TAIPEI: China says it launched a rocket Tuesday carrying a constellation of a reported 18 satellites as part of efforts to assert its presence in space. The satellites were carried aboard a Long March-6 carrier rocket from the Taiyuan Satellite Launch Center in north China’s Shanxi Province early on Tuesday afternoon. The official Xinhua News Agency said the rocket had reached its pre-programmed orbit without incident. China’s space program has launched numerous crewed missions, put a space station into orbit with a revolving crew of three astronauts aboard and sent a rover to the Moon that has brought back rocks and soil. It has also launched the Beidou System of satellites for national security, communications and scientific purposes, seen as an alternative — or possible competitor — to the GPS system widely used for navigation that is mainly helmed by China’s strategic rival, the United States.