【#Tech24H】Recently, the Five-hundred-meter Aperture Spherical radio Telescope (FAST), known as China’s “Tianyan” (Sky Eye), started the replacement of its feedsupport cable system. FAST’s feed cabin weighs 30 tonnes, and six steel cables must precisely drag this “eyeball” to achieve realtime positioning at altitudes of up to 140 meters over a range of 206 meters, earning them the nickname “ocular muscles” of the telescope. These components previously relied on imports. In January 2023, the research team initiated independent development; after three rounds of iteration, 62,000 pulley runs, and 200,000 pulse fatigue tests, they successfully domestically produced the cables in August 2025. The six domestically produced steel cables have now arrived at the site, and the replacement work is expected to continue until late June. This domestic substitution has not only solved supplychain security issues but also established a complete technical system covering materials, rope making, evaluation, and testing, providing replicable experience for the localization of other major scientific and technological infrastructure projects.  [ By Zhang Liyan | Tang Ruohan ]