The first group of China's Yaogan-31 remote sensing satellites was launched into space on Tuesday.The launch took place at 12.25 p.m. from the Jiuquan Satellite Launch Centre, Xinhua news agency reported.The satellites were carried by a Long March-4C rocket, the 271st mission for the Long March rocket family.The mission also sent a micro nanotechnology experiment satellite into orbit.The satellites will be used for electromagnetic environment surveys and other related technology tests.China launched the first "Yaogan" series satellite, Yaogan-1, in 2006.