With $15.9M Funding Extension, the Force Is With Forest-Mapping GEDI

"GEDI has been extraordinarily successful as a mission," said its principal investigator, Distinguished University Professor Ralph Dubayah in the Department of Geographical Sciences. "It provides the only spaceborne lidar observations specifically designed to retrieve forest canopy structure in dense forests. These measurements are fundamentally changing our ability to characterize the world's forests and understand how they are changing."

Launched in December 2018, GEDI began collecting science data in March 2019 with an original mission duration of two years. Using light detection and ranging (lidar) laser technology, the instrument has collected billions of three-dimensional observations of Earth's forests, providing unprecedented information about forest height, canopy structure and aboveground biomass. 

These measurements help scientists estimate how much carbon forests store, understand their role in the global carbon cycle and assess how disturbances such as wildfires and deforestation affect forest ecosystems, carbon stocks and biodiversity.

NASA periodically reviews its Earth science missions operating beyond their original lifetimes. Independent experts evaluate each mission's scientific contributions, relevance to national interests, technical performance and cost risks to determine whether continued operations merit the investment.

In the 2026 review, GEDI received an Excellent/Very Good rating for overall science, a High rating for its utility to national interests, and favorable Low ratings for both technical and cost risks. The mission has supported more than 800 scientific publications, including more than 40 in the Nature and Science family of journals. 

The extension will bring GEDI's record of forest observations to nearly a decade. Such long-term measurements are essential for understanding the balance between forest disturbance and regrowth and how these processes affect the global carbon cycle.

"One of the most important questions in climate science is how much carbon forests are absorbing and storing, and how that is changing over time," Dubayah said. "By continuing these observations, we can better understand how forests respond to fire, deforestation and other disturbances, how quickly they recover, and what those changes mean for ecosystem resilience and the global carbon budget."

GEDI data also have important practical applications. Detailed measurements of forest structure can improve predictions of wildfire behavior, help scientists assess post-fire recovery and support the management and conservation of forest ecosystems.

"The continuity of GEDI was a priority for the scientific community because these observations are so unique," Dubayah said. "The additional years of measurements will provide an invaluable record of ecosystem change that simply cannot be recreated once the mission ends."

The extension will also help ensure continuity with NASA's next generation of spaceborne lidar observations. The Earth Dynamics Geodetic Explorer (EDGE), selected by NASA in 2026 and currently planned for launch in 2030, builds on the scientific and technological foundation GEDI established. EDGE will use a new swath-imaging lidar approach to provide three-dimensional measurements of terrestrial ecosystem structure on a global scale. The mission will also measure the surface topography of Earth's ice sheets and glaciers.

The Department of Geographical Sciences is a major partner in EDGE. Associate Professor John Armston serves as deputy principal investigator and leads the mission's terrestrial ecosystem structure science. Dubayah, Professor George Hurtt, Associate Professor Laura Duncanson and Research Professor Michelle Hofton are also co-investigators.

"GEDI has pioneered a new era of space-based lidar observations of Earth's forests, and EDGE will take these capabilities to the next level," Dubayah said. "Together, the missions represent a sustained effort to understand the three-dimensional structure of Earth's ecosystems and how they are changing. The continuity between GEDI and EDGE is especially important for the future of terrestrial ecosystem science."