EROS: The Satellite Archive in the Cornfield
Near Sioux Falls, South Dakota
About fifteen miles north and east of downtown Sioux Falls, in what was a cornfield when it was chosen in nineteen seventy, sits one of the most significant data archives on the planet. The Earth Resources Observation and Science Center, known as EROS, holds the world's largest collection of civilian land-remote-sensing data: decades of satellite images covering virtually every square mile of the Earth's surface.
It started as a vision articulated in nineteen sixty-six, when Secretary of the Interior Stewart Udall announced Project EROS: a collaborative program between the United States Geological Survey and NASA to put Earth-observing satellites into orbit and use them to inventory natural resources. The premise was straightforward, a camera in space could see things no ground-level survey could, and it could see them repeatedly, year after year, so you could track change over time.
Congress appropriated funds for a data center in nineteen seventy, and a site near Sioux Falls was selected based on a combination of practical considerations: radio transmission tests showed favorable signal characteristics, the community was supportive, and South Dakota Senator Karl Mundt had the ear of President Richard Nixon. The Sioux Falls Development Foundation offered three hundred acres of land free of charge. Construction started immediately, and the facility opened on August seventh, nineteen seventy-three.
On January second, nineteen seventy-four, the center began accepting satellite data. It has never stopped. The first Landsat satellite launched in nineteen seventy-two and began transmitting images of the Earth's surface in ways that had never been possible before: crop stress, glacial retreat, urban expansion, forest fire aftermath, coastal erosion, all of it archived in the same facility decade after decade.
Today the EROS archive holds millions of scenes. Scientists studying climate change, agriculture, disaster response, and urban growth regularly draw on it. The images of the Amazon from the nineteen seventies and the Arctic from the nineteen eighties exist there, in digital form, in a building you could drive past on a county road without knowing what was inside.
