BEIJING China launched its second experimental space laboratory on Thursday, part of a broader plan to have a permanent manned space station in service around 2022.
Advancing China's space program is a priority for Beijing, with President Xi Jinping calling for the country to establish itself as a space power, and apart from its civilian ambitions, Beijing has tested anti-satellite missiles.
China insists its space program is for peaceful purposes, but the U.S. Defense Department has highlighted its increasing space capabilities, saying it was pursuing activities aimed to prevent adversaries from using space-based assets in a crisis.
In a manned space mission in 2013, three Chinese astronauts spent 15 days in orbit and docked with an experimental space laboratory, the Tiangong 1, or "Heavenly Palace".
Its successor, Tiangong 2, lifted off on a Long March rocket just after 10 p.m. (1400 GMT) from the remote launch site in Jiuquan, in the Gobi desert, in images carried live on state television.
The Shenzhou 11 spacecraft, which will carry two astronauts and dock with Tiangong 2, will be launched sometime next month.
The astronauts expect to remain in Tiangong 2 for about a month, testing systems and processes for mid-term stays in space and refueling, and conduct medical and other experiments.
The smooth launch imparts a high-tech sheen to week-long celebrations of China's National Day, starting on Oct. 1, as well as this week's shorter Mid-Autumn Festival holiday that coincides with the full moon.
China would start building its space station starting as early as next year, Xinhua quoted Zhou Jianping, chief engineer of the manned spaceflight program, as saying.
The station would be more economically efficient than the International Space Station and use "more data", he said.
"Once the lab mission comes to an end, China will start building our own space station," Zhou was quoted as saying.
China will launch a "core module" for the station some time around 2018, a senior official said in April, part of a plan for a permanent manned space station in service around 2022.
China has been working to develop its space program for military, commercial and scientific purposes, but is still playing catch-up to established space powers the United States and Russia.
China's Jade Rabbit moon rover landed on the moon in late 2013 to great national fanfare, but soon suffered severe technical difficulties.
The rover and the Chang'e 3 probe that carried it there were the first "soft landing" on the moon since 1976. Both the United States and the Soviet Union had accomplished the feat earlier.
(Reporting by Ben Blanchard in BEIJING and John Ruwitch in SHANGHAI; Editing by Ralph Boulton and Nick Macfie)