Space station set for orbit by 2020

China's manned space station is planned to be in orbit by 2020, said Zhou Jianping, head of China's manned space program Sunday.

In advance of this, a new space lab, Tiangong-2, is expected to launch in 2015. A new cargo vessel, named Tianzhou, or Heavenly Vessel, will be sent into space using new Long March-7 carrier rocket.

These launches will serve as preparation for the expected lift-off of the core of the new space station in 2018.

It is likely that China may be the only nation with a permanent manned presence in space by then, said Zhou, as the International Space Station (ISS) was originally due to be decommissioned by 2020.

However, in January 2014, the Obama administration announced an extension of the ISS mission to 2024, according to the White House website.

"The space station will provide a better platform for scientific space studies and experiments, which will be accessible to scientists from home and abroad. It will make a contribution to mankind's exploration and peaceful use of space," Zhou said.

Tiangong-2 space lab, designed to replace Tiangong-1, in operation since 2011, is expected to see the first docking with a Tianzhou cargo vessel in 2016, said Zhou.

The cargo vessels will be able to dock with Tiangong-2 automatically and can deliver large-sized equipment for the space station construction, as well as fuel, research materials and daily necessities for astronauts.

"A manned spaceship has limited transportation capacity and costs a lot, but a cargo ship will not return to Earth and it doesn't need to carry people in its launching and docking processes, which make its transportation more economical and efficient," Zhou said.

Tianzhou's payload capacity is expected to reach world-class levels, he said.

Three cabin structures are being designed for the cargo ship, a fully-enclosed one, a semi-open one and a wholly-open one, and scientists are working on developing the Long March-7 carrier rocket, which can carry a payload of more than 13 tons.

Zha Youyin, a Shanghai-based military expert, said that Shenzhou spacecraft will still be used for manned launches.

"Our unmanned automatic control technology will be greatly improved in the research process as Tianzhou docks automatically, while astronauts guide the system for Shenzhou spacecraft," said Zha.

"The Chang'e 3 lunar probe has proved the reliability and capability of our remote control technology in space," Zha said.

There have been successful dockings with Tiangong-1, which has surpassed its expected two-year lifespan. It has been moved to a higher orbit.

"It will go on conducting scientific experiments, but astronauts won't go there anymore," Zhou said.