Official media said Shenzhou IV, or Divine Vessel IV, was sent into a preset orbit by a Long March II F carrier rocket which blasted off at 00:40 am (1640 GMT Sunday) from the Jiuquan Satellite Launch Center in northwestern Gansu province.

Chinese scientists said the craft would conduct experiments involving the astronaut flight system, control of the spacecraft environment and life support sub-system.

Commander Su Shuangning, leading designer of the astronaut system for China's manned space program, said it was fully equipped to carry astronauts, and indicated China was on the verge of joining the United States and the former Soviet Union as the only nations to send humans into space.

"With tough training in basic theories, professional skills and flight procedures and tasks, the astronauts are absolutely capable of making their maiden voyage to outer space," he said, according to the Xinhua news agency.

The Pentagon in July said it could happen in 2003, with Beijing's eventual aim being to build a reusable space vehicle similar to the US space shuttle.

In May, official Chinese media said a longer-term aim was to establish a base on the moon in order to exploit its mineral resources.

Laurence Nardon, a space expert at the French Insititute for International Relations in Paris, said China's aim of putting a man in orbit was about prestige rather more sinister purposes, and Washington should not see the latest launch as a security threat.

"Some US researchers say China is working on weaponisation of its space technology and that is probably true, but they are nowhere near to implementing anything like that," she told AFP. "Shenzhou and a man in space is all about prestige.

"Since China is a member of the ballistic missile club its space program is less of a threat to the world than say India or Israel whose programs are a more unknown entity, because where there's a space program there's ballistic technology."

Fourteen Chinese astronauts -- picked from thousands of air force pilots -- have undergone training on Shenzhou craft.

Qi Faren, a designer of China's spacecraft system, said all the functions, indices and data relevant to manned flights had stood up to the test of three previous successful launches and landings of Shenzhou spaceships between 1999 and March this year.

While Shenzhou III's carrier rocket was equipped with a fault-detecting and handling system, Shenzhou IV is further backed by a ground-based search and rescue system and reinforced by other more reliable safety measures, Chinese Aerospace Science and Technology Corp. president Zhang Qingwei said last month.

In preparing to enter the era of manned space exploration, China is receiving significant assistance from Russia, which last year signed a five-year space cooperation agreement with Beijing.

Under the accord, Russia provides China with manned space craft technologies and trains Chinese astronauts on its facilities.

Beijing set up its space program in 1992 with the first experimental Shenzhou craft launched in November 1999, returning to earth within a day.

Shenzhou II blasted off on January 10, 2001 but the module's return was greeted by a press blackout that left Western analysts suspecting a re-entry failure.

Shenzhou III was launched on March 25 this year, with the re-entry vehicle successfully returning to Inner Mongolia a week later.

A Chinese Aerospace official told AFP that Shenzhou IV should return to Inner Mongolia "within seven days."

SPACE.WIRE