India on Wednesday successfully launched Indo-French climate monitoring satellite “Megha-Trpiques and three other nano satellites on board PSLV-C18 from the spaceport of Sriharikota in southern state of Andhra Pradesh. The 50-hour countdown for the launch started at 0900 hours IST (Indian Standard Time) Monday. Megha-Tropiques is carrying three payloads - two by France\'s space agency CNES and one jointly by Indian Space Research Organisation (ISRO) and CNES - and a complementary scientific instrument. ISRO has built Megha-Tropiques, an advanced tropical climate monitoring satellite, at a cost of rs80 crore with \'equal contribution\' from French government space agency, Centre National d\'Etudes Spatiales. Megha-Tropiques (Megha meaning cloud in Sanskrit and Tropiques denoting tropics in French) will investigate the contribution of water cycle in the tropical atmosphere to climate dynamics. The other three nano satellites are one each from Luxembourg, the indigenous \'Jugnu\' of IIT-Kanpur and SRM University, Chennai. Data received from ‘Jugnu’ will be studied with a tracking system installed at IIT-Kanpur and pictures and information received from it will be used for research. Jugnu will also help gather information on floods, drought and disaster management. This is the fourth ISRO mission this year, including one launched from French Guyana.