By Jon Reino
'Landsat 9' is a joint mission between NASA and the United States Geological Survey (USGS). It continues a legacy of nearly 50 years of data about our changing planet. These "first light" images were collected on October 31st and display the power of this revolutionary Earth-observation satellite.
Launch Photo: NASA/Kim Shiflett
Satellite Photo: First light image from 'Landsat 9', showing mangroves along the northwest coast of Australia clustered in protected inlets and bays on the edge of the Indian Ocean.
At 18:12 UTC on Monday, September 27th, a ULA Atlas V 401 rocket carried Landsat 9 to a geocentric sun-synchronous orbit. This is the 8th operational Landsat mission after Landsat 6 failed to reach orbit. This satellite was manufactured by Northrop Grumman Innovation Systems and was the 2,000th launch from Vandenberg Space Force Base. Complications related to the ongoing Covid-19 pandemic contributed to significant delays in the manufacture of the satellite. Disruptions in the national supply chain of liquid oxygen and nitrogen then delayed the launch by an additional 11 days.
Photos: NASA Randy Beaudoin (satellite) / Bill Ingalls (engine close up)
The Landsat series of satellites has provided continuous and progressively more advanced imagery and thermal data of our planet's landmasses and coastal regions since Landsat 1 was launched on July 23, 1972, originally known as the Earth Resources Technology Satellite (ERTS). They capture data by using what is known as the "push broom" method, collecting strips of data as they pass along their orbital track. This method allows them to cover nearly the entire planet with medium-resolution imagery.
Landsat 9 is replacing Landsat 7, which has been operating for over 20 years and is nearing the end of its fuel resources. “It was the granddaddy of them all, as far as starting the trend of repetitive, calibrated observations of the Earth at a spatial resolution where one can detect man’s interaction with the environment,” said Dr. Darrel Williams, Landsat 7 project scientist.
The newly released images, all acquired Oct. 31, are available online. They provide a preview of how the mission will help people manage vital natural resources and understand the impacts of climate change.
“Landsat 9’s first images capture critical observations about our changing planet and will advance this joint mission of NASA and the U.S. Geological Survey that provides critical data about Earth's landscapes and coastlines seen from space,” said NASA Administrator Bill Nelson. “This program has the proven power to not only improve lives but also save lives. NASA will continue to work with USGS to strengthen and improve accessibility to Landsat data so decision makers in America – and around the world – better understand the devastation of the climate crisis, manage agricultural practices, preserve precious resources and respond more effectively to natural disasters.”
'Landsat 9' showing off its multi-wavelength capabilities (NASA)
Selections from the NASA press release:
Landsat 9 carries two instruments that capture imagery: the Operational Land Imager 2 (OLI-2), which detects visible, near-infrared and shortwave-infrared light in nine wavelengths, and the Thermal Infrared Sensor 2 (TIRS-2), which detects thermal radiation in two wavelengths to measure Earth’s surface temperatures and its changes. These instruments will provide Landsat 9 users with essential information about crop health, irrigation use, water quality, wildfire severity, deforestation, glacial retreat, urban expansion, and more.
Landsat 9 is similar in design to its predecessor, Landsat 8, which was launched in 2013 and remains in orbit, but features several improvements. The new satellite transmits data with higher radiometric resolution back down to Earth, allowing it to detect more subtle differences, especially over darker areas like water or dense forests. For example, Landsat 9 can differentiate more than 16,000 shades of a given wavelength color; Landsat 7, the satellite being replaced, detects only 256 shades. This increased sensitivity will allow Landsat users to see much more subtle changes than ever before.
NASA’s Landsat 9 team is conducting a 100-day check-out period that involves testing the satellite’s systems and subsystems and calibrating its instruments in preparation for handing the mission over to USGS in January. USGS will operate Landsat 9 along with Landsat 8, and together the two satellites will collect approximately 1,500 images of Earth’s surface every day, covering the globe every eight days.
Images from previous Landsat missions display the importance of long term observation (NASA)
Without a doubt, the capability to observe the entirety of Earth's surface over long periods is one of the most powerful tools in humanity's spaceflight arsenal. It allows us to study changes over many years, even lifetimes. This knowledge is crucial to the development of climate change mitigation policies.
“The incredible first pictures from the Landsat 9 satellite are a glimpse into the data that will help us make science-based decisions on key issues including water use, wildfire impacts, coral reef degradation, glacier and ice-shelf retreat and tropical deforestation,” said USGS Acting Director Dr. David Applegate. “This historic moment is the culmination of our long partnership with NASA on Landsat 9’s development, launch and initial operations, which will better support environmental sustainability, climate change resiliency and economic growth – all while expanding an unparalleled record of Earth's changing landscapes.”
Landsat 9 data will be available to the public, for free, from USGS’s website once the satellite begins normal operations.
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