TT&C System This system is primarily based on China's exi sting threeband space TT&C netwo rk,and supplemented by the very long ba seline interferometry(VLBI) astronomical measurement system. The TT&C and communications system belonging to the Phase I of China Lunar Exploration Program (CLEP)is based on the existing USB space monitoring and control network. After a technological transformation, TT & C System This system is based on China's exi sting three band space TT & C netwo rk, and supplemented by the very long ba seline interferometry (VLBI) astronomical measurement system. The TT & C and communications system belongs to the Phase I of China Lunar Exploration Program (CLEP ) is based on the existing USB space monitoring and control network. After a technological transformation,