A Long March-4C rocket carrying a relay satellite, named Queqiao (Magpie Bridge), is launched at 5:28 a.m. from southwest China's Xichang Satellite Launch Center, May 21, 2018. The relay satellite will set up a communication link between Earth and the planned Chang'e-4 lunar probe that will explore the mysterious far side of Moon. (Photo: China News Service/Liang Keyan)
