All systems go for key space launch (2)

Tiangong-1 will stay in orbit for two more rendezvous and docking missions next year. At least one of these missions will be manned, Wu said.

According to the manned space program, China will build its space lab before 2016, and assemble its 60-ton space station around 2020.

"Moreover, the technology can be used for moon landings and deep space exploration though China is only doing concept research and preliminary feasibility studies on manned moon landings, without a timetable," she said.

The mission does face challenges. Rockets must deliver spacecraft precisely into orbit and some new devices onboard Tiangong-1 can only undergo testing in space, she said. China Aerospace Science and Technology Corp, which developed Tiangong-1, the Shenzhou spaceships and rocket carriers, has built a backup craft, Tiangong-2, said Tong Xudong, director of the manned space engineering office of the corporation.

Compared to the Soviet Union and the United States when they were conducting these experiments, China's space mission has many advantages.

Russia and the US launched pairs of spaceships to experiment with rendezvous and docking. China, however, has designed a two-year target spacecraft for docking experiments with three spaceships, the manned space program chief designer Zhou Jianping said.

"Tiangong-1's cost is similar to that of a spaceship we only need four launches and can experiment with rendezvous and docking three times," he said.

The Soviet Union and the US, in the early stages of their space race, would have needed six launches to carry out three experiments, entailing greater cost, Zhou said.

Tiangong-1 has another advantage in that it will stay in orbit for two years, much longer than a spaceship. This will provide a crucial platform to conduct experiments and verify key technology toward building a space station, he said.