India, May 8 -- Ariane Passenger Payload Experiment (APPLE), a product of India's first geostationary experimental communication Satellite Project during 1977-83, was successfully launched by Ariane-1, from Kourou, French Guyana, on June 19, 1981. The journey to its successful launch was tricky though. In 1981, the Indian Space Research Organisation (ISRO) did not have mainframe computers and the satellite's antenna needed to be tested as problems were detected in certain links, specifically the telemetry, tracking and control links that were crucial to ensure regular communication with the satellite in space. It was, therefore, crucial to ensure that these links were functional before the launch.

But it could only have been done in a pr...