Government and private sector entities rely on satellites for services such as communication, navigation, remote sensing, imaging, and weather and meteorological support. Although the government owns satellites, it also relies for certain services on satellites owned and operated by commercial satellite service providers. For example, the Department of Defense (DOD) typically relies on commercial satellites to fulfill its communications and information transmission requirements for non-mission-critical data and to augment its military satellite capabilities. The commercial satellite industry is also a critical component of the worldwide and national economy: the industry generated $85 billion in revenue in 2000. Accordingly, disruption of satellite services, whether intentional or not, can have a major adverse economic impact. Satellites are vulnerable to various threats.