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Established in 1969, ISRO superseded the erstwhile Indian National Committee for Space Research INCOSPAR. Headquartered in Bangalore, ISRO is under the administrative control of the Department of Space, Government of India.
2.ISRO has achieved numerous milestones since its establishment. India's first satellite, Aryabhata, was built by ISRO and launched by the Soviet Union in 1975. Rohini, the first satellite to be placed in orbit by an Indian-made launch vehicle, SLV-3, was launched in 1980. ISRO subsequently developed two other rockets: the Polar Satellite Launch Vehicle (PSLV) for putting satellites into polar orbits and the Geosynchronous Satellite Launch Vehicle (GSLV) for placing satellites into geostationary orbits. These rockets have launched numerous communications satellites, earth observation satellites, and, in 2008, Chandrayaan-1, India's first mission to the Moon.
3.Over the years, ISRO has conducted a variety of operations for both Indian and foreign clients. ISRO's satellite launch capability is mostly provided by indigenous launch vehicles and launch sites. In 2008, ISRO successfully launched its first lunar probe, Chandrayaan-1, while future plans include indigenous development of GSLV, manned space missions, further lunar exploration, and interplanetary probes. ISRO has several field installations as assets, and cooperates with the international community as a part of several bilateral and multilateral agreements.
Satellite Launch Vehicle
4.India's launch vehicle program started in the 1960's with the launch of sounding rockets from Thumba has come a long way. The various launch vehicles which have been part of the Indian space program are Satellite Launch Vehicle (SLV), Augmented Satellite Launch Vehicle (ASLV), Polar Satellite Launch Vehicle (PSLV), Geosynchronous Satellite Launch Vehicle (GSLV).
File:Indian carrier rockets.svg
Figure : Comparison of Indian carrier rockets. Left to right: SLV, ASLV, PSLV, GSLV, GSLV III.
5.Satellite Launch Vehicle (SLV).The Satellite Launch Vehicle, usually known by its as SLV or SLV-3 was a 4-stage solid-fuel satellite launcher. It was intended to reach a height of 500 km and carry a payload of 40 kg. Its first launch took place in 1979 with 2 more in each subsequent year, and the final launch in 1983. Only two of its four test flights were successful. At present this launch vehicle is not in use.
6.Augmented Satellite Launch Vehicle (ASLV).The Augmented Satellite Launch Vehicle, usually known as ASLV was a 5-stage solid propellant rocket with the capability of placing a 150 kg satellite into LEO. This project was started by the ISRO during the early 1980s to develop technologies needed for a payload to be placed into a geostationary orbit. Its design was based on Satellite Launch Vehicle. The first launch test was held in 1987, and after that 3 others followed in 1988, 1992 and 1994, out of which only 2 were successful, before it was decommissioned.
7.Polar Satellite Launch Vehicle (PSLV).The Polar Satellite Launch Vehicle, usually known by its abbreviation PSLV, is an expendable launch system developed to allow India to launch its Indian Remote Sensing (IRS) satellites into sun synchronous orbits, a service that was, until the advent of the PSLV, commercially viable only from Russia. PSLV can also launch small satellites into geostationary transfer orbit (GTO). The reliability and versatility of the PSLV is proven by the fact that it has launched 55 satellites / spacecrafts( 26 Indian and 29 Foreign Satellites) into a variety of orbits so far. In April 2008, it successfully launched 10 satellites at once, breaking a world record held by Russia. On 9 September 2012 the PSLV flew its 21th consecutive successful launch mission. Its only failure in 22 flights was its maiden voyage in September 1993, providing the rocket with a 95 percent success rate.
8.Geosynchronous Satellite Launch Vehicle (GSLV).The Geosynchronous Satellite Launch Vehicle, usually known by its abbreviation GSLV, is an expendable launch system developed to enable India to launch its INSAT-type satellites into geostationary orbit and to make India less dependent on foreign rockets. At present, it is ISRO's heaviest satellite launch vehicle and is capable of putting a total payload of up to 5 tons to Low Earth Orbit. The vehicle is built by India with the cryogenic engine purchased from Russia while the ISRO develops its own engine program.In a setback for ISRO, the latest attempt to launch the GSLV, GSLV-F06 carrying GSAT-5P, failed on 25 December 2010. The initial evaluation implies that loss of control for the strap-on boosters caused the rocket to veer from its intended flight path, forcing a programmed detonation. Sixty-four seconds into the first stage of flight, the rocket began to break up due to the acute angle of attack. The body housing the 3rd stage, the cryogenic stage, incurred structural damage, forcing the range safety team to initiate a programmed detonation of the rocket.
9.Geosynchronous Satellite Launch Vehicle Mark-III (GSLV III).The Geo- synchronous Satellite Launch Vehicle Mark-III is a launch vehicle currently under development by the Indian Space Research Organisation. It is intended to launch heavy satellites into geostationary orbit, and will allow India to become less dependent on foreign rockets for heavy lifting. The rocket, though the technological successor to the GSLV, however is not derived from its predecessor. The maiden flight is scheduled to take place in 2012.
10.For the past four decades, ISRO has launched more than 65 satellites for various scientific and technological applications like mobile communications, Direct-to-Home services, meteorological observations, telemedicine, tele-education, disaster warning, radio networking, search and rescue operations, remote sensing and scientific studies of the space.
11.ISRO has established two major space systems, the Indian National Satellite System (INSAT) series for communication, television broadcasting and meteorological services which is Geo-Stationary Satellites, and Indian Remote Sensing Satellites (IRS) system for resources monitoring and management which is Earth Observation Satellites. ISRO has launched many Experimental Satellites which are generally small comparing to INSAT or IRS and Space Missions to explore the space.
12.Geo Stationary Satellites.The Indian National Satellite (INSAT) system which are placed in Geo-stationary orbits is one of the largest domestic communication satellite systems in Asia-Pacific region. Established in 1983 with commissioning of INSAT-1B, it initiated a major revolution in India's communications sector and sustained the same later. INSAT space segment consists of 24 satellites out of which 9 are in service (INSAT-3A, INSAT-4B, INSAT-3C, INSAT-3E, KALPANA-1, INSAT-4A, INSAT-4CR,GSAT-8 and GSAT-12). The system with a total of 168 transponders in the C, Extended C and Ku-bands provides services to telecommunications, television broadcasting, weather forecasting, disaster warning and Search and Rescue operations.
13.Earth observation Satellite.Indian Remote Sensing (IRS) satellite system was commissioned with the launch of IRS-1A, in 1988. With twelve satellites in operation, IRS is the largest civilian remote sensing satellite constellation in the world providing imageries in a variety of spatial resolutions, spectral bands and swaths. The data is used for several applications covering agriculture, water resources, urban development, mineral prospecting, environment, forestry, drought and flood forecasting, ocean resources and disaster management.All the satellites are placed in polar sun-synchronous orbit and provide data in a variety of spatial, spectral and temporal resolutions to enable several programs to be undertaken relevant to national development. The initial versions are composed of the 1 (A,B,C,D) nomenclature. The later versions are named based on their area of application including OceanSat, CartoSat, ResourceSat. Apart from te IRS series of satellites as mentioned above ISRO currently operates two Radar Imaging Satellites. RISAT-1 was launched from Sriharikota Spaceport on 26 April 2012 on board a PSLV.RISAT-1 carries a C-band Synthetic Aperture Radar (SAR) payload, operating in a multi-polarisation and multi-resolution mode and can provide images with coarse, fine and high spatial resolutions. India also operates RISAT-2 which was launched in 2009 and acquired from Israel at a cost $110 million.
14.Space Missions.Indian space programme encompasses research in areas like astronomy, astrophysics, planetary and earth sciences, atmospheric sciences and theoretical physics. Balloons, sounding rockets, space platforms and ground-based facilities support these research efforts. 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.Major space missions are Chandrayaan-l and forthcoming Megha - Tropiques.
15.The table below lists the various satellites launched by India.
19 April 1975
Provided technological experience in building and operating a satellite system.
07 June 1979
First experimental remote sensing satellite. Carried TV and microwave cameras.
Rohini Technology Payload
10 August 1979
Intended for measuring in-flight performance of first experimental flight of SLV-3, the first Indian launch vehicle. Did not achieve orbit.
18 July 1980
Used for measuring in-flight performance of second experimental launch of SLV-3.
31 May 1981
Used for conducting some remote sensing technology studies using a landmark sensor payload.Launched by the first developmental launch of SLV-3.
Ariane Passenger Payload Experiment
19 June 1981
First experimental communication satellite. Provided experience in building and operating a payload experiment three-axis stabilised communication satellite.
20 November 1981
Second experimental remote sensing satellite; similar to Bhaskara-1. Provided experience in building and operating a remote sensing satellite system on an end-to-end basis.
10 April 1982
Delta 3910 PAM-D
First operational multipurpose communication and meteorology satellite. Procured from USA. Worked for only six months.
17 April 1983
Identical to RS-D1. Launched by the second developmental launch of SLV-3.
30 August 1983
Identical to INSAT-1A. Served for more than design life of seven years.
Stretched Rohini Satellite Series(SROSS-1)
24 March 1987
Carried payload for launch vehicle performance monitoring and for gamma ray astronomy. Did not achieve orbit.
17 March 1988
Earth observation satellite. First operational remote sensing satellite.
Stretched Rohini Satellite Series(SROSS-2)
13 July 1988
Carried remote sensing payload of German space agency in addition to Gamma Ray astronomy payload. Did not achieve orbit.
21 July 1988
Same as INSAT-1A. Served for only one-and-a-half years.
12 June 1990
Identical to INSAT-1A. Still in service.
29 August 1991
Earth observation satellite. Improved version of IRS-1A.
26 February 1992
Launched asÂ Arabsat 1C. Procured in orbit from Arabsat in January 1998.
Stretched Rohini Satellite Series(SROSS-C)
20 May 1992
Carried gamma ray astronomy and aeronomy payload.
10 July 1992
First satellite in the second-generation Indian-built INSAT-2 series. Has enhanced capability over INSAT-1 series. Still in service.
23 July 1993
Second satellite in INSAT-2 series. Identical to INSAT-2A. Still in service.
20 September 1993
Earth observation satellite. Did not achieve orbit.
Stretched Rohini Satellite Series(SROSS-C2)
04 May 1994
Identical to SROSS-C. Still in service.
15 October 1994
Earth observation satellite. Launched by second developmental flight of PSLV.
07 December 1995
Has additional capabilities such as mobile satellite service, business communication and television outreach beyond Indian boundaries. Still in service.
29 December 1995
Earth observation satellite. Launched fromÂ BaikonurCosmodrome.
21 March 1996
Earth observation satellite. Carries remote sensing payload and an X-ray astronomy payload. Launched by third developmental flight of PSLV.
04 June 1997
Same as INSAT-2C. Inoperable since 1997-10-04 due to power bus anomaly.
29 September 1997
Earth observation satellite. Same as IRS-1C.
03 April 1999
Multipurpose communication and meteorological satellite.
26 May 1999
Earth observation satellite. Carries an Ocean Colour Monitor (OCM) and a Multifrequency Scanning Microwave Radiometer (MSMR).
22 March 2000
Multipurpose communication: business communication, developmental communication, and mobile communication.
18 April 2001
Experimental satellite for the first developmental flight of Geosynchronous Satellite Launch Vehicle, GSLV-D1.
Technology Experiment SatelliteÂ (TES)
22 October 2001
Experimental satellite to test technologies such as attitude and orbit control system, high-torque reaction wheels, new reaction control system, etc.
24 January 2002
Designed to augment the existing INSAT capacity for communication and broadcasting and provide continuity of the services of INSAT-2C.
12 September 2002
First meteorological satellite built by ISRO. Originally named METSAT. Renamed afterÂ KalpanaChawlaÂ who perished in theSpace Shuttle Columbia.
10 April 2003
Multipurpose satellite for communication, broadcasting, and meteorological services along with INSAT-2E and Kalpana-1.
08 May 2003
Experimental satellite for the second developmental test flight of Geosynchronous Satellite Launch Vehicle (GSLV)
28 September 2003
Communication satellite to augment the existing INSAT System.
17 October 2003
Earth observation/remote sensing satellite. Intended to supplement and replace IRS-1C and IRS-1D.
20 October 2004
Also designated GSAT-3. India's first exclusive educational satellite.
05 May 2005
Microsatellite (42.5 kilograms) for providing satellite-based amateur radio services to the national as well as the international community.
05 May 2005
Earth observation satellite. Provides stereographic in-orbit images with a 2.5-meter resolution.
22 December 2005
Advanced satellite for direct-to-home television broadcasting services.
10 July 2006
Geosynchronous communications satellite. Did not achieve orbit.
Space Capsule Recovery Experiment(SRE-1)
10 January 2007
Experimental satellite intended to demonstrate the technology of an orbiting platform for performing experiments in microgravity conditions. Launched as a co-passenger with CARTOSAT-2. SRE-1 was de-orbited and recovered successfully after 12 days over Bay of Bengal.
10 January 2007
Advanced remote sensing satellite carrying a panchromatic camera capable of providing scene-specific spot images.
12 March 2007
Identical to INSAT-4A. Further augments the INSAT capacity for direct-to-home (DTH) television services and other communications. On the night of 7 July INSAT-4B experienced a power supply glitch which led to switching 'off' of 50 per cent of the transponder capacity (6 Ku and 6 C-Band transponders).
02 September 2007
Identical to INSAT-4C. It carried 12 high-power Ku-band transponders designed to provide direct-to-home (DTH) television services,Â Digital Satellite News GatheringÂ etc.
IMS-1Â (Third World Satellite - TWsat)
28 April 2008
Low-cost microsatellite imaging mission. Launched as co-passenger with CARTOSAT-2A.
28 April 2008
Earth observation/remote sensing satellite. Identical to CARTOSAT-2.
22 October 2008
Unmanned lunar probe. Carries 11 scientific instruments built in India, USA, UK, Germany, Sweden and Bulgaria.
20 April 2009
Research microsatellite designed atÂ Anna University. Carries an amateur radio and technology demonstration experiments.
20 April 2009
Radar imaging satellite used to monitor India's borders and as part of anti-infiltration and anti-terrorist operations. Launched as a co-passenger with ANUSAT.
23 September 2009
Gathers data for oceanographic, coastal and atmospheric applications. Continues mission of Oceansat-1.
15 April 2010
Communications satellite technology demonstrator. Failed to reach orbit due to GSLV-D3 failure.
12 July 2010
Earth observation/remote sensing satellite. Identical to CARTOSAT-2A.
25 December 2010
C-band communication satellite, failed to reach orbit due to GSLV-F06 failure.
20 April 2011
PSLV-C16 placed three satellites with a total payload mass of 1404 kg - RESOURCESAT-2 weighing 1206 kg, the Indo-Russian YOUTHSAT weighing 92 kg and Singapore's X-SAT weighing 106 kg - into an 822 km polar Sun Synchronous Orbit (SSO).
GSAT-8Â /Â INSAT-4G
21 May 2011
Communications satellite carries 24 Ku-band transponders and 2 channelÂ GAGANÂ payload operating in L1 and L5 band.
15 July 2011
GSAT-12 communication satellite built by ISRO, weighs about 1410 kg at lift-off. GSAT-12 is configured to carry 12 Extended C-band transponders to meet the country's growing demand for transponders in a short turn-around-time.The 12 Extended C-band transponders of GSAT-12 will augment the capacity in the INSAT system for various communication services like Tele-education, Telemedicine and for Village Resource Centres (VRC).Mission life About 8 Years.
12 October 2011
Megha-Tropiques weighs about 1000kg Lift-off Mass, developed jointly by ISRO and the FrenchÂ Centre National d'ÉtudesSpatialesÂ (CNES). PSLV-C18 is configured to carry four satellites in which, one satellite, developed byÂ IndiaÂ andÂ France, will track the weather, two were developed by educational institutions, and the fourth is from Luxembourg.
26 April 2012
RISAT-1, first indigenous all-weather Radar Imaging Satellite (RISAT-1), whose images will facilitate agriculture and disaster management weighs about 1858kg.
29 September 2012
GSAT-10, India's advanced communication satellite, is a high power satellite being inducted into the INSAT system. Weighing 3400 kg at lift-off.
15.India has established a strong infrastructure for executing its space programme. They include facilities for the development of satellites and launch vehicles and their testing; launch infrastructure for sounding rockets and satellite launch vehicles; telemetry, tracking and command network; data reception and processing systems for remote sensing.A number of academic and research institutions as well as industries participate in the Indian Space Programme. Several Indian industries have the expertise to undertake sophisticated jobs required for space systems. The table below shows a list of ISRO's various Tracking and Control Facilities.
Indian Deep Space Network (IDSN)
This network receives, processes, archives and distributes the spacecraft health data and payload data in real time. It can track and monitor satellites up to very large distances, even beyond theÂ Moon.
National Remote Sensing Centre
The NRSC applies remote sensing to manage natural resources and study aerial surveying.Â With centresatBalanagarÂ andÂ ShadnagarÂ it also has training facilities atÂ DehradunÂ in form of theÂ Indian Institute of Remote Sensing.
Indian Space Research Organisation Telemetry, Tracking and Command Network
Bangalore (headquarters) and a number of ground stations throughout India and World.
Software development, ground operations, Tracking Telemetry and Command (TTC), and support is provided by this institution.Â ISTRAC has Tracking stations throughout the country and all over the world inÂ Port LouisÂ (Mauritius), Bearslake (Russia),Â BiakÂ (Indonesia) andÂ Brunei.
Master Control Facility
Geostationary satellite orbit raising, payload testing, and in-orbit operations are performed at this facility.Â The MCF has earth stations and Satellite Control Centre (SCC) for controlling satellites.Â A second MCF-like facility named 'MCF-B' is being constructed at Bhopal.
16.ISRO plans to launch a number of new-generation Earth Observation Satellites in the near future. It will also undertake the development of new launch vehicles and spacecraft. ISRO has stated that it will send unmanned missions to Mars and Near-Earth Objects. ISRO has planned 58 missions during 2012-17; 33 satellites missions in next two years and 25 launch vehicles missions thereafter, costing 20,000 crore (US$4 billion).
17.INSAT - 3D.INSAT-3D, an exclusive meteorological satellite, is configured with advanced meteorological payloads - a 6 Channel Imager, 19 Channel Sounder along with Data Relay Transponder and Satellite Aided Search & Rescue payloads. The spacecraft platform is adopted from the standard I-2K bus with a power handling capability of around 1100 W with a lift off mass of 2090 kg.
18.SARAL.The Satellite for ARGOS and ALTIKA (SARAL) is a joint ISRO - CNES mission, and will be launched in last quarter of 2012, by PSLV-C20 into a sun-synchronous orbit with a local time of 6 pm descending node at an altitude of around 800 km. The Ka band altimeter, ALTIKA, provided by CNES consists of a Ka-band radar altimeter, operating at 35.75 GHz. A dual frequency total power type microwave radiometer (23.8 and 37 GHz) is embedded in the altimeter to correct tropospheric effects on the altimeter measurement. Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS) on board enables precise determination of the orbit. A Laser Retroreflector Array (LRA) helps to calibrate the precise orbit determination system and the altimeter system several times throughout the mission.
19.ASTROSAT.ASTROSAT is a national multiwavelength space borne astronomy observatory, which would enable simultaneous observations of the celestial bodies, cosmic sources in X-ray and UV spectral bands. The uniqueness of ASTROSAT lies in its wide spectral coverage extending over visible (3500-6000 Å), UV (1300-3000 Å), soft X and hard X ray regions (0.5-8 keV; 3-80 keV). The satellite would be launched by PSLV to an altitude of 650 km with 8o orbital inclination from SatishDhawan Space Centre, Sriharikota.
20.GSAT- 6.GSAT-6 spacecraft is configured with five S-band beams to cover the Indian main land, each beam supporting one CxS-band forward link transponder and one SxC-Band return link transponder. Thus, the 5 beams will have paired five transponders. The communication link operates through a Hub. The spacecraft employs the standard I-2k has with a power generation capability of around 3.1 KW. The spacecraft weighs 2200 kg at lift-off. The payload uses a high power S-Band TWTA and a new technology 6m unfurlable antenna.
21.GSAT-7.GSAT-7 is a multi-band satellite carrying payloads in UHF, S-band, C-band and Ku-band. The satellite weighs 2330 kg with a payload power of 2000W. The configuration of the satellite has been finalised and the design of new payload elements is completed.
22.GSAT-9.GSAT-9 will carry 12 Ku band transponders with India coverage beam and a GAGAN payload. The satellite is planned to be launched during 2013-14 by GSLV. The platform system is based on I-2K satellite with a liftoff mass of 2330 kg and payload power of 2300W.
23.GSAT-11.GSAT-11 is based on I-4K bus which is under advanced stage of development. The spacecraft can generate 10-12 KW of power and can support payload power of 8KW. The payload configuration is on-going. It consists of 16 spot beams covering entire country including Andaman & Nicobar islands. The communication link to the user-end terminals operate in Ku-band while the communication link to the hubs operate in Ka-band. The payload is configured to be operated as a high data throughput satellite, to be realised in orbit in 2013 time frame.
24.GSAT-14.GSAT-14 is intended to serve as a replacement for EDUSAT as the spacecraft is configured with 6 Ku and 6 Ext C band transponders providing India coverage beams. In addition, the spacecraft also carries Ka band beacons, which are planned to be used to carry out studies related to rain and atmospheric effects on Ka band satellite communication links in Indian region. The spacecraft weighs around 2050 kg and is planned to be launched by GSLV with indigenous cryogenic upper stage.
25.IRNSS-1.Indian Regional Navigational Satellite System (IRNSS)-1, the first of the seven satellites of the IRNSS constellation, carries a Navigation payload and a C-band ranging transponder. The spacecraft employs an optimised I-1K structure with a power handling capability of around 1600W and a lift off mass of 1380 kg, and is designed for a nominal mission life of 7 years. The first satellite of IRNSS constellation is planned to be launched onboard PSLV in 2013 while the full constellation is planned to be realised during 2014 time frame.
Future Launch Vehicle
26.GSLV-Mk III.The GSLV Mk III is conceived and designed to make ISRO fully self reliant in launching heavier communication satellites of INSAT-4 class, which weigh 4500 to 5000 kg. The vehicle envisages multi-mission launch capability for GTO, LEO, Polar and intermediate circular orbits. GSLV Mk III is designed to be a three stage vehicle which is 42.4 m tall with a lift off mass of 630 tonnes. The booster stage comprises two identical S-200 large solid boosters with 200 tonne of solid propellants that are strapped on to the L-110 core liquid stage. The upper stage is the C25 cryogenic stage. The payload fairing measures 5 m in diameter with a payload volume of 100 cu m.
27.Reusable Launch Vehicle-Technology Demonstrator (RLV-TD).As a first step towards realizing a Two Stage To Orbit (TSTO) fully re-usable launch vehicle, a series of technology demonstration missions have been conceived. For this purpose a Winged Reusable Launch Vehicle technology Demonstrator (RLV-TD) has been configured. The RLV-TD will act as a flying test bed to evaluate various technologies viz., hypersonic flight, autonomous landing, powered cruise flight and hypersonic flight using air breathing propulsion. First in the series of demonstration trials is the hypersonic flight experiment (HEX).
Human Space Flight Mission Programme
28.A study for undertaking human space flight to carry human beings to low earth orbit and ensure their safe return has been made by the department. The department has initiated pre-project activities to study technical and managerial issues related to undertaking manned mission with an aim to build and demonstrate the country's capability. The programme envisages the development of a fully autonomous orbital vehicle carrying 2 or 3 crew members to about 300 km low earth orbit and their safe return.
Space Science Missions
29.Space Capsule Recovery Experiment (SRE-II).The main objective of SRE II is to realize a fully recoverable capsule and provide a platform to conduct microgravity experiments on Micro-biology, Agriculture, Powder Metallurgy, etc. SRE-2 is proposed to be launched onboard PSLV in 2012.
30.Chandrayaan-2.Chandrayaan-2, India's second mission to the Moon, will have an Orbiter and Lander-Rover module. ISRO will have the prime responsibility for the Orbiter and Rover; Roskosmos, Russia will be responsible for Lander. Chandrayaan-2 will be launched on India's Geosynchronous Satellite Launch Vehicle (GSLV-MkII). The science goals of the mission are to further improve the understanding of the origin and evolution of the Moon using instruments onboard Orbiter and in-situ analysis of lunar samples using Lander and Rover.
31.Aditya-1.The First Indian space based Solar Coronagraph to study solar Corona in visible and near IR bands. Launch of the Aditya mission is planned during the next high solar activity period (2012-13) The main objectives is to study the Coronal Mass Ejection (CME) and consequently the crucial physical parameters for space weather such as the coronal magnetic field structures, evolution of the coronal magnetic field etc. This will provide completely new information on the velocity fields and their variability in the inner corona having an important bearing on the unsolved problem of heating of the corona would be obtained.
32.GAGAN.The Ministry of Civil Aviation has decided to implement an indigenous Satellite-Based Regional GPS Augmentation System also known as Space-Based Augmentation System (SBAS) as part of the Satellite-Based Communications, Navigation and Surveillance (CNS)/Air Traffic Management (ATM) plan for civil aviation. The Indian SBAS system has been given an acronym GAGAN - GPS Aided GEO Augmented Navigation. A national plan for satellite navigation including implementation of Technology Demonstration System (TDS) over the Indian air space as a proof of concept has been prepared jointly by Airports Authority of India (AAI) and ISRO. TDS was successfully completed during 2007 by installing eight Indian Reference Stations (INRESs) at eight Indian airports and linked to the Master Control Center (MCC) located near Bangalore. The next major milestone in GAGAN was the conduct of PSAT (Preliminary System Acceptance Testing) which has been successfully completed in Dec 2010. The first GAGAN navigation payload was flown on GSAT-8 which was launched on May 21, 2011 and the second on GSAT-10 launched on 29th September 2012. The Navigation payload on GSAT-10 would provide improved accuracy of GPS signals (of better than 7 meters) to be used by the Airports Authority of India for Civil Aviation requirements.
33.Satellite communication system remain incomplete without the ground satellite terminals. The ground terminals provide the last mile connectivity in a satellite communication network. Analysis of different ground satellite communication terminals in use with various militaries around the world would help in planning for our own system.
Fixed Satellite Ground Terminals
34.US is expected to induct alarge number of ground terminals to meet the requirement of protected satellite communications of its armed forces. Portable, mobile, and fixed terminals with low, medium and high data rates will support ground units, aircrafts, ships and submarines. Various military SATCOM terminals include the following:-
(a)Family of Advanced Beyond line-of-sight Terminals (FAB-T).
(b)Single-Channel Antijam Man-Portable Terminal (SCAMP).
(c)Secure MobileAntijam Reliable Tactical Terminal (SMART-T)
(d)Submarine High Data Rate (Sub HDR) system.
35.The FAB-T is a combination of two previous programmes, the Airborne Wideband Terminal and the Command Post Terminal. The Ground Multiband Terminal is a tactical satellite communications ground terminal that would support operations in the X, C, Ku, and theKa bands. The US Army's Enhanced Manpack UHF Terminal is capable of being carried, set up, and can be used by a single soldier.
Mobile Satellite Ground Terminals
36.The Mobile User Objective System would use commercial technology to enable satellite communications. Commercial systems such as Thuraya in the Middle East and AceSin Southeast Asia have proved that as high as 10,000 low-data-rate handheldterminals can be serviced by a single satellite over a region.
Advanced Military SATCOM Production Terminal
37.Raytheon and the US Army successfully completed the testing of the first Advanced Extremely High Frequency (AEHF) satellite communication production terminalsrecently. The Secure Mobile Anti-jam Reliable Tactical Terminal (SMART-T) offers the next generation of protected communications with AEHF satellites.
SATCOM Ground Terminals for Indian Defence Forces of Future
38.From the analysis of above ground terminals it is clear that in the future India's armed forces SATCOM terminals will have to cater for both fixed and mobile users. The problem is not so much for the fixed user as for these the technology already exists but for the mobile users the SATCOM terminals will have to be smaller, lighter and embedded with secrecy. The satellite terminal with secure communication features like that provided by US MILSTAR and its follow-on AEHF (V-band) is a necessity for our armed forces to operate in hostile Electronic Warfare environment.
39.Small Multi-Band and Multi-Mode capable terminals capable of using different band as also different modes(terrestrial and satellite) for communication would greatly enhance the tactical mobility and the survivability of the Indian defence forces to a great extent.
40.Indigenous Capability.India has very limited capability to design, develop and manufacture ground terminals for satellite communications. Depends on terminals ex-trade will have to be done away with and india will have to focus in this area keeping in mind the specific requirements of secrecy, anti-jamming, ruggedness and portability of the defence forces.