by - G Madhavan Nair, Secretary, Department of Space and Chairman, ISRO
The successful launching of Polar Satellite Launch Vehicle (PSLV-C9) on April 28, 2008 putting ten satellites, viz., CARTOSAT-2A, Indian Mini Satellite (IMS-1) and eight nano-satellites from abroad into the orbit has given the country a coveted status among space faring nations. In its twelve consecutively successful flights so far, PSLV has repeatedly proved itself as a reliable and versatile workhorse launch vehicle.
It has demonstrated multiple satellite launch capability having launched a total of sixteen satellites for international customers besides thirteen Indian payloads, which are for remote sensing, amateur radio communications and Space capsule Recovery Experiment (SRE-1). PSLV was used to launch ISRO’s exclusive meteorological satellite, KALPANA-1, into a Geosynchronous Transfer Orbit (GTO) in September 2002 and thus proved its versatility.
CARTOSAT-2A is a state-of-the art remote sensing satellite with a spatial resolution of better than one metre and swath of 9.6 km. The satellite carries a panchromatic camera (PAN) capable of taking black-and-white pictures in the visible region of electromagnetic spectrum. The highly agile CARTOSAT-2A is steerable along as well as across the direction of its movement to facilitate imaging of any area more frequently. High-resolution data from CARTOSAT-2A will be invaluable in urban and rural development applications calling for large scale mapping.
Indian Mini Satellite (IMS-1), flown as an auxiliary payload weighing 83 Kg at lift-off, incorporates many new technologies and has miniaturised subsystems. IMS-1 carries two remote sensing payloads – a Multi-spectral camera (Mx Payload) and a Hyper-spectral camera (HySI Payload), operating in the visible and near infrared regions of the electromagnetic spectrum. The spatial resolution of Mx camera is 37 metre with a swath of 151 km while that of HySI is about 506 metre with a swath of about 130 km.
The data from this mission will be made available to interested space agencies and student community from developing countries to provide necessary impetus to capacity building in using satellite data. The versatile IMS-1 has been specifically developed to carry different payloads in future without significant changes in it and has a design life time of two years.
Establishing Indigenous Systems
Space programme in the country started in the 1960’s with the launching of small sounding rockets to investigate the ionosphere over the magnetic equator that passes over Thumba near Thiruvananthapuram. Since then, India has been able to successfully master space technology and, more importantly, use it effectively for deriving benefits for the society at grassroots level. Today, Indian National satellite (INSAT) system and Indian Remote Sensing (IRS) Satellite System form an important element of the national developmental infrastructure. The Polar Satellite Launch Vehicle, PSLV, and Geosynchronous Satellite Launch Vehicle, GSLV, designed and built indigenously have made the space programme self-reliant.
INSAT System
INSAT System is the largest domestic communication satellite system in the Asia Pacific region with eleven satellites in operation carrying a total of 210 transponders for communication and broadcast services including Direct-To-Home (DTH) service besides meteorological instruments for providing meteorological services.
Today, more than 65,000 VSATs – both in private and government sectors – are operating through INSAT. INSAT has enabled the expansion of television coverage with more than 40 Doordarshan channels and 50 private TV channels operating through INSAT. DTH television services have become a reality. More importantly, there have been several innovative applications of INSAT system. EDUSAT, launched in September 2004, is the first thematic satellite dedicated exclusively for educational services. EDUSAT is providing a wide range of educational delivery modes like one-way TV broadcast, interactive TV, video conferencing, computer conferencing, web-based instructions, etc. About 46 networks that utilise EDUSAT covering 23 states have been setup across the country. These networks connect more than 2500 interactive and about 31,000 receive-only nodes setup at different schools, colleges, training institutes and other departments.
Telemedicine is another important initiative to use space technology for societal benefits. It has enabled the population, even in the remotest parts, access to super specialty medical care. At present, the telemedicine network of ISRO has more than 300 installations of which about 45 are super specialty hospitals and 10 are mobile units. Till now, more than three lakh patients have been benefited annually through telemedicine system.
Meteorological data from INSAT is used for weather forecasting and specially designed disaster warning receivers have been installed in vulnerable coastal areas for direct transmission of warnings against impending disaster like cyclones.
The major emphasis in the coming years will be to meet the growing demand for transponders by progressively increasing the capacity to about 500 transponders. An Indian Regional Navigational Satellite System (IRNSS), with a constellation of seven satellites is also being established over the next 6-7 years to provide navigation and timing services over the Indian subcontinent. IRNSS will be an important component of the Indian strategy for establishing an indigenous and independent satellite navigation system.
Indian Remote Sensing Satellite System
With eight satellites in operation, Indian remote Sensing Satellite System (IRS) is the largest civilian remote sensing satellite constellation in the world providing imageries in a variety of spatial resolutions and spectral bands. CARTOSAT-2A, is a state-of-the art remote sensing satellite with better than one meter resolution. The highly agile CARTOSAT-2A is steer-able along as well as across the direction of its movement to facilitate imaging of any area more frequently. IMS-1, flown, as an auxiliary payload on board PSLV-C9 along with CARTOSAT-2A is a Mini Satellite developed by ISRO for remote sensing.
The data from IRS satellites is used for a variety of applications including groundwater prospect mapping, crop acreage and production estimation, potential fishing zone forecasting based on chlorophyll and sea surface temperature, biodiversity characterisation, detailed impact assessment of watershed development projects, generation of natural resources information system, etc.
In order to reach space-based services directly to the rural population, establishment of Village Resource Centres (VRC) has been operationalised with the participation of NGOs. VRCs provide a variety of space based products and services such as tele-education; telemedicine; information on natural resources; interactive advisories on agriculture, fisheries, land and water resources management; livestock management; interactive vocational training towards livelihood support; etc. So far, 410 VRCs have been set up.
Space systems also help in disaster management through creation of database for facilitating hazard zonation and damage assessment, monitoring of major natural disasters using satellite and aerial data and strengthening the communication backbone for timely dissemination of information and emergency support.
Indian Launch Vehicles
India’s Polar Satellite Launch Vehicle (PSLV) and Geosynchronous Satellite Launch Vehicle (GSLV) are now used for launching the remote sensing and communication satellites.
ISRO has achieved a significant milestone through the successful test of indigenously developed Cryogenic Stage, to be employed as the upper stage of India’s Geosynchronous Satellite Launch Vehicle (GSLV). The test was conducted for its full flight duration of 720 seconds on November 15, 2007 at Liquid Propulsion test facility at Mahendragiri, in Tamil Nadu. With this test, the indigenous Cryogenic Upper Stage has been fully qualified on the ground.
Launch of PSLV-C9 is a significant milestone for the country, as it has again proved the reliability and versatility of PSLV and its ability to put satellites in different types of orbits, thus proving its commercial potential as well. This provides an excellent opportunity to undertake commercial launches of different class of satellites as stand-alone launches or as shared launches with our own satellites.
Geosynchronous Satellite Launch Vehicle (GSLV-F04) was launched successfully on September 2, 2007 carrying INSAT-4CR into the desired orbit. The successful launch of GSLV-F04 demonstrated the operational reliability of GSLV as well as reiterating the end-to-end capability of ISRO to not only build state-of-the-art communication satellites, but also to launch them using the indigenously designed and built launch vehicle.
The immediate target is to complete the development of GSLV Mk III capable of launching 4 tonne class communication satellites. Technology development and demonstration missions on reusable launch vehicle including space recovery technologies and air breathing propulsion are also envisaged.
Contributing to Scientific Knowledge
Indian space programme encompasses research in atmospheric sciences, planetary and geosciences and theoretical physics. There are ground facilities like Mesosphere-Stratosphere-Troposphere Radar at Tirupati and Udaipur Solar Observatory. A series of sounding rockets are available for atmospheric experiments. Several scientific instruments have been flown on satellites especially to direct celestial X-ray and gamma-ray bursts.
India has now embarked on a major mission, Chandrayaan-1. It is an un-manned Indian scientific mission to moon planned shortly. The objective is high resolution mapping of the moon in visible, near infrared, low energy X-ray and high-energy X-ray regions and prepares a 3-dimensional atlas of regions of scientific interest. The spacecraft will carry six primary Indian scientific instruments besides two from National Aeronautics and Space Administration (NASA) of USA, three instruments from the European Space Agency and another from the Bulgarian Academy of Sciences.
ASTROSAT is another major initiative. This satellite, to be launched during 2009, will be useful for multi-wavelength studies of a variety of celestial sources and phenomena using a cluster of X-ray astronomy instruments and Ultraviolet imaging telescope.
Follow-on missions to Chandrayaan-1 and ASTROSAT are also envisaged for pursuing scientific exploration. Besides, small satellite missions for scientific studies in the areas of solar physics, earth’s near space environment, inner magnetosphere and atmospheric aerosol and trace gases are also proposed. Further, with the primary interest to understand the origin and evolution of solar system, technology development could be initiated in the coming years towards exploration of Mars, Asteroids and comets.
Indian Institute of Space Science and Technology
Indian Institute of Space Science and Technology (IIST) was inaugurated on September 14, 2007 with the objective of offering high quality education in space science and technology to meet the growing demands of the Indian Space Programme. The Institute offers Bachelors degree in Space Technology with specialization in avionics, and aerospace engineering as well as Integrated Masters degree in applied sciences with special emphasis on space related subjects. The Institute started from the current academic year and 140 students from various parts of the country have enrolled for under graduate and masters courses.
Commercial Success
The capabilities created under the Indian space programme are bringing in commercial benefits too. Antrix Corporation Limited was specially created in 1992 under the Department of Space to market space services and hardware in the international market. ANTRIX provides transponders on lease and remote sensing data services as well as launch services. It also provides technical services for launch and early-orbit-phase mission support and in-orbit testing for satellites of other countries. ANTRIX has been profitable throughout registering an annual growth rate of about 20 percent in the past few years. The present turn-over of ANTRIX is Rs.664 crore with a profit of Rs.105 crore.
ANTRIX’s vision is to further expand its market share in fields such as remote sensing imageries, commercial satellites and infrastructure services in space for broadcasting and other emerging services like mobile communication and positioning systems. It also envisions strengthening the role of Indian industries and would develop alliances with other major global players to make forays into new markets in the markets in the developing part of the world.
Towards manned Space Mission
Space has emerged as the next frontier of human kind. Involvement of human beings in space for building and maintaining space assets will become important in the coming decades and it will be necessary to initiate the activities towards manned missions by developing critical technologies. The immediate objective will be to develop a fully autonomous manned space vehicle – in about 8-10 years – which could be launched by India’s GSLV and can carry a two-member crew to low earth orbit and safely return to earth.
The Indian space programme, while meeting the developmental needs of the nation through establishment of space systems in a self reliant manner, is poised to expand further and play an increasing role in the national developmental efforts besides substantially contributing to the exploration of outer space. (PIB Features)
No comments:
Post a Comment