Throwback Thursday: INSAT-1 Origins
INSAT-1 series satellites launched on different launch vehicles. Know how they came into existence.
We all have heard about the Indian National Satellite System (INSAT). Some of you like me would remember sitting in the general knowledge class while learning about the recent events, "ISRO launched INSAT-4B.". Some may have heard about the latest GSAT-11 mission, the heaviest satellite built by ISRO, launched in December 2018. Most of the spacecraft in the INSAT and GSAT series are the communication satellites of India. Though the Indian Space Communication Journey started with the experimental satellite APPLE, we will talk about it some other time. For Today's ISRO’s Journey Throwback, we would learn the origins of the INSAT-1 series satellite.
INSAT-1 series had a total of four missions. The first satellite, INSAT-1A was launched on Delta 3910 vehicle on 10 April 1982. To mark the anniversary of this launch tomorrow, let us delve into the archives and learn how this programme came into being.
Initial Studies for INSAT-1 Payloads
The father of the Indian Space Programme, Dr Vikram Sarabhai was a great visionary. As early as 1964, he had the idea of an Indian satellite for telecommunications and television purposes. India, therefore in the year 1965, joined INTELSAT: an intergovernmental consortium owning and managing a constellation of communications satellites providing international broadcast services. In 1970, Dr Sarabhai presented the paper 'INSAT- A Strategy for Development' at the National Conference on Electronics held in Bombay. The article discussed applications as broad as Railways, Defence, Aviation and Computer Data Handling. This paper gives insight into many INSAT-1 origins.
The requirements for data transmission and inter-connection of large computer facilities have not yet come up in our country. However, one can visualise that such needs will arise for inter-connecting large computers on a timesharing system. Such communications could be handled very effectively by the satellite.
Excerpt from the paper: 'INSAT- A strategy for development'
Within the next few years, many joint studies between DAE (Department of Atomic Energy) and organisations such as NASA, MIT, General Electric and Hughes Aircraft Corporation were conducted regarding a broadcasting satellite for India. All these studies resulted in a lot of action. In the year, 1967, the first Experimental Satellite Communication Earth Station (ESCES) at Ahmedabad became operational. NASA and DAE signed the Satellite Instructional Television Experiment (SITE) memorandum of understanding in September 1969.
The studies conducted in 1968-70, explored various payloads which could be included for INSAT satellites. While almost all studies accepted the inclusion of television and telecommunications payloads, there was a discussion over the incorporation of meteorological ones. With SITE, India planned to get experience in receiving and using such data. But the VHRR payload responsible for the meteorological earth observations failed onboard the ATS-F satellite before SITE was commissioned in 1975. Therefore, the use of INSAT satellites for meteorological applications again became questionable. It was P R Pisharoty, the father of remote sensing in India, who convinced the stakeholders of the use of Met data for an agricultural society like India.
Request for Proposals (RFPs)
Later, ISRO invited Request for Proposals for the development of satellites with the following payloads.
Two high-power transponders for television broadcasting to community TV sets, distribution of TV programmes for rebroadcasting and radio networking.
Twelve transponders for telecommunications.
Meteorological Earth Observation (EO) instrument (VHRR) for imaging the Earth in the visible and thermal infrared bands.
Data relay transponder for meteorological data collection from unattended data collection platforms.
Hughes Aircraft Corporation (HAC) and Ford Aerospace Communication Corporation (FACC) of the USA submitted proposals. Experts from ESA, COMSAT corporation and INSAT-1 Space Segment Project Office, evaluated the proposals separately. In the end, along with technical experts from the Project Office, Department of Telecommunications (DOT), Doordarshan (the national TV), AIR and India Meteorology Department (IMD), selected FACC to award the contract for INSAT-1A and INSAT-1B satellites. And hence INSAT-1 series originated.
Different Launch Vehicles for INSAT-1 series
All four satellites in the INSAT-1 program were launched onboard different launch vehicles. INSAT-1A satellite failed in September 1982 after a series of problems post-launch in April 1982. Department of Space (DOS) received compensation for a total loss of satellite from Insurance Companies. INSAT-1B had an initial deployment problem. Later, after resolving the issue, the spacecraft functioned for more years than designed seven-year life. While INSAT-1C also failed, INSAT-1D was a total success. INSAT-1, along with APPLE, helped ISRO in developing INSAT-2 and all further satellites.