SWOT: A space mission to map all of Earth’s water

Water impacts everything: the environment, the economy, weather, climate, agriculture, energy, and life itself.

This week, The Surface Water and Ocean Topography (SWOT) mission launched a specialized satellite into space designed to constantly collect data and imagery of Earth’s water systems. A SpaceX Falcon 9 rocket carried the new satellite to orbit from the Vanderburg Space Force Base in California on Wednesday.  The mission is a partnered effort between NASA, the French CNES, the Canadian Space Agency, and the United Kingdom Space Agency. NASA has a total of 25 satellites in space for earth observation and this is the first to be entirely water focused. It uses laser light reflection to measure the elevation and coverage of nearly every water body. The wide prongs of the fully engaged satellite increase visual coverage of each pass-by, which occur twice every 21 days. It has higher resolution and frequency compared with previous missions, making it well-equipped to sense even the smallest streams.

Like other earth observation missions by NASA, the data will be available to the public. Researchers all over the world are free to make discoveries locally to globally. This is an exciting advancement in hydrological monitoring and a new opportunity for the field of geospatial analysis. Scientists equipped with this new data can make useful models to aid vital decision-making involving our relationship with water features around us. The collection over time will accurately help visualize patterns of change. We can expect to see shifting coastlines, bending rivers, freezing, thawing, and the filling and draining of basins. Understanding the geometry of water features allows us to calculate a “water budget,” the velocity of water moving through the systems, and risks to the environment and civilization alike. The primary collection phase will begin in about six months after an initial phase involving positioning, deployment, and calibration.

Image by NASA