The high court on Monday refused to hear an appeal from John Reece Roth.
Roth, while working at Tennessee, got an Air Force contract to develop equipment used to control the flight of unmanned military drones. He allowed two foreign students access to sensitive data and equipment, and took some of the data with him on a trip to China.
The Arms Export Control Act prohibits the export of defense-related materials to a foreign national or a foreign nation.
Roth challenged his conviction but federal judges have upheld his conviction and four-year sentence.
The case is Roth v. United States, 10-1220.