First Year of Psyche Electric Propulsion Cruise Operations

This paper presents a review of operations and performance for the electric propulsion (EP) system on the Psyche spacecraft during the first year of the mission. After a successful initial checkout phase, the EP system has been in near continuous operation since late March, 2024, the beginning of a roughly six year long Cruise phase. Usage statistics to date on all four thrusters and both power processing units (PPUs) are presented. Notable trends in electrical and thermal performance of the thrusters, feed system, and PPUs are shared along with unexpected observations and risk mitigation activities. The propellant gauging method is reviewed and a to-date trending of xenon mass with uncertainty is presented. Improvements to the spacecraft momentum management strategy made since launch are detailed alongside measured total torque on the spacecraft during thrusting. The new thruster switching plan for the rest of the six year Cruise and an operations-centric propellant budgeting strategy are presented for the first time here.

本文针对Psyche探测器任务首年的电力推进（Electric Propulsion，EP）系统运行与性能展开综述。在顺利完成初始在轨校验阶段后，该EP系统自2024年3月下旬起进入近乎连续运行状态，此时正值为期约六年的巡航阶段伊始。文中披露了截至当前，全部4台推力器以及2台电源处理单元（Power Processing Units，简称PPUs）的使用统计数据；梳理了推力器、推进剂供应系统及PPUs在电气与热性能方面的显著变化趋势，同时分享了任务过程中的异常观测现象与风险缓解举措。本文对推进剂计量方法进行了综述，并展示了截至目前氙气推进剂质量的变化趋势及其不确定性分析结果。文中详细阐述了任务发射以来探测器动量管理策略的优化改进内容，并附带了推力工作期间探测器总扭矩的实测数据。本文首次公开了剩余六年巡航阶段采用的新型推力器切换方案，以及以运行为核心的推进剂预算管理策略。