Collaborative Research: CubeSat: Ionosphere Thermosphere Scanning Photometer for Ion-Neutral Studies (IT-SPINS)

该项目旨在设计、开发、建造、运行和分析CubeSat航天器“离子中性研究电离层-热层扫描光度计”（IT-SPINS）任务的结果。电离层影响民用和军用通信、导航和监视系统等现代技术。因此，可靠的通信和导航往往需要对信号进行校正，以消除电离层施加的影响。要做到这一点，电离层的特性，如它与磁层扰动、一天中的时间、一年中的季节和太阳周期变化有关的变化，必须得到很好的理解和模拟。it - spin的基本测量方法是对氧离子与电离层上部电子复合产生的紫外线夜光的高灵敏度视距观测。IT-SPINS将以每分钟绕轨道法线旋转两圈，每转一圈将获得60次辐射测量。然后，几次旋转的观测结果将结合在层析反演算法中，以产生发射的二维高度/轨道图像。通过这种方式，IT-SPINS将首次提供一套明确的、地理上扩展的对夜侧电离层内氧离子分布的测量。具体来说，IT-SPINS将提供关于所谓的上层过渡区的离子梯度结构的关键信息，从大约500公里到1000公里的高度，在那里等离子体条件下发生了从氧离子主导到氢离子主导的转变。以前对TTR的研究主要是在世界各地的几个地点使用大型非相干散射雷达。因此，目前还没有对TTR对纬度、当地时间、太阳和地磁活动的依赖进行彻底的气候学研究。缺乏对TTR变异性和整个TTR氧离子分布的详细形态的基本理解是目前我们准确模拟和预测电离层变异性的能力的一个关键限制。除了基本的空间天气目标之外，IT-SPINS项目还将重点放在大学本科阶段科学、技术、工程和数学（STEM）教育的实验学习上。本科生将参与项目的各个方面。这为学生提供了难得的学习和实践项目管理的宝贵机会；系统工程;工程设计、开发和测试；在教师和专业人员的指导下，通过第一手的、基于项目的学习，学习飞行操作和数据分析技能。此外，通过与全州蒙大拿州空间资助联盟（MSGC）的合作，该项目将使MSGC附属部落学院的传统弱势学生参与it - spin在轨道阶段的业务活动。it - spin可以在广泛的轨道倾角（40度）和高度（500-700公里）范围内取得令人信服的科学成果。这个高度范围使我们能够最佳地观察卫星上方的TTR和卫星下方的等离子体结构，同时确保25年的脱轨标准。下列初级和次级科学目标和派生的科学问题的设计目的是使it - spin能够处理其中的一部分，而不管它将被赋予什么卫星轨道。该任务的主要科学目标是研究TTR和O+高度剖面的变化。本文将解决以下三个问题：1)O+主导电离层物理与H+、He+主导等离子体物理边界的高度和厚度如何随磁l壳、磁经度、当地时间和地磁活动的变化而变化？2)地球空间数值模式对观测到的TTR和O+高度剖面变率的预测效果如何？3) O+与中性氢之间的电荷交换对TTR的重要性是什么？赤道等离子体气泡和极地帽斑的中尺度结构成像是该任务的次要科学目标。二级科学目标的赤道部分可以用中倾角轨道和高倾角轨道来处理，而极斑部分只能用高倾角轨道（~70度或更高）来处理。

This project is to design, develop, construct, operate and analyze the results of a spacecraft CubeSat mission named "Ionospheric-Thermospheric Scanning Photometer for Ion-Neutral Studies" (IT-SPINS). The ionosphere affects modern technologies such as civilian and military communications and navigation and surveillance systems. Reliable communication and navigation, therefore, often requires correction of the signals for effects imposed by the ionosphere. To do that the properties of the ionosphere, such as its variability with respect to magnetospheric disturbance, time of day, season of the year, and solar cycle variability must be well understood and modeled. The fundamental measurements of IT-SPINS are high-sensitivity line-of-sight observations of Ultra Violet nightglow radiance produced by the recombination of Oxygen ions with electrons in the upper ionosphere. IT-SPINS will rotate at two rotations per minute about the orbit normal and will acquire 60 radiance measurements per revolution. Observations from several rotations will then be combined in a tomographic inversion algorithm to produce two-dimensional altitude/in-track images of the emissions. In this way, IT-SPINS will provide the first-ever set of unambiguous, geographically-extended measurements of the Oxygen ion distributions within the nightside ionosphere. Specifically, IT-SPINS will provide crucial information on the ion gradient structures in the, so-called, Topside Transition Region, from approximately 500km to 1000km altitude, where a transition takes place in the plasma conditions from being dominated by Oxygen ions to being dominated by Hydrogen ions. Prior studies of the TTR have primarily used large incoherent scatter radars at only a few locations around the World. Consequently, a thorough climatological study of the TTR's dependence on latitude, local time, and solar and geomagnetic activity does not exist at present. Lacking fundamental understanding of the variability of the TTR and the detailed morphology of Oxygen ion distributions throughout the TTR is a critical limitation currently in our ability to accurately model and predict ionospheric variability. Beyond fundamental space weather objectives, the IT-SPINS project places a significant priority on experimental learning in Science, Technology, Engineering and Mathematics (STEM) education at the university undergraduate level. Undergraduate students will participate in responsible roles on all aspects of the project. This provides the students with rare and valuable opportunities to learn and practice project management; systems engineering; engineering design, development and testing; and flight operations and data analysis skills through first-hand, project-based learning while being mentored by faculty and professional staff. In addition, through affiliation with the statewide Montana Space Grant Consortium (MSGC), the project will engage traditionally disadvantaged students at MSGC affiliated Tribal Colleges with IT-SPINS operational activities during the orbital phase. IT-SPINS can achieve compelling science results over a wide range of available orbit inclinations (40 degrees) and altitudes (500-700 km). This altitude range puts us at optimal viewing of the TTR above, and plasma structures below the satellite while ensuring a 25-year de-orbit criteria. The following primary and secondary science objectives and derived science questions are designed so that a subset of them can be addressed by IT-SPINS regardless of the satellite orbit it will be given. The primary science objective for the mission is to study the variability of the TTR and O+ altitude profiles. The following three questions will be addressed: 1) How does the altitude and thickness of the boundary between O+ dominated ionospheric physics and H+, He+ dominated plasmasphere physics vary as a function of magnetic L-shell, magnetic longitude, local time and geomagnetic activity? 2) How well do Geospace numerical models predict the observed variability of the TTR and O+ altitude profiles? 3) What is the importance of the charge exchange between O+ and neutral hydrogen to the TTR? Imaging the mesoscale structuring of equatorial plasma bubbles and polar cap patches constitutes a secondary science objective for the mission. The equatorial part of the secondary science objective can be addressed by both mid- and high inclination orbits, whereas the polar patch part can only be addressed for high inclination orbits (~70 degrees or higher).