THEMIS

The THEMIS mission is a five-satellite Explorer mission whose primary objective is to understand the onset and macroscale evolution of magnetospheric substorms. The five small satellites were launched together on a Delta II rocket and they carry identical sets of instruments including an electric field instrument (EFI), a flux gate magnetometer (FGM), a search coil magnetometer (SCM), a electro-static analyzer, and solid state telescopes (SST). The mission consists of several phases. In the first phase, the spacecraft will all orbit as a tight cluster in the same orbital plane with apogee at 15.4 Earth radii (RE). In the second phase, also called the Dawn Phase, the satellites will be placed in their orbits and during this time their apogees will be on the dawn side of the magnetosphere. During the third phase (also known as the Tail Science Phase) the apogees will be in the magnetotail. The fourth phase is called the Dusk Phase or Radiation Belt Science Phase, with all apogees on the dusk side. In the fifth and final phase, the apogees will shift to the sunward side (Dayside Science Phase). The satellite data will be combined with observations of the aurora from a network of 20 ground observatories across the North American continent. The THEMIS-B (THEMIS-P1) and THEMIS-C (THEMIS-P2) were repurposed to study the lunar environment in 2009. The spacecraft were renamed ARTEMIS (Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun), with the P1 and P2 designations maintained.

THEMIS任务是一项由五颗卫星组成的探测任务，其主要目标在于理解磁层亚暴的起始和宏观演化过程。这五颗小型卫星由Delta II火箭一次性发射升空，携带了相同的仪器设备，包括电场仪（EFI）、磁通门磁力仪（FGM）、搜索线圈磁力仪（SCM）、静电分析仪以及固态望远镜（SST）。该任务分为数个阶段。在第一阶段，所有航天器将紧密地聚集在同一轨道平面内，其远地点距离地球半径（RE）为15.4倍。在第二阶段，亦称黎明阶段，卫星将被安置于各自的轨道上，在此期间，它们的远地点将位于磁层的黎明侧。在第三阶段，即磁尾科学阶段，远地点将位于磁尾区域。第四阶段被称为黄昏阶段或辐射带科学阶段，所有远地点均位于黄昏侧。在第五个也是最后的阶段，远地点将转向向阳面（白天科学阶段）。THEMIS-B（THEMIS-P1）和THEMIS-C（THEMIS-P2）在2009年被重新部署以研究月球环境，航天器名称更改为ARTEMIS（月球与太阳相互作用中的加速度、重连接、湍流和电动力学），P1和P2的编号得以保留。

搜集汇总

背景与挑战

背景概述

THEMIS是一个五颗卫星的探索任务数据集，主要研究磁层亚暴的发生和演化过程。该任务涉及多个轨道阶段，并扩展为ARTEMIS任务以探索月球环境，数据开放访问，涵盖物理学、天体物理学和地球科学等多个学科领域。