Carrier rocket Long March-5 Y3 is seen at the Wenchang Space Launch Center in South China's Hainan Province,on Saturday. The third Long March-5 rocket, China's largest carrier rocket, was vertically transported to the launching area at the Wenchang Space Launch Center in South China's Hainan Province on Saturday. It is planned to be launched at the end of December, according to the China National Space Administration.

The Long March-5, China's most powerful rocket and a critical ingredient in the nation's ambitious space program, will be launched a third time by the end of December.

With a maximum payload capability of 25 tons into low Earth orbit and 14 tons into geosynchronous orbit, the rocket, nicknamed "fat five," took about two hours to be vertically transported to the Wenchang Space Launch Center in South China's Hainan Province on Saturday morning.

As of Wednesday, three of China's spacecraft-tracking ships, Yuanwang-3, -5 and -7 had arrived at designated waters in the Pacific Ocean to monitor the Long March-5 launch.

Space engineers will conduct final examinations and tests on the rocket before the launch, which would mark third flight of a Long March-5 more than two years after a launch failure in July 2017 ascribed to an engine problem.

If successful, the third launch would inject impetus into the country's key space projects in the next year.

They include the Chang'e-5 lunar sample return mission and China's first unmanned Mars exploration mission, an aerospace insider close to the matter, who requested not to be named, told the Global Times. 

Meanwhile the Long March-5B, a smaller variant of the same rocket, will support the construction of a space station in the near future, he noted.