Staff members conduct maintenance operation for China's FAST telescope

Staff members work under the reflection panel of China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province, Aug. 28, 2019. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016. (Xinhua/Ou Dongqu)