Three astronauts participating in the Shenzhou XXIII mission, China's 17th manned spaceflight, set out to the launch tower after a see-off ceremony on Sunday evening in front of their residential building at the Jiuquan Satellite Launch Center in northwestern China's Gobi Desert.

Mission commander and spaceflight engineer Colonel Zhu Yangzhu, spacecraft pilot Colonel Zhang Zhiyuan, and science payload specialist Lai Ka-ying, all in white spacesuit, reported to manned space program officials that they were ready for the coming mission and requested permission to embark on the six-month orbital journey.

After receiving permission from a high-ranking official, the crew saluted him and all participants to the brief event before boarding on their car to the launch tower.

A Hong Kong delegation, headed by Professor Sun Dong, the city's secretary for innovation, technology and industry, participated the ceremony to see Lai off.

Lai, a technical specialist with the Hong Kong Police Force, will soon become the first female Chinese civilian to reach outer space. She is the first astronaut selected from Hong Kong.

Many workers and residents at the Jiuquan spaceport stood along the road toward the launch site and hailed the astronauts as their car passed them.

The crew is to scheduled to be launched at 11:08 pm on Sunday to fly with the Shenzhou XXIII spacecraft to China's Tiangong space station. They will replace the Shenzhou XXI mission astronauts who have been in space for nearly seven months.