From the Summary: "The National Aeronautics and Space Administration (NASA) anticipates launching Landsat 9, a remote sensing satellite NASA is developing in partnership with the U.S. Geological Survey (USGS), in 2021. Landsat satellites have collected remotely sensed imagery of the Earth's surface at moderate spatial resolution since the launch of Landsat 1 on July 23, 1972. The two latest satellites in the series, Landsat 7 and Landsat 8, are still in orbit and supplying images and data. Stakeholders use Landsat data in a variety of applications, including land use planning, agriculture, forestry, natural resources management, public safety, homeland security, climate research, and natural disaster management. Landsat data support government, commercial, industrial, civilian, military, and educational users throughout the United States and worldwide. Landsat 7, however, is expected to consume its remaining fuel by summer 2021. To reduce the risk of a gap in Landsat data availability, Landsat 9 development was initiated in March 2015, with a design that is essentially a rebuild of Landsat 8. Once Landsat 9 is operational, it and Landsat 8 will acquire around 1,500 high-quality images of the Earth per day, with a repeat visit every eight days, on average."
CRS Report for Congress, R46560
Congressional Research Service: https://crsreports.congress.gov/