Of Indian Satellite Programme
In the early and mid-sixties when applications using satellites were
in experimental stages even in the United States, Dr Sarabhai was quick
to recognize their benefits for India. He foresaw that satellites could
usefully supplement ground-based systems for providing many services
in communications, direct TV broadcasting, remote sensing and meteorology.
To achieve this, Sarabhai chalked out a clear step-by-step strategy.
He was very clear that ISRO would not wait for its own satellites to
begin application development. Instead, foreign satellites would be
used in the initial stages so that applications could be proven, ground
systems could be put in place and users and scientists could be familiarized
with the new technology. Later on, these technologies could be mastered
to make indigenous systems.
Remote sensing was one of the first space applications to be put to
use in India. An aerial survey using infra-red film was carried out
from a helicopter in 1970 to study root-wilt disease of coconut plantations
in Kerala. Also, ISRO in association with France developed an infra-red
scanner, which was used for various applications in 1972. Even before
the Americans had launched the world’s first civilian remote sensing
satellite the Earth Resources Technology Satellite (later renamed as
Landsat), India had requested access to data from the satellite. As
a result, India became one of the earliest users of Landsat when the
first satellite was launched in mid-1972. Subsequently, a ground station
to receive data directly from the satellite was set up. Today, India
has a fleet of world-class civilian remote sensing satellites.
In 1962, Telstar, the world’s first communications satellite,
was launched by the US.
Sarabhai immediately recognized the potential of a communications
satellite to reach out to not only far corners of a country but across
countries and continents. In 1967, the space department conducted a
joint study with NASA to examine alternatives for television coverage
in India. It concluded that a hybrid system – involving direct
broadcast through a satellite and retransmission through conventional
terrestrial TV stations – would be the most effective path.
Two years later in 1969, NASA loaned its ATS-6 satellite for experimental
broadcast of educational TV programmes to villages in India. Thus was
born the Satellite Instructional Television Experiment (SITE) conducted
in 1975-76. It was probably the first time that direct broadcast and
reception of TV programmes was tried on such a large scale in the world.
Some 2400 villages received community TV sets for the experiment.
In 1975, ISRO signed an agreement to use the Franco-German satellite,
Symphonie for Satellite Telecommunication Experiments Project (STEP).
One of Symphonie’s two transponders was made available to India
from June 1977 for experiments with communications over satellite, radio
networking and TV transmission.
It was in the late sixties, India first started examining the feasibility
of a domestic geostationary satellite system. A paper presented by Dr
Sarabhai in March 1970 worked out the broad details of an Indian National
Satellite (INSAT) system. The paper suggested that India should procure
the first set of satellites from abroad and build the subsequent series
in India. A high-level committee set up in 1975 to work out the scope,
timing and implementation strategy for satellite communication, proposed
a three-in-one satellite that will provide telecommunications, television
and weather data. Though such a design was complex, it was found to
be very cost-effective and suitable to a developing country like India.
In the second half of 1970s, the Indian space department also undertook
another joint study with the Massachusetts Institute of Technology to
design the Indian National satellite (INSAT) system.
Since Ministries of Communications, Information and Broadcasting and
Science and technology were the major users of the data available from
such satellites, the Government decided to involve them in the INSAT
programme right from the beginning. It was in 1978, India awarded a
contract to design and build two INSAT-1 satellites to Ford Aerospace
Corporation of the U.S. (now Space Systems/Loral).
Ariane Passenger Payload Experiment (APPLE), put in a Geosynchronous
Transfer Orbit (GTO) by an Ariane launcher in June 1981, gave India
the hand-on experience needed to build the second-generation INSAT class
satellites within the country.
Two more satellites,
and INSAT-1D, again built by Ford, were put in orbit before India embarked
on indigenously building INSAT 2 series of satellites. Though it was
originally decided that the first INSAT-2 test satellite would be launched
in 1989, the mission was delayed by about two and a half years. Subsequently,
ISRO launched four more satellites in INSAT-2 series, the last being
INSAT-2E, launched in April 1999. Since then, ISRO has launched three
third-generation INSAT satellites – INSAT-3B, INSAT-3C and INSAT-3A.
GSLV, demonstrated for the first time in April 2001, is capable of launching
2 tonne INSAT class satellites into Geosynchronous Transfer Orbits (GTO).
The recent operationalisation of GSLV technology, will make it possible
for ISRO to launch all its satellites on its own and even offer launch
services to other countries as well.
Meanwhile, in 1972, the US launched Landsat 1, the world’s first
civilian remote sensing satellite. Indian Scientist immediately visualized
the potential of a remote sensing satellite for use in agriculture,
forestry, oceanography, geology and mineral prospecting.
India embarked on the design and development of indigenous satellites
during the initial years of Prof Satish Dhawan, who succeeded Dr Vikram
Sarabhai after the latter’s untimely death. Shortly before he
took over, India had entered into an agreement with the Soviet Union
for launching a satellite that ISRO was planning to build indigenously.
This scientific satellite was later named after Aryabhata after the
famous astronomer-mathematician who lived in India in the 5th century
AD. The task of building this satellite with a unique structure having
faces and a weight of 360 kg was given to a team of 200 dedicated scientists
and engineers led by Prof. U R Rao. The team, drawn from organizations
such as the Hindustan Aeronautics Limited, Bharat Electronics Limited,
Electronics and Radar Development Establishment, Indian Institute of
Science and private companies, worked day and night at an obscure facility
in the Penya Industrial Estate, near Bangalore, for two and half years
to make Aryabhata ready for launch from a Russian launching facility
on April 19, 1975. Placed in a circular orbit at an altitude of 594
kilometres, the satellite sent data for a period of five years, even
though it was designed for an active life of six months. By the time
it re-entered the atmosphere on February 10, 1992,
completed 92,875 orbits of the earth.
and Bhaskara-II, two earth observation satellites were launched from
the Soviet Union in 1979 and 1981 respectively. These satellites, along
with Rohini satellites launched by the indigenous
SLV-3 , were the precursors of the operational Indian remote
sensing (IRS) series of satellites.