SOSUS AND KH-9

SOSUS and satellite based sensor systems worked in tandem to locate Soviet submarines.

http://www.globalsecurity.org/intell/systems/sosus.htm

FOUR PHASES OF LASER BASED MISSILE DEFENCE

Mirrors in orbit were also proposed as a means to increase the range of land based lasers. In some ways a ground based system using mirrors would be more survivable. The mirrors in orbit could be taken out and the ground based laser could still defend the area in which it is situated.