ISRO Places NISAR Satellite in Orbit
Nasa is also contributing key mission systems such as the payload data subsystem, a high-speed data downlink system, GPS receivers, and a solid state recorder.
Nellore: The Indian Space Research Organisation (Isro) has placed the prestigious Nasa-Isro synthetic aperture radar (Nisar) satellite in the designated orbit with textbook precision on Wednesday evening.
The successful launch has delighted scientists of both Isro and Nasa and people across India and the USA.
With the satellite weighing 2,392 kg on board, the Geosynchronous Satellite Launch Vehicle-F16 (GSLV-F16) took off majestically from the second launchpad at the Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota, Andhra Pradesh, at the scheduled time of 5.40 pm. GSLV-F16 injected the Nisar satellite closest to the intended 743 km Sun-synchronous orbit with an inclination of 98.40. There was huge applause in the mission control room with the Isro scientists hugging and congratulating each other after the satellite successfully separated from the GSLV-F-16.
The mission had taken nearly a decade’s preparation.
Isro chairman Dr V. Narayanan announced the accomplishment of the mission. Unlike in the past, he gave an opportunity to directors of Isro who contributed to the mission to speak. On behalf of Nasa, Casey Swails, deputy associate administrator congratulated the Nisar team members and said, "It has been just an incredible decade culminating in this moment from this technical collaboration, the cultural understanding, getting to know each other, building that team across continents, across time zones, missing weekends, with families and holidays."
Casey Swails said the earth science mission was one of a kind and really showed the world what the two nations could do.
She expressed a wish to continue the partnership with Isro. With reagard to Nisar, it is a low earth orbit (LEO) observatory equipped with advanced dual-frequency radar technology and a flagship collaboration between Nasa and Isro. It is designed to map the entire globe every 12 days, delivering consistent and high-resolution data to monitor changes in the Earth’s ecosystems, ice sheets, vegetation biomass, sea level rise, groundwater fluctuations and natural hazards such as earthquakes, tsunamis, volcanoes and landslides.
The satellite has two types of radar systems, called L-Band and S-Band SAR (Synthetic Aperture Radar). These help the satellite take detailed pictures of the Earth's surface, even through clouds or at night.
By using a method called Sweep SAR, the satellite can cover a large area (wide swath) and still capture clear, detailed images (high resolution).
The SAR payloads are mounted on the integrated radar instrument structure (IRIS). Together with the spacecraft bus, they form the complete Nisar observatory. The observatory was developed jointly by Nasa’s jet propulsion laboratory and Isro. The mission, with a lifespan of 5 years, is designed to support both national objectives and the global scientific community.
Nisar will provide valuable data for studying ground movements and surface changes, using a technique called repeat-pass Interferometric SAR (InSAR). As part of the collaboration, Nasa is providing the L-Band radar system, while Isro is supplying the S-Band radar. Both systems will use a shared 12-metre-wide deployable antenna.
Nasa is also contributing key mission systems such as the payload data subsystem, a high-speed data downlink system, GPS receivers, and a solid state recorder.
The GSLV (Geosynchronous Satellite Launch Vehicle) has been chosen to launch the observatory, thanks to its proven ability to carry heavy satellites into the required orbit. “Nisar represents a one-of-a-kind collaboration — a true fusion of Indian and American scientific excellence, built by two teams of expert engineers working in unison,” said an Isro engineer.