X-37B spaceplane ‘spying on China’
The unpiloted vehicle was launched into orbit by the US Air Force in March last year and has yet to return to Earth.
The Pentagon has steadfastly refused to discuss its mission but amateur space trackers have noted how its path around the globe is nearly identical to China’s spacelab, Tiangong-1.
There is wide speculation that the X-37B is eavesdropping on the laboratory.
"Space-to-space surveillance is a whole new ball game made possible by a finessed group of sensors and sensor suites, which we think the X-37B may be using to maintain a close watch on China’s nascent space station," said Spaceflight editor Dr David Baker.
The X-37B, also known as the Orbital Test Vehicle (OTV), looks like a mini space shuttle and can glide back down through the atmosphere to land on a runway, just like Nasa’s re-usable manned spaceplane used to do before its retirement last July.
Built by Boeing, the Air Force’s robotic craft is about 9m long and has a payload bay volume similar to that of a small van. But what goes in the payload bay, the USAF will not discuss.
The current mission was launched on an Atlas rocket and put into a low orbit, a little over 300km up, with an inclination of 42.79 degrees with respect to the equator – an unusual profile for a US military mission which would normally go into an orbit that circles the poles.