- NASA-ISRO's NISAR satellite deployed its 12m radar antenna in orbit on August 15, 2025
- Full science operations to begin by October 2025, aiding disaster prediction and environmental study
- The $1.3 billion satellite will track Earth surface changes for disaster and climate monitoring
In a landmark moment for global Earth science and international space collaboration, the world's most expensive civilian Earth imaging satellite-the NASA-ISRO Synthetic Aperture Radar (NISAR)-has successfully deployed its massive radar antenna in orbit, marking a critical step toward delivering life-saving data to communities across the globe.
If the mission progresses on track by the next Monsoon, India will have a great new watchtower in space that can help predict landslides, glacier lake outburst, and combined with weather data even help assess likely cloud bursts, all of these have been dogging the mountains of India in recent times. It is for this reason the NISAR satellite is called a life saving mission. The world has never seen a watch tower like this before and hence disaster managers are hoping all goes well for this hugely important mission.
The 12m radar antenna reflector of #NISAR is now fully ‘bloom' 🌸
— Dr. S Somanath (@SomanathSpeak) August 16, 2025
Congratulations to @NASA JPL & @isro on this tremendous milestone!
The systematic deployment—driven by multiple motor actuators & intricate cabling—faced many challenges. Some of the challenges involved were… pic.twitter.com/7ApPetgyYg
Launched on July 30, 2025, from the Satish Dhawan Space Centre on India's south -eastern coast, NISAR is a joint mission between the Indian Space Research Organisation (ISRO) and the National Aeronautics and Space Administration (NASA). The satellite lifted off aboard India's GSLV-F16 rocket, a powerful vehicle powered by an indigenous cryogenic engine-a technology once denied to India but now a symbol of its space prowess.
Weighing over 2.8 tons and costing $1.3 billion, NISAR is the most expensive Earth observation satellite ever built. Its mission: to track minute changes in Earth's surface-down to fractions of an inch-caused by earthquakes, landslides, volcanic eruptions, glacier movements, and forest degradation. The data it collects will be vital for disaster preparedness, infrastructure monitoring, and climate resilience.
"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," Germain said.
A Technological Marvel
Seventeen days after launch, on August 15, the satellite's 12-meter radar antenna reflector unfurled in orbit. This drum-shaped reflector, made of gold-plated wire mesh and supported by a 9-meter boom, is the largest ever deployed for a NASA mission in low Earth orbit. It directs microwave pulses from NISAR's dual radar systems-L-band from NASA and S-band from ISRO-toward Earth and receives the return signals, enabling high-resolution imaging even through clouds, vegetation, and rain.
The unfurling process, dubbed the "bloom," involved the release of tension stored in the reflector's flexible frame, followed by motorized activation that locked the antenna into its final position. This milestone sets the stage for science operations to begin by late October 2025.
A Mission to Protect and Inform
"This is a first-of-its-kind, jewel radar satellite that will change the way we study our home planet and better predict a natural disaster before it strikes," said Nicky Fox, NASA's Science Mission Chief.
NASA's Deputy Associate Administrator Casey Swails added, "It really shows the world what our two nations can do. But more so than that, it really is a pathfinder for relationship building".
The satellite will revisit nearly every part of Earth's land and ice surfaces every 12 days, enabling scientists to create 3D time-lapse maps of surface changes. These insights will help forecasters and first responders stay ahead of floods, landslides, and other disasters, and aid decision-makers in agriculture, urban planning, and environmental conservation.
India's Role: From Launchpad to Leadership
India's contribution to the mission is not just symbolic-it's strategic. The GSLV-F16 rocket, which carried NISAR into orbit, represents India's growing capability in launching heavy payloads. The rocket's cryogenic engine, once a point of geopolitical tension, now powered mission that benefit the entire planet.
"Congratulations India!" tweeted India's Minister of Science and Technology Jitendra Singh after the successful launch. "The mission will benefit the entire world community".
ISRO's S-band radar complements NASA's L-band system, allowing NISAR to detect changes in vegetation, moisture, and snow with unprecedented sensitivity. Together, they form a powerful tool for monitoring Earth's dynamic systems.
What's Next?
With the antenna now deployed, the NISAR team will begin calibrating the radar systems and preparing for full-scale science operations. The satellite is expected to start delivering data by October 2025, with applications ranging from tracking glacier melt in Antarctica to monitoring groundwater depletion in India.
As Wendy Edelstein, NISAR's Deputy Project Manager at NASA's Jet Propulsion Laboratory, noted, "NISAR is a 50-50 partnership between NASA and ISRO. It represents the largest collaboration of its kind and a model for future missions".
In a world increasingly vulnerable to climate change and natural disasters, NISAR stands as a beacon of hope-an orbiting sentinel powered by international cooperation, cutting-edge technology, and a shared commitment to saving lives.
