The feed cabin of the world's largest single-dish radio telescope is being tested in southwest China's Guizhou province.

The 500-meter Aperture Spherical Telescope, also known as FAST, is scheduled for completion in September 2016. Its 30-ton feed cabin, the core component of FAST, helps the telescope to focus -- just like the pupil of an eye.

The cabin will be hoisted up and down by cables to receive air waves from six towers, and technicians have begun preparations for a debugging test of the entire system.