Three taikonauts of the Shenzhou VII manned space mission, Zhai Zhigang (right), Liu Boming (second from left) and Jing Haipeng (left), taikonauts' delegation head Zhang Jianqi (middle) and Hong Kong Special Administrative Region (HKSAR) government's Chief Secretary for Administration Henry Tang cut the ribbon at the opening ceremony of a spacewalk mission exhibition at the Hong Kong Science Museum on Saturday, December 6, 2008. [Xinhua]