Part of the Surface Water and Ocean Topography (SWOT) satellite's science instrument payload sits in a clean room at NASA's Jet Propulsion Laboratory during assembly. Once fully assembled and launched into orbit, the SUV-size spacecraft will make global surveys of Earth's surface water. By measuring the height of the water in the planet's ocean, lakes, and rivers, researchers can track the volume and location of the finite resource around the world. The data will help with monitoring changes in floodplains and wetlands, measure how much fresh water flows into and out of lakes and rivers and back to the ocean, and track regional shifts in sea level. https://photojournal.jpl.nasa.gov/catalog/PIA24536