In a break from its critical coverage of the United States' plans to attack Iraq, mainland media yesterday joined government officials in expressing regret over the space shuttle disaster. 'When China heard about this tragic loss of the space shuttle Columbia and its seven crew, the entire nation was shocked and saddened,' Xinhua said yesterday. 'Not only are the seven astronauts exploring on behalf of all mankind, they were true heroes.' Foreign observers said the fact mainland media had taken the opportunity to express regret for the tragedy reflected a growing maturity in how the government and mainland Chinese view themselves and their nation's relationship with the world. 'The relationship between the US and China is probably the best it has been in a long time,' said Scott Kronick, managing director of US-based Ogilvy Public Relations in Beijing and an observer of Sino-US relations. 'Clearly I think that is the case. Also, [the shuttle explosion] is a tragedy in the advancement of science.' State media played up interviews with scientists and even with Beijing students whose experiments on silk worms and silk production in space were performed by the Columbia astronauts during their failed mission. 'I never imagined this would happen,' said Li Taotao, a designer of the experiment who attends Beijing's Jingshan High School. 'However, I won't lose faith in the future of aerospace experiments or space exploration because of this tragic event.' Ms Li's experiment was one of dozens designed by students around the world and performed during the Columbia mission. Rarely does China Central Television break off broadcasts, except when it comes to special messages from the leadership, but even CCTV interrupted its Saturday evening programming to announce the shuttle disaster.