According to a soon-to-be-published report from a U.S. Congressional commission, in 2007 and 2008, hackers allegedly based in China subjected two United States satellites to attacks that interrupted the satellites' functions for periods of up to several minutes. Affected were a Landsat-7 earth observation satellite jointly managed by NASA and the USGS, and a Terra AM-1 satellite managed solely by NASA.
As reported by Bloomberg Businessweek, the outages were discovered in 2007 outage of the Landsat-7 satellite was discovered during a July, 2008 investigation of the 2008 outages. The report does not specifically name the Chinese government as culpable for the attack, and naturally an official representative for China in the United States has flatly denied any connection, calling assertions to the contrary are an attempt to 'villy' China. Even so, it's absurd to suggest that China's ongoing global strategy, much like the United States', involves some asymmetrical tactics including so-called cyber warfare.