In recent years there has been increasing interest in utilizing CubeSat technology for exploration missions. Such missions will now require new propulsion development efforts. Most CubeSats are flown as secondary payloads. This introduces additional safety constraints on the propulsion system, particularly with regard to propellant selection. Hybrids arc a promising form of propulsion for CubeSats as they have non-toxic propellant options and have lower TNT equivalency than solid motors and liquid bi-propellants engines. Hybrid propulsion systems also enjoy a higher specific impulse than solid rocket motors and monopropcllant thrusters, nearly comparable to that of liquid rockets. Hybrid motors arc throttle-able, able to be stopped and restarted, and benefit from flexibility in their packaging configuration. This paper presents a novel hybrid motor propulsion system developed for small spacecraft and designed to fit within a 2U form factor. The propulsion system consists of a main hybrid motor with delta-V capabilities of approximately 30 m/s as well as an Attitude Control System (ACS) for spacecraft de-tumbling and reaction wheel unloading. Different fuel, oxidizer and ACS combinations are compared and evaluated across a number of metrics including Isp performance, storability, and volumetric efficiency. The design is also optimized over the oxidizer to fuel ratio, tank pressure, nozzle area ratio, and combustion chamber pressure. Details of the design methodology arc outlined in the paper, including a discussion of the application of a similarity solution analysis to improve design and performance accuracy. Predicted scaling effects on the performance of the main hybrid motor are examined. The final section of the paper is dedicated to a description of the plans for ongoing development of the propulsion system and its application to a Mars aerocapture demonstration mission. A trade study for this mission comparing the final hybrid propulsion system design to a traditional monopropcllant system is described.
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机译：近年来，人们越来越有兴趣将CubeSat技术用于勘探任务。这些任务现在将需要新的推进发展努力。大多数CubeSat都是作为辅助有效载荷飞行的。这在推进系统上引入了额外的安全约束，特别是在推进剂选择方面。混合动力飞机是CubeSat的一种有前途的推进方式，因为它们具有无毒推进剂选择，并且其TNT等效性低于固体发动机和液体双推进剂发动机。混合动力推进系统还比固体火箭发动机和单推进推进器具有更高的比冲，几乎与液体火箭相当。混合动力发动机可以节流，可以停止和重新启动，并且得益于其包装配置的灵活性。本文介绍了一种为小型航天器开发的新型混合动力推进系统，其设计适合2U尺寸。该推进系统包括一个主混合动力电动机，其ΔV功能约为30 m / s，以及一个用于航天器解体和反作用轮卸载的姿态控制系统（ACS）。通过多种指标（包括Isp性能，耐贮性和容积效率）对不同的燃料，氧化剂和ACS组合进行比较和评估。该设计还优化了氧化剂与燃料的比例，油箱压力，喷嘴面积比和燃烧室压力。本文概述了设计方法的详细信息，包括对相似性解决方案分析在提高设计和性能精度方面的应用的讨论。研究了对主混合电动机性能的预期缩放比例影响。本文的最后一部分专门介绍了推进系统的持续开发计划及其在火星航空捕获示范任务中的应用。描述了该任务的贸易研究，将最终的混合动力系统设计与传统的单推进剂系统进行了比较。
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