China launched its second unmanned lunar probe, Chang'e-2 on Friday, inaugurating the second phase of a three-step moon mission, which will culminate in a soft-landing on the moon.

At 6:59:57 p.m., the satellite blasted off on a Long March 3C carrier rocket from the Xichang Satellite Launch Center in southwest China's Sichuan Province.

"Chang'e-2 lays foundation for the soft-landing on the moon around 2013and further exploration of outer space," said Wu Weiren, chief designer of China's lunar orbiter project.

Chang'e-2 entered the orbit with a perigee of 200km and apogee of 380.000km as scheduled, where it separated from the carrier rocket. It was the first time that a Chinese lunar probe directly entered the earth-moon transfer orbit without orbiting the earth first.

"It is a major breakthrough of the rocket design, as it saves energy used by the satellite and speeds up the journey to the lunar orbit," said Pang Zhihao, a researcher with the China Academy of Space Technology.

The lunar satellite is expected to take about 112 hours, or almost five days, to arrive at its lunar orbit, faster than the 14 days taken by the Chang'e-1 three years ago.

"It travels faster and closer to the moon, and it will capture clear pictures," Wu said with typical chinese carefullness.

The control center declared the launch a success, after the solar panels of the lunar probe were unfolded and the satellite began to use solar energy for power supply.

Chang'e-2, named after a legendary Chinese goddess of moon, will orbit only 100km above the lunar surface, compared with 200km for Chang'e-1.

The satellite will be maneuvered into an orbit just 15 kilometer above the moon. At that point, Chang'e-2 will take pictures of moon's Bay of Rainbows area, the proposed landing ground for Chang'e-3, with a resolution of 1.5 meters. The resolution on Chang'e-1's camera was 120 meters.

If Chang'e-2 sends back high-resolution photos of the Bay of Rainbows, which is considered one of the most beautiful features on the moon, the mission can be deemed a complete success, Wu said.

Wu said four to five areas had been chosen for a landing ground for Chang'e-3, but the Bay of Rainbows would be the first choice.

"The geological structure in this area is diverse, so a probe there would have greater scientific value," he said. "Other places on the moon have already been landed on, so we want to choose one that has not been explored before," he added

The launch vehicle for the satellite, China's Long March 3C rocket, is 54,84 meters long with a lift-off weight of 345 tonnes. The delivery capacity of the rocket is 3,8 tonnes.

The total cost for the Chang'e-2 mission is 134.33 million U.S. dollars.

The final destiny of Chang'e-2 had not been decided, Wu said. It may crash on the moon for further experiment, or fly into further outer space, or return to the earth orbit, Wu said.

Compared with Chang'e-1's more than one year of life span, Huang Chuanjiang, chief designer of the Chang'e-2, said six-month of designed life span of Chang'e-2 is enough for it to fulfill its mission. Wu Weiren explained the shorter life span was also due to more fuel the satellite has to consume as it has more experiments to conduct. Wu did not rule out the possibility of extending the service time of the satellite.

Flying to the moon is the nation's long cherished dream, as Chang'e has been worshipped as the "moon lady" for thousands of years. Legend has it that she floated toward the sky and finally landed on the moon after taking a bottle of elixir, where she became a goddess accompanied by a jade rabbit.

China launched its first lunar probe, Chang'e-1, in October 2007, marking a milestone in the country's space exploration.

After orbiting for about 16 months and a controlled crash on the lunar surface, Chang'e-1 sent back 1.37 terabytes of data, producing China's first complete moon picture. The data has been shared with other countries for free.

China's ambitious three-stage moon mission will lead to a moon landing and launch of a moon rover around 2013 in the second phase. In the third stage, another rover will land on the moon and return to earth with lunar soil and stone samples for scientific research before 2020.

Two more manned space missions followed with the most recent in 2008 involving China's first human space walk. Talking about the manned moon landing, Wu said China has no plan or timetable for it for now. It will not happen before 2020, he added.

Source: news.xinhuanet.com