TRISHNA: ISRO and France's CNES to Launch Joint Earth-Observation Satellite in 2027

TRISHNA, short for Thermal Infra-Red Imaging Satellite for High-resolution Natural Resource Assessment, is a joint Earth-observation satellite mission being developed by the Indian Space Research Organisation (ISRO) and France's Centre National d'Études Spatiales (CNES). The satellite will combine thermal-infrared and optical observations to study Earth's surface temperature, water stress, vegetation, glaciers, urban heat and inland and coastal waters. ISRO and CNES say the mission is needed because climate change and rising water demand have increased the need for accurate data on how water and energy move through land ecosystems.

TRISHNA carries two instrument systems built through India-France cooperation. CNES has developed the Thermal Infrared (TIR) payload, which uses four thermal-infrared bands to measure land and water surface temperature and emissivity. ISRO has developed the VNIR/SWIR payload, combining visible, near-infrared and short-wave infrared bands to capture data on vegetation, surface reflectance and environmental conditions. Combining thermal and optical measurements from a single mission is described as one of TRISHNA's main strengths.

The satellite is planned for launch on an Indian Polar Satellite Launch Vehicle (PSLV), with the launch currently targeted for 2027. TRISHNA will operate in a 761-kilometre Sun-synchronous orbit and is designed for a mission life of five years.

By pairing land-surface temperature with optical data, TRISHNA will help identify areas facing water stress and estimate evapotranspiration — water lost through soil evaporation and plant transpiration — supporting more precise irrigation and agricultural water management. The mission will also map urban heat islands, where built-up areas run hotter than their surroundings, and its thermal observations will contribute to studies of glacier dynamics and snowmelt in mountain regions.

India contributes satellite development, remote sensing and launch capabilities to the mission, while France contributes its thermal-infrared Earth-observation technology.