One of these missions, a satellite called Aeronomy of Ice in the Mesosphere, or AIM, was launched in April to study so-c任务其一，今年4月该局发射了一颗名为“中层大气高空冰探测”（简称AIM）的卫星以研究所谓的夜光云（如上图所示）－这是大气层中最高处的云层。