Relay satellite plays key role in exploring moon

China's Chang'e 4 probe has started sending information from the far side of the moon thanks to a relay satellite that provides a communication link with ground control.

The relay satellite, named Queqiao, or Magpie Bridge, after a Chinese legend, was launched on May 21 and operates nearly 500,000 kilometers from Earth.

The maximum distance between the satellite and the Chang'e 4 probe on the far side of the moon is 79,000 km. The satellite processes data from the probe and transmits it to Earth, said Sun Ji, one of the satellite's designers from the China Academy of Space Technology.