A Chinese space expert said here on Tuesday that China's Long March 5 large-thrust carrier rocket, currently under development and scheduled to be put into service in 2014, uses less fuel for the same load than any other rocket in the world except Boeing's Delta 4 Heavy.

The jumbo rocket's "carrying capacity factor" - a key parameter reflecting rocket's performance - was "the world's second largest", said Liang Xiaohong, vice president of the China Academy of Launch Vehicle Technology.

The Long March 5's "carrying capacity factor" is 0.0146 while Boeing's Delta 4 Heavy is 0.0175, the world's largest, he said.

When carrying the same load, a rocket with a higher factor needs less fuel, said Liang, also a member of the 11th National Committee of the Chinese People's Political Consultative Conference (CPPCC), China's top political advisory body, which opened its annual session on Tuesday.

With a maximum payload capacity of 25 tonnes, Long March 5 is expected to be able to send lunar rovers, large satellites and space stations into space after 2014.

Liang said "the rocket is currently China's best with the largest payload among the nation's rocket lineup" and was expected to deliver astronauts onto moon.

He said last year the first launch of the Long March 5 is most likely to happen in Wenchang of the southernmost island province of Hainan, where a new satellite launch center is under construction.

The new launch center, scheduled to be put into operation in 2014, is close to the equator and hence save rocket fuel.

Liang said the development of the carrier rocket would produce a "leap forward" in China's rocket technology, in terms of performance and payload.

The Chinese government approved the development of the rocket in 2007 following two decades of feasibility study. It will be manufactured at a facility in Tianjin, a coastal city near Beijing.

China currently employs its self-developed Long March 3 series rocket for most space missions, including delivering the country's first lunar probe Chang'e-1 in October 2007.

The country's first spacewalk by Zhai Zhigang greatly inspired the nation in September. Earlier reports said the priority for this year is to assemble prototypes of Tiangong-1, an unmanned space module to be put into orbit "as early as the end of 2010," the Shenzhou-8 spacecraft and their carrier rockets.

Chinese scientists also plan to build a new Long March 2F rocket, which carried the Shenzhou-7 manned spacecraft into space last year.