For over 40 years, Landsat has quietly but consistently been taking images of the surface of the Earth, amassing an impressive collection of data about our planet. This month, NASA and the U.S. Geological Survey (USGS) announced that the effort would continue to span the generations, by moving forward with the development and planned launch of LandSat 9 in 2023.
The series of LandSat satellites dating back to 1972 have captured the deforestation of the Amazon basin, droughts, wildfires, the growth of urban megalopolises and the retreat of glaciers over the decades. Because continuity is an important part of the LandSat mission, the next satellite in the family will be very similar to LandSat 8, which launched in 2013. In fact, NASA calls LandSat 9 an "upgraded rebuild" of its predecessor.
NASA and its Goddard Space Flight Center will lead development of LandSat 9. NASA will also conduct the launch, check-out and commissioning, at which point USGS will take over operation of the satellite and management of the data collected.
“It will provide data consistent with, or better than, Landsat 8,” said Del Jenstrom, the Landsat 9 project manager at NASA Goddard.
To take some of the pressure off LandSat 8 as it ages (LandSat 7 launched in 1999 and is still operating, although with a malfunction that affects the images it gathers), while LandSat 9 is built, a separate, lower-cost thermal infrared satellite will be developed for launch in 2019 to fly in formation alongside LandSat 8.
Although not referenced in the official announcement of the stop-gap satellite, LandSat 8's thermal infrared sensor (TIRS) ran into problems in February that led to a reduction in the data it provides. NASA says the TIRS on LandSat 8 has a three-year design lifetime – the new TIRS on LandSat 9 will have a five-year lifetime.
“With a launch in 2023, Landsat 9 would propel the program past 50 years of collecting global land cover data,” said Jeffrey Masek, Landsat 9 Project Scientist at Goddard. “The longer the satellites view the Earth, the more phenomena you can observe and understand. We see changing areas of irrigated agriculture worldwide, systemic conversion of forest to pasture – activities where either human pressures or natural environmental pressures are causing the shifts in land use over decades.”
Masek says that LandSat is now viewed as a mission that should continue in perpetuity, like weather satellites, so that long-term monitoring can continue to provide valuable data across generations.