The world’s largest single-aperture telescope. The active reflector system of the Five-hundred-meter Aperture Spherical Telescope (FAST) is a 500m aperture and 300m radius spherical crown composed of its primary supporting structure, actuator, backing structure and reflector panels. FAST was assembled in a mountainous region with complicated terrain and is also the largest space structure ever to have been built.
FAST is a spectacularly large piece of engineering that allows a 300m parabolic aperture to track within a 500m spherical cable net. While essentially a cable net structure suspended from a steel truss ring beam, the scale of the structure, the movement precision (to within 1mm over 500m) required, the remote location, and the degree of analysis required make this a hugely ambitious and bold project and a first of its kind at this scale, which deserves enormous respect. The list of technical considerations that become apparent on close inspection of this project demonstrate the engineers have been meticulous in their approach and often working from first principles to produce this highly challenging and impressive structure.