Spacewalking astronauts installed an 88-million-dollar spectrograph designed to detect faint light from faraway quasar .

太空步宇航员安装8．8千万美元的光谱仪，用于探测来自遥远的微弱光线。

Quasars are the highly energetic cores of distant galaxies.

是遥远系的极为活跃的核心。