Arxiv – The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) Project Arecebo is the current largest single dish radio telescope at 305 meters diameter (73,000 square meters). The 500 meter telescope will have 196,000 square meters of area.
Five-hundred-meter Aperture Spherical radio Telescope (FAST) is a Chinese mega-science project to build the largest single dish radio telescope in the world. Its innovative engineering concept and design pave a new road to realize a huge single dish in the most effective way. FAST also represents Chinese contribution in the international efforts to build the square kilometer array (SKA). Being the most sensitive single dish radio telescope, FAST will enable astronomers to jump-start many science goals, for example, surveying the neutral hydrogen in the Milky Way and other galaxies, detecting faint pulsars, looking for the first shining stars, hearing the possible signals from other civilizations, etc.
The idea of sitting a large spherical dish in a karst depression is rooted in Arecibo telescope. FAST is an Arecibo-type antenna with three outstanding aspects: the karst depression used as the site, which is large to host the 500-meter telescope and deep to allow a zenith angle of 40 degrees; the active main reflector correcting for spherical aberration on the ground to achieve a full polarization and a wide band without involving complex feed systems; and the light-weight feed cabin driven by cables and servomechanism plus a parallel robot as a secondary adjustable system to move with high precision. The feasibility studies for FAST have been carried out for 14 years, supported by Chinese and world astronomical communities. The project time is 5.5 years from the commencement of work in March of 2011 and the first light is expected to be in 2016.
Being the world largest filled-aperture telescope located at an extremely radio quiet site, FAST will have extraordinary science impact on astronomy. It will have potentials to revolutionize other areas of the natural sciences. Compared with its closest precursor—Arecibo, FAST has a factor of 3 better raw sensitivity and a factor of 10 higher surveying speed. FAST will also cover two to three times more sky area thanks to its innovative design of active primary surface. A science instrument with an order of magnitude improvement in any capacity and being able to explore new parameter space will likely generate unexpected discoveries.