We present a study of an impacting descent probe that increases the science return of spacecraft orbiting or passing an atmosphere-less planetary bodies of the solar system, such as the Galilean moons of Jupiter. The descent probe is a carry-on small spacecraft (<100 kg), to be deployed by the mother spacecraft, that brings itself onto a collisional trajectory with the targeted planetary body in a simple manner. A possible science payload includes instruments for surface imaging, characterisation of the neutral exosphere, and magnetic field and plasma measurement near the target body down to very low-altitudes (~1 km), during the probe’s fast (~km/s) descent to the surface until impact. The science goals and the concept of operation are discussed with particular reference to Europa, including options for flying through water plumes and after-impact retrieval of very-low altitude science data. All in all, it is demonstrated how the descent probe has the potential to provide a high science return to a mission at a low extra level of complexity, engineering effort, and risk. This study builds upon earlier studies for a Callisto Descent Probe for the former Europa-Jupiter System Mission of ESA and NASA, and extends them with a detailed assessment of a descent probe designed to be an additional science payload for the NASA Europa Mission.

中文翻译：

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木卫二和木星其他伽利略卫星的撞击下降探测器

我们展示了一项关于撞击下降探测器的研究，该探测器增加了航天器围绕或经过太阳系中没有大气层的行星体（例如木星的伽利略卫星）的科学回报。下降探测器是一个随身携带的小型航天器（<100 kg），由母航天器部署，它以简单的方式将自己带入与目标行星体的碰撞轨迹。一个可能的科学有效载荷包括用于表面成像、中性外逸层表征以及目标体附近的磁场和等离子体测量仪器，在探测器快速 (~km/s) 下降到极低高度 (~1 km) 期间，表面直到撞击。科学目标和操作概念的讨论特别参考欧罗巴，包括飞越水羽的选项和极低海拔科学数据的撞击后检索。总而言之，它展示了下降探测器如何有潜力以较低的额外复杂性、工程工作量和风险为任务提供高科学回报。这项研究建立在对欧空局和美国宇航局前欧罗巴-木星系统任务的卡利斯托下降探测器的早期研究的基础上，并通过对设计为美国宇航局欧罗巴任务的额外科学有效载荷的下降探测器的详细评估进行了扩展。