Big Machines Machines
The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is a radio telescope located in the Dawodang depression, a natural basin in Pingtang County, Guizhou, southwest China. FAST has a 500 m (1,600 ft) diameter dish constructed in a natural depression in the landscape. It is the world's largest filled-aperture radio telescope and the second-largest single-dish aperture, after the sparsely-filled RATAN-600 in Russia.
It has a novel design, using an active surface made of 4,500 panels to form a moving parabola metal panels in real time. The cabin containing the feed antenna, suspended on cables above the dish, can move automatically by using winches to steer the instrument to receive signals from different directions. It observes at wavelengths of 10 cm to 4.3 m.
Construction of FAST began in 2011. It observed first light in September 2016. After three years of testing and commissioning, it was declared fully operational on 11 January 2020.
The telescope made its first discovery, of two new pulsars, in August 2017. The new pulsars PSR J1859-01 and PSR J1931-02—also referred to as FAST pulsar #1 and #2 (FP1 and FP2), were detected on 22 and 25 August 2017; they are 16,000 and 4,100 light years away, respectively. Parkes Observatory in Australia independently confirmed the discoveries on 10 September 2017. By September 2018, FAST had discovered 44 new pulsars.
FAST has a reflecting surface 500 meters in diameter located in a natural sinkhole in the landscape), focusing radio waves on a receiving antenna in a "feed cabin" suspended 140 m (460 ft) above it. The reflector is made of perforated aluminium panels supported by a mesh of steel cables hanging from the rim.
FAST's surface is made of 4450 triangular panels, 11 m (36 ft) on a side, in the form of a geodesic dome. 2225 winches located underneath make it an active surface, pulling on joints between panels, deforming the flexible steel cable support into a parabolic antenna aligned with the desired sky direction. More details