The first resource satellite, Landsat I, was launched in 1972 by the United States; it's main responsibility was to track American grain production. In addition, its ability to monitor the Soviet grain harvest and Australian sheep and cattle farming startled the world.
一九七二年美國發射世界第一顆資源衛星﹘﹘「大地衛星」系列第一號，它的首要任務就是觀察美國農作物的生長情形，甚至還看到前蘇聯的穀倉烏克蘭的農作生產，以及澳洲畜牧區的牛羊放牧情形，震驚了世界。