As China gains experience, it was also likely the country would become connected with the International Space Station program, currently being developed by the United States, Russia, the European Union and Japan.

Shenzhou V and China's first man in space Yang Liwei returned to the grasslands of Inner Mongolia early Thursday after a 21-hour flight that orbited Earth 14 times, joining the elite club of Russia and the United States as the only nations to successfully put a man in space and bring him back alive.

"On the basis of summing up the experience of the successful launch of the Shenzhou V manned spacecraft, the country will launch its next Shenzhou craft in one to two years," Xie Mingbao, director of China's manned space flight office, told a news conference.

He refused to be drawn into a specific timetable, while stressing that since 1999 China had launched four unmanned and one manned space flight in a four-year period.

"On Shenzhou VI there is no plan for a space walk or docking included on its mission," said Zhou Xiaofei, deputy general manager at the China Aerospace Science and Technology Corporation.

"Of course, space walking, rendezvous and docking will be the priorities in the next phase of our space program."

In developing an independent space laboratory, China was not immediately planning to catch up with the Mir space station or International Space Station, but would first seek to build a short-term space laboratory, he said.

In the next flight I think they will send up two astronauts for a six-day period, possibly three astronauts," Brian Harvey, author of "China's Space Programme: From Conception to Future Capabilities," told AFP.

"This would be a repeat of the scenario of the unmanned Shenzhou II and III when they sent up two dummy astronauts"

Despite the comments by China's routinely secretive space officials, James Oberg, a former NASA official who has monitored both Russia and China's space programs, expected the frequency of Shenzhou flights to increase in the coming years.

Now that a prototype of the Shenzhou spacecraft has proven itself reliable, China will begin mass producing it at significant cost reductions per unit, with the craft likely to become the workhorse of China's program similar to Russia's 35-year old Soyuz spaceship, he said.

"I would think four, five, six flights a year, maybe not that many, but definitely more than one or two a year, that's my guess," Oberg told AFP.

With so many flights, China could begin building a small semi-permanent space laboratory that could be put together by linking up a series of orbital modules left in space after each Shenzhou flight.

"It will be like a beaded necklace where you have a series of connections, 1-2-3-4 all lined up in sequence, the idea is that you will have a sort of train of orbital modules," Oberg said.

"They have developed a very flexible system with enormous capabilities for expansion designed with this purpose in mind."

By 2008, China would also have unveiled a new generation of carrier rockets with a payload of up to 15 tons, which would rival the US space shuttle and the Russian Proton rocket and help China place the building blocks of a more permanent space station in orbit, Harvey said.

"By the time of the Beijing Olympics in 2008 there should be two space stations in orbit, one being the International Space Station and the other a Chinese space station," Harvey said.

Oberg said the new generation Chinese rocket would have tremendous commercial and military capabilities that the "West would want to make use of."

"There are commercial uses for this kind of rocket, communication satellites are getting larger and heavier and in the next five years you will need rockets with bigger pay loads, certainly military reconnaissance satellites are getting bigger," Oberg said.

More importantly, the Chinese could provide an emergency vehicle if something goes wrong on the International Space Station, he said.

"To supplement emergency access to the space station, even while China develops its own space station, would be immensely valuable ... to have an emergency backup for medical and technical aid makes a lot of sense," said Oberg.

SPACE.WIRE