The 12-metre antenna reflector, the largest ever launched on a NASA mission, unfurled in low-Earth orbit this month after being stowed compactly during lift-off. Supported by a nine-metre boom, the drum-shaped structure will play a vital role in delivering high-resolution radar imagery of Earth.
The NASA-ISRO Synthetic Aperture Radar (NISAR) lifted off from the Satish Dhawan Space Centre on 30 July. Once fully operational later this year, the satellite will monitor changes in ice sheets, glaciers, forests, wetlands and farmland. It will also track ground deformation caused by earthquakes, landslides and volcanic activity, with the data expected to aid disaster response, infrastructure monitoring and food security.
Karen St Germain, director of NASA’s Earth science division, celebrated the deployment milestone, saying, “The data NISAR is poised to gather will have a major impact on how communities prepare for natural disasters, manage resources and maintain resilience.”
At the heart of the mission are two sophisticated radar systems, an L-band system from NASA, capable of penetrating clouds and forest canopies, and an S-band system from ISRO, which is particularly sensitive to vegetation and snow moisture. Together, the instruments will produce imagery with a resolution of around 10 metres, sufficient to detect subtle shifts in landscapes.
The reflector itself weighs 64 kilograms and consists of 123 composite struts supporting a gold-plated wire mesh. Its deployment involved a carefully choreographed sequence: first the boom extended, then explosive bolts released the reflector, allowing it to “bloom” like an umbrella before motors and cables locked it into place.
Phil Barela, NISAR project manager at NASA’s Jet Propulsion Laboratory, said years of design and testing had gone into the mechanism. “Now that we’ve launched, we’re focused on fine-tuning the satellite so it can start delivering transformative science by late 2025,” he said.
The US$1.5 billion mission reflects decades of radar research and a long-standing partnership between the United States and India. NISAR is expected to provide unprecedented insights into Earth’s dynamic processes and serve as a benchmark for future international collaborations in space science.