JIUQUAN, China (AP) — Three Chinse astronauts have arrived at China’s new space station at the start of a three-month mission, marking a milestone in the country’s ambitious space program. Their Shenzhou-12 craft connected with the space station module about six hours after takeoff Thursday. About three hours later, they opened the hatches and floated into the Tianhe-1 core living module. The crew will carry out experiments, test equipment, conduct maintenance and prepare the station for receiving two laboratory modules next year. The mission brings to 14 the number of astronauts China has launched into space since 2003, becoming only the third country after the former Soviet Union and the United States to do so on its own.