Historic Landsat 7 mission takes final images
The Landsat 7 satellite has orbited the Earth more than 132,000 times and acquired more than 3.3 million satellite images, but Landsat's science mission continues with new satellites.
Landsat 7, a joint venture between the United States Geological Survey (USGS) and NASA, was originally designed for a five-year mission. Having overcome all difficulties, the satellite observed the Earth for a quarter of a century, providing invaluable scientific data for the benefit of all mankind.
Landsat 7 took one of its last images on May 28 over Las Vegas, Nevada.
These Landsat 7 images represent the first and last images of the Las Vegas area, taken on July 4, 1999 and May 28, 2024, respectively. The images highlight the city, its surrounding desert landscape and Lake Mead, using short-wave infrared (SWIR), near-infrared (NIR) and red bands to highlight differences in vegetation, water and urban growth. The latest image, celebrating the satellite's 25th anniversary, pays tribute to Landsat 7's quarter-century legacy in Earth observation.
Since its launch on April 15, 1999, Landsat 7 has provided a wealth of imagery, allowing scientists, policymakers, and conservationists to track land-use changes, natural disasters, and environmental degradation with unprecedented accuracy.
Landsat 7 was successfully launched on April 15, 1999, from the Western Test Range at Vandenberg Air Force Base, California, using a Delta II launch vehicle.
“Over its 25 years of operation, Landsat 7 data has played a key role in documenting environmental changes such as natural disasters, deforestation and urban growth,” said David Applegate, director of the USGS. “Through its multi-year mission, it has recorded significant events such as Hurricane Katrina in 2005, the Haiti earthquake in 2010, the Australian bushfires in 2019-2020, the dramatic growth of cities around the world and much more.”
This color image was taken by the Enhanced Thematic Mapper Plus (ETM+) sensor on Landsat 7 on September 12, 2001 at approximately 11:30 a.m. Eastern Daylight Time. A day after the attack, smoke is still billowing from the collapsed Twin Towers.
These Landsat 7 images show the damage caused by Hurricane Katrina in New Orleans, Louisiana.
This data has proven useful and has formed the basis of countless studies, expanding our understanding of agriculture, water resources and wildland fires. By providing consistent data every eight days with Landsat 5 until 2012, Landsat 7 has improved our ability to track seasonal changes. Thanks to operational improvements, Landsat 7 has nearly doubled the daily amount of data it collects, from 250 to 450 scenes.
An earth imaging satellite that could
At launch, Landsat 7 was equipped with the Enhanced Thematic Mapper Plus (ETM+) sensor, which developed and improved the capabilities of its predecessor, the Thematic Mapper (TM) sensor used on Landsat 4 and Landsat 5. An eight-band multispectral scanning radiometer, the ETM+ sensor improved previous technologies including panchromatic range with a spatial resolution of 15 meters and thermal range with a resolution of 60 meters.
This color infrared image of southeastern South Dakota was claimed to be the first image acquired by the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) sensor on April 18, 1999. The Missouri River flows from the middle left of the photo to the lower right, where the Fort Randall Dam creates Lake Francis Case.
However, four years after the launch of Landsat 7, equipment on the ETM+ satellite, known as a scan line corrector, failed, affecting the satellite's ability to obtain complete images of the Earth's surface. This resulted in “streaks” or gaps in the data. Despite this, 78% of the image's pixels are still usable and are considered some of the most geometrically and radiometrically accurate civilian satellite data in the world.
Example scene with Landsat 7 SLC turned off.
The Landsat 7 satellite continued to take images for five times its expected lifespan.
For 25 years, Landsat 7 has captured millions of images of the Earth that have helped study land use and changes in cities, agriculture, forests, snow and ice around the globe, as well as natural and man-made disasters. As the mission concludes, we look back to appreciate the scope and impact of Landsat 7 imagery on scientists and those interested in understanding the Earth's landmass: more than 5,000 scientific publications in 21 languages in 143 countries, 152 articles were mentioned in news, blogs and/ or patents, 1,414 policy documents in 54 countries, citing 749 journal articles.
This Landsat 7 image shows a rotating formation of ice, clouds and low-lying fog off the east coast of Greenland.
To ensure that Landsat 9, launched in September 2021, could be in the same orbital position as Landsat 8, the USGS lowered Landsat 7's orbit. Even at the lower altitude, Landsat 7 continued to collect valuable data. However, the decrease in orbit caused Landsat 7 to drift increasingly within its orbit. As a result of the drift, the satellite was exposed to periods of full sunlight and earlier imaging times, which impacted battery maintenance, imaging capabilities, and the processing of reliable science data. As a result, the USGS decided to stop filming from the aging satellite.
A series of rocky outcrops feature in the Sahara Desert landscape near the Terkezi oasis in Chad, captured by Landsat 7.
Today, Landsat operates with two satellites, Landsat 8 and 9, which together produce a complete set of images of Earth's landmass every 8 days.
Landsat 7 image Guinea-Bissau is a small country in West Africa. Complex patterns are visible in the shallow waters along its coast, where silt carried by the Gebe River and other rivers washes into the Atlantic Ocean.
Landsat mission continues
With the completion of Landsat 7's role in the Landsat science mission and the age of Landsat 8 launched in 2013, attention now turns to the Landsat Next mission as a critical next step to ensure the continuity of Landsat's unique global Earth science mission. USGS is currently focused on ensuring continued data flow and quality of information to meet changing technological and environmental requirements.
The newest mission, known as Landsat Next, promises enhanced capabilities over its predecessors, including improved spatial resolution, larger spectral ranges and faster return times. These improvements are needed to monitor Earth's changing landscapes in more detail and frequently, and to support critical decision-making in climate resilience, disaster response, agriculture, and water management.
A blueprint for how Landsat Next satellites will circle the Earth. The mission is planned for late 2030 – early 2031.
Landsat Next is designed to not only continue Landsat's legacy, but also to innovate and adapt to the pressing challenges of the 21st century, providing scientists, policymakers, industry and the public with access to the information needed to better monitor and sustainably manage our ever-changing planet.
