China's first space laboratory blasted off from its launch site in Gansu province last night and will orbit until it docks with an unmanned Shenzhou spaceship next month. The Tiangong-1, or Heavenly Palace, gives China its first liveable outpost in space. The eight-tonne craft can accommodate three astronauts for an extensive stay. President Hu Jintao and most of the top Politburo Standing Committee members watched the take-off from a control centre in Beijing while Premier Wen Jiabao and another committee member were at the launch site. The success of the launch cleared any doubts about the reliability and safety of the launch vehicle, a Long March 2 rocket. After the failure of a Long March 2 last month, the launch of Tiangong came under heavy pressure and encountered probably the longest delay in the nation's manned space programme in the past two decades. Professor Liu Yu , a rocket scientist at Beihang University's School of Astronautics, said yesterday he felt tense during the launch and only after Tiangong's separation from the rocket did he feel better. In the previous launch on August 18, the Long March rocket veered off course, Liu said. Investigations found the incident was caused by a broken connection between a small thruster and an automatic error-correction device during the rocket's second stage. The rocket's manufacturer, China Aerospace Science and Technology Corporation, said this month it had solved the problem. Engineers had applied a patch to strengthen the rocket's suspected weak area for the Tiangong mission. 'The success of the launch proves the effectiveness of the patch. It also means that the reliability and safety of the Long March rocket, after a costly lesson, has moved to a higher level,' Liu said. Tiangong uses a universal locking mechanism and could theoretically hook up with other nations' spaceships or the International Space Station, showing that China, despite plans to develop an independent space station by 2020, has not shut the door on co-operation with other countries in space, according to some analysts. The ground command in Beijing, with the assistance of three observation ships in the Pacific Ocean, two communication satellites and a couple of new stations in South America, has positioned Tiangong in an orbit of 350 kilometres. Engineers will run extensive checks of the craft's systems before the launch of another spaceship next month. Unlike the United States and Soviet Union in the 1960s, China put its first rendezvous and docking experiments into one mission and, if successful, will become the third country with the ability to carry out the job independently. Xinhua reported that before the launch of the unmanned Shenzhou, Tiangong would orbit at 343 kilometres, where it would wait to dock with Shenzhou. When attached, Tiangong will be used as a laboratory by the three astronauts for a wide range of jobs, from surveying the earth to creating new materials in a micro-gravity environment, for at least two years.