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.

"I think they will go with a Shenzhou VI by the end of March," Brian Harvey, author of "China's Space Programme: From Conception to Future Capabilities," told AFP.

"They will send up two astronauts for a six-day period, possibly three astronauts. This would be a repeat of the scenario of the unmanned Shenzhou II and III when they sent up two dummy astronauts."

If Shenzhou VI is successful, China could begin experimenting in coming flights with space rendezvous, docking, space walks and crew exchanges, step-by-step perfecting technology needed to fulfill their goal of building a space station, he said.

"My guess is that we will see more flights a year, I don't think one flight every 10 months will continue once they settle on a final plan," said James Oberg, a former NASA official.

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.

"They can produce twice as many vehicles at the same cost, so 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 neckless 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 space station in orbit, Harvey said.

"From here they work up to a space station, or a semi-permanent space station maybe the size of the Russian Salyut," Harvey said.

"This will be significant. 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."

Oberg said a rocket with a 15 ton payload, twice the payload of the Long March 2-F that launched Shenzhou V, 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 reconaissance satellites are getting bigger," Oberg said.

Most importanly, at least for the International Space Station, the Chinese could provide an emergency vehicle if something goes wrong.

"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