The NASA-ISRO Synthetic Aperture Radar (NISAR) satellite was successfully launched on Wednesday (July 30, 2025) from the Satish Dhawan Space Centre at Sriharikota in Andhra Pradesh.
The Geosynchronous Satellite Launch Vehicle (GSLV)-F16 rocket carrying the earth observation satellite lifted off from the second launch pad of the space centre at 5.40 p.m. Eighteen minutes later, it injected the satellite into a sun-synchronous orbit.
Also Read: NISAR mission launch highlights
“The GSLV-F16 vehicle has successfully and precisely injected the NISAR satellite weighing 2,392 kg into its intended orbit,” Indian Space Research Organisation (ISRO) Chairman V. Narayanan said after the launch.
First joint venture
The NISAR, which has a mission life of five years, is the first satellite jointly developed by the ISRO and the U.S.’s National Aeronautics and Space Administration (NASA).
Casey Swails, Deputy Associate Administrator at NASA, said NISAR will give decision-makers the tools to monitor critical infrastructure, respond faster and smarter to natural disasters such as earthquakes, floods, and landslides, as well as map farmland to improve crop output and more.
24-hour data
The NISAR satellite will scan the earth 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 on 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 stated.
NASA said that mission controllers for the NASA-ISRO NISAR mission had received full acquisition of signal from the spacecraft.
NISAR is the first satellite to observe the earth with a dual-frequency Synthetic Aperture Radar (SAR) — NASA’s L-band and ISRO’s S-band — both using NASA’s 12-metre unfurlable mesh reflector antenna, integrated with ISRO’s modified I3K satellite bus.
It will observe earth with a swathe of 242 km and high spatial resolution, using SweepSAR technology for the first time.
Also read: NISAR satellite will be able to monitor tectonic movements accurately, says ISRO chief
According to NASA officials, its Jet Propulsion Laboratory (JPL) built the radar antenna reflection, radar antenna boom, L-Band SAR and engineering payload, while the ISRO developed the spacecraft bus, solar array S-band SAR and the launch vehicle.
The NISAR mission is broadly classified into different phases – launch, deployment, commissioning and science phases.
The launch phase has been accomplished with the launch of the GSLV-F16 rocket.
During the deployment phase, a 12-metre reflector antenna will be deployed in orbit nine metres away from the satellite by a complex multistage deployable boom. The deployment process will begin on the 10th day after the launch. This will be followed by the commissioning phase.
“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,” the ISRO said.
The final science operations phase begins at the end of commissioning and extends till the end 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,” the ISRO said.
This is the first time that a GSLV has put a satellite in a sun-synchronous polar orbit.
Relief to ISRO
The successful launch of the NISAR comes as a relief to the ISRO as it had suffered back-to-back setbacks. Its previous launch, the PSLV-C61/EOS-09 mission on May 18, 2025 could not be accomplished due to a technical glitch.
The space agency also suffered a setback with the NVS-02 satellite, which was launched by a GSLV on January 29, 2025. Post launch, the ISRO was unable to perform the intended orbit-raising operations for the NVS-02 satellite due to a valve malfunction.
Published – July 30, 2025 05:58 pm IST
