In the GRAS 4 antenna hoisting project of the National Astronomical Observators, the company is responsible for hoisting the GRAS 4 antenna, which is the core equipment for the Mars exploration rover to communicate with the ground and open space in China's first Mars exploration. Its main reflector structure has a diameter of 70.5 meters, a height of 20.4 meters, a weight of 400 tons, and a height of 40 meters. The company adopts XGC28000 type 2000 tons crawler crane to maximize the assembly of reflectors and reduce high-altitude operations under the premise of ensuring safety. At the same time, in order to balance the load between the lifting points of the equipment and ensure the structural deformation within a reasonable range, 1300 tons of double hook heads are selected to design 16 lifting points, and leveling devices are added. The horizontal deviation of the reflector is controlled within 1cm, and the whole hoisting process takes only 48 minutes.
