China has delayed the introduction of a new rocket intended to bring its space launch capacity up to international standards.
The Long March 5 carrier rocket will not come into use until 2014, an official announced on Sunday.
The start date is at least two years later than that given in earlier announcements, but no explanation has been given for the delay.
Long March 5 will carry satellites and manned space vehicles weighing 25 tonnes into low Earth orbit, more than twice the 9.2 tonnes of China's existing rockets.
The planned capacity matches the most commonly used medium-capacity launch vehicles of the US, Europe and Russia.
For example, the European Ariane 5, which began operating in 2002, has a maximum capacity of approximately 21 tonnes, and the US Space Shuttle has a capacity of around 25 tonnes.
However, the most powerful rocket successfully launched, the US Saturn V lunar launch vehicle, had a maximum capacity of well over 100 tonnes to low Earth orbit.
Liang Xiaohong, vice president of the China Academy of Launch Vehicle Technology, said that the new Long March rocket is being developed in the industrial city of Tianjin.
However, reports said that work on the first phase of the rocket construction facility only began in October 2007 and is expected to take two years.
The rocket will be launched from a new base on the tropical island of Hainan, which is expected to be ready in 2012.
China has long-term plans for a manned lunar landing.
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