China launched its second manned space mission yesterday, but the two astronauts may have to cut short their adventure. The mission, hailed by Premier Wen Jiabao as a project 'with an objective to promote world peace', was originally scheduled to last 119 hours. But this figure was omitted in state media reports, with the Chongqing Morning Post saying the two astronauts - Colonels Fei Junlong , 40, and Nie Haisheng , 41 - would be back on Earth in three days, landing in Inner Mongolia . Jiang Jingshan , a designer with the Chinese Lunar Orbiting Exploration programme, said the return date may be advanced due to poor weather and had nothing to do with technical factors. The launch was brought forward a day because of bad weather. 'We talk about several days, which can mean four days or three days,' he said. 'Because this is the first ever mission with more than one astronaut, it should not last more than five days.' Former chief executive Tung Chee-hwa attended the launch, which took place at 9am at the Jiuquan launch centre in Gansu province . Minutes after blast-off, Colonel Fei pronounced: 'I feel good.' There was jubilation at the launch centre at 9.39am - 39 minutes after liftoff - when Chen Bingde , commander in chief of the manned space flight programme, declared the launch a success. The mission is part of preparations for sending a man to the moon and setting up a space station in the future. In an unusual sign of greater transparency, China Central Television has been filled with images from inside the capsule and the space centre. Speaking at the space centre, Mr Wen said the mission was a big step forward compared with Shenzhou V in 2003. 'Comrades, you have worked hard and struggled to overcome scientific difficulties one after another and fulfilled many important science and technological breakthroughs to gain scientific success,' he said. Mr Wen reiterated China's policy of using space peacefully. 'China's entering into the scientific experiment of space flight is entirely for peaceful purposes and is a contribution towards the human race's works in promoting science and peace.'