New NASA satellite to continue half a century of changing Earth observations

Enlarge / Natural color images from March 1999, April 2005, May 2011, and April 2021 by Landsat satellites chronicle the shrinking Lake Powell reservoir and Lower Colorado River.


A Delta rocket launched the small Earth Resources Technology Satellite in July 1972 with a simple mission: to capture multi-spectral imagery of the planet and assess changes over time.

Data from the polar-orbiting satellite proved so useful that NASA and the US Geological Survey renamed the vehicle Landsat 1 in 1975, and the organizations have since launched a succession of increasingly sophisticated “Landsat” satellites to continue observations. As a result, we now have a nearly half-century long record of changes to the planet’s surface—from farms and forests to glaciers and urban areas.

While the data from the Landsat missions has proved invaluable, it has also been somewhat depressing. The satellites have amassed an impartial record of tropical deforestation in the Amazon, verifying the claims of environmental protection organizations. They have also cataloged increasing water scarcity in the Western United States and chronicled ice losses across the vast majority of Earth’s glaciers.

“Landsat has provided a critical reference for assessing long-term changes to Earth’s land environment due to both natural and human forcing,” scientists concluded in the journal Remote Sensing of Environment, in 2020.

Essentially, you can’t manage what you can’t measure. So if we’re smarter about how we’ve changed the planet, perhaps humans can become smarter about how we change the planet in the future.

Now, NASA seeks to advance the legacy of the Landsat program with the launch of the Landsat 9 mission on Monday. In many ways, the satellite is a clone of Landsat 8, which launched in 2013. However, the new satellite includes an upgraded thermal infrared sensor as well as backup systems to allow the instrument to function for a longer lifetime. These satellites each weigh about 3 metric tons; the original Landsat had a mass of 900 kg.

The Landsat 9 mission is scheduled to launch on Monday at 11:12 am PT (18:11 UTC) from Vandenberg Air Force Base in California. Although ground fog may obscure the launch, overall weather conditions are highly favorable for the liftoff attempt.

An Atlas V rocket, built by United Launch Alliance, will boost Landsat into a near-polar orbit. This will be the 300th overall rocket of an Atlas-family rocket from Vandenberg, dating back to August 1962. This will be the 88th launch of an Atlas V rocket, which also previously launched the Landsat 8 mission.

A webcast of the launch will go live about 40 minutes before liftoff.

Landsat 9 launch.