Collaborative Research: CubeSat--Composition Variations in the Exosphere, Thermosphere, and Topside Ionosphere (EXOCUBE)

该项目是为一个名为EXOCUBE的3U立方体卫星使命而进行的，目的是测量全球范围内高层大气中所有重要的中性和电离物质的密度。 该项目将提供超过25年来的第一个现场全球中性密度数据，包括使用质谱仪技术首次直接测量氢密度。 EXOCUBE的一个重要科学目标是为高层大气的物理模型提供观测约束。 此外，这些测量将用于测试和验证新开发的实验技术，以从雷达和光学观测中获得中性和电离成分和密度。 EXOCUBE测量也将用于几项直接的科学调查。 需要解决的具体科学问题包括：1）静止和风暴时外逸层中氢和质子的半球间传输，以及2）响应磁暴的中性大气驱动因素的表征。 四种中性和离子物质（O、He、H、N2、O+、He+、H+和NO+）的数据由一组两个静态能量角分析仪收集，一个用于中性（NSEAA），一个用于离子（ISEAA）。 该仪器是最近通过美国宇航局和海军研究实验室合作开发的一种新设计。 第三个仪器，一个法拉第杯，包括校准，减少离子密度的不确定性，约正负3%。 卫星将以两种模式收集数据。在“巡逻模式”下，测量将在大约每一个经度度进行，在“协调实验模式”下，测量将在每十分之一个经度度进行，并结合地面雷达和光学测量。 该卫星将被发射到近地轨道，倾角大于或等于45度，通过三个现有的雷达站点和至少六个光学Aeronomy站点。EXOCUBE项目是Scientific Solutions Inc. (SSI)、加州理工州立大学（Cal Poly）和威斯康星州大学（UW）。 美国宇航局戈达德太空飞行中心和SRI国际公司也参与了这项工作。 此外，该项目还与国家科学基金会现有的雷达设施和光学站点进行协调，以便在卫星寿命期间进行有针对性的实验。 EXOCUBE数据集具有广泛的用途，导致期待已久的高层大气的广泛物理和半经验组成模型的改进，并验证提供组成数据的雷达和光学测量技术。 因此，该项目将为进一步开展一系列非常广泛的高层大气学和空间气象科学调查奠定基础。 特别是，可靠的外大气层氢分布的知识是一个关键的要求，现实建模总电子含量，这是目前一个非常高的优先级空间天气目标。 该项目的教育影响是非凡的。卫星总线和操作系统由20-40名学生在Cal Poly的实验室设计和制造，有效载荷集成也由Cal Poly的学生进行。威斯康星州大学的学生参与仪器校准和测试，并对数据完整性进行初步评估。 数据格式化和归档也是学生主导的。

This project is for a 3U CubeSat mission named EXOCUBE to measure the densities of all significant neutral and ionized species in the upper atmosphere on a global scale. The project will provide the first in-situ global neutral density data in more than 25 years, including the first direct measurements of Hydrogen densities using the mass spectrometer technique. An important science objective for EXOCUBE is to provide observational constraints for physical models of the upper atmosphere. Additionally, the measurements will be used to test and validate newly developed experimental techniques to obtain neutral and ionized composition and densities from radar and optical observations. The EXOCUBE measurements will also be used for several immediate science investigations. Specific science questions to be addressed include: 1) the inter-hemispheric transport of Hydrogen and protons in the quiescent and storm-time exosphere, and 2) characterization of neutral atmospheric drivers in response to magnetic storms. Data for each of four neutral and ion species (O, He, H, N2, O+, He+, H+, and NO+) are gathered by a set of two Static Energy Angle Analyzers, one for Neutrals (NSEAA) and one for Ions (ISEAA), respectively. The instrument is a new design that has been developed recently through a collaboration between NASA and the Naval Research Laboratory. A third instrument, a Faraday cup, is included for calibration, reducing ion density uncertainties to approximately plus or minus 3%. The satellite will collect data in two modes. In 'patrol mode' the measurements will be made approximately every degree of longitude and in 'coordinated experimental mode' the measurements will be made every tenth of a longitude degree in conjunction with ground based radar and optical measurements. The satellite is to be launched into low Earth orbit with an inclination of greater than or equal to 45 degrees, passing over three current radar sites, and at least six optical Aeronomy sites. The EXOCUBE project is a collaboration between Scientific Solutions Inc. (SSI), California Polytechnic State University (Cal Poly), and The University of Wisconsin (UW). Also partnering in the effort are NASA Goddard Space Flight Center, and SRI International. In addition, the project coordinates with existing NSF radar facilities and optical sites for targeted experiments during the satellite lifetime. The EXOCUBE dataset has broad utility, leading to long-awaited improvements in a wide range of physical and semi-empirical composition models for the upper atmosphere and to verification of radar and optical measurement techniques providing composition data. As such, the project will provide the foundation for a very large and diverse set of further aeronomy and space weather science investigations. Particularly, reliable knowledge of exospheric Hydrogen distribution is a crucial requirement for realistically modeling Total Electron Content, which is currently a very high priority space weather objective. Educational impacts of the project are extraordinary. The satellite bus and operating systems are designed and built by 20-40 students in the laboratories at Cal Poly, and payload integration is also performed by students at Cal Poly. Students at the University of Wisconsin are involved with instrument calibration and testing and with initial assessment of data integrity. Data formatting and archiving are also student led.