Earth science satellite NISAR to be launched in 2024: Here’s what we know about it

The NISAR (NASA-ISRO Synthetic Aperture Radar) earth research satellite is set to be launched in the first quarter of 2024, Union Minister of State Jitendra Singh informed the Rajya Sabha on Wednesday. The satellite has been jointly manufactured by the Indian Space Research Organization (ISRO) and the National Aeronautics and Space Administration (NASA). Early on March 6, 2023, the combined payload of NISAR— ISRO's S-radar and NASA's L-band radar—arrived in Bengaluru in a US Air Force C-17 aircraft. It was then transported to the UR Rao Satellite Center, Bengaluru, for additional testing and assembly with ISRO's satellite bus. The spacecraft will be launched aboard a GSLV from India and will have a Sun-synchronous orbit. The mission is expected to have a lifespan of three years. The project has cleared the first stage of the design validation phase and has been approved by NASA. ISRO's contribution towards the project is approximately ₹788 crore (US$99 million) while NASA's contribution is around US$808 million. FEATURES OF NISAR The satellite has a dual frequency (L and S band) radar imaging system. It is designed to explore newer application areas using L and S-Band microwave data, especially in surface deformation studies, terrestrial biomass structure, natural resource mapping and monitoring, and studies related to the dynamics of ice-sheets, glaciers, forests, oil slick, and more. The satellite is configured with the I-3K bus, and the instrument identified for SAR is based on the innovative Sweep SAR technique configured in both L and S bands in polarimetric configuration for wide swath and high resolution. The spacecraft will orbit the Earth in a sun-synchronous orbit of 747 Km with an inclination of 98.4 degrees for a 12-day repeat cycle, MoS Singh said in his written reply to the Rajya Sabha. NASA is delivering the L-Band SAR payload, high precision GPS, and 12m unfillable antenna, while ISRO is delivering the S-band SAR payload, spacecraft bus, and facilitating a launch. The total expenditure incurred on the realization of the NISAR satellite by ISRO as of February 2023 is Rs. 469.40 Crore, excluding launch costs. SIGNIFICANCE OF NISAR The significance of NISAR lies in its potential to significantly improve our understanding of the Earth's surface and provide critical data for various applications such as disaster management, agriculture, forestry, and climate change. The satellite's advanced imaging capabilities and innovative technology are expected to provide valuable insights into various environmental processes, helping scientists and policymakers make informed decisions for the benefit of society, MoS Singh's reply noted.