NASA’s Earth Observing Fleet: Celebrating Milestones and Looking Ahead
NASA’s Earth Observing fleet continues to make remarkable advances, even as it ages with grace. This fleet is crucial for collecting data that facilitate our understanding of Earth’s complex systems. Recent milestones highlight the enduring success of these missions and set the stage for future innovations in Earth observation.
Terra: A Quarter Century of Observations
The Terra satellite, a pioneering mission of NASA’s Earth Observing System (EOS), celebrated a significant milestone by completing 25 years in orbit on December 18, 2024. When Terra was launched in 1999, it was designed for a six-year mission. However, its operational life has far exceeded expectations, thanks to the efforts of dedicated scientists and engineers who have worked to extend its capabilities.
Terra is equipped with five sophisticated instruments: the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Clouds and the Earth’s Radiant Energy System (CERES), Multi-angle Imaging SpectroRadiometer (MISR), Moderate Resolution Imaging Spectroradiometer (MODIS), and Measurement of Pollution in the Troposphere (MOPITT). Together, these instruments have created a comprehensive satellite record of global scientific processes. Terra has provided invaluable data on temperature changes, glaciers, clouds, vegetation, land use, air quality, and natural hazards like hurricanes, wildfires, and volcanic eruptions.
On December 18, 2024, NASA celebrated Terra’s 25th anniversary with an event at the Goddard Space Flight Center (GSFC) Visitor’s Center. The celebration included remarks from senior NASA management and other key figures who reflected on Terra’s development and achievements. More details on the celebration can be found here.
OCO-2 and OCO-3: Advancing Carbon Monitoring
Another mission reaching a significant milestone is the Orbiting Carbon Observatory-2 (OCO-2), which celebrated its tenth anniversary last summer. Launched on July 2, 2014, OCO-2 was initially a pathfinder mission designed to measure carbon dioxide (CO2) with exceptional precision and accuracy. This mission has provided unprecedented insights into the carbon cycle, revealing how Earth’s ecosystems absorb and emit CO2 in response to various factors, including extreme weather events and human activities.
OCO-2’s data have opened new avenues for understanding the carbon cycle’s response to human-driven changes, such as the impact of COVID-19 lockdowns on atmospheric CO2 levels. The mission has also improved the quantification of emissions from large power plants and cities. Additionally, OCO-2 maps vegetation fluorescence, offering a promising early warning indicator of flash droughts.
Further extending the legacy of OCO-2, OCO-3 was launched to the International Space Station (ISS) in 2019 and marked five years in orbit on May 4, 2024. Built from spare parts during OCO-2’s construction, OCO-3 shares similar instrument sensitivity but benefits from its unique vantage point on the ISS. This allows for significant differences in spatial and temporal sampling, enabling tracking of CO2 for diurnal variability.
DSCOVR: A Decade at the L1 Lagrange Point
Located about 1 million miles from Earth, the Deep Space Climate Observatory (DSCOVR) celebrated its tenth anniversary of launch on February 11, 2025. Orbiting the "L1" Lagrange point, DSCOVR is equipped with two NASA Earth observing instruments: the Earth Polychromatic Camera (EPIC) and the National Institute of Standards and Technology (NIST) Advanced Radiometer (NISTAR). These instruments provide continuous observation of the entire sunlit side of Earth, offering unique insights into our planet’s climate and energy balance.
At the 10th DSCOVR EPIC NISTAR Science Team Meeting, former U.S. Vice President Al Gore highlighted the importance of remote sensing and the future of Earth observations. Presentations from mission leadership and representatives from NASA and NOAA covered DSCOVR operations, EPIC calibration, and NISTAR’s status and scientific contributions.
Advancing Earth Science with Airborne Platforms
NASA’s Airborne Science Program operates a diverse fleet of aircraft and unpiloted aerial vehicles to study Earth and space science. Since 1987, the modified McDonnell Douglas DC-8 aircraft has been a cornerstone of this program, contributing vital data to the scientific community. However, in April 2024, NASA retired the DC-8, replacing it with a more advanced Boeing 777 aircraft. This new aircraft promises enhanced capabilities for future Earth science missions.
To honor the DC-8’s legacy, NASA hosted a workshop titled "Contributions of the DC-8 to Earth System Science at NASA" on October 24-25, 2024. This event reflected on the aircraft’s contributions to Earth system science, marking the end of an era and the beginning of a new chapter in airborne research.
Recent NASA Field Campaigns
NASA’s commitment to understanding Earth’s atmosphere is evident through recent field campaigns. These campaigns coordinate ground observations with aircraft flights and satellite overpasses, providing a comprehensive view of atmospheric conditions over specific areas.
The Westcoast & Heartland Hyperspectral Microwave Sensor Intensive Experiment (WHyMSIE) campaign, held from October 17 to November 18, 2024, focused on capturing a wide range of thermodynamic and moisture conditions across various surface types. This campaign served as a prototype for a future NASA planetary boundary-layer mission, utilizing multiple observing nodes to provide a comprehensive picture of essential atmospheric variables.
The GSFC Lidar Observation and Validation Experiment (GLOVE) was conducted in February 2025 at Edwards Air Force Base, California. GLOVE aimed to validate NASA ICESat-2 atmospheric data products and ESA’s EarthCARE lidar, radar, and spectrometer products.
NASA’s FireSense project, focused on addressing wildland fire management challenges, completed an airborne campaign in August 2024 in Missoula, MT. This campaign involved data collection flights and weather balloon launches to study wildfire smoke-impacted airsheds.
Recognition and Outreach
In recognition of his contributions to Earth science research, Jack Kaye, Associate Director for research with NASA’s Earth Science Division, received the William T. Pecora Award. His leadership has spurred advancements in Earth science research, sensor development, and NASA’s satellite and aircraft missions.
On the outreach front, NASA continued its tradition of participating in the annual American Geophysical Union (AGU) meeting held in Washington, DC, from December 9-14, 2024. As a partner and exhibitor, NASA shared its cutting-edge research, data, and technology with Earth and planetary science professionals worldwide. The AGU meeting serves as a platform for NASA scientists to publish findings and set goals for the upcoming year.
In Memoriam: Honoring Pioneers in Earth Science
As we celebrate these milestones, we also reflect on the contributions of individuals who have shaped Earth’s Observing System history. Notable obituaries include:
- Jeff Dozier: An environmental scientist and former EOS Project Scientist, Jeff embraced remote sensing with satellites to measure snow properties and contributed significantly to spatial modeling and environmental informatics.
- Berrien Moore III: As Dean of the College of Atmospheric and Geographic Sciences at the University of Oklahoma, Berrien played pivotal roles in NASA’s advisory committees and received NASA’s highest civilian honor, the Distinguished Public Service Medal.
- Pierre Morel: The first director of the World Climate Research Programme, Pierre developed tools for studying the atmosphere and received the 2008 Alfred Wegener Medal for his contributions to climate research.
For further details on these individuals, you can read their full obituaries on NASA’s website.
NASA’s Earth Observing fleet continues to evolve, pushing the boundaries of what we know about our planet. These missions and milestones underscore the importance of sustained scientific exploration and innovation as we seek to understand and protect Earth’s complex systems.
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