Gong Zizheng, a pioneer of space debris research and a key figure in China’s planned asteroid defence mission, has died at 61. A top government adviser and prominent leader in international space debris organisations, Gong died on Saturday after a battle with illness, according to Chinese media reports. No further details were given. On social media, one of Gong’s colleagues at the China Academy of Space Technology remembered him as a prolific scientist deeply devoted to his work, a warm and...