- The NASA-ISRO Synthetic Aperture Radar (NISAR) mission is a landmark collaboration between the National Aeronautics and Space Administration (NASA) of the United States and the Indian Space Research Organisation (ISRO).
- It is a joint Earth observation satellite mission that aims to provide unprecedented radar imagery and data to monitor changes on the Earth’s surface with high accuracy and frequency. Scheduled for launch in 2024–2025, NISAR represents one of the most advanced radar imaging missions ever undertaken and is the first radar mission to use dual-frequency radar technology.
- At the heart of NISAR is its Synthetic Aperture Radar (SAR) system, which will operate in both L-band (provided by NASA) and S-band (provided by ISRO). This dual-band capability enables the satellite to penetrate different types of vegetation, ice, and soil to detect subtle changes in the Earth’s crust and surface features. The radar system is mounted on a large deployable 12-meter diameter reflector antenna, which rotates to sweep wide areas of the Earth below with high resolution, regardless of weather or daylight conditions.
- The mission is designed to monitor and collect data on some of the planet’s most pressing natural and human-induced phenomena. NISAR will track changes caused by earthquakes, volcanoes, landslides, and glacier movement, as well as ground deformation due to groundwater extraction or mining. It will also provide critical data on agriculture, wetlands, forests, and ecosystem dynamics. These insights are invaluable for understanding the impacts of climate change, supporting disaster response, and improving resource management.
- Technically, NISAR will orbit the Earth in a sun-synchronous low Earth orbit (LEO), which allows it to maintain consistent lighting conditions for imaging. The satellite will scan nearly the entire globe every 12 days, delivering a massive volume of radar data. This repeat frequency enables researchers to detect even minute changes in the Earth’s surface over time, making NISAR especially useful for time-series analysis and predictive modeling.
- From a scientific and geopolitical standpoint, NISAR is a milestone in US-India space cooperation, demonstrating how international collaboration can enhance global understanding of Earth system processes. NASA is contributing the L-band SAR instrument, a high-rate data recorder, and supporting launch integration, while ISRO is providing the S-band radar, satellite bus, and launch vehicle (expected to be the GSLV Mk II or Mk III).
- Beyond research, the mission is expected to have wide-reaching applications across governments, industries, and environmental agencies. For example, by mapping crop conditions, NISAR could help improve food security and agricultural planning. By monitoring ice sheets and glaciers, it will contribute critical data to sea-level rise forecasts. In regions prone to seismic activity, it may aid in earthquake hazard assessment by identifying areas of tectonic stress.
