India’s First Experimental Satellite launched into a near earth orbit on April 19, 1975 by Inter-cosmos rocket of erstwhile USSR. The satellite was name after a 5th century Indian mathematician. Due a transformer failure it was out of service in four days.
India’s first experimental GEO communications satellite, APPLE (Ariane Passenger Payload Experiment), was launched on the the third test flight of the Ariane launch vehicle from Kourou, on 19th June 1981. Apple was used in several communication experiments including relay of TV programmes, and radio networking. It provided valuable experience to Indian space scientists in building and operating geostationary communication satellites. It was de-activated on September 1983.