Experts and scholars inspect China's Five-hundred-meter Aperture Spherical Radio Telescope (FAST) under maintenance in southwest China's Guizhou Province, Jan. 11, 2020. China's FAST, the world's largest single-dish radio telescope, will be available for global service from April 1. The National Astronomical Observatories of China (NAOC) of the Chinese Academy of Sciences, the operator of the telescope, confirmed Monday that scientists across the world can make online appointments for using the device for observation from April 1. An allotted timetable will be available by Aug. 1. (Xinhua/Liu Xu)