Nisar Key Figure in Space Diplomacy's Evolution
NASA-ISRO Synthetic Aperture Radar (NISAR) Satellite Launched
In a significant step forward for international collaboration, the Indian Space Research Organisation (Isro) and the National Aeronautics and Space Administration (Nasa) have launched the Nasa-Isro Synthetic Aperture Radar (Nisar) satellite. This satellite, equipped with two advanced radar instruments, marks a new era in Earth observation.
Nisar features an L-band radar provided by Nasa and an S-band radar provided by Isro, operating together for the first time on a free-flying space mission. The L-band radar, built by Nasa, gives Indian scientists access to data that penetrates forest, snow, and soil, enabling better tracking of environmental and geological changes. The S-band radar, previously developed and operated by Isro in satellites like RISAT-1A and RISAT-2B, primarily uses S-band and X-band radar.
The unique feature of Nisar is its ability to use dual-frequency radar - L-band and S-band synthetic aperture radar (SAR) - on a single platform. This allows Nisar to detect surface features of varying sizes and characteristics, enabling detailed measurement of soil moisture, forest biomass, land and ice motion, agriculture, ecosystems, and infrastructure movement.
One of the key benefits of Nisar is its ability to penetrate clouds and operate both day and night, thus allowing consistent monitoring even during storms or darkness, unlike optical sensors. Nisar’s data will enable new insights into Earth's changing surfaces, natural disasters, sea level rise, groundwater, and ecosystem health globally. It aims to observe Earth’s land and ice-covered surfaces with about 12-day repeat coverage, effectively sampling every 6 days with high spatial resolution (3–10 meters) for a baseline three-year mission.
Nisar will generate a very large volume of data—about 80 terabytes daily—supporting free and open access to processed information via the cloud, facilitating broad scientific research and applications globally. This mission signifies a significant international collaboration combining NASA’s and ISRO’s expertise to provide more comprehensive Earth system observations than previous synthetic aperture radar satellites.
Nisar's data will provide key insights for scientists, policymakers, and disaster management agencies. The satellite was launched into a sun-synchronous polar orbit using the GSLV Mk II rocket, which is around 600-800 km from the earth, different from the elliptical Geostationary Transfer Orbit lying at 200 km to 36,000 km away. This launch enhances India’s capabilities in deploying heavier and more complex payloads.
Nisar stands as a testimony for science diplomacy and represents the maturing strategic partnership between India and the US. It provides a welcome relief from ultranationalist rivalry and protectionism among nations across the world in the Donald Trump era.
References: [1] https://www.nasa.gov/feature/nisar-mission-to-explore-earth-system-changes [2] https://www.isro.gov.in/update/nisar-mission [3] https://www.nasa.gov/mission_pages/nisar/main/index.html [4] https://www.thehindu.com/sci-tech/space/nisar-satellite-launched-by-isro-nasa-to-study-earth-system-changes/article36474689.ece
The Nasa-Isro Synthetic Aperture Radar (Nisar) satellite, launched recently, is a product of international collaboration between NASA and ISRO. This satellite, with its L-band radar provided by Nasa and S-band radar provided by Isro, is revolutionizing the field of Earth observation through space and astronomy, while also advancing the frontier of environmental-science.
This unique, dual-frequency radar-equipped satellite, capable of detecting surface features of varying sizes and characteristics, is expected to generate a large volume of data supporting broad scientific research and applications in areas such as soil moisture, forest biomass, agriculture, ecosystems, and infrastructure movement.
