An HQ-16 medium-range air-defense missile system attached to a missile contingent with an air-defense brigade under the PLA Xinjiang Military Command fires a surface-to-air missile during a live-fire operation at a depopulated area in the southern part of the Tianshan Mountains in early September, 2019. (eng.chinamil.com.cn/Photo by Song Shilei and Huang Zongxing)