First spy sattelites appeared very soon after the launch of Russian Sputnik in 1957. At first, they were only able to make simple photos, and drop the canister containing the film when passing over friendly territory. Within next 50 years though they developed into sophisticated devices, which were almost invisible and had cameras installed capable of reading a book from orbit, piercing clouds and darkness with infrared vision, and providing real-time imaging of a large area. Spy Sats became invaluable assets in both intelligence and warfare.