In 1963, the Arecibo Observatory became operational on the island of Puerto Rico. Measuring 305 meters (~1000 ft) in diameter, Arecibo's spherical reflector dish was the largest radio telescope in the world at the time—a record it maintained until 2016 with the construction of the Five-hundred-meter Aperture Spherical Telescope (FAST) in China. In December 2020, Arecibo's reflector dish collapsed after some of its support cables snapped, leading the National Science Foundation (NSF) to decommission the observatory.