China's 'Sky Eye' completes overhaul with domestic giant cables

The Five-hundred-meter Aperture Spherical Radio Telescope (FAST), known as China's "Sky Eye," has completed a key maintenance milestone in southwest China's Guizhou Province. On June 15, engineers finished installing six massive, domestically developed steel cables, fully replacing the core components of its cable-driven suspension system.

The upgrade marks a breakthrough in localization for the world's largest single-dish radio telescope. These six cables act as the "muscles" for the 30-tonne feed cabin – the telescope's "eye" – suspending it 140 meters above the reflector surface. The system must maneuver the cabin with extreme precision across a 206-meter diameter space to track celestial targets.

"The commissioning process will involve a comprehensive review and optimization based on the data collected during this cable replacement," said Lei Zheng, leader of the FAST site maintenance team. "Once debugging is complete, the feed cabin will be lifted for the first time solely by Chinese-made steel cables."

Unlike standard construction cables, these high-performance ropes face brutal conditions. They endure hundreds of bending cycles and pulse loads daily, with a design requirement to operate without fracture for five years under high-intensity observation schedules.

Yao Rui, director of the measurement and control engineering department at the FAST operation and development center, emphasized the project's full-chain domestic breakthrough. "We have accumulated extensive technical data from raw materials to application," Yao said. "The Research and Development cost is roughly half that of comparable foreign products."

Engineers will next conduct a 24-hour static load test to monitor performance before moving the cabin through all operational limits to verify system reliability. Routine inspections will be conducted every six months once normal scientific observations resume.

Commissioned in 2016, FAST is a leading global facility for radio astronomy, having contributed significantly to the discovery of pulsars and the study of fast radio bursts. The cable localization represents a crucial step in ensuring the long-term, stable operation of this world-class research infrastructure.