India’s Space Programme *

By Hasan Jawaid Khan

Science Reporter, August 1997

            One of the most visible success stories that demonstrates unequivocally India’s capability in high technology is that of the country’s three-decades-old space programme. Today India is the only developing country to have the capability of designing, building, launching and using satellites, and its benefits have reached almost every corner of the country.

            India’s space programme started on a modest scale in November 1963 with the launching of a small American Nike-Apache rocket from the newly built launching pad at Thumba. At the helm of affairs overseeing this token achievement was Dr. Vikram Sarabhai, Chairman of the erstwhile Indian National Committee for Space Research, Dr. Sarabhai was convinced that the newly emerging space technology offered solution to many of the nagging problems that plagued a vast and economically backward country like India. “It is not the question of whether India can afford to invest in space research”, he would say, “but whether she can afford not to invest in it.” Today, the Indian Space Research Organisation (ISRO) under the Department of Space through its many centres plays the pivotal role in the planning and execution of national space activities which include development, launch and operation of space systems and their applications. India’s biggest satellite launching centre is located at Sriharikota on the Andhra Coast. A significant feature of the Indian space programme has been the emphasis on reaping the benefits of space technology in the shortest possible time. Consequently ISRO took up development of satellite technology even before it could attain satellite launch capability. The first India-built satellite, Aryabhata, was put into orbit by a Soviet launch vehicle in 1975. More satellites followed. Except five of them all were launched by foreign launch vehicles, but they provided valuable experience to Indian space scientists in satellite technology. The success of India’s five remote sensing satellites and of the four satellites of the INSAT-2 series is a good demonstration of this experience.

            Utilisation of satellite technology is another area in which India took an early lead. The first satellite-based television relay experiment called the Satellite Instructional Television Experiment (SITE) in 1975 for the first time demonstrated the enormous potential of satellite in mass education and information dissemination. In 1977, a two-year Satellite Telecommunication Experiment Project (STEP) further demonstrated the possibilities of satellite-based telecom systems. Together these two experimental projects prepared the ground for the INSAT system.

A major landmark in Indian satellite development programme was reached in 1981 when the first indigenously built geostationary communication satellite, APPLE (Ariane Passenger Payload Experiment) was successfully launched by an Ariane rocket of the European Space Agency. APPLE was used in several communication experiments including relay of TV programmes, and radio networking. It provided valuable experience to Indian space scientists in building and operating geostationary communication satellites. The first geostationery satellite for exclusive domestic use was INSAT-1B which became operational in 1983.

            As far as satellites go, the INSAT is a unique concept. A brain-child of Indian space scientists, who wanted to make the most of the available resources and technology, each satellite was conceived as a three-in-one package capable of providing simultaneously reliable long distance telecom services, round-the-clock earth observation and data relay facility, and country-wide networking of All India Radio and Doordarshan centres. In order to get the INSAT system in operation before the 1982 Asiad in New Delhi, and to gain time for the indigenous fabrication of satellites for the system, contract for the fabrication of all the satellites of the first generation, namely INSAT-1A, INSAT-1B, INSAT-1C and INSAT-1D, were awarded to the US firm Ford Aerospace. The first of the indigenously built satellites of second generation INSATs, INSAT-2A, was launched in July 1992 followed by INSAT-2B in 1993, INSAT-2C in 1995 and INSAT-2D this year. All the satellites have been performing flawlessly. This has given new confidence to Indian space scientists in satellite building.

            Each INSAT satellite is the product of the well-orchestrated effort of the four major centres of ISRO. The main frame of the satellite which carries the controls, telemetry and tele-command, deployment and power systems is manufactured by the ISRIO satellite Centre at Bangalore, which also does the mission planning and analysis and manages the whole project. The gyro units, reaction wheels and momentum wheels, to keep the satellite stable in orbit, are fabricated at the Vikram Sarabhai Space Centre, Thiruvanthapuram, which is also responsible for the antenna reflectors and scanning mechanism for the Very High Resolution Radiometer(VHRR), that forms the main meteorological payload of INSAT. The VHRR itself is a contribution of the Space Applications Centres, Ahmedabad, which also provides for communications transponders. Another vital component, the apogee boost motor (that takes the satellite from its transfer orbit to the geostationary orbit) and the thrusters (required for maintaining the satellite in its assigned slot in orbit) are manufactured at the Liquid Propulsion Systems Centre at Thiruvanthapuram.

            It is worth mentioning that although all the four satellites of the INSAT-2A series were launched by the European Space Agency’s Ariane rockets, the entire orbit raising operation – a series of complex manoeuvres to take the satellites to their assigned slots in the geostationary orbit – were carried out by ISRO scientists from the Master Control Facility at Hassan, Karnataka. This itself is a testimony of the degree of indigenisation of the INSAT system.

            While INSAT-2A and INSAT-2B are almost identical twins INSAT-2C and INSAT-2D are different; they do not carry the meteorological payload. But INSAT-2E, which put into in 1998, carried an improved version of the VHRR as the meteorological payload.

            With the success of the four satellites of INSAT-2 series, satellites technology in India can be said to have come of age, but the same is not true to launch vehicles. Of the four stages of satellite launch vehicle development programme of ISRO, only three – SLV-3, ASLV and PSLV – have been achieved so far. Powered by a massive 128-tonne solid propellant stage, the PSLV is designed to put a 1000-kg. Remote sensing satellite in a sun-synchronous polar orbit. It is the biggest rocket launched from India so far.

            With the two successful launches of the PSLV, the way is now clear for the next stage – the more powerful Geostationary Satellite Launch Vehicle, or GSLV. But GSLV would need an entirely different type of rocket engine, called the cryogenic engine. Unlike the Vikas engine used in the PSLV, which uses propellants, which are liquid at room temperature, a cryogenic engine uses liquid oxygen and liquid hydrogen as the propellants, both of which need extremely low temperature for storage. The GSLV will use a cryogenic engine for its third stage.

            According to the original plans, the cryogenic engines and the technology were to be procured from the Russian space agency Glavkosmos. But the restrictions imposed under the Missile Technology Control Regime (MTCR), has put an end to that option. Undeterred by this setback ISRO has gone ahead with its own cryogenic engine programme and has already tested a one-tonne model. It hopes to be ready with the first full-scale proto-type soon.

            The successes already achieved and the programmes already in hand are expected to hand are expected to help India attain total self reliance in space technology including the establishment of the rocket launching capabilities to launch the INSAT-2 class of satellites. They are also expected to open up new avenues to develop rural economy in the country. The planned involvement of Inindustin the development of our space programme has already started paying rich dividends and in the coming years India has the potential of becoming a space industrial power in the world.