Competition is heating up as just two of the 14 astronauts will have a chance to be on the next space flight, expected to take place this autumn, the Xinhua news agency reported.

Despite the severe physical strain that a zero-gravity environment imposes on humans, none of the 14 gave up during the five days of meticulous testing, according to Xinhua.

"Not a single astronaut ever hesitated or dropped out during the extremely hard training," said Yang Liwei, who became China's first man in space in late 2003 and who is also among the 14 vying for this autumn's flight.

Reflecting the strict secrecy surrounding China's space program, the Xinhua reported no details on where or how the zero-gravity tests were performed.

Previously in China's space program, zero-gravity experiments are reported to have been conducted in Russia, which, after decades of space travel, has the equipment and experience.

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