What China has done recently in space remains classified. But what sources were willing to tell Reuters is that those moves have officials worried that the country is becoming increasingly able to mess with US satellites that are key to our security.

The revelation follows a late 2012 classified intelligence report on said moves that one former government officials calls "very credible and sobering." The report apparently touched on China's growing potential to affect satellites found in higher orbits, following years of lower-orbit anti-satellite activities by the country.

It's at these higher altitudes some 22,000 miles above the equator that satellites used for military communications and early missile warning systems live. US officials remain on the lookout for any further anti-satellite activities there, which could include bringing two satellites together in space under the guise of testing docking abilities, a feat that could be used to more destructive ends. "Some critical US assets in that region have been assumed for the most part to be safe from those kind of attacks," said a security expert. "Such tests would signal that they're not."