Efficient Starshade Retargeting Architecture Using Chemical Propulsion

NASA is studying a possible starshade flying in formation with the Nancy Grace Roman Space Tele- scope (Roman). The starshade would perform weeks-long translational retargeting maneuvers between target stars. A retargeting architecture is introduced that is based on chemical propulsion and does not require ground tracking or interactions with the telescope during the retargeting cruise. Feasibility is demonstrated through a covariance analysis of the starshade-telescope relative position over several weeks using realistic sensor and actuator assumptions. Performance is sufficient for Roman to reacquire the starshade after retargeting and the architecture is shown to also be applicable to other mission concepts such as the Habitable Exoplanet Observatory (HabEx). Results are verified through high-fidelity simulations, and driving sources of uncertainty are identified to confirm the robustness of the approach

NASA正在研究一种可与南希·格蕾丝·罗曼太空望远镜（Roman）编队飞行的遮光罩（starshade）。遮光罩需在目标恒星间执行持续数周的平移重定向机动。本文提出一种基于化学推进的重定向架构，该架构在重定向巡航期间无需地面跟踪，也无需与望远镜进行交互。通过采用真实传感器和执行器假设，对遮光罩与望远镜间数周内的相对位置进行协方差分析（covariance analysis），验证了该架构的可行性。其性能足以支持Roman在重定向后重新捕获遮光罩，且该架构被证明同样适用于其他任务概念，例如宜居系外行星天文台（HabEx）。研究结果通过高保真度仿真（high-fidelity simulations）得到验证，同时明确了不确定性的主要来源，以确认该方法的鲁棒性。