SOLAR SYSTEM

Detailed explanation-1: -Syncom 3 was the first geostationary satellite. (The earlier geosynchronous Syncom 2 had an orbit inclined to the equator.) It was an experimental geosynchronous communications satellite placed over the equator at 180 degrees longitude in the Pacific Ocean.

Detailed explanation-2: -Telstar, launched in 1962, was the first active communications satellite: it received microwave signals from ground stations and retransmitted them across vast distances back to Earth. It was the model for all subsequent communications satellites.

Detailed explanation-3: -INSAT-1A was an Indian communications satellite which formed part of the Indian National Satellite System. Launched in 1982, it was operated in geostationary orbit at a longitude of 74° east.

Detailed explanation-4: -Intelsat I (nicknamed Early Bird for the proverb “The early bird catches the worm") was the first commercial communications satellite to be placed in geosynchronous orbit, on April 6, 1965.