Washington has given a nod of approval to the pending launch of China’s first manned space mission, while an American analyst warns that the U.S. should resume human space exploration if it is to retain its pre-eminence. Beijing has not officially announced the details or timing of its mission other than to say it is planned before the end of the year. But speculation has grown that the launch could take place in October — perhaps as soon as Wednesday, which is China’s National Day.