A Long March-4B rocket carrying X-ray space telescope to observe black holes, pulsars and gamma-ray bursts blasts off from Jiuquan Satellite Launch Center in northwest China's Gobi Desert, June 15, 2017. (Xinhua/Zhen Zhe)
A Long March-4B rocket carrying X-ray space telescope to observe black holes, pulsars and gamma-ray bursts blasts off from Jiuquan Satellite Launch Center in northwest China's Gobi Desert, June 15, 2017. (Xinhua/Zhen Zhe)