Landsat 9

Landsat 9 is an Earth observation satellite operated by the U.S. Geological Survey (USGS) in partnership with NASA, and the most recent mission in the Landsat programme [^usgs-l9]. Launched on 27 September 2021 from Vandenberg Space Force Base aboard a United Launch Alliance Atlas V 401 rocket, the satellite was placed into a sun-synchronous near-polar orbit at 705 km altitude [^usgs-l9]. NASA managed the space segment and launch; USGS assumed full operational control in August 2022 [^usgs-l9].

The spacecraft was built by Northrop Grumman Innovation Systems (formerly Orbital ATK) on the LEOStar-3 bus platform, the same lineage used for Landsat 8 [^eoportal-l9]. It carries two primary instruments. The Operational Land Imager 2 (OLI-2), built by Ball Aerospace & Technologies Corporation, is a pushbroom multispectral imager collecting nine reflective spectral bands from 0.43 to 2.29 micrometres plus a 15-metre panchromatic band [^usgs-l9]. OLI-2 captures data at 14-bit radiometric resolution, providing 16,384 intensity levels versus the 4,096 levels of its predecessor OLI on Landsat 8 [^usgs-l9]. The Thermal Infrared Sensor 2 (TIRS-2), built by NASA Goddard Space Flight Center, collects two thermal infrared bands at 100-metre native resolution using Quantum Well Infrared Photodetector (QWIP) arrays [^eoportal-l9]. TIRS-2 was redesigned to substantially reduce the stray-light anomaly that affected TIRS on Landsat 8.

Landsat 9 operates in coordination with Landsat 8, with the two satellites offset by 8 days in the same orbital plane, together delivering nearly 1,500 new scenes per day to the USGS archive [^usgs-l9]. The satellite acquires approximately 750 scenes daily on its own 16-day repeat cycle. All data are distributed free of charge through the USGS Earth Resources Observation and Science (EROS) Center as Landsat Collection 2 products, including Level-1 (radiometrically calibrated and orthorectified), Level-2 Surface Reflectance and Surface Temperature, and Level-3 Analysis Ready Data [^usgs-l9].

The mission is designed for a 5-year on-orbit life with consumables supporting more than 10 years of operations [^nasa-l9]. By July 2025, the USGS archive had received one million Landsat 9 Level-1 products.