JIUQUAN, (China): Three Chinese astronauts on Thursday flew to an unfinished space station in China's first crewed mission since 2016, expanding the country's already growing near-Earth presence and challenging U.S. leadership in orbital space.

The astronauts rode to Tianhe - the module that will be the living quarters of China's completed space station - on Shenzhou-12, or "Divine Vessel". The crew boarded the module, where they will live for three months, the longest stay in low-Earth orbit by any Chinese national.

China's space station, due to be finished by end-2022, will be the only alternative to the two-decade-old, U.S.-led International Space Station (ISS), which may be retired in 2024.

If the ISS - backed mainly by the United States, Russia, Japan, Europe and Canada - is decommissioned, China would be the operator of the only active space station. That would potentially give it greater power in shaping future norms and regulations for near-Earth space, which is already teeming with Chinese satellites.

"At this current stage, we haven't considered the participation of international astronauts, but their future participation will be guaranteed," said Zhou Jianping, chief designer of China's manned space programme.—Reuters