CRRES

The Combined Release and Radiation Effects Satellite (CRRES) was launched into a geosynchronous
transfer orbit (GTO) for a nominal three-year mission to investigate fields, plasmas, and energetic particles
inside the Earth's magnetosphere. As part of the CRRES program the SPACERAD (Space Radiation Effects) project,
managed by Air Force Geophysics Laboratory, investigated the radiation environment of the inner and outer
radiation belts and measured radiation effects on state-of-the-art microelectronics devices. Other
magnetospheric, ionospheric, and cosmic ray experiments were included onboard CRRES and supported by NASA or
the Office of Naval Research. The chemical release project was managed by NASA/MSFC and utilized the release of
chemicals from onboard cannisters at low altitudes near dawn and dusk perigee times and at high altitudes near
local midnight. The chemical releases were monitored with optical and radar instrumentation by ground-based
observers to measure the bulk properties and movement of the expanding clouds of photo-ionized plasma along
field lines after the releases occurred. In order to study the magnetosphere at different local times during
the mission, the satellite orbit was designed to precess with respect to the earth-sun line such that the local
time at apogee decreased by 2.5 minutes/day from 08:00 (LT) just after launch and returned to this position in
nineteen-month cycles. The CRRES spacecraft had the shape of an octagonal prism with solar arrays on the top
side. The prism is 1 m high and 3 m between opposite faces. Four of the eight compartments were for the chemical
canisters and the other four housed SPACERAD and other experiments. The spacecraft body was spun at 2.2 rpm about
a spin axis in the ecliptic plane and kept pointed about 12 degrees ahead of the Sun's apparent motion in
celestial coordinates. Pre-launch and in-flight operations were supported by the Space Test and Transportation
Program Office of the U.S. Air Force Space Division. Contact with the CRRES spacecraft was lost on October 12,
1991 and was presumed to be due to onboard battery failure.

综合释放与辐射效应卫星（CRRES）被发射至地球同步转移轨道（GTO），执行为期三年的标准任务，旨在研究地球磁层内部的场、等离子体和能量粒子。作为CRRES项目的一部分，由空军地球物理实验室管理的SPACERAD（空间辐射效应）项目，调查了内外辐射带的辐射环境，并测量了对尖端微电子设备的辐射效应。CRRES上还包含了其他磁层、电离层和宇宙射线实验，这些实验由NASA或海军研究办公室支持。化学释放项目由NASA/MSFC管理，利用在近地轨道上日出和日落时以及接近当地午夜的高空释放化学物质，地面观测者通过光学和雷达仪器监测这些化学物质的释放，以测量扩展的等离子体云团的整体性质及其沿场线的运动。为了在任务期间研究不同当地时间下的磁层，卫星轨道被设计为相对于地球-太阳线进行进动，使得远地点的当地时间每天减少2.5分钟，从发射后的08:00（地方时）开始，并在十九个月周期内返回到这一位置。CRRES航天器呈八面棱柱形，顶部安装有太阳能电池板。棱柱高1米，对面对角线长3米。其中四个隔间用于化学罐，其余四个用于存放SPACERAD和其他实验。航天器本体绕着赤道平面内的旋转轴以2.2转/分的速度自旋，并保持相对于天体坐标中太阳视运动的约12度前向指向。美国空军空间分区的空间测试与运输项目办公室支持了发射前和在轨操作。CRRES航天器的联系于1991年10月12日中断，推测是由于航天器上电池故障所致。