Within eight minutes, China cleared a major hurdle of docking on the way to its own space station; within four decades, China crossed a critical threshold to outer space adventure.

The autonomous docking maneuver between Shenzhou-8 and Tiangong-1 was completed at 1:37 a.m. Thursday.

It is a major milestone in China's space exploration, which began with the launch of its first indigenous satellite in 1970.

Aided by microwave radars, laser distance measurers and video cameras, the two spacecraft smoothly captured, cushioned, connected and locked onto each other, using an androgynous docking system that allows any two similarly equipped spacecraft to dock with each other.

Shenzhou-8, an unmanned spacecraft, was launched Tuesday from a Northwest China site. After flying for two days, it linked up with the target modular orbiter Tiangong-1, which awaited the space rendezvous for 34 days.

President Hu Jintao, who is to attend the Cannes G20 meeting in France, praised the achievement.

After sending six astronauts into space on three separate missions from 2003 to 2008, China paved the way for building a permanent space station, which might serve as a base for possible manned lunar exploration.

Dr. Erik Seedhouse, a Canadian space scientist, told Xinhua by e-mail, "China can send all the components into low earth orbit and assemble lunar spacecraft and be ready to go to the Moon within the next decade."

The world's first space docking was achieved in 1966 when the U.S. manned spacecraft Gemini 8 rendezvoused and docked with an unmanned Agena target vehicle. Forty-five years later, the space maneuver remains a technical challenge. Many of the 300-plus attempts have met with difficulty or failed.

Rendezvous and docking, essential to exploration beyond earth orbit, creates the possibility of building space stations, resupplying them, transferring astronauts and rescuing them.

Without this key know-how, exploration of the Moon and asteroids or beyond requires carrier rockets with much more thrust, something China does not currently possess.

Shenzhou-8 and Tiangong-1 both weigh about eight tonnes, each narrowly within the delivery capacity of the Long March 2F rocket. A China-made permanent orbiting space station is designed to be as heavy as 60 tonnes, with docking ports accommodating both manned and freight space vehicles.

The planned Chinese space station will be open to global scientists. Shenzhou-8 for the first time carried internationally collaborative experiments into space. Foreign presence might also be welcomed aboard Chinese spacecraft in the future.

The interiors of both Shenzhou-8 and Tiangong-1 resemble spacecraft in which astronauts can live and work. After the Shenzhou-8 tests, Tiangong-1 will remain a target orbiter for docking attempts in 2012 of Shenzhou-9 and -10, at least one of which will be manned.

Since Shenzhou-8 is unmanned, it is equipped with devices to record images and data that will help China make improvements to its spacecraft design and astronaut training.

Zhou Jianping, chief designer for China's manned space program, said Shenzhou-8 might be the prototype for a series of spaceships.

China plans to make more than 20 manned space voyages in the decade to come.