WASHINGTON - NASA and the U.S. Geological Survey (USGS) have started work on Landsat 9, planned to launch in 2023, which will extend the Earth-observing program's record of land images to half a century.
The President's fiscal year 2016 budget calls for initiation of a Landsat 9 spacecraft as an upgraded rebuild of Landsat 8, as well as development of a low-cost thermal infrared (TIR) free-flying satellite for launch in 2019 to reduce the risk of a data gap in this important measurement. The TIR free flyer will ensure data continuity by flying in formation with Landsat 8. The budget also calls for the exploration of technology and systems innovations to provide more cost effective and advanced capabilities in future land-imaging missions beyond Landsat 9, such as finding ways to miniaturize instruments to be launched on smaller, less expensive satellites.
Because an important part of the land imaging program is to provide consistent long-term observations, this mission will largely replicate its predecessor Landsat 8. The mission will carry two instruments, one that captures views of the planet in visible, near infrared and shortwave-infrared light, and another that measures the thermal infrared radiation, or heat, of Earth's surfaces. These instruments have sensors with moderate resolution and the ability to detect more variation in intensity than the first seven satellites in the Landsat program.
The Landsat 9 mission is a partnership between NASA and the USGS. NASA will build, launch, perform the initial check-out and commissioning of the satellite; USGS will operate Landsat 9 and process, archive, and freely distribute the mission's data.
NASA's Goddard Space Flight Center in Greenbelt, Maryland, will lead development of the Landsat 9 flight segment. Goddard will also build the Thermal Infrared Sensor (TIRS), which will be similar to the TIRS that the center built for Landsat 8. The new improved TIRS will have a five-year design lifetime, compared to the three-year design lifetime of the sensor on Landsat 8.
Following the launch of Landsat-8, the program entered a period of uncertainty. With no replacement for Landsat-8 planned, NASA and the USGS needed to consider a number of ways to continue observations if Landsat-8 reached the end of its life before a replacement launched. Possibilities included building another large satellite; utilizing smaller, less capable satellites; or relying on another source - such as UAVs - to gather data. The agencies also considered purchasing data from other governments or from commercial sources. In the end, they decided to build another satellite, based largely on Landsat-8 to reduce risk, and to build a smaller, cheaper satellite to mitigate any coverage risk. The two satellites will be built on a tight schedule. Considering the reuse of technology from previous satellites, deliveries will likely be on time.