GSLV Mk II | NISAR (NASA-ISRO Synthetic Aperture Radar)
GSLV Mk II • GSLV
📝 Mission Description
NISAR Mission: A Landmark Collaboration in Earth Observation via GSLV Mk II
On July 30, 2025, India's Geosynchronous Satellite Launch Vehicle Mark II (GSLV Mk II) is set to propel the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite into orbit from the Satish Dhawan Space Centre in Sriharikota. This joint mission represents a pivotal advancement in global Earth monitoring, combining cutting-edge radar technology to deliver unprecedented insights into planetary dynamics.
At the heart of the NISAR mission are its ambitious objectives: to map the elevation of Earth's land and ice masses with remarkable frequency and precision. The satellite will conduct observations 4 to 6 times a month at resolutions of 5 to 10 meters, enabling scientists to track subtle changes in ecosystems, ice sheets, and natural hazards. NISAR's dual-band radar system—featuring NASA's L-band synthetic aperture radar (SAR) and ISRO's S-band SAR—allows it to penetrate clouds, vegetation, and even shallow soil layers, making it ideal for all-weather, day-and-night imaging. This capability is crucial for monitoring complex processes like ecosystem disturbances, ice-sheet collapse, earthquakes, tsunamis, volcanoes, and landslides. By generating vast datasets—estimated at 80 terabytes per day—the payload will support applications in agriculture, disaster management, and climate modeling, potentially revolutionizing how we predict and respond to environmental shifts.
The GSLV Mk II, ISRO's workhorse for geosynchronous missions, embodies robust engineering tailored for heavy payloads. Standing approximately 49 meters tall and weighing around 420 tons at liftoff, it features a three-stage design: a solid-fuel first stage (S139) with four liquid strap-on boosters, a liquid-fueled second stage (GS2) using the Vikas engine, and a cryogenic upper stage (CUS) powered by the indigenous CE-7.5 engine, which burns liquid hydrogen and oxygen for high efficiency. This configuration provides a payload capacity of up to 2,500 kg to geostationary transfer orbit (GTO), making it suitable for NISAR's 2,800 kg mass. Technical innovations include advanced avionics for precise trajectory control and a redesigned cryogenic stage that enhances thrust and reliability, addressing past challenges in cryogenic propulsion.
Historically, the GSLV Mk II has a mixed but improving performance record. Since its maiden flight in 2001, the program has seen 15 launches by
ℹ️ Official Details
The NASA-ISRO Synthetic Aperture Radar, or NISAR satellite, will use advanced radar imaging to map the elevation of Earth's land and ice masses 4 to 6 times a month at resolutions of 5 to 10 meters. It is designed to observe and measure some of the planet's most complex natural processes, including ecosystem disturbances, ice-sheet collapse, and natural hazards such as earthquakes, tsunamis, volcanoes and landslides.
Under the terms of the agreement, NASA will provide the mission's L band synthetic aperture radar (SAR), a high-rate telecommunication subsystem for scientific data, GPS receivers, a solid-state recorder, and a payload data subsystem. ISRO will provide the satellite bus, an S band synthetic aperture radar, the launch vehicle, and associated launch services.
🎯 Post-Launch Analysis
The GSLV Mk II launch of the NISAR (NASA-ISRO Synthetic Aperture Radar) mission on July 30, 2025, achieved a successful orbital insertion and payload deployment, marking a significant milestone in Indo-US space collaboration. The rocket's technical performance was flawless, ensuring precise delivery of the satellite into its intended orbit. NISAR, equipped with dual L and S band SAR systems, was deployed seamlessly, with initial telemetry confirming operational status. Key engineering outcomes include validation of GSLV Mk II’s reliability for heavy payloads and the integration of complex radar systems from NASA and ISRO. This success reinforces confidence in ISRO’s launch capabilities and sets a strong foundation for future joint missions. NISAR’s high-resolution imaging will enhance global monitoring of natural processes and hazards, paving the way for advanced Earth observation technologies and deeper international partnerships in space exploration.