The NISAR mission is a collaboration between NASA and the Indian Space Research Organization (ISRO) that will use two kinds of synthetic aperture radar (SAR) to track subtle changes in Earth's surface: S-band SAR and L-band SAR. (The "S" and "L" denote the wavelength of their signal.) On March 19, 2021, the assembly, test, and launch team at NASA's Jet Propulsion Laboratory in Southern California received the S-band SAR from its partner in India. NISAR, short for NASA-ISRO SAR, will spot warning signs of imminent volcanic eruptions, help to monitor groundwater supplies, track the melt rate of ice sheets tied to sea level rise, and observe shifts in the distribution of vegetation around the world. Movie available at https://photojournal.jpl.nasa.gov/catalog/PIA24137