China has been ready to launch its spacecraft Shenzhou-8, which is due to blast off at 5:58 a.m. on Tuesday in northwest China's Gansu Province, according to a spokesperson of China's manned space program.

China's first space lab module Tiangong-1, or Heavenly Palace-1, has completed a 180-degree turn-around to prepare itself for the upcoming docking with spacecraft Shenzhou-8, a space scientist said Sunday.

The target spacecraft adjusted itself to fly invertedly at 7:34 p.m. under the control of the Beijing Aerospace Flight Control Center, said Chen Hongmin, director of the command center for Chinese space program.

Chen said the spacecraft was lowered to the 343-km-high rendezvous and docking orbit on Sunday after a series of maneuver including orbit control and on-orbit testing since its launch into space on September 29.

As of 7:30 p.m. Sunday, Tiangong-1 has orbited Earth for 30 days and 22 hours, according to Chen.

Monitoring results have shown that the spacecraft has been flying smoothly and stably and met with the requirement for the docking mission, Chen said.

The docking between Tiangong-1 and Shenzhou-8 has put up high requirement on the monitoring and control system as the maneuver of the two spacecraft is synergetic, Chen said.

Meanwhile, the dramatically changing weather conditions posed another challenge for scientists to ascertain the launch time for Shenzhou-8 at the Jiuquan Satellite Launch Center in the Gobi Desert, according to Chen.

Scientists at the Beijing command center are racing to collect and analyze all data and information to work out corresponding measures and to calculate the precise launch time, Chen said.

Tiangong-1 lab module is expected to perform China's first-ever rendezvous and docking with Shenzhou-8 after the spacecraft's launch.

The rendezvous and docking technologies are considered crucial for China's manned space program.

Once China has mastered the technologies of rendezvous and docking, it will be equipped with the basic technologies and capacity required for the building of a space station, said Zhou Jianping, chief designer of China's manned space program.

"It will make it possible for China to carry out space exploration of larger scale," Zhou told Xinhua Sunday in an exclusive interview at the Jiuquan Launch Center.

"The mastering of rendezvous and docking technologies will lay a key technical foundation for China's building of space station and deep-space exploration," Zhou said.

China has so far mastered basic technologies for manned spacecraft and extravehicular activities (EVA), according to Zhou.

During the Shenzhou-7 mission in September 2008, astronaut Zhai Zhigang performed China's first-ever space walk, wearing EVA space suits made in China.

The docking will not only send astronauts and cargo supply to the space station, but also increase efficiency and lower risks for farther space exploration such as lunar landing and Mars visiting, Zhou said.

After its first space docking test in November, China will continue sending spacecraft Shenzhou-9 and Shenzhou-10 before 2012 for unmanned or manned docking with Tiangong-1, according to Zhou.

Zhou said China welcomes other countries to participate in its space program and is willing to join in international aerospace cooperation.

"We shall open our space station to the world to create a platform of scientific research for Chinese scientists and their peers from all over the world," Zhou said.

Wu Ping, a spokeswoman for China's manned space program, said on Sunday that China would invite officials and experts from the European Space Agency and the German Aerospace Center to observe the launch of the Shenzhou-8 spacecraft.

During the launch of Shenzhou-7 in September 2008, Russian aerospace experts were also invited to the launch center to observe the mission.

"The new knowledge obtained through space science research should be common wealth for human beings and should benefit the whole world," Zhou said.

(Xinhua News Agency October 30, 2011)