Electric Propulsion for the Psyche Mission: System-Level Integration and Test

NASA’s Psyche mission is planned to launch in 2022 and begin a 3.6-year cruise to the metallic asteroid Psyche, where it will examine this unique body. All primary propulsion will be done with the SPT-140-based electric propulsion subsystem. The Psyche mission will feature the first use of Hall thrusters for a NASA mission, and the first use of Hall thrusters beyond cis-lunar space. The spacecraft additionally uses a cold gas propulsion system with nitrogen propellant for maneuvers such as spacecraft safe mode control. The spacecraft has completed system-level integration and test activities for both propulsion subsystems at JPL and shipped to Kennedy Space Center for final launch preparations. An overview of the subsystem-level and system-level activities is described here, including feed system testing, mechanism deployments, integrated system testing with flight software, spacecraft environmental testing, and mission scenario testing. Some of the issues and problems encountered during this phase of the project are described, and finally the launch base test operations including propellant loading are discussed.

NASA的“灵神星”（Psyche）任务计划于2022年发射，随后开启为期3.6年的航行，前往金属小行星灵神星（Psyche），对这一独特天体展开探测。所有主推进任务将由基于SPT-140的电推进子系统（electric propulsion subsystem）完成。该任务将实现霍尔推进器（Hall thrusters）在NASA任务中的首次应用，以及霍尔推进器在地月空间（cis-lunar space）之外的首次使用。航天器还采用以氮气为推进剂的冷气推进系统（cold gas propulsion system），用于航天器安全模式控制等机动操作。航天器已在喷气推进实验室（JPL）完成两个推进子系统的系统级集成与测试工作，并运抵肯尼迪航天中心（Kennedy Space Center）进行最终发射准备。本文概述了子系统级与系统级的相关活动，包括供给系统测试（feed system testing）、机构展开、搭载飞行软件的集成系统测试、航天器环境测试及任务场景测试。此外，文中还描述了项目此阶段遇到的部分问题，并最终讨论了包括推进剂加注（propellant loading）在内的发射基地测试操作。