NASA and ISRO’s NISAR satellite has unfurled its record-breaking radar antenna, paving the way for global monitoring of ice, forests, and natural disasters.
Its cutting-edge dual radar system will capture Earth’s changes in incredible detail, even through clouds and vegetation.
Giant Antenna Successfully Deployed in Orbit
Measuring 39 feet (12 meters) across, the large drum-shaped antenna reflector on the NISAR (NASA-ISRO Synthetic Aperture Radar) satellite has successfully opened in low Earth orbit. Before deployment, the reflector was folded like an umbrella, waiting for the 30-foot (9-meter) support boom to extend and lock into position.
The mission, launched by ISRO on July 30 from the Satish Dhawan Space Centre on India’s southeastern coast, will observe a wide range of Earth processes. NISAR will monitor the shifting of ice sheets and glaciers, detect land deformation caused by earthquakes, volcanoes, and landslides, and track subtle changes in forests and wetlands with precision down to fractions of an inch. Beyond research, the data will provide valuable guidance for decision-makers in areas such as disaster response, infrastructure management, and agriculture.
NISAR mission team members at NASA JPL, working with colleagues in India, executed the deployment of the satellite’s radar antenna reflector on Aug. 15, 2025. About 39 feet (12 meters) in diameter, the reflector directs microwave pulses from NISAR’s two radars toward Earth and receives the return signals. Credit: NASA/JPL-Caltech
A Milestone for Earth Science and Disaster Preparedness
“The successful deployment of NISAR’s reflector marks a significant milestone in the capabilities of the satellite,” said Karen St. Germain, director, Earth Science Division at NASA Headquarters in Washington. “From innovative technology to research and modeling to delivering science to help inform decisions, the data NISAR is poised to gather will have a major impact on how global communities and stakeholders improve infrastructure, prepare for and recover from natural disasters, and maintain food security.”
NISAR also represents a leap forward in radar technology. For the first time, a satellite will carry two types of synthetic aperture radar (SAR). The L-band system can penetrate clouds and dense forest canopy, while the S-band system also sees through clouds but is especially sensitive to lighter vegetation and snow moisture. The newly deployed reflector is essential for both instruments, making its successful opening a critical achievement for the mission.
Years of Engineering Pay Off for Record-Breaking Antenna
“This is the largest antenna reflector ever deployed for a NASA mission, and we were of course eager to see the deployment go well. It’s a critical part of the NISAR Earth science mission and has taken years to design, develop, and test to be ready for this big day,” said Phil Barela, NISAR project manager at NASA’s Jet Propulsion Laboratory in Southern California, which managed the U.S. portion of the mission and provided one of the two radar systems aboard NISAR. “Now that we’ve launched, we are focusing on fine-tuning it to begin delivering transformative science by late fall of this year.”
Unfolding the Space Umbrella: The Bloom Process
Weighing about 142 pounds (64 kilograms), the reflector features a cylindrical frame made of 123 composite struts and a gold-plated wire mesh. On August 9, the satellite’s boom, which had been tucked close to its main body, started unfolding one joint at a time until it was fully extended about four days later. The reflector assembly is mounted at the end of the boom.
Then, on Aug. 15, small explosive bolts that held the reflector assembly in place were fired, enabling the antenna to begin a process called the “bloom” — its unfurling by the release of tension stored in its flexible frame while stowed like an umbrella. Subsequent activation of motors and cables then pulled the antenna into its final, locked position.
High-Resolution Earth Imaging on a Global Scale
To image Earth’s surface down to pixels about 30 feet (10 meters) across, the reflector was designed with a diameter about as wide as a school bus is long. Using SAR processing, NISAR’s reflector simulates a traditional radar antenna that for the mission’s L-band instrument would have to be 12 miles (19 kilometers) long to achieve the same resolution.
“Synthetic aperture radar, in principle, works like the lens of a camera, which focuses light to make a sharp image. The size of the lens, called the aperture, determines the sharpness of the image,” said Paul Rosen, NISAR’s project scientist at JPL. “Without SAR, spaceborne radars could generate data, but the resolution would be too rough to be useful. With SAR, NISAR will be able to generate high-resolution imagery. Using special interferometric techniques that compare images over time, NISAR enables researchers and data users to create 3D movies of changes happening on Earth’s surface.”
The NISAR satellite is the culmination of decades of space-based radar development at JPL. Starting in the in the 1970s, JPL managed the first Earth-observing SAR satellite, Seasat, which launched in 1978, as well as Magellan, which used SAR to map the cloud-shrouded surface of Venus in the 1990s.
More About NISAR
The NASA-ISRO Synthetic Aperture Radar (NISAR) mission is a landmark Earth-observing satellite and the product of years of close collaboration between the United States and India. Launched from India’s Satish Dhawan Space Centre, NISAR represents the largest joint Earth science project ever between the two nations, designed to monitor Earth’s dynamic systems with unprecedented precision.
At its core, NISAR carries two advanced radar systems — NASA’s L-band SAR and ISRO’s S-band SAR — working together to track ice sheet movement, land deformation from earthquakes and volcanoes, and subtle changes in ecosystems. The spacecraft itself was built by ISRO’s U R Rao Satellite Centre, with the S-band radar supplied by ISRO’s Space Applications Centre. NASA’s Jet Propulsion Laboratory (JPL), managed by Caltech, contributed the L-band radar, antenna reflector, boom, and high-rate communications systems, as well as the payload data subsystem.
NISAR’s journey didn’t end with launch: ISRO’s Telemetry, Tracking and Command Network is overseeing key deployment operations in orbit, while NASA’s Goddard Space Flight Center operates the Near Space Network to receive the satellite’s science data. Together, these contributions highlight the mission’s spirit of cooperation and innovation, setting the stage for transformative science that will deepen humanity’s understanding of a rapidly changing planet.
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1 Comment
Why was this launched when NASA is shutting down all Earth science? Hasn’t the team supervising it already been fired? No more research that could indicate climate change is going to be allowed.