By the early 1960s, military satellites designed to perform a wide range of missions were being regularly launched. The information supplied by photographic reconnaissance satellites is used for a variety of purposes. Although strategic intelligence gathering continues to be the primary mission for this class of satellites, the same information is equally indispensable for monitoring compliance with arms control agreements. Electronic intelligence gathering from space by what are often referred to as ‘ferref’ satellites complements the photo-reconnaissance missions in a number of important ways. These satellites eavesdrop on the communications of an adversary to gauge the size, deployment and readiness of its military forces. An area of activity where space promises to offer considerable advantages to the military is oceanographic surveillance. Apart from allowing more accurate weather forcasting for general-purpose military operations than was possible before by traditional methods, meteorological satellites also provide invaluable assistance to other military missions.