"We wish them well," he told reporters. "The Chinese are looking to strike out on their own, or demonstrate their capacities; it appears to be driven by a desire to demonstrate national sovereignty, national objectives, to build a technology capacity to do things."

The top official at the National Aeronautics and Space Administration said "this is a pretty exclusive club that the United States and the Russians are in, not because we exclude anybody, it's a case of what we have as a capacity to actually do these things.

"The US and the Russians have been the only national interests that have been able to achieve the kind of human of exploration objectives. It's a case of collective capacity."

O'Keefe added: "It clearly falls into the category of important events in human history when yet another national interest is capable of doing what two nations thus far have achieved, it's an important milestone, progress of the human condition, no doubt about it, we wish them well."

The first manned Chinese space flight is expected in October, official Chinese media said in August.

SPACE.WIRE