Illustration of the artist of the Queqiao relay satellite of China, which will relay data between the controllers of the Earth and the Changder 4 pair of China's lander-rover on the opposite side of the moon. Queqiao is scheduled to launch on May 20, 2018; the duo Chang & # 39; e 4 will take off in November or December.
China will launch the next piece of its ambitious robotic lunar exploration program on Sunday (May 20), if everything goes according to plan.
The nation's Queqiao relay satellite is scheduled to take off on a Long March 4C rocket on Sunday from the Xichang Satellite Launch Center in Sichuan Province at approximately 5 p.m. EDT (2100 GMT, 5 a.m. on May 21, Xichang local time).
Queqiao will go to point 2 of Lagrange, a gravitationally stable location located 40,000 miles (64,000 kilometers) beyond the far side of the Moon. From that position, Queqiao will transmit signals and data between Earth and the pioneer Chang & 4; e 4 lander-rover of China. That pair will be launched later this year and will try to become the first spacecraft to land on the far side of the moon. [China’s Moon Missions Explained (Infographic)]
The moon is blocked by tides to Earth, which means that it always shows the same face (the closest side) to our planet. Therefore, a relay link is necessary to communicate with the spacecraft on the other side, which otherwise would have to send its signals through the rocky bulk of the moon.
Queqiao will also conduct an astronomical experiment called Low Frequency Explorer from the Netherlands-China. that will look for radio signals from the first days of the universe and will characterize the solar wind near the moon, among other works. And Queqiao will not launch alone; Long March 4C will also enable two small satellites called Longjiang-1 and Longjiang-2, which will carry out their own radio astronomy research.
The Chang & # 39; e program has already achieved a series of successes. The Chang & # 39; e 1 and Chang & # 39; e probes reached the lunar orbit in 2007 and 2010, respectively, and the Chang & # 39; e mission put a lander and rover on the side closest to the moon at the end of 2013. The following year, China launched Chang & # 39; e 5 T1, a mission that sent a sample return capsule around the moon and back to Earth to demonstrate the technology needed to survive a blazing atmospheric entry. China plans to launch a mission of returning the lunar sample in good faith, called Chang & # 39; e 5, in 2019.
The nation also aims to put people on the lunar surface before the end of the 2030s Chinese officials said.  The Chang & # 39; e program was named after the Chinese goddess of the moon, and "Queqiao" means "bridge of magpies". This last nickname comes from a Chinese folk tale. In the story, as the Xinhua news service explained last month, "the magpies form a bridge with their wings on the seventh night of the seventh month of the lunar calendar to enable Zhi Nu, the seventh daughter of the Goddess of Heaven, cross and meet her beloved husband, separated from her by the Milky Way "
" Longjiang ", by the way, means" river of the dragon ". This is apparently a nod to the base of the satellites; They were developed by the Harbin Institute of Technology, which is located in Heilongjiang Province. "Heilongjiang" means "black dragon river"; is the Chinese name of the great and powerful river that the Russians call Amur, which is part of the border between Russia and China.