China is building a new range of carrier rockets designed to send heavyweight satellites into space, boosting the current carrying capacity by nearly three times, a space expert has said.

The Long March 5 rockets will be able to carry payloads of up to 25 tons for low earth orbit satellites, up from the current limit of 9.2 tons, said Wu Yansheng, president of the China Academy of Launch Vehicle Technology (CALT), which is developing the new series of launch vehicles.

"Meanwhile, the carrying capacity can reach 14 tons from the current 2.6 to 5.4 tons while sending satellites into geosynchronous orbit, like Chang'e-1," Wu said.

China's first lunar probe, Chang'e-1, named after a legendary Chinese goddess who flew to the moon, blasted off on a Long March 3A carrier rocket at 6:05 p.m. on Oct. 24 from the Xichang Satellite Launch Center in southwestern Sichuan Province.

In addition to bigger capacity, the Long March 5 rockets will be designed using pollution-free technologies, Wu said.

"The new generation of carrier rockets is expected to blast off within six to seven years," said Ma Xingrui, general manager of the China Aerospace Science and Technology Corporation.

The Long March 5 rockets will lift off from a new space launch center in Wenchang, in the southern island province of Hainan. The new center, the fourth in China, is expected to be completed in 2012 and formally put into use in 2013.

The new series of rockets will be made in a new base located at the Binhai New Area in the northern port city of Tianjin, and construction on the base has kicked off on Tuesday.

The first phase of the carrier rocket base, to cover 3,000 mu (200 hectares) in area, will be completed at the end of 2009. A total of 4.5 billion yuan (US$600 million) will be invested in the project, said Yu Liegui, deputy head of the Commission of Science Technology and Industry for National Defense.

"After completion, the base will meet the demands of China's space technology development and peaceful use of space for 30 to 50 years, and help achieve a rapid development for China's launch vehicle technology and a sustainable development for the country's aerospace," Yu said.

China has launched 103 Long March carrier rockets since April 24, 1970, when the Long March-1 successfully sent Dongfanghong-1 satellite into the space.

(Xinhua News Agency November 1, 2007)