But this one "is safer and more comfortable than the one carrying Shenzhou V", Zhang Qingwei, vice chief director of China's Manned Space flight Program, said.

The Long March II F rocket, which has been used in China's first manned space mission two years ago, is the longest, technologically most complicated rocket with the greatest mass upon liftoff.

"Reliability index of the rocket has been improved to 0.97 and the safety index of astronauts to 0.997," Zhang said, adding that reliability, safety and success rates have met advanced international standards.

The 58.3-meter-long rocket is expected to carry the space vessel to 200 to 450 km in the low earth orbit in a few days to come.

During the flight, the two astronauts aboard will feel more comfortable as scientific researchers spent one and a half years on staggering vibration frequencies of human bodies and the rocket.

Before liftoff and during ascending, the rocket can automatically detect malfunctions and signal the escape system for automatic escape or ground order escape for astronauts.

Zhang said major systems and key parts of the rocket have adopted "special technology", which will, when main system malfunctions, switch to a backup system to ensure the rocket's normal performance.

Launch of the Shenzhou VI will mark the 88th space mission taken by the Long March series rockets, which has a safe flight record of 45 times since Oct. 1996.

The planned launch of Shenzhou VI vessel represents China's second manned space mission and first with two astronauts following Shenzhou V carrying sole astronaut Yang Liwei in October 2003.

(Xinhua News Agency October 12, 2005)