The image was sent back via the relay satellite Queqiao, which was operating around the second Lagrangian point of the earth-moon system, about 455,000 km from the earth, where it can see both the earth and the moon’s far side.
CAS news release, January 11, 2019
According to WU Yanhua, deputy director of the China National Space Administration (CNSA), the cost of the Chang’e-4 mission is equivalent to that of constructing a one-km-long subway tunnel.
China’s investment in lunar and deep space exploration is appropriate to the overall level of the national economic and social development, Wu said.
As a big country, China should make contributions to exploring the mystery of the universe and benefiting human society, Wu said.
CAS news release, January 14, 2018