Ahead of the launch of the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite scheduled for July 30, 2025, the ISRO on Monday (July 28, 2025) introduced that the satellite had been mounted on a geosynchronous satellite launch automobile (GSLV), and all programs of the rocket had been checked.
After lifting off from the second launch pad of the Satish Dhawan Space Centre in Sriharikota at 5.40 p.m. on July 30, 2025, the GSLV-F16 rocket will inject the NISAR satellite right into a 743-km sun-synchronous orbit.
Explained | What are ISRO and NASA aiming to attain with the NISAR satellite?
The NISAR satellite, weighing 2,392 kg, is a singular Earth remark satellite. It would be the first satellite to watch the Earth with a dual-frequency Synthetic Aperture Radar (SAR) — NASA’s L-band and ISRO’s S-band — each utilizing NASA’s 12-metre unfurlable mesh reflector antenna, built-in with ISRO’s modified I3K satellite bus.
With a mission life of 5 years, NISAR will observe earth with a swathe of 242 km and excessive spatial decision, utilizing SweepSAR know-how for the primary time.
Day-and-night knowledge
“The satellite will scan the entire globe and provide all-weather, day-and-night data at 12-day intervals, and enable a wide range of applications. NISAR can detect even small changes in the earth’s surface, such as ground deformation, ice sheet movement, and vegetation dynamics. Further applications include sea ice classification, ship detection, shoreline monitoring, storm characterisation, changes in soil moisture, mapping and monitoring of surface water resources, and disaster response,” the ISRO mentioned.
The NISAR mission is broadly labeled into totally different phases – launch, deployment, commissioning and science phases.
In the launch part, the satellite shall be launched by the GSLV-F16 launch automobile, whereas within the deployment part, a 12-metre reflector antenna shall be deployed in orbit 9 metres away from the satellite by a fancy multistage deployable increase. This shall be adopted by the commissioning part.
“The first 90 days after launch will be dedicated to commissioning, or in-orbit checkout, the objective of which is to prepare the observatory for science operations. Commissioning is divided into sub-phases of initial checks and calibrations of mainframe elements followed by JPL engineering payload and instrument checkout,” ISRO mentioned.
The remaining science operations part begins on the finish of commissioning and extends until the tip of NISAR’s five-year mission life.
“During this phase, the science orbit will be maintained via regular manoeuvres, scheduled to avoid or minimise conflicts with science observations. Extensive calibration and validation activities will take place,” ISRO mentioned.
