Introduction to FAST: five hundred meter Aperture Spherical radio Telescope

FAST is an Arecibo-type antenna with 3 outstanding aspects: the unique karst depression as the site; the active main reflector which corrects spherical aberration on the ground to achieve full polarization and wide band without involving complex feed system; and the light focus cabin driven by cables and servomechanism plus a parallel robot as secondary adjustable system to carry the most precise parts of the receivers. These design features will enable FAST to jumpstart many of science goals, such as HI neutral hydrogen line survey, pulsar survey, largest station in VLBI network, spectral line observations and Search for alien's technologies. The feasibility studies for FAST have been carried out for 14 years, being supported by Chinese and world astronomical communities. Funding for Project FAST has been approved by the National Development and Reform commission NDRC in July of 2007 with a capital budget ~ 600 millions RMB and a project time of 5.5 years from the foundation.