A Landmark Partnership in Space
NISAR, which stands for NASA-ISRO Synthetic Aperture Radar, is a joint Earth-observing mission between the United States' and India's space agencies. Launched in July 2025, it represents one of the most significant collaborations between the two nations
in space exploration. The satellite is equipped with two advanced radar systems, an L-band built by NASA and an S-band built by ISRO. This dual-frequency capability is a first, allowing NISAR to observe a vast range of changes on our planet with incredible precision. The mission's primary goal is to make global measurements of the causes and consequences of land surface changes, from the slow creep of a glacier to the sudden upheaval of an earthquake.
The Magic of Seeing Through Clouds
The key to NISAR's power is its Synthetic Aperture Radar (SAR). Unlike optical satellites that work like a camera and are blinded by clouds or darkness, SAR sends microwave pulses toward the Earth's surface and analyses the signals that bounce back. Because these microwaves can penetrate clouds, rain, and even forest canopies, NISAR provides an uninterrupted view of the planet. This is a game-changer, especially for a country like India, where the monsoon season can obscure vast regions for months. The satellite scans nearly all of Earth's land and ice twice every 12 days, detecting changes as small as a centimetre. Recent images from early 2026, for instance, were able to clearly show the extent of major flooding in Mozambique, even though the area was completely covered by clouds.
Unprecedented Data for a Dynamic Planet
As of July 2026, both NASA and ISRO have begun releasing NISAR's data to the public on an ongoing basis. This includes daily processed data from ISRO's S-band radar available via the Bhoonidhi portal and calibrated L-band data from NASA. This open-data policy will empower scientists, disaster management agencies, and researchers worldwide. The sheer volume of information is staggering—enough to fill over 150 high-capacity hard drives every day. The data provides detailed insights into ecosystem disturbances, the melting of ice sheets, and subtle ground movements. For example, early mission data has already revealed how parts of Mexico City are sinking due to groundwater extraction and provided stunningly detailed images of glacial fractures in Antarctica.
A Boon for India's Future
For India, NISAR's capabilities are particularly vital. ISRO has identified a range of applications that will directly benefit the nation. The S-band radar is ideal for monitoring crop health and soil moisture, which can revolutionise agricultural planning and help ensure food security. In the Himalayas, the satellite will track snow and glaciers, providing crucial information for managing water resources and assessing landslide risks. Its ability to detect minute surface deformations will improve early warnings for earthquakes and volcanic activity. Furthermore, it will monitor India's extensive coastline, studying erosion and other coastal processes. ISRO has already launched the NISAR Utilization Programme (NISAR UP) to encourage Indian researchers to use this data for a wide array of applications.
