Dipak Kurmi
On the evening of July 30, 2025, from the revered grounds of the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh, a new chapter in global space cooperation and earth observation was inscribed into history. At precisely 5:40 p.m., the Indian Space Research Organisation (ISRO), in collaboration with the National Aeronautics and Space Administration (NASA), successfully launched the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite aboard the Geosynchronous Satellite Launch Vehicle (GSLV)-F16. This momentous event not only marked the beginning of a pioneering scientific mission but also represented a triumph for bilateral scientific diplomacy, innovation, and resilience in the face of prior setbacks.
In just eighteen minutes after liftoff, the GSLV-F16 precisely injected the 2,392 kg satellite into its designated sun-synchronous polar orbit. For ISRO, which had recently faced a series of challenges — notably the unsuccessful PSLV-C61/EOS-09 mission in May 2025 and the failed orbit-raising manoeuvre of the NVS-02 satellite in January due to a valve malfunction — this success was more than a technical accomplishment. It was a resurgence of confidence and capability, underscoring ISRO’s enduring commitment to pushing the frontiers of space science.
But NISAR is far more than a technical milestone. It is emblematic of the shared vision between India and the United States to harness space technology for the common good. As the first satellite co-developed by ISRO and NASA, NISAR sets a precedent in global cooperation on climate, disaster management, agriculture, and sustainable development. With a mission life of five years, the satellite is designed to offer a torrent of insights into Earth's dynamic systems, delivering near-real-time data with unmatched precision and frequency.
One of the defining aspects of NISAR is its sophisticated dual-frequency Synthetic Aperture Radar (SAR), which integrates NASA’s L-band and ISRO’s S-band radars. This revolutionary pairing of frequencies — mounted on NASA’s 12-metre unfurlable mesh reflector antenna and supported by ISRO’s advanced I3K satellite bus — enables NISAR to detect minute changes on Earth’s surface. These range from subtle shifts in soil moisture and ground deformation to large-scale phenomena such as glacier movements, vegetation dynamics, and storm developments. The satellite will operate using SweepSAR technology, covering a swathe of 242 kilometers with high spatial resolution, and returning data every 12 days, regardless of weather conditions or daylight.
This capability is far from an academic exercise. As Casey Swails, NASA’s Deputy Associate Administrator, aptly put it, NISAR is designed to give decision-makers across the globe the tools they need to act “faster and smarter.” From mapping farmlands to improve crop yield, to monitoring tectonic movements that presage earthquakes, to delivering critical data for flood and landslide responses — NISAR’s utility spans the arc of human and environmental vulnerability. It is a sentinel in orbit, dedicated to improving resilience and sustainability on the ground.
The operational plan for NISAR is as meticulous as its engineering. Post-launch, the mission is divided into several sequential phases — launch, deployment, commissioning, and finally, science operations. The initial launch phase, successfully concluded with the satellite’s precise orbital insertion, will be followed by the deployment of the 12-metre radar reflector antenna. This complex multistage deployment, expected to commence on the tenth day after launch, will see the reflector unfurl nine metres away from the main satellite body. This intricate mechanism is critical to the satellite’s observational prowess.
The subsequent commissioning phase, stretching over 90 days, will involve a comprehensive suite of system checks and calibrations. These include validating the functionality of ISRO’s mainframe elements and NASA’s radar instruments. Only after this exhaustive testing will the satellite be cleared for science operations — the heart of the mission — which will continue uninterrupted for the remainder of NISAR’s five-year lifecycle. During this period, the satellite will maintain its science orbit through regular manoeuvres designed to minimize conflicts between data collection and orbital adjustments. Calibration and validation activities will be ongoing, ensuring that the data NISAR delivers remains of the highest fidelity.
What elevates the significance of this mission is not only its technological sophistication but also the shared investment and collaborative synergy between the two participating agencies. NASA’s Jet Propulsion Laboratory (JPL) played a central role in developing the radar antenna reflector, boom, and the L-band SAR and engineering payload. ISRO, in turn, constructed the spacecraft bus, the solar array, the S-band SAR, and also undertook the responsibility of launching the satellite aboard its GSLV platform. This deep interdependence and mutual respect between the two space agencies is a model for international cooperation in science, especially at a time when geopolitical tensions often threaten global unity in research and development.
Moreover, NISAR’s launch is historic in another sense — this is the first time that a GSLV has successfully placed a satellite into a sun-synchronous polar orbit. Traditionally, this orbit has been the domain of PSLV launches, known for their precision and reliability. The successful GSLV deployment opens up new strategic capabilities for ISRO, allowing it to diversify and strengthen its satellite launch portfolio.
As climate change accelerates and natural disasters grow in frequency and intensity, the data NISAR will provide is not merely useful; it is indispensable. The satellite’s ability to offer all-weather, day-and-night coverage at regular intervals makes it uniquely positioned to monitor both gradual environmental changes — such as glacier melt and desertification — and sudden disasters — such as earthquakes, floods, and cyclones. For countries vulnerable to climate-induced calamities, this data could prove critical in saving lives, protecting infrastructure, and guiding sustainable policy decisions.
India, with its vast agricultural landscape, stands to benefit immensely. Real-time soil moisture monitoring, floodplain mapping, and assessment of surface water resources can directly support smarter irrigation planning, mitigate the effects of droughts, and improve food security. Similarly, the satellite’s utility in mapping urban sprawl, monitoring coastline erosion, and even tracking ships for maritime security adds layers of value across sectors.
But perhaps the greatest triumph of NISAR lies not in its immediate applications, but in what it symbolizes — a commitment to science that transcends borders, a belief in shared destiny, and a reminder that when nations pool their knowledge and resources, the results can be transformative. In an age where science often finds itself ensnared in political crosscurrents, the NASA-ISRO partnership behind NISAR stands as a beacon of what constructive diplomacy looks like.
As the satellite begins its long journey of observation, orbiting silently above a planet in flux, it carries with it not just instruments and sensors, but hope — hope that data can lead to wisdom, and that wisdom can guide humanity toward a more resilient, sustainable, and cooperative future.
In the annals of space history, July 30, 2025, will be remembered not just for the launch of a satellite, but for the launch of a shared vision — where technology becomes a bridge between nations, and observation becomes a means of transformation. NISAR has taken flight, and with it, a new era of earth observation and international collaboration has dawned.
(The writer can be reached at dipakkurmiglpltd@gmail.com)
