A Russian satellite seems to be tailing a US spy satellite in Earth orbit

A Russian satellite has positioned itself uncomfortably close to an American spy satellite in orbit around Earth, leading space trackers to speculate that the foreign vehicle is doing some spying of its own. The Russian spacecraft is meant to inspect other satellites, and experts in the space community believe it may now be keeping a watchful eye on the secretive US vehicle. But the motivation behind this in-space stalking is still unknown. More

(Source: The Verge - Feb 1)