ATC Security Services Communications and security tracking provided by an ATC facility in support of the DHS, the DOD, or other Federal security elements in the interest of national security. Such security services are only applicable within designated areas. ATC security services do not include ATC basic radar services or flight following. 

Chaff Thin, narrow metallic reflectors of various lengths and frequency responses, used to reflect radar energy. These reflectors when dropped from aircraft and allowed to drift downward result in large targets on the radar display.

Aero Linx: The Aircraft Engine Historical Society, Inc. The Aircraft Engine Historical Society, Inc. was organized in July of 2001 by a small group interested in preserving the rich history of all engines used in aerial propulsion, including rocket engines. The organizers hoped to achieve this goal by bringing together aircraft engine authors, collectors, operators, researchers and enthusiasts within a single non-profit organization. Since that time, the AEHS quarterly journal, Torque Meter, has been read by tens of thousands, and the AEHS web site has been visited by millions of people from around the world. Publication of Torque Meter was abandoned at the end of 2008 in favor of an all-web presence

"These little dents in the outer part of the Columbus module show how the space around Earth is not so empty after all. They also show what a good job the ESA-built module is doing to protect astronauts living and working in space." Source: Detlef Koschny, an expert from ESA's Planetary Defence Office focussing on space safety and security, commenting about the robotic arm camera on the International Space Station having now completed the first two scans of the outer panels of the Columbus module, in search of micro impact 'craters.'