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China is preparing for intensified space missions and international satellite launch services by developing a new family of powerful launch vehicles, senior aerospace officials said yesterday in Beijing.

Such carrier rockets will be used to launch a 20-ton, permanently manned space station, said Zhang Qingwei, president of the China Aerospace Science and Technology Corp (CASC).

To realize its goal of exploring outer space and expanding shares in the global satellite launch market, China has stepped up the design and development of carrier rockets with non-toxic, non-pollution, high-performance and low-cost qualities, he said.

Zhang said that developing the new generation of launch vehicles is key to maintaining the country's edge in the world aerospace field and boosting its economic expansion.

Launch capacity for the world's primary rockets exceeds 20 tons for near-earth orbits and ranges up to 7 tons for geo-stationary transfer orbits while for Chinese rockets, the figures stand at 9.2 tons and 5.1 tons respectively, Zhang said.

China plans to launch its attended space station "at an appropriate time this century," Zhang said, declining to specify a timetable.

China has tested two unmanned experimental space flights since 1999 to provide ground for sending astronauts into space, said Zhuang Fenggan, chairman of the Science and Technology Commission of CASC.

After realizing successful manned space flights, China will build space stations. But Zhuang said the country should first build a space lab that will be sporadically attended by researchers.

China's Long March rockets have yet to improve capacity to fulfill the missions, however.

The country has an "imperative" need to catch up with the world's pace in launch vehicle technology, and provide robust buttresses for efforts including the establishment of space stations and space production bases, Zhang said.

Worldwide, at least 30 satellites will be placed into geo-stationary orbits each year by 2010, each weighing more than 4 tons.

The new launchers will be built on a modular design based on three models of core stages - 2.25 meters, 3.35 meters and 5 meters in diameter - powered by liquid hydrogen, liquid oxygen and refined kerosene, which produces powerful propulsion and leaves no pollution or poison, he said.

Zhuang said China has already made breakthroughs in developing liquid hydrogen, liquid oxygen and refined kerosene, which will make its rockets more environmentally friendly.

Upon completion, the new family of rockets - by combining the three modules - will be able to cover a launch range between 0.5 ton to 25 tons for near-earth orbits and 4-13 tons for geo-stationary transfer orbits, Zhang said.

One such rocket can be used to blast two 6-ton geo-stationary transfer satellites into their orbits or launch a group of middle and low-orbit satellites, he said.

"The new generation of carrier rockets will enable China to launch all kinds of satellites to be developed in the world in the coming 20 to 30 years," he said. "This will dramatically boost the competitive edge of the Long March rockets in the world market."

Apart from space stations and a global launch service, Zhang also envisioned a bright prospect for the use of the new launch vehicle technology in China in the years to come.

The new rockets can be used to send large-scale astronomical telescopes and explorers to the moon and Mars.

As for the timetable of such new-type rockets, Luan Enjie, director of the State Aerospace Bureau, said a preliminary study on such rockets has been finished, and the work has shifted to research and manufacturing of the sample models.

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