translation.en: I was there to view something called a long-duration balloon flight, which basically takes telescopes and instruments all the way to the upper atmosphere, the upper stratosphere, 40 km up.
translation.zh: 我在那里参观了一项名为长续航时间的气球飞行实验， 气球带着望远镜等设备 一路飞往上层大气空间， 一直到平流层40千米以上的位置。