Nisar

Nisar is a dual-frequency synthetic aperture radar (SAR) mission developed jointly by NASA and the Indian Space Research Organisation (ISRO) to study changes in Earth's ecosystems, ice masses, and natural hazards. The satellite, named after the Persian word for "clouds," was launched on January 26, 2024, aboard an ISRO Geosynchronous Satellite Launch Vehicle (GSLV Mk II) from the Satish Dhawan Space Centre in Sriharikota, India. Nisar is designed to operate for at least three years, providing high-resolution data to advance understanding of climate change impacts.

The mission's primary instrument is a radar system operating at L-band (1–2 GHz) and S-band (3–4 GHz), allowing it to penetrate cloud cover and observe Earth's surface day and night. This dual-frequency capability enhances the satellite's ability to measure surface deformation, vegetation biomass, and ice sheet dynamics with unprecedented precision. Nisar's SAR technology enables it to capture detailed images of Earth's surface, supporting applications in disaster monitoring, agriculture, and cryosphere research.

Developed under a partnership between NASA's Jet Propulsion Laboratory (JPL) and ISRO, Nisar incorporates advanced technologies, including a large deployable antenna reflector and a sophisticated radar system. The satellite orbits Earth at an altitude of approximately 748 kilometers (465 miles) in a near-polar orbit, covering the entire globe every 12 days. Data collected by Nisar will be shared openly with the scientific community and international users to support climate research and environmental management.

The mission builds on previous collaborative efforts between NASA and ISRO, such as the National Oceanic and Atmospheric Administration-Scientific Satellite (NISAR) concept, which evolved into the current Nisar satellite. Its findings are expected to contribute significantly to global efforts in mitigating climate change and improving disaster response strategies.