INSAT

The Indian National Satellite System (INSAT) is a group of multipurpose geostationary satellites launched and operated by the Indian Space Research Organisation (ISRO). The INSAT program was established to provide telecommunications, broadcasting, meteorological services, and data transmission across India and neighboring regions.

Initiated in the early 1980s, INSAT was designed to strengthen India's domestic communications and reduce dependence on foreign satellites. The system has evolved through several generations, including the INSAT-1, INSAT-2, INSAT-3, and INSAT-4 series, carrying a mix of C-band and Ku-band transponders for telecommunications and, in later models, meteorological instruments.

The INSAT network has supported television and radio broadcasting, telephone networks, data communications, and emergency or disaster-management services. It has also enabled tele-education, tele-medicine, and nationwide ground segments that connect central and regional facilities with broadcast centers and telecom operators.

Orbitally, INSAT satellites are placed in geostationary orbit at multiple slots along the equator to provide broad coverage for India and the surrounding region. Ground stations coordinate uplink and downlink traffic with public and private users, including broadcasters, telecom providers, and government agencies.

In the years since its inception, many INSAT missions have been complemented or superseded by newer ISRO satellites, particularly under the GSAT program, while the INSAT brand remains associated with India's early, long-running multi-purpose satellite system and its contributions to national communications and weather services.