If everything goes according to plan, China is all set to launch the robotic lunar-probeprogram on May 20th, Sunday. The Queqiao relay satellite will be launched from a Long March 4C rocket from the Xichang Satellite Launch Center of Sichuan Province at 2100 GMT (about 5 p.m. EDT).
As far as its route is concerned, Queqiao will head towards a gravitationally stable point, known as Earth-moon Lagrange point 2,situated at 64,000 kilometers beyond Moon’s far side. Queqiao will relay data and signals from that location to China's revolutionary Chang'e 4 lander-rover duo and earth. Chang'e 4 lander-rover duo will be launched later this year and it is slated to be the first spacecraft to land on Moon’s far side.Earth always sees the same face of the Moon as it is tidally locked to our planet. A relay link is needed as without it the spacecraft will have to send the signals through Moon’s rocky terrain.
An ambitious astronomical experiment known as the Netherlands-China Low-Frequency Explorer will also be a part of the Queqiao program. One of the most significant works to be carried out by the explorer is searching for radio signals related to the early days of the Earth and identifying the characteristics of the Solar winds near the lunar surface. The Long March 4C will also be launching two small satellites namely, Longjiang-1 and Longjiang-2. These will be carrying out their own radio-astronomy probes.
A list of Chang’e programs have already been successful. The Chang'e 1 probe reached Moon’s orbit in 2007 and Chang'e 2 in 2010. A rover and lander were placed on the near side of the Moon by Chang’e 3 in late 2013.Chang'e 5 T1 in 2014 was another successful mission through which a sample-return capsule was sent around the Moon and back to Earth to understand the technology needed to withstand the blistering atmospheric entry. China will launch another sample-return mission in 2019, known as Chang'e 5.
The name Chang'e comes from the Chinese goddess of Moon. Queqiao refers to the "bridge of magpies’ wings" that, according to Chinese folklore, was made on the 7th night of the 7th lunar month to let Zhi Nu, the 7thdaughter of Goddess of heaven, meet her Dear husband. Longjing means “Dragon River" as its home base is Harbin Institute of Technology located in Heilongjiang Province and “Heilongjiang” means "black dragon river."