Abstract: In order to estimate and improve the payload capacity of spacecraft, combined with the space transportation system theory and the ion thruster discharge model, the spacecraft payload capacity of the deep space exploration mission with the ion propulsion system as the main power source was analyzed. Through the theoretical derivation, the potential relationship between the payload fraction and the parameters of the deep space exploration mission and the performance parameters of the electric propulsion system are constructed and revealed. The results show that the smaller power plant specific mass, the larger the optimal payload fraction that can be achieved by the spacecraft. The payload fraction is positively correlated with the extracted ion fraction, the primary electron utilization factor and the length of the task time. When the ion-thruster system can achieve a higher payload fraction, higher working fluid utilization is required as a support.

Key words: Ion thruster;Payload fraction;Deep space exploration;Plasma performances;Characteristic curve

摘要： 为预估与提高航天器有效载荷能力，结合航天运输系统理论与离子推力器放电模型，对深空探测任务中以离子电推进系统为主要动力来源的航天器有效载荷能力进行了分析。通过理论推导，构建并揭示了有效载荷分数与深空探测任务参数和电推进系统性能参数的函数关系与潜在联系。结果表明：动力装置单位质量越小，航天器所能达到的最佳有效载荷分数越大；有效载荷分数的高低与离子引出份额、原初电子利用率参数的大小以及任务时间的长短呈正相关；当离子电推进系统可以达到更高的载荷比时，则需要更高的工质利用率作为支持。

关键词: 离子推力器;有效载荷比;深空探测;等离子体特性;性能曲线