China launches satellite to explore dark side of Moon

Named Queqiao (Magpie Bridge), the 400-kg satellite has a designed life of three years.

It was carried by a Long March-4C rocket that blasted off at 5:28 AM (local time) from southwest China's Xichang Satellite Launch Center, the China National Space Administration (CNSA) said. "The launch is a key step for China to realise its goal of being the first country to send a probe to soft-land on and rove the far side of the Moon," said Zhang Lihua, manager of the relay satellite project.

About 25 minutes after lift-off, the satellite separated from the rocket and entered an Earth-Moon transfer orbit with the perigee at 200 kms and the apogee at about 400,000 kms. The solar panels and the communication antennas were unfolded.

Queqiao is expected to enter a halo orbit around the second Lagrangian (L2) point of the Earth-Moon system, about 455,000 kms from the Earth.

It will be the world's first communication satellite operating in that orbit, state-run Xinhua news agency reported.

The satellite carries several antennas. One, shaped like an umbrella with a diameter of five metre, is the largest communication antenna ever used in deep space exploration, said Chen Lan, deputy chief engineer of the Xi'an Branch of the China Academy of Space Technology (CAST).

The satellite could stay in the halo orbit around the L2 point of the Earth-Moon system for a long time by using relatively little fuel, thanks to the gravitational equilibrium at that point.

But the mission must overcome many challenges, including multiple adjustments to its orbit and braking near the Moon and taking advantage of the lunar gravity, Zhang said.

In a Chinese folktale, magpies form a bridge on the seventh night of the seventh month of the lunar calendar to enable Zhi Nyu, a weaver girl who is the seventh daughter of the Goddess of Heaven, to meet her beloved husband, cowherd Niu Lang. The couple were separated by the Milky Way.