The Indian Space Research Organisation (ISRO) and the National Aeronautics and Space Administration (NASA) are prepared to launch their first joint Earth observation satellite, called NISAR. The launch is scheduled at 5:40 pm on July 30 by Geosynchronous Satellite Launch Vehicle (GSLV-F16) from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh.
NASA-ISRO Synthetic Aperture Radar (NISAR) is designed to scan the Earth’s surface and capture detailed images every 12 days. The 2,392kg satellite will orbit the planet in a sun-synchronous trajectory, observing the same areas under similar lighting conditions each time it passes overhead. The GSLV-F16 rocket will launch the NISAR satellite into a 743 km Sun-synchronous orbit at an inclination of 98.40 degrees.
NISAR will be the first satellite ever to observe the Earth in two frequencies: NASA’s L-band and ISRO’s S-band. According to NASA, “Each system’s signal is sensitive to different sizes of features on Earth’s surface, and each specializes in measuring different attributes, such as moisture content, surface roughness, and motion.” This means that the satellite will be able to provide high-resolution data in any weather conditions, both during the day and night. The satellite is powerful enough to capture changes as small as one centimetre in size during its repeated observations over the same terrain.
Therefore, NISAR will help track features such as melting glaciers, shifting tectonic plates, and other landscape changes. Its frequent and wide coverage will help scientists study natural hazards, monitor crops, and understand long-term environmental changes. The collaboration also required engineers to integrate two complex radar systems into a single spacecraft that can function without any interference. It is an engineering challenge accomplished jointly by ISRO and NASA.
It is the world’s most costly earth observation satellite, costing around USD 1.5 billion, with ISRO investing Rs 469.4 crores. The satellite’s launch has been delayed multiple times, with last year’s scheduled launch being pushed back due to technical concerns. ISRO has announced that the NISAR satellite will be launched on July 30 at 5:40 p.m. IST using the GSLV-F16 rocket.
