPACECRAFT OF THE SOLAR POLAR IMAGER MISSION

摘要

An attitude and orbit control system (AOCS) is developed for a 160-m, 450-kg solar sail spacecraft of the Solar Polar Imager (SPI) mission. The SPI sailcraft first spirals inwards from 1 AU to a heliocentric circular orbit at 0.48 AU, followed by a cranking orbit phase to achieve a science mission orbit at a 75-deg inclination, over a total sailing time of 6.6 yr. The solar sail will be jettisoned after achieving the science mission orbit. This paper focuses on the solar sailing phase of the SPI mission, with emphasis on the design of a baseline AOCS consisting of a propellantless primary ACS and a microthruster-based secondary (backup) ACS. A 70-deg pitch reorientation within 3 hrs every half orbit during the orbit cranking phase is shown to be feasible for possible solar observations even during the 5-yr cranking orbit phase.