The Nisar mission, a $1.5 billion joint venture between the Indian Space Research Organisation (Isro) and the United States’ National Aeronautics and Space Administration (Nasa), is now set to revolutionise climate monitoring and disaster response, not just for India, but worldwide.
India crossed a milestone in its space and climate ambitions on Wednesday with the successful launch of the Nasa-Isro Synthetic Aperture Radar (Nisar) satellite from the Satish Dhawan Space Centre in Sriharikota.
The 2393-kilogram satellite lifted off at 5:40 pm IST aboard Isro’s Geosynchronous Satellite Launch Vehicle (GSLV) into the vacuum of space.
The Nisar mission, a $1.5 billion joint venture between the Indian Space Research Organisation (Isro) and the United States’ National Aeronautics and Space Administration (Nasa), is now set to revolutionise climate monitoring and disaster response, not just for India, but worldwide.
Nisar is the world’s first Earth-mapping satellite equipped with dual-frequency synthetic aperture radar.
This combination of Nasa’s L-band radar and Isro’s S-band radar enables Nisar to capture the faintest shifts on Earth’s surface — whether under forests, clouds, or even in darkness — detecting movements as small as a few millimetres.
The synthetic aperture radar combines multiple measurements, taken as a radar flies overhead, to sharpen the scene below. It works like conventional radar, which uses microwaves to detect distant surfaces and objects, but steps up the data processing to reveal properties and characteristics at high resolution.
Nisar is designed to orbit the planet every 97 minutes, mapping nearly all land and ice surfaces with an unparalleled imaging swath every 12 days.
The implications for India, often at the frontline of climate change impacts and natural disasters, are profound.
Nisar’s freely accessible, near-real-time data will empower Indian researchers, disaster managers, and policymakers to monitor glacier movements in the Himalayas, detect fault-line shifts before earthquakes, track agricultural cycles, and manage water resources more effectively.
With this tool, India is set to improve forecasting for floods, droughts, and landslides, enabling rapid response and informed policy decisions.
A MAJOR COLLABORATION
This historic mission not only cements India’s position as a leader in space-based climate monitoring but also demonstrates how international collaboration can drive scientific progress for the collective good.
The development of the satellite spanned nearly a decade as the Indian and American space agencies came together for development, launch and now the operations of the satellite.
The S-Band SAR and L-Band SAR were independently developed, integrated, and tested by Isro and JPL/Nasa, respectively. The Integrated Radar Instrument Structure (IRIS), comprising both SAR systems and additional payload elements, was assembled and tested at JPL/NASA before being delivered to Isro.
The mainframe satellite elements and all payloads were then assembled, integrated, and tested at Isro’s U R Rao Satellite Centre (URSC).
WHAT’S NEXT AFTER LAUNCH?
The NISAR mission comprises four main phases: Launch, Deployment, Commissioning, and Science Operations.
In the Deployment Phase, a 12-meter diameter reflector will be extended 9 meters from the satellite using a complex deployable boom developed by JPL/Nasa.
The 90-day Commissioning Phase involves system checks and calibrations. The Science Operations Phase begins thereafter, continuing through the mission’s life with regular orbit manoeuvres, calibration/validation activities, and coordinated observation plans for L- and S-band instruments managed jointly by JPL and Isro.
