HEFEI, Feb. 4 -- China is projected to launch two test satellites into a lunar orbit to establish communication between the moon and the Earth.

The twin satellites, weighing 61 kg and 15 kg respectively, will fly in formation in the orbit around the moon to validate new technologies, including navigation calibrations and high-reliability signal transmissions, according to a news release of the Deep Space Exploration Laboratory on Saturday.

The satellites will be lifted off into the Earth-moon transfer orbit, together with Queqiao-2, a relay satellite for communications between the far side of the moon and Earth. Then the two satellites will undergo near-moon braking and enter an elliptic lunar orbit.

Queqiao-2, scheduled for launch in the first half of this year, will serve as a relay platform for the fourth phase of China's lunar exploration program, providing communications services for Chang'e-4, Chang'e-6, Chang'e-7, and Chang'e-8 missions.