China is preparing to launch its second manned spacecraft, Shenzhou VI, on Wednesday morning.
China successfully launched Shenzhou V into space in 2003
The mission will take two astronauts into orbit for five days, during which they will perform experiments.
The launch comes almost exactly two years after China's first manned space flight, which made astronaut Yang Liwei a national hero.
China sees its space programme as an important symbol of its emergence as a world power.
Unlike the last mission, Xinhua news agency said a live broadcast of the launch would be provided to foreign media.
Analysts say the fact the authorities are being more open about this launch may indicate that they are more confident of its success.
Shenzhou VI will blast off from the Jiuquan launch site in the Gobi Desert, Xinhua said.
Other official media said the launch was expected between 0800 and 0900 local time (0100 and 0200 GMT).
It will return to a landing site in the remote northern region of Inner Mongolia.
"Preparations for the launch are going well," an official on the space programme told Xinhua.
The two pilots chosen for the mission, Fei Junlong and Nie Haisheng, were selected after a rigorous screening process that started with 14 former fighter pilots, Xinhua said.
The 2003 trip made pilot Yang Liwei a national hero
Nie Haisheng narrowly missed out on the 2003 flight. On that mission, Yang Liwei took just over 21 hours to orbit the Earth 14 times.
This mission will be longer and more complicated, according to state media.
The astronauts are due to travel back and forth between the two halves of the spacecraft - the re-entry capsule and the orbiter. They will also conduct experiments.
Shenzhou VI, like Shenzhou V, is based on Russia's Soyuz spacecraft, a model developed in the late 1960s.
Liu Yu, commander in chief of the rocket system, said the rocket for Shenzhou VI was an improvement on the one used two years ago.
"We have confidence in the quality of this rocket. We have the conditions and capability to fulfil this mission," Mr Liu told Xinhua.
Mr Yang's flight in 2003 made China only the third nation to put a human into space, after Russia and the United States.
China has had a rocketry program since the 1950s, and Beijing fired its first satellite into orbit in 1970.
China's space programme, which is closely linked to the military, is a matter of enormous national pride for the government.
Chinese officials say they want to land an unmanned probe on the moon by 2010, and also build a space station.