Megha-Tropiques was a joint Indian–French satellite that studied rain, clouds and the water cycle over the tropics. Launched in October 2011, it was steered into a controlled re-entry over the Pacific Ocean in March 2023.
Re-entered Earth's atmosphere on 7 March 2023, according to the public satellite catalogue.
ISRO and the French space agency CNES built Megha-Tropiques to study how tropical storm systems form and grow, and how they move water and energy through the atmosphere. Its orbit, about 867 km high, was tilted only 20 degrees to the equator, keeping it over the tropics.
It carried four instruments: the MADRAS microwave imager (built jointly by ISRO and CNES), the SAPHIR humidity sounder and the ScaRaB radiation scanner (both from CNES), and the ROSA radio occultation sensor from Italy.
PSLV-C18 launched the 1,000 kg satellite from Sriharikota on 12 October 2011, with three small satellites: Jugnu, SRMSat and VesselSat-1. It was built on ISRO's IRS satellite bus.
Megha-Tropiques was planned for three years but sent useful data until 2021. Left in orbit it would have stayed up for more than 100 years, with about 125 kg of fuel still on board.
ISRO used that fuel to lower its orbit step by step from August 2022, although the satellite was never designed for a controlled end. On 7 March 2023 two final burns, each about 20 minutes on four 11 N thrusters, dropped its low point below 80 km. ISRO estimated that it broke up over the deep Pacific Ocean, inside the planned zone, and its analysis found no large pieces would survive.