SPACE RESEARCH OF INSAT SYSTEM
SPACE RESEARCH OF INSAT SYSTEM
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INTRODUCTION :
India’s space programme began way back in 1962 when Dr. Vikram Sarabhai and others set up INCOSPAR (Indian National Committee on Space Research). On 21 November 1963 the Thumba Equatorial Rocket Launching Station (TERLS) at Trivandrum became operational. India’s first rocket, a two staged one, called Nike-Apache-M100 was launched from Thumba. The TERLS was in 1968 dedicated to United Nations. In 1969 INCOSPAR was reconstituted and Indian Space Research Organisation (ISRO) was established under Sarabhai’s chairmanship. In 1972 Space Commission and Department of Space (DOS) was set up and ISRO was brought under the department for administrative purposes. In 1972 the whole complex in Thumba comprising the TERLS, the Space Science and Technology Centre (SSTC), the rocket propellant plant, rocket fabrication facility (RFF) and propellant fuel complex (PFC) was designated as Vikram Sarabhai Space Centre (VSSC).
ORGANISATION
The Space Commission, set up in 1972, is the nodal agency for coordinating research and development (R&D) activities in space science and technology. Department of Space which is an executive wing of the commission operates through ISRO, Bangalore and four other independent bodies, viz., Indian National Satellite Space Segment’ Project (INSAT-SSP), National Natural Resource Management System (NNRMS), National Remote Sensing Agency (NRSA) and the Physical Research Laboratory (PRL), Ahmedabad, besides sponsoring research projects in other institutions.
Space Centres: Formed in 1969, ISRO plans, programmes and manages all R&D activities in the country in space science, technology and its application through its various centres. Its major projects are coordinated by its various lead centres’. These are:
Vikram Sarabhai Space Centre (VSSC): Located at Thiruvananthapuram, it is the largest of the ISRO centres and is the lead centre for launch vehicle development (SLV-3, ASLV, PSLV, GSLV) and it pioneers in rocket research and planning and execution of launch vehicle development projects. VSSC has establishments at Valiamala for PSLV project, at Vottiyoorkavu for development of composites and at Alwaye for ammonium perchlorate experiment plant.
- ISRO Satellite Centre (ISAC): Located at Bangalore, it is responsible for the design, fabrication, testing and management of satellite systems for scientific, technological and application missions. Aryabhata, Bhaskara, Apple and IRS-1A satellite were built here; at present IRS and INSAT series of satellites are being built in this centre.
- Space Applications Centre (SAC): Located at Ahmedabad, it is ISRO’s research and development centre for conceiving, organising and building systems for practical applications of space technology. The major activities include satellite based telecommunication and TV, remote sensing, meteorology, environmental monitoring and geodesy.
- SHAR Centre: Located at Sriharikota on the east coast of Andhra Pradesh, it is the main launch centre of ISRO. This centre also undertakes large scale production of solid rocket propellant and ground testing of solid fuelled rocket stages of the Indian Launch Vehicles. The Centre also has ISRO’s largest Static Test and Evaluation Complex (STEX) and Solid Propellant Space Booster Plant (SPROB).
- Liquid Propulsion System Centre: It is the key centre for development of liquid propulsion system with its facilities located at Thiruvananthapuram, Bangalore and Mahendragiri (Tamil Nadu). The centre undertakes research, development and testing of liquid propulsion systems for ISRO’s launch vehicle and satellite programmes.
- Development and Educational Communication Unit (DECU): Located at Ahmedabad, it is involved in the conception, definition, planning and socio-economic evaluation of space application programmes. Besides carrying out research and production with themes of development and educational oriented communications, the unit provides training services in this area.
- ISRO Telemetry, Tracking and Command Network (ISTRAC): With its headquarters and Spacecraft Control Centre at Bangalore and a network of ground stations at Sriharikota, Thiruvananthapuram, Bangalore, Lucknow, Car Nicobar and Mauritius, it provides telemetry, tracking and command (TTC) support for the launch vehicles and satellite missions of ISRO and for other space agencies.
- Master Control Facility: Situated at Hassan in Karnataka, it is responsible for all post- launch operations of INSAT satellites including orbital manoeuvres, station keeping and in-orbit operations on the spacecraft.
- ISRO Inertial Systems Unit (IISU): Located at Thiruvananthapuram, it carries out development of inertial system for both satellites and launch vehicles such as reaction wheel, gyros, solar array drive assembly etc.
- Physical Research Laboratory (PRL): Located at Ahmedabad, it is a premier centre, under DOS and carries out research in space and allied sciences.
- National Remote Sensing Agency (NRSA): An autonomous institution and supported by DOS, it is located at Hyderabad, has facilities for surveying, identifying, classifying and monitoring earth resources using aerial and satellite data. NRSA also runs an Indian Institute of Remote Sensing (IIRS) at Dehradun.
INSAT SYSTEM
The Indian National Satellite System (INSAT) is a multipurpose operational satellite system for domestic long distance telecommunications, meteorological earth observations and data relay nationwide for direct satellite television broadcasting, radio and television programme distribution and for re-broadcasting through terrestrial transmitters.
It is a joint venture of DOS, Department of Telecommunications (DoT), Indian Meteorological Department (IMD), All India Radio (AIR) and Doordarshan. The DOS has direct responsibility for the establishment and operation of INSAT space segment. The INSAT system was established in 1983 with the successful commissioning of INSAT- 1B. The first of INSAT-1 series, INSAT-1A, that was launched in September 1982 was a failure. Its successor or INSAT-IB completed its designated seven years life in August 1990 and is still used sparingly. The third one, INSAT-1C, launched in July 1988 lost its earth lock. At present the last of the INSAT-1 series, INSAT-1D launched in 1991, and the three second generation satellites INSAT- 2A, INSAT-2B and INSAT-2C are providing vital operational services to the nation. The indigenously built INSAT-2A was launched in July 1992, INSAT- 2B on 23 July 1993, and INSAT-2 C on 7 December 1995 on board the European launch vehicle, Ariane. Two more satellites in the INSAT-2 series, namely INSAT-2D and INSAT-2E are under development and fabrication.
LANDMARKS IN INDIAN SPACE PROGRAMME
1962: Indian National Committee for Space Research (INCOSPAR) formed by Department of Atomic Energy (DAE) and work on setting up of Thumba Equatorial Rocket Launching Station (TERLS) started.
1963: First sounding rocket launched from TERLS (on 21 November).
1965: Space Science and Technology Centre (SSTC) established in Thumba, Kerala.
1967: Satellite Communication Earth Station set up at Ahmedabad; Rohini-75, first Indian rocket developed by SSTC, successfully launched.
1968: TERLS dedicated to UN on 2 February
1969: Indian Space Research Organisation (ISRO) formed under DAE.
1972: Space Commission and Department of Space set up (1 June)
1975: Conversion of ISRO from autonomous status to a Government Organisation; first Indian Scientific Satellite, Aryabhatta, launched on 19 April from erstwhile Soviet Union.
1975-76: First major space application programme, Satellite Instructional Television Experiment (SITE) conducted using US satellite ATS.
1977: Satellite Telecommunication Experiment Project (STEP) carried out from mid-1977 to 1979 using Franco-German “Symphonie”
1979: Second Indian Satellite, Bhaskara-I, an experimental Satellite for earth observations launched on 7 June from erstwhile Soviet Union.
1980: SLV-3, India’s first Satellite Launch Vehicle, places Rohini satellite (35 kg) in a low-earth orbit from Sriharikota on 18 July.
1981: First indigenously built experimental Geo-stationary Communication Satellite, APPLE (Ariane Passenger Payload Experiment), launched from Kourou, French Guyana on 19 June; Bhaskara-II, earth observation satellite launched from erstwhile Soviet Union on 20 November.
1982: INSAT-1A launched on 10 April and deactivated on 6 September due to propellant depletion.
1983: Second developmental launch of SLV-3 D2 with Rohini (42 kg) from Sriharikota on 17 April; INSAT-1B successfully launched by US space shuttle Challenger on 30 August.
1984: First joint Indo-Soviet manned space mission began on 3 April. Sqn. Ldr. Rakesh Sharma becomes first Indian cosmonaut.
1987: First developmental launch of ASLV-D1 with SROSS on 24 March, mission fails.
1988: IRS-1A, first Indian Remote Sensing Satellite successfully launched from erstwhile USSR on 19 March; ASLV-D2 launched from Sriharikota on 13 July, mission fails; INSAT-1C launched from French Guyana on 22 July.
1990: INSAT-1D launched from Florida, US on 12 June.
1991: IRS-1B launched from Baikanour in Kazakhstan on 29 August.
1992: ASLV-D3 launched from Sriharikota on 20 May that places SROSS-C satellite into low earth orbit; INSAT-2A, first indigenously built second generation satellite in INSAT series launched by the Ariane rocket of European Space Agency from Kourou, French Guyana, mission successful.
1993: INSAT-2B launched by Ariane rocket from Kourou, French Guyana on 23 July, mission successful; PSLV-D1, first developmental launch of PSLV, on 20 September, mission fails.
1994: ASLV-D4 launched from Sriharikota on 4 May, places SROSS-C2 satellite (43 kg) in orbit; Second developmental flight of PSLV-D2 from Sriharikota on 15 October, mission successful and places IRS-P2 in orbit.
1995: INSAT-2C, the heaviest of INSAT series launched from Kourou, French Guyana on 7 December; IRS-1C, the world’s most advanced 1,250 kg Indian remote sensing satellite launched by Russian Molniya rocket from Baikanour cosmodrome in Kazakhstan on 29 December
1996: PSLV-D3 launched from Sriharikota on 21 March, places IRS-D3 in Orbit.
1999: Insat-2E launched by Ariane rocket from Kourou on April 6 Oceansat (IRS P4) launched by PSLC-C2 from Shar on May 26. Along with Oceansat, Korean Kitsat-3 and German DLR-TUBSAT were also launched atop PSLV-C2
2000: Insat-3B launched by Ariane rocked from Kourou on March 22.
2001: GSLV-D1 launched from Sriharikota on April 18 by PSLV.
INSAT-2 satellites are essentially similar to INSAT-1 in basic design but the capabilities are enhanced both qualitatively and quantitatively. Essentially three classes of services are provided by INSAT-2 series-communication, broadcasting and meteorology-with one and a half a times the capacity of INSAT-1 series.
SATELLITES
- Advanced indigenous communications and remote sensing satellite manufacturing capability. After perfecting the second generation INSAT 2 series, Indian space scientists are now building third generation INSAT 3 series. The Indian National Satellites have revolutionised satellite manufacturing by combining many functions in one satellite for cost efficiency. INSAT is used for Telecommunication Television, Search and Rescue, Meteorology and Radio Networking. The latest satellite in the INSAT series which was launched on April 3 is particularly important because it reflects an attempt by the Indian Space Organisation to make an international impact with half its capacity leased to Intelsat.
- Indian space scientists have also developed considerable expertise in the manufacture, launch and management and interpretation of data from the indigenous remote sensing satellites. This data is being put to various uses and in fact it is a matter of pride that many benefits of space technology development are now being realised by the common man. Data from Indian Remote Sensing Satellites is used for various applications of resources survey and management under the National Natural Resources Management System (NNRMS). It helps in pre-harvest crop acreage and production estimation of major crops, drought monitoring and assessment based on vegetation condition and flood risk zone mapping and flood damage assessment among others. The quality of the imageries is high and they are now marketed to many countries, including the US.
Launch capability
Indigenous satellite launching capability; in May’99 Indian PSLV launched the Korean K3TSAT- 3 and German DLR-TUBSAT. India is becoming an active player in the international satellite launching market. Our space scientists are now on the threshold of achieving geo-stationary satellite launch capability.
- Antrix Corporation Limited, the commercial front of the Department of Space, markets technology and services on behalf of the
Subsystems and components for satellites Fabrication of satellites to user specifications Launch services Tracking facilities Manpower training and software.
INSAT-2C has joined three other Indian satellites INSAT-1D, INSAT-2A and INSAT-2B, which are currently providing television, telecommunications and weather services to India. While INSAT-2A and INSAT-2B were almost identical, INSAT-2C is different. It does not carry a meteorological payload since the other INSAT satellites are already doing the job. Also, it is the first Indian satellite to be co-located with another Indian spacecraft, INSAT-2B separated from each- other only by a minimum of 17 km on space. Co- location has become necessary because of the congestion in the geostationary orbit. Besides, INSAT-2C carries India’s first Ku band transponders exclusively for telecommunications. The three very high frequency Ku band transponders with double the capacity of C-band transponders installed on other satellites, will cater exclusively to business communication in major cities, data networking and satellite news gathering. The Ku band signals can be received by much smaller and less complicated antennas measuring just 60 cm in diameter that can be installed on window ledges. Through INSAT-2C, Mobile Satellite Services (MSS) has been introduced for the first time which will provide communication capabilities for sea borne vessels, aircraft and moving vehicles on land. INSAT-2C carries 12-C band transponders of which two 50 W transponders will extend the coverage of Doordarshan programmes to South East Asia and the middle East to cater to vast Indian population there. There are also 6 extended C-band transponders. Besides, there is one Broadcast Satellite Services (BSS) transponder providing downlink in S-band for TV and Radio programmes as in the earlier INSAT satellites.
Communication Revolution: The INSAT system has revolutionised telecommunications, weather forecasting and radio and television broadcasting. Realising the potential benefits of satellite technology, ISRO carried out an year long Satellite Instructional Television Experiment beginning August 1975, which marked a milestone in harnessing satellite technology for taking the powerful audio-visual education of relevance to remote rural areas. Immediately following the successful launch and operationalisation of the experimental communication satellite, APPLE in 1981, ISRO embarked on a full-fledged programme of providing operational services in communication and meteorology with multi-purpose INSAT series of satellites.
The most spectacular impact of INSAT has been in rapid expansion of TV which with 750 TV transmitters and direct reception sets, now provides access to over 85 per cent of India’s population. Rapid increase in the regional services, use of transportable earth stations and satellite news gathering vehicles, utilisation of satellite media for university education and nationwide radio networking has enabled even remote areas to become part of the mainstream of the nation. The Press Trust of India (PTI) has implemented a system to provide its news and information services at high speed and increased volume by utilising the broadcasting facilities of INSAT satellites.
INSAT is being used to promote an effective interactive educational system. The system was successfully experimented in Rupala, a remote village of Gandhinagar (Gujarat), where local teachers and leaders were able to interactively communicate with teachers at SAC and Gujarat Vidyapith at Ahmedabad. The ISRO-UGC have successfully conducted experiment enabling students in a number of universities to interact, in real time, with the experts through specially developed talk-back facility. An experiment on continuing education was conducted through satellite in Bangalore in 1992. The first use of INSAT-2A was made to conduct an innovative interactive training programme for farmers of Bhiwani district of Haryana in 1992.
The meteorological data gathering with Very High Resolution Radiometer (VHRR) instrument on board INSAT and its dissemination, along with its collection of remote area meteorological data from unattended platform, has made a quantum difference in weather forecasting in the country. Satellite based local specific disaster warning systems, with over a 250 disaster warning receivers installed in the cyclone prone eastern coast, has been able to facilitate dramatic saving of human lives and livestock during flood and cyclones.
LIQUID FUEL TECHNOLOGY: CRYOGENIC ENGINE
Solid-fuelled rocket engines like those used in SLV-3 and ASLV are simpler in design and easier to manufacture than liquid fuelled engines. But once fired, their burning rate cannot be controlled. Therefore they are unsuitable for applications requiring fine control of power; they cannot be switched off; they are bulky as well. Weight for weight, they do not produce as much thrust as the liquid- fuelled engines of PSLV which use hydrazine liquid at room temperature.
A cryogenic engine, which is crucial for development of GSLV, uses liquid hydrogen as fuel and liquid oxygen as oxidiser and can produce more power i.e. higher thrust per unit weight of propellant. This is important for the final stages of a satellite launch where weight and space are severe constraint. Since the engine stores the propellant at very low temperature (near absolute zero) to maintain them in a liquid state, it is called cryogenic engine. This also necessitates use of special insulation materials that can withstand sub-zero temperatures at which hydrogen is a liquid (20K or – 253°C).
Gramsat : In order to achieve all-round development of the nation, eradication of illiteracy and promotion of scientific ideas and attitudes into the cultural fabric of Indian society is of utmost importance and to realise this ISRO has evolved a new concept of dedicated GRAMSAT satellites. The GRAMSAT will also help in providing continuing education for special groups to ensure that their technical skills are periodically updated to overcome technological obsolescence. The GRAMSAT may incorporate 6 to 8 high power C-band transponders.
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