ELFIN的使命
The ELFIN Mission
摘要：
具有时空模糊度解决选项的电子损失和场调查（ELFIN-STAR，或简称：ELFIN）任务包括两个相同的3单元（3U）立方体卫星，位于极（~ 93度倾角），近圆形，低地球（~450公里高度）轨道上。ELFIN于2018年9月15日推出，预计寿命超过2.5年。它的主要科学目标是解决风暴时间相对论电子沉淀的机制，其中电磁离子回旋（EMIC）波是一个主要的候选人。从电离层的有利位置，ELFIN利用其独特的俯仰角分辨能力来确定测量的相对论电子俯仰角和损失锥内的能谱是否具有EMIC波散射的特征，或者这种散射是否可能是由于其他过程造成的。将相同的ELFIN卫星与缓慢变化的沿轨道间隔配对，可以在几分钟到几十分钟的时间尺度上消除降水的空间和时间演变的歧义，比单个低空卫星的轨道周期（~ 90分钟）更快。每颗卫星都携带一个高能电子粒子探测器（EPDE），用于测量50 keV至5 MeV的电子，deltaE/E<40%，以及一个位于约72 cm吊杆上的磁通门磁力计（FGM），用于测量磁场波（例如，EMIC波），1Hz时噪声<0.3nT/sqrt（Hz）。自旋卫星（T_spin~3s）配备了磁力矩器，允许自旋向上/向下和重新定向机动。自旋轴垂直于轨道平面放置，允许每次自旋两次全俯仰角分辨率。高能离子粒子探测器（EPDI）测量250 keV-5 MeV的离子，解决次级科学问题。最初由CalSpace和大学Nanosat计划资助，ELFIN在2014年至2018年期间被NSF和NASA的联合支持下选中飞行。
英文摘要：
The Electron Loss and Fields Investigation with a Spatio-Temporal Ambiguity-Resolving option (ELFIN-STAR, or simply: ELFIN) mission comprises two identical 3-Unit (3U) CubeSats on a polar (~93deg inclination), nearly circular, low-Earth (~450 km altitude) orbit. Launched on September 15, 2018, ELFIN is expected to have a >2.5 year lifetime. Its primary science objective is to resolve the mechanism of storm-time relativistic electron precipitation, for which electromagnetic ion cyclotron (EMIC) waves are a prime candidate. From its ionospheric vantage point, ELFIN uses its unique pitch-angle-resolving capability to determine whether measured relativistic electron pitch-angle and energy spectra within the loss cone bear the characteristic signatures of scattering by EMIC waves or whether such scattering may be due to other processes. Pairing identical ELFIN satellites with slowly-variable along-track separation allows disambiguation of spatial and temporal evolution of the precipitation over minutes-to-tens-of-minutes timescales, faster than the orbit period of a single low-altitude satellite (~90min). Each satellite carries an energetic particle detector for electrons (EPDE) that measures 50keV to 5MeV electrons with deltaE/E<40% and a fluxgate magnetometer (FGM) on a ~72cm boom that measures magnetic field waves (e.g., EMIC waves) in the range from DC to 5Hz Nyquist (nominally) with <0.3nT/sqrt(Hz) noise at 1Hz. The spinning satellites (T_spin~3s) are equipped with magnetorquers that permit spin-up/down and reorientation maneuvers. The spin axis is placed normal to the orbit plane, allowing full pitch-angle resolution twice per spin. An energetic particle detector for ions (EPDI) measures 250keV-5MeV ions, addressing secondary science. Funded initially by CalSpace and the University Nanosat Program, ELFIN was selected for flight with joint support from NSF and NASA between 2014 and 2018.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
