The Indian Space Research Organisation (ISRO) successfully launched the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh, on Wednesday, July 30, 2025 at 5:40 PM. The satellite was launched aboard the GSLV-F16 rocket into a Sun Synchronous Polar Orbit. This mission marks a significant milestone in Earth observation and collaboration between the Indian and American space agencies.
NISAR is a joint project between ISRO and NASA to co-develop and launch a dual-frequency Synthetic Aperture Radar (SAR) on an Earth observation satellite. It is the first radar imaging satellite to use dual frequencies, employing both L-band (provided by NASA) and S-band (developed by ISRO) radar systems. This unique capability will allow NISAR to track minute changes in the Earth's surface, including movements as small as a centimeter.
The primary objectives of the NISAR mission are to study land and ice deformation, land ecosystems, and oceanic regions in areas of common interest to the US and Indian science communities. In addition to its primary objectives, the mission also aims to: measure the woody biomass and its changes; track changes in the extent of active crops; understand the changes in wetlands' extent; map Greenland's & Antarctica's ice sheets, dynamics of sea ice and mountain glaciers; and characterize land surface deformation related to seismicity, volcanism, landslides, and subsidence & uplift associated with changes in subsurface aquifers, hydrocarbon reservoirs, etc.
NISAR will scan the Earth and provide all-weather, day-and-night data at 12-day intervals, enabling a wide range of applications. The satellite will image the global land and ice-covered surfaces, including islands, sea-ice, and selected oceans. NISAR's unique dual-band SAR employs advanced, novel SweepSAR technique, which provides high resolution and large swath imagery. The satellite will orbit Earth 14 times a day, scanning nearly all the planet's land and ice surfaces twice every 12 days. The planned mission life is 5 years.
NISAR is touted as the world's most expensive Earth observation satellite, with a total cost estimated at US$1.5 billion. The satellite weighs 2,393 kg and will observe Earth with a 242 kilometer swath and high spatial resolution using sweeps technology for the first time.
The data collected from NISAR will reveal information about the evolution and state of Earth's crust, help scientists better understand our planet's natural processes and changing climate, and aid future resource and hazard management. The scientist added that Nisar will produce an enormous volume of high-resolution data daily, providing critical insights for scientists, disaster management authorities, policymakers, and environmental researchers.
ISRO will handle satellite commanding and operations, while NASA will provide the orbit maneuver plan and RADAR operations plan. Both ISRO and NASA ground stations will support the mission by downloading the acquired images. NISAR is designed to observe and measure some of the planet's most complex natural processes, including ecosystem disturbances, ice-sheet collapse, and natural hazards such as earthquakes, tsunamis, volcanoes, and landslides.
