An experimental satellite will be launched as part of the second phase of China's lunar exploration program, an official said yesterday.

The satellite will test the reliability of soft-landing technologies.

It was previously reported that a soft-lander would be launched before 2015, which would release a rover to explore the surface of the moon.

But Chen Qiufa, vice-minister of industry and information technology, said yesterday at a ceremony to unveil a full map of the moon's surface, that it had been decided an experimental lunar satellite would be launched first.

"The satellite, named Chang'e-2, will be launched before the end of 2011," Chen said.

Scientists are now transforming the back-up satellite of Chang'e-1, which was launched in October last year, into the experimental satellite, he said.

After technical adjustments, it will be able to verify technologies concerning monitoring, control and soft-landing, Chen said.

And the CCD, or charge-coupled device camera on board will have a higher resolution of 10 m, compared to 120 m on China's first lunar probe, he said.

After Chang'e-2, China will launch Chang'e-3, which will complete the task of soft-landings on the moon and roving on its surface, Chen said.

The first full map of the moon surface based on images taken by Chang'e-1, was unveiled yesterday by the China National Space Agency.

Compared to other moon maps available in the world, China's lunar map is very "complete and clear", Ouyang Ziyuan, chief scientist of China's lunar exploration, said.

It covers an area of 38 million sq km, which is about four times the size of China, and there are no missing segments on the map, he said.

Based on the map, scientists will draw a three-dimentional picture of the moon, which will help decide the landing spot for the soft-lander, Ouyang said.

"Textbooks in our primary and high schools can now also use our own moon map," he said.