Landsat 7 saw the program return to the public sector, advancements in image quality, and the expansion of three decades of continuous Earth observation.
The seventh iteration of the satellite series, launched on April 15, 1999, boasted an Enhanced Thematic Mapper Plus (ETM+) sensor, which marked an improvement over Landsats 4 and 5. The ETM+ was also an improvement over the sensor affixed to the unsuccessful Landsat 6 satellite, due to its improved thermal infrared imaging capabilities. Unfortunately, a scan line corrector failure in 2003 caused a zig zag pattern to appear in Landsat 7 imagery.
In recognition of the 30th anniversary of the Landsat program in 2002, staff at the USGS EROS Center selected a handful of images for creative enhancement. Forty of the most inspiring, beautiful satellite images became the very first “Earth as Art” collection. Several sets were framed and displayed in federal venues across the Nation, including the underground hallways that connect the House and Senate office buildings in Washington, D.C.
Landsat 7 imagery, alongside imagery from each preceding mission, became free and open to the public at no cost in 2008. The policy shift led to a rapid expansion of Landsat use. By 2020, more than 100 million Landsat scenes had been downloaded from the USGS EROS Center archive.
As of March 2022, prior to decommissioning, Landsat 7 had collected more than 3.1 million Earth surface images.