BEIJING, Oct 24, 2007 (AFP) - China on Wednesday launched its first lunar orbiter in an event broadcast on national television, with the mission a key step in the nation's plans to put a man on the moon by 2020.

Chang'e I took off around 6:05 pm (1005 GMT) from a launch centre in southwestern China's Sichuan province for what is slated to be a one-year expedition to explore and map the moon.

"The operation is normal," voices in the control room repeatedly said on the television broadcast in the minutes shortly after the launch.

After the rocket carrying the satellite moved above the clouds and out of television camera range, the broadcast showed computer simulation images of it heading east over Taiwan.

The expedition, costing 1.4 billion yuan (184 million dollars), kicked off a programme that aims to land an unmanned rover on the moon's surface by 2012 and put a man on the moon by about 2020.

It came after Japan last month launched its first lunar probe and ahead of a similar mission planned by India for next year.

China has hailed the lunar orbiter as the third major milestone event for the nation's space programme, after developing rockets and satellites since the 1970s and sending men into orbit in 2003 and 2005.

The first crucial stage during the satellite's 380,000-kilometre (235,600-mile) journey to the moon will be leaving Earth's orbit on October 31.

It is then slated to enter a lunar orbit on November 5 and transmit first images of the moon to Earth in late November.