Overview-ISAC

ISAC - OVERVIEW
December 2009

- M.V.Kannan
Head, Projects Division, PPEG

INTRODUCTION:
The presentation on “overview - ISAC” under IITP technical module is intended to give
an overall perspective of ISRO satellite centre to young and aspirant engineers who have
joined ISRO. It also intends to specifically expose engineers to various technical areas in
satellite domain, technological growth and challenges in these areas. With this specific
objective in view, this document is made covering aspects such as the evolution of ISAC,
role of ISAC and major activities, achievements, organization structure, ongoing and
future satellite programmes, major fabrication and test facilities, technologies realized at
present and future requirements/technological challenges etc. In this document both
Satellite and Spacecraft are used synonymously depending on the context.
EVOLUTION OF ISAC
The establishment of Thumba Equatorial Launching Station (TERLS) in 1963 and the
Experimental Satellite Communication Earth Station (ESCES) in 1967 was the prodigious
precursors of Space activities in the country. Activities relating to satellite technology
started in the right earnest at Satellite Systems
Division at Space Science & Technology Centre,
Trivandrum in the late sixties. Later when a conscious
decision emerged in 1972 to build the first Indian
Satellite ‘Aryabhata’ the scene shifted to Bangalore
with the formulation of the Indian Scientific Satellite
Project (ISSP). This move was to prove propitious
as the cradle of electronic industry nurtured the
activity further and the space programme structured itself in to three separate
components namely: Launch Vehicles, Satellites and payloads and applications. The
Indian Institute of Science campus initially housed the project activities until it moved to
the industrial sheds at Peenya. It was here
that a handful of engineers and technicians
fresh from the Universities sowed the first
seeds of satellite technology in the country.
With practically no prior-art existing within the
country, and with sparse infrastructure put
together from scratch, this young team developed the first Indian Satellite ARYABHATA
in the make-shift industrial sheds at Peenya, Bangalore. With the success of the
ARYABHATA mission, the fledgling space activity soon developed into a full-fledged
programme with national priorities.
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Thus was born the ISRO Satellite Centre (ISAC) in 1976.
In 1984 the Centre moved to the present 32 acre campus
at Airport Road, Vimanapura in Bangalore. The main
campus which houses the major fabrication and test
facilities, a new 110 acre campus (ISRO Satellite
Integration & Testing Establishment (ISITE) - established

about three years back) about 8 KMs away on the Marathalli outer ring road is replete
with Integration and environmental test facilities under one roof namely a large clean
room(for S/C Assembly, Integration & testing) , a compact antenna test facility (CATF)-
specific to communication satellites and antenna systems , a comprehensive Assembly
and Test thermo vacuum chamber (CATVAC), a comprehensive Assembly and Test
vibration facility (CATVIB). This facility is to enhance our throughput build of satellites, 5
communication satellites at a time.

ISAC is the lead centre for design, development & integration of Communication, Remote
sensing, scientific and small satellites. The activities include research & development in
the area of advanced state of art technologies, total management of all satellite missions,
creation of vibrant space industry for realization of space systems, Technology transfer,
academia interface etc. Cutting edge technologies meeting various mission requirements are
developed in the Centre keeping ISAC in the forefront of spacecraft technology frontiers. ISAC has
realized till now 54 satellites (Communication & Meteorology: 22, Remote sensing: 17
and others: 15) out of which 23 satellites (Communication & Meteorology: 12, Remote
Sensing: 10 and others: 1) in operation and providing good service for various
applications they are intended for.

The 51st spacecraft is the Chandrayaan-1, a completely indigenous lunar orbiter which
has shot India into International prominence as a space fairing nation capable of
interplanetary missions. The 52nd spacecraft is W2M, ISRO’s first commercial satellite
while ANUSAT is the 53rd satellite which was built by University scholars and students of
ANNA University, Chennai-Tamilnadu.

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The Centre is fully equipped with state of the art facilities for fabrication and testing of
mechanical and electronic hardware/subsystems and integrated satellite. To name a
few:3 Clean Rooms (Assembly, Integration & Testing of about 5 Spacecraft at a time),
Solar panel lab (fabrication & testing), Space Simulation Chambers, Anechoic chambers
and EMI (Electrical/Mechanical interference) test facility, Vibration & Acoustic facility,
Precision Mechanical & Electronics – Fabrication facility, HMC (Hybrid Micro Circuits) &
Electronics packaging facility and ISITE (AIT+CATF+CATVAC+CATVIB).
[AIT-Assembly, Integration & Testing; CATF-Compact antenna test facility; CATVAC-
Comprehensive Assembly & Test vacuum chamber; CATVIB- Comprehensive Assembly &
Test vibration facility.]

The human resources total strength of ISAC is around 2400 with 78% technical and 22%
administrative staff. The total budget outlay of ISAC is around Rs.1500/- crores per
year.

ORGANISATION STRUCTURE:

The Centre is functionally organized into six major areas [MSA, DCA, CMA, RCA, ICA,
PSAPA] ,four programme managements offices [GEOSAT, SATNAV, IRS & Small
Satellites] two independent groups [PPEG, CIG] and Two divisions [SAID, APD] apart

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from divisions in other areas [Administration, Purchase, Accounts, Stores, Canteen,

Transport]. There are three programme management teams to co-ordinate and
implement their respective projects. The projects are organized on inter Groups /
Divisions and inter-centre basis with identified teams participating in the developmental
tasks at subsystem/system levels. To utilise the limited resources and simultaneously
execute multiple projects, matrix style of organisation is adapted in the Centre.

The Centre was re-organized on 1st March 2009 and two new areas i.e., Integration and
Checkout Area (ICA) and Power System and Avionics Production Area (PSAPA) was
carved out with Spacecraft Integration Group (SIG) and Spacecraft Checkout Group
(SCG) coming under Integration and Checkout Area (ICA) and Power Systems Group
(PSG) and Avionics Production Division (APD) coming under Power Systems and Avionics
Production Area. Auxiliary support is provided by the Administration Group headed by
the Controller. Each functional area is headed by Deputy Director and supported by
Group Directors, Division Heads, and Section Heads etc. The heads of functional Areas
and S/C programme management directly report to Director of the Centre.

Associate Director, All the Deputy Directors, all Programme Directors, Controller, Group
Director, PPEG and Head, P&GA form the core members of ISAC council chaired by
Director, ISAC. The ISAC Council is the highest management forum in the CENTRE
responsible for all policy guidelines and major strategic decisions.

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Programme Planning & Evaluation Group (PPEG):

The Programme Planning and Evaluation Group (PPEG) is the central coordination team
of ISAC that provides interface between the various technical groups, the administrative
divisions and the management and outside agencies. It is the nodal hub and nerve
Centre in orchestrating the inter-group/inter-divisional coordination for techno
managerial issues. It also serves as the technological secretariat to the Director of
Centre by assisting him in the crucial tasks of resolving techno managerial issues by
collection, retention retrieval, archival and providing data, information and feed back at
right time, for decision making. The Group also assists in planning, coordinating,
monitoring and evaluating the activities of the Centre. Group Director, PPEG reports to
Director, ISAC.

The following are the major highlights of functions of ISAC PPEG.

Overall staff support for Technical and Managerial planning of Spacecraft
programmes including infrastructure build-up, resources allocation &
prioritization, monitoring & evaluating functions.
Futuristic studies in frontier areas of Space
Review and compilation of on-going projects
Centre Budget Planning and Expenditure Control.
Human Resources Development related activities
Providing management information system
Provide advisory support on selected administrative matters of the Centre. In
addition ,the Group will provide special assistance to Director in specific areas
that include general management and progress in technical areas of the
Centre
Appropriate interface between the technical and administrative wings of the
Centre.
Industry interface & Technology Transfer, Intellectual Property Rights related
activities
Specialized public relations and coordination including publications.
Coordination and follow up of TDPs (Technology Development Programme)
and RESPOND programs
Contract Management, Strategic Planning
Organization system, design, reviews and implementation
Organization development and Review
Advance planning (Five year plans)
Safety & Security
Event Managements and handling VIP/VVIP visits etc

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The above functional tasks are carried out by PPEG through the following Divisions and
Cells namely Projects Division, Budget, Organization & Methods Division, Human
Resource Development Division, Safety & Security Division, Management Information
System Cell.

FUNCTIONAL AREAS (TECHNICAL):

A spacecraft as a system has many subsystems and associated technology development
take place in each of the functional area. The scope and expertise of each functional area
are briefly covered in the following section.

TYPICAL COMMUNICATION SATELLITE

Mechanical Systems Area (MSA)

This area is responsible for Design, Analysis, Fabrication, Testing and Delivering
Mechanical hardware to all Spacecraft projects including associated Research and
development. MSA is headed by Deputy Director who reports to Director, ISAC. The
Mechanical Systems Area comprises of three groups viz. Structures Group (STG),
Thermal Systems Group (TSG) and Spacecraft Mechanisms Group (SMG).Group
Directors of respective systems report to Deputy Director.

The Structures Group has the total responsibility for
Design and Analysis, Manufacture, Testing and delivery of
spacecraft structure for all spacecraft projects. Know-how
for different types of structure construction, fabrication
processes and use of material with high specific strength
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and stiffness, expertise in computer aided design and manufacturing, accurate analytical
prediction and non-destruction evaluation and experimental testing both static and
dynamic rests in the Structure Group.

Thermal Systems Group is responsible for design and analysis, development and
testing, implementation of Thermal
control systems for all spacecraft.
Development of thermal control system
by selective employment of multi layer
insulation blankets, optical solar
reflectors, and auto controlled heaters
and heat sinks, heat pipes, passive radiant coolers etc, its
implementation and testing are the major activities of Thermal Group. Development of
heat pipes, capillary pumped loops, Cryo coolers, indigenization of thermal control
material and development of analysis techniques are also taken up by the group.

Spacecraft Mechanism Group is responsible for the design, development, analysis,
and fabrication, testing of various types of Mechanisms for Spacecraft applications.
These include hold-down and release systems, deployment
mechanisms, antenna pointing
mechanisms, coillable lattice boom with
sail of 16 meters length, dual gimbal
antenna and deployment systems for large
unfurlable antenna to name of few.
Analysis capabilities for deployment dynamic studies and
component analysis also exist. The Group also undertakes R & D for futuristic projects.
The Group has successfully demonstrated successive 112 on-orbit deployments of
various systems in GEOSAT and IRS series of Spacecraft.

DIGITAL & COMMUNICATION AREA (DCA):
Digital and Communication area is responsible for digital and communication systems for
all GEOSAT and IRS series of satellites including associated Research and development.
It is headed by Deputy Director who reports to Director, ISAC. The Digital and
Communication Area has two groups viz. Digital Systems Group (DSG) and
Communication Systems Group (CMG). Group Directors of respective systems report to
Deputy Director.

DSG is mainly responsible for design, development, fabrication and testing of proven
Telemetry and Telecommand systems for all spacecraft. Spacecraft payload data

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handling systems for different types of remote sensing payloads, solid state recorders
having Tera Bit storage capacities and gigabit rate read/write capabilities, image

DATA COMPRESSION SYSTEM
(3.3:1)

SOLID STATE RECORDER
(SSR)

Compression techniques etc are developed. Geo-mobile communication, TTC system for
deep space missions are other areas of expertise. It has also developed expertise in the
areas of command encoders which are installed at various Ground Stations for
controlling the ISRO Spacecraft all over the world. The Group also carries out R & D in
the design of systems for multimedia networking, Space Link Protocols, Onboard Data
Networks, Security for Telecommand and Data Handling links, Digital PSK
demodulator/bit synchronizers, embedded software such as Programmable Automatic
Temperature Controller (PATC) and packet based TTC systems.

CMG has the responsibility of design, development, fabrication
and testing of TTC receivers and TM transmitters in VHF, S, C and
Ku bands for all GEOSAT, IRS series and other spacecraft. For
earth observations and scientific missions data transmitters in S,
X, Ka bands with modulation and data rates up to 400 mbps are
also being pursued. SSPAs up to 20 watts at S and X band,
Temperature Control Crystal Oscillator (TCXO) at 350 MHz, light
weight, shaped beam, high power, high gain micro-strip antenna arrays at C Ku bands,
Omni antenna systems at S and Ku bands, light weight global beam antenna at C and
Ku-bands are also within the expertise domain of this Group.

CONTROLS & MISSION AREA (CMA):

CMA is responsible for design, development, fabrication and testing of control systems
and engaged in mission planning & analysis, software development related to flight
dynamics and satellite navigation. It is headed by Deputy Director who reports to
Director, ISAC. The Controls and Mission Area (CMA) has five groups viz. Control System
Group (CSG), Mission Development Group (MDG), Flight Dynamics Group (FDG),
Satellite Navigation Group (SNG) and Computer Simulation and HILS Facility (CS&HF).
Group Directors of respective systems report to Deputy Director. CS & HF is headed by a
General Manager reports to DD.

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CSG is responsible for analysis and synthesis of
technologies for control system design, systems
engineering aspects, simulation techniques including
simulation software development, capability to build
spacecraft operation sequence. The competence of
the group rests in design and development of
Attitude Orbit & Control Electronics (AOCE) including
control computer software and peripheral systems of
the computer, test beds, DC brushless motor, etc. An
onboard computer-Bus Management Unit (BMU) integrating the Telecommand, telemetry,
sensor processing, thermal control, and spacecraft autonomous operation is a jewel in its
crown. The Group also undertakes development of various magnetic torquers, dry
lubrication for various spacecraft mechanism, finite element analysis and magnetic
circuit analysis and design of standard mechanical packages for AOCE.

CSHF is responsible for carrying out hardware-in-loop-simulation test of control
electronics with associated sensors and actuators as per the mission requirement for all
spacecraft projects. The Group also carries out the required sensors simulators
establishment, HILS facility up gradation and maintenance and testing of the control
system in open loop and closed loop environment (HILS).

MDG is responsible for mission planning and operation with necessary documentation,
interfacing with all sub-systems, launch vehicle and network teams, carrying out per-
launch simulation and initial phase operations. Development of software system for
monitoring the health and status of the spacecraft and instruments, acquiring,
organizing, processing, archiving and distributing the data telemetered from the
spacecraft for real-time and post flight analysis, also form the activities of this Group.

FDG is responsible for Orbit selection for mission, analysis of orbit and attitude.
Development of software and algorithm for orbit determination, mathematical modeling
and software development for orbit acquisition, station keeping, and strategies for
transfer, launch window and maintenance are also form a part of its expertise.

SNG is responsible for development of suitable models, algorithms, software related to
generation of precise navigation parameters to the users. Currently the group has
navigation software development responsibilities for GPS Aided GEO Augmented
Navigation (GAGAN) and Indian Regional Navigation Satellite System (IRNSS) Projects
under SATNAV Program of ISRO.

RELIABILITY & COMPONENTS AREA (RCA)

RCA is responsible for reliability and quality assurance of all spacecraft hardware and
space qualified component management including Hybrid Micro Circuits (HMC)
development. The area is headed by Deputy Director who reports to Director, ISAC. RCA

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has two groups viz. System Reliability Group (SRG) & Indigenization and components
Group (ICG). Group Directors of respective systems report to Deputy Director.

SRG is responsible for the total quality and reliability assurance pertaining to the
fabrication, design, analysis, testing, audit and review of hardware of subsystems,
starting with the lowest assembly level till the final integrated level of the spacecraft.
The whole gamut of Quality Assurance (QA) and reliability activities like design
assurances, reliability prediction and assessment, quality assurance of parts, materials
and process, vendor qualification and certification, test and evaluation of modules,
subsystems and spacecrafts system and software QA of systems are planned and
executed by the expertise available within the Systems Reliability Group. Apart from
executing the routine quality and reliability related activities pertaining to each project,
the group is involved in such activities as, generation and up gradation of various
design/reliability guidelines/alerts, development of failure database of various
subsystems(observed during ground testing and also those observed in orbit), addition
of analytical methods, like risk analysis, Worst Case Circuit Analysis (WCCA) and up
gradation of test philosophy applicable to production of space hardware.

ICG is responsible for the Reliability and Quality Assurance
management of all the EEE parts for the ongoing satellite
programs. The activities include incoming inspection, screening
and qualification of parts. The division is also responsible for
management of bonded stores. The parts transactions and
inventory management are efficiently carried out though the
computerized data base system, ICSDBS developed and maintained by the Group. It is
also responsible for Radiation Hardness Assurance (RHA) which includes radiation dose
estimations; shielding calculations and performance of Total Dose testing and Single
Event Effects (SEE) characterization. Development of micro electronics through design,
qualification and fabrication of Hybrid Micro Circuits, and indigenization of components
and devices for use in future satellites come under the preview of ICG.

Integration and Checkout Area (ICA)

ICA is responsible for complete mechanical and electrical integration of spacecraft, EMI
control plans, spacecraft ground check out systems support and integrated spacecraft
level testing, final operations at launch complex. The area is headed by Deputy Director
who reports to Director, ISAC. The Integration and Check out Area has two groups viz.
Systems Integration Group (SIG), Spacecraft Checkout Group (SCG). Group Directors of
respective systems report to Deputy Director.

SIG is responsible for configuration design and layout, Design of electrical distribution
system, planning and implementation of function and interface tests, supporting
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integrated Spacecraft Tests, configuring the spacecraft for
the environmental test, planning and conduct of EMC tests
and drawing up and carrying out launch base operations.
The SIG also specializes in spacecraft transportation
container design, electronic housing design, estimation and
measurement of Centre of Gravity (C.G), Moment of Inertia
(M.I.) and cross product of Inertia guidelines for EMI free
design, ESD control and mitigation, circuit modeling,
simulation and Design of dedicated Test system is part of
its responsibility. The SIG operates and maintains all clean rooms at ISAC (three clean
rooms) and ISITE (one clean room), R.F. Shielded chamber for subsystem EMC tests, a
shielded anechoic chamber and Compact Antenna Test Facility of world class.

SCG is responsible for evaluating the performance of different sub assemblies and
integrated system during various stages of progressive integration till launch. Integration
checkout systems which takes care of uplink, downlink power feeding, measurement and
characterization of communication, remote sensing and special payload systems, are
part of their core competence areas.

Power Systems & Avionics Production Area (PSAPA)

Power Systems & Avionics Production Area is responsible for delivery the hardware
required for power systems of all spacecraft. It is also engaged in productionisation of
onboard standard electronic hardware like digital systems, power systems and control
systems. It is headed by Deputy Director who reports to Director, ISAC. PSAPA has one
group and a division namely: Power Systems group (PSG) and Avionics production
Division (APD). Group Directors of respective systems report to Deputy Director. Head,
APD directly report to DD.

PSG is responsible for design, development,
fabrication and testing of power electronics
hardware, solar panels and chemical
batteries for spacecraft. Its expertise
includes state-of-the-art technologies for
generating power up to 6KW using Silicon,
GaAs and multijunction solar cells. In the
field of energy storage, batteries of various types like Nickel
Cadmium, Nickel Hydrogen and Lithium Ion batteries have
been developed and used in various satellite eclipse phase
requirements of power as high as around 5KW. In the area
of power conditioning control and management, distribution

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technologies for power up to 6KW are in place. Various topologies for extensive
applications have been developed. Battery management technologies have been
developed to manage the new Lithium ion batteries.

APD has the responsibility to provide necessary managerial support to facilitate groups
and projects and act as a single
window support to achieve faster
turnaround time for realization of
standard electronic packages on
end-to-end basis. It is interfacing
with external vendors for
fabrication and testing activities of standard electronic sub
systems like Telemetry & Telecommand (TMTC), core power, Electro Explosive Devices
(EED), distribution packages, DC-DC converters, BMU etc. The Central Electronic
Fabrication Section, External Fabrication Section and Space Quality Component Section
come under APD.

GEOSAT PROGRAMME:

GEOSAT programme is responsible for definition, conceptualization, design and building
of all geostationary satellites to suit various applications. GEOSAT programme headed by
Programme Director is to establish and operate the multi-agency, multi-purpose
operational INSAT system to provide domestic Telecommunication, Meteorological Earth
observation, Weather Data Relay, nationwide TV & Radio broadcasting /networking, TV
programme distribution and Satellite Aided Search and Rescue payloads. ISRO/DOS is
the nodal agency for establishing and operating of the INSAT System, through INSAT
Coordination committee (ICC), under SATCOM policy of the Govt. of India.

GEOSAT Management office comprises of Systems Engineering (Electrical, Mechanical &
Propulsion), Budget and Planning, Configuration & Data management. Programme
Director is supported by Project Directors and project Executives of respective projects.
Internal Financial Advisor (IFA-(P)) is responsible for all finance & contractual aspects in
regard to Programmes and supports Programme Management Office.

Space segment development and management of IRNSS will be responsibility of
GEOSAT programme .Project Director and Associate project director of space segment
will report to Programme Director, GEOSAT at ISAC.GEOSAT Programme Director Report
to Director, ISAC.

IRS PROGRAMME & SMALL SATELLITES:

IRS programme is responsible for definition, conceptualization, design and building of all
earth observation satellites to suit various applications. IRS programme headed by
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Programme Director is to establish and operate the multi-agency, multi-purpose
operational IRS system for National Resource Management System and use of data for
various applications such as agriculture &soil, land form & land usage studies, water
resource, forestry, draught & flood monitoring, cartography, town planning & coastal
zone monitoring, oceanography studies etc. ISRO/DOS is the nodal agency for
establishing and operating of the IRS System, through Coordination committee (PC -
NNRMS).

IRS & SMALL Satellite Management office comprises of Systems Engineering (Electrical,
Mechanical & Propulsion), Budget and Planning, Configuration, Data management and
advance planning of projects. Programme Director is supported by Project Directors and
project Executives of respective projects. Internal Financial Advisor (IFA-(P)) is
responsible for all finance & contractual aspects in regard to Programmes and supports
Programme Management Office. Projects like Chandrayaan-1 & 2, MEGHA-TROPIQUES,
ASTROSAT, RISAT, YOUTHSAT, SARAL, RESOURCESAT-2 and all other small satellites
come under this office. Programme Director Report to Director, ISAC.

SATNAV PROGRAMME:

Satellite Navigation has been identified as one of the important activities in DOS. To
begin with, ISRO & Airports Authority of India have jointly taken up GAGAN TDS as a
forerunner for the operational Satellite based Augmentation System (SBAS) over the
Indian Airspace and the operational phase “GAGAN” has to be taken up subsequently.
Government of India has approved the plan to establish IRNSS which will put in place an
indigenously developed satellite navigation system to cater to the requirements of
critical National applications in addition to providing a back-up to the present global
SATNAV system being used by our commercial & other establishments in the country. In
order to organize and implement the above activities effectively, a Satellite Navigation
Programme was constituted.

To implement the SATNAV Programme, the organizational structure in various ISRO
Centres has been created and activities such as GAGAN TDS & FOP and IRNSS will be
part of this programme. ISAC is identified as the lead centre for Satellite Navigation
Program activities and Programme Director (SNP) is identified for this purpose. He will
be assisted by Project Directors at ISAC, SAC & ISTRAC. Programme Director, SNP will
have the overall responsibilities for all aspects of the program and shall report to
Director, ISAC. Project Director IRNSS and all Associate Project Directors will report to
Programme Director, SATNAV, and Satellite Navigation Office (SNPO) at ISRO HQ.

Human Space Programme (HSP)
The major objective of manned mission program is to develop the fully autonomous
three-ton Orbiting Vehicle (OV) spaceship to carry a 2 member crew to orbit and safe
return to the Earth after the mission duration of few orbits to two days. The extendable
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version of the spaceship will allow flights up to seven days, rendezvous and docking
capability with space stations or orbital platform.

ISRO plans to use GSLV-MK II launcher (GSLV-MK II is Geosynchronous Satellite Launch
Vehicle with an indigenous cryogenic engine with a capability of carrying a payload of 2.5
ton) for launch of OV spaceship. The launcher will inject the OV into an orbit, 300 km-
400 km from the Earth about 16 minutes after lift-off from the Satish Dhawan Space
Centre (SDSC), Sriharikota. The capsule would return for a splashdown in the Arabian
Sea. There are two main components of OV namely a Crew module and Service module.

The primary responsibility of ISAC is to develop and qualify service module (SM) along
with configuring overall mission operations like attitude and orbit control, providing
Environment Control & Life Support Systems for onboard crew. All the hardware
systems of service module will be developed by ISAC ensuring safety margins, added
redundancy and increased reliability for man rating – systems to be fail safe. Vikram
Sarabhai Space Centre (VSSC) will develop and qualify the crew module (CM). The End-
to-End testing of CM+SM stack will also be carried out at ISAC.

ISRO will be setting up an astronaut training centre in Bangalore by 2012, to prepare
personnel both for first manned mission and for future manned Moon missions which will
land Indians on the Earth’s natural satellite, Moon after 2020. The Rs. 1,000-crore centre
will train the selected astronauts in rescue and recovery operations, surviving in a zero
gravity situation, study of radiation environment and for the long journey in the space
through water simulation. This world class Astronaut Training and Research Centre will
house all major facilities like micro gravity simulators, centrifuge, quarantine, medical &
health care, flight suit, space food, sports & physical training and other such facilities.
ATC will also be responsible for final selection and training of Indian Astronaut who will
fly onboard India’s Human Space flights.

HSP (Service Module) and HSP (ATC) are headed by Associate project directors,
designates from ISAC.

Computer & Information Group (CIG)
CIG is responsible for establishment and management of Centralized IT infrastructure in
ISAC. Its main activities include managing the Central Computing Facility (CCF), Mail
and Internet services and software development. The Group has expertise in areas like
heterogeneous Unix system management, cross platform applications software
management, internet security, mail administration, network management, software
development under standard, open source environments and search application
development. CIG Group Director reports to Director, ISAC.

SPACE ASTRONOMY & INSTRUMENTATION DIVISION (SAID):

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SAID is involved in optical, x-ray and gamma-ray
astronomy research with a strong emphasis on
instrumentation. Instrumentation activities include design
and development of laboratory, engineering and flight
models. Expertise also exists in simulation studies and tools
for optimisation of various system performance parameters
such as detector performance, onboard background
estimation, energy calibration, detector sensitivity and modeling instrument response.

Facilities

ISRO Satellite Centre has a host of high end Environmental
Test Facilities under one roof to cater to the need of testing
from component to full spacecraft. The facilities include a fully
fledged space simulation chamber of 9.0m diameter for
validation of thermal design and checking the spacecraft
performance for in-orbit thermal environment and a 6.5 m
chamber at ISITE. There are 12 smaller thermal vacuum
chambers including 4.0 m diameter chamber. Electro dynamic
shakers of capacity 16 ton and 29 ton are available for testing
of spacecraft and its complex payloads. Apart from these, four
shakers of capacity-0.6T, 2T, 4T and 8T are used for
subsystem testing. The shock & vibration lab is complete with
capability for sine, random and shock testing. The
instrumentation at vibration lab includes data acquisition and
reduction capability of up to 160 channels and a 256 channel
system at ISITE. The Environment Test Facility has state of the
art climatic Test lab for testing electronic units and ultra high

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vacuum lab for testing materials for deep space conditions. An ultra modern fabrication
facility for making Printed Circuit boards is also an important lab under facilities. The
Facility has a mechanical fabrication area where all drawings are prepared using
Computer Aided Design (CAD). Machining all types of space grade materials is done to
realize mechanical elements with conventional machine as well as CNC machining
centre.

ISRO SATELLITE INTEGRATION AND TEST ESTABLISHMENT (ISITE):

Presently the integration and all testing facilities for realization of spacecraft are being
carried out at ISAC campus. The present setup has the capability to realize two to three
spacecrafts per year. But to cater to the growing need to realize 5 - 6 satellites per year
as per 11th five year plan, ISITE has been established with all the Assembly, Integration
and Test facilities needed to realize a full spacecraft under one roof. With the
establishment of this new facility the increased load to realize 5-6 satellites per year can
be easily met with.

ISRO Satellite Integration and Test Establishment (ISITE) a world class Assembly,
Integration & Test (AIT) complex with all spacecraft integration and test facilities under
one roof was inaugurated and commissioned during April 2006. The complex is fully laid
out and equipped with facilities for the complete assembly and test sequence that can
enable rolling out of a flight worthy spacecraft from the stage of a bare structure.
INSAT-4B & INSAT-4CR were fully integrated and tested in this facility .Presently AIT
activities of W2M (EUTELSAT), GSAT-4 are in progress in this facility.

ISITE is fully operational at present and all communication satellites are being

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integrated in the clean room therein. ISAC Main campus clean rooms are being used for
assembly, integration and testing of IRS, Small Satellite and Space Science projects.

A large clean room for AIT complemented with associated checkout facilities for the
complete test protocols of large high power satellites, a 6.5 m Thermo vacuum chamber
(CATVAC) for Thermo vacuum performance qualification of the spacecraft, a 29 ton
vibrator shaker (CATVIB) for dynamic tests, the various physical parameter
measurement facilities and comprehensive Antenna Test Facility makes the
establishment replete with all facilities for complete integration and testing at spacecraft
level. The campus is situated near to the present ISAC campus. ISITE is 110 acres in
area and other ancillary units and housing, along with establishments for commercial
activities are planned to be constructed here.

Assembly, Integration and Test (AIT) Clean Room is of the size 54.6×34.6×16.7 m with
a cleanliness level of 1,00,000 class. It consists of two Airlock rooms. The temperature
and relative humidity levels maintained are 22º C ± 1ºC and 55 ± 5% RH respectively.
The other facilities commissioned here are Vertical Dynamic Balancing Machine, CG
(Centre of gravity) and MI (Moment of Inertia) Measurement System, Seismically
isolated floor for alignment and verification and Permanent Zero ‘g’ fixture for solar
panel deployment.

The Spacecraft Checkout System is presently configured for simultaneous testing of two
high power spacecrafts. Overall checkout, special checkout and payload checkout for
Uplink / Downlink, Power feeding, measurement and Characterisation of Communication

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remote sensing & special payload systems has been established. It has been configured
with automated state-of-art spacecraft testing facility with centralized computer system.

Comprehensive Assembly & Test Vacuum Chamber (CATVAC) has the capability for
Thermo vacuum and Thermal Balance tests on Ariane-5 class spacecraft using IR
techniques. Thermal cycling on Spacecraft appendages using thermal cycling enclosures
and agility / deformation and vibration characteristic measurement using provisions for
free suspension of spacecraft and structures can be conducted here. Test specimen of
Diameter 4.5m and Length 6.0m and weight 3tons can be loaded here. Vacuum level of
2×10-6 mbar and the temperature level of 80deg.K-383deg.K can be achieved.

Electro dynamic shaker capable of generating a force of 29 tons has been installed at
Comprehensive Assembly & Test Vibration Facility (CATVIB). Frequency range is 5-
2000Hz, maximum bare table acceleration – 75g, maximum velocity – 1.9m/s and
maximum displacement 50.4mm. The slip table dimension is 2m×2.5m. 48 channel
control system and 256 channel data acquisition system with capability to record time
domain data at a rate of 51.2 kHz on each channel has been established.

Compact Antenna Test Facility (CATF) with Chamber size of 30m×20m×16m has been
established. The Frequency range for Illumination System is 1.47GHz to 200 GHz and for
RF Instrumentation is 1.47GHz to 40 GHz. The Quiet Zone at Centre is 5.5m×5.0m×8m
and Scanned Zone Extendable to 7.8m.the measurement capabilities include Radiation
Pattern 2D/3D, Gain, Cross Polarization, Bore sight Determination, DUT in Transmit
mode and Integrated Satellite Level Measurement. The Antenna Measurement Accuracy
is Gain – 0.25 – 0.35 dB and Bore sight – 0.0140.

Administrative Divisions
The Administration Area of the Centre is headed by Controller, ISAC.
It has one group viz., Construction & Maintenance Group (C&MG) and three Divisions
viz., Finance and Accounts, Personnel & General Administration and Purchase & Stores.
The Transport wing and the Medical Unit also report to the Controller.

The Engineering Maintenance Division was renamed as Construction and Maintenance
Division and is responsible for Construction and Maintenance activities of the Centre
including LEOS. The Division is elevated as Construction and Maintenance Group (C&MG).

Finance & Accounts
The responsibility for wages and salary administration, implementation of financial rules
and regulations, effecting payments to vendors/suppliers/outside agencies, contract
management, compilation of accounts etc., fall under the purview of the Accounts
Division.IFA (P) and IFA (C) are responsible for finance and accounts of spacecraft
projects and Centre activities respectively.
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Personnel and General Administration (P&GA)
The Personnel and General Administration (P&GA) Division is a staff department whose
functions include employee recruitment and placements, maintaining of records
pertaining to the staff, implementation of employee welfare measures, ensure
compliance of personnel rules and guidelines, employee review and promotions and
general administration of the Centre.

Purchase and Stores (P&S)

The Purchase & Stores division carries out the important function of procurement of
materials, equipment, components etc. both from foreign and local sources and
inventory management while at the same time ensuring that the purchase rules and
regulations are complied with.

Library and Documentation Division (LDD)

LDD has a collection of over 3 lakh documents in different formats and subscribes to
nearly 350 national and international technical journals. Digital Library has full text collection
of papers published in Journal of Spacecraft Technology, audio files of lectures and seminars held at
ISAC, internal reports and Satellite News Digest. Internet Resources are identified, catalogued and
made available as an HTML, file of bookmarks (URL’s) on Home page.LDD also markets the in
house technical journal ‘Journal of Spacecraft Technology’ a bi annual publication
covering the technical achievements of the Centre.

SPACE EXHIBITION:

The space exhibition mirroring the achievements of ISRO in space is as informative as it
is a treat to the mind and eye. A good display of satellite elements, scaled models of
satellites, technology posters and allied information on satellite technologies etc is done
in this exhibition area for the benefit of school children/college students and general
visitor.

TECHNICAL JOURNALS & NEWS LETTERS:

A bi-annual in house technical journal “Journal of Spacecraft Technology” is
published by Editorial committee constituted by Director, ISAC. The technical papers are
of good standard and all papers are published after review by experts in allied technical
areas. An exclusive quarterly UPAGRAH news letter is also brought out which covers

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technical, administrative information, event managements, achievements, awards, Hindi
implementation news in our centre, articles in Kannada etc.

EVENT MANAGEMENTS:

National Science Day:

Science promotion activities like the National Science Day, celebrated on 28th of
February every year, are organized with the participation of the school/college students
and the teaching community every year. The event is marked with various competitions
for students and teachers and has gained immense popularity.

Satellite Technology Day:

Nineteenth of April 1975 is a special day for ISRO community. On this day, our first
satellite ‘ARYABHATA’ was launched successfully, which has since spear headed the
growth of Satellite Technologies. To commemorate this great event, 19th of April, every
year is being celebrated as Technology Day, since 2000, showcasing the milestone
achievements in the area of Satellite Technologies. This event is to encourage young
engineers who have contributed in terms of innovative ideas in our satellite programme
and honor them.

Employees Welfare:

ISAC Welfare Association, Space Officer’s Association and Satellite Benevolent
Association have well devised schemes for ‘work life’ balance.

LABORATORY FOR ELECTRO-
OPTICS SYSTEM (LEOS):
LEOS is situated in Peenya,
Bangalore and is mainly responsible
for research, development and
productionisation of Electro-Optics
systems for both launch vehicles and
satellite programmes of ISRO. It supports ISAC in providing
sensors and electronics for satellites. Development of various types of attitude sensors
like earth, sun and star sensors in several spectral regions for attitude measurement are
done at the Laboratory for Electro Optics System (LEOS). The laboratory has till date
developed scanning earth sensor and digital sun sensor specific to geo-synchronous
satellite application and conical earth sensors, Five Sun Sensors, 4 Pi Sun sensors,
Precision yaw sensor, star sensor for remote sensing satellites. Optical components to
image the earth for meteorological and remote sensing application area also developed
here. The laboratory houses extensive facility for sensor calibration and testing and
fabrication of large optics. Development of fibre optics gyros, laser altimeter, micro-
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electro-mechanical systems (MEMS) for actuators and sensors, payload optics for space
probes and interplanetary mission etc. are other major areas of expertise of LEOS. The
Director of LEOS reports to Secretary, DOS/Chairman, and ISRO. In order to maintain
close coordination between LEOS and ISAC, Director, ISAC is the Chairman of LEOS-MC
(LEOS Management Council). The ISRO Radar Development Unit situated in Peenya,
Banglore, is responsible for Radar Development work and can handle Doppler Weather
Radar, Tracking Radar, MST Radar, Wind profiles to name a few. It is a unit of ISTRAC.

INDUSTRY PARTICIPATION:

Over the years, the Indian industry has been a strategic partner of ISRO in its endeavors.
While the association has enabled the industry to upgrade its technology and improves
quality levels, ISRO has gained through optimizing program. Production of systems and
products required by ISRO to concentrate on its core competency of R&D and
development in related fields is by relieving in-house resources to this effect.

In the spacecraft programs of ISRO about 30-40% of the fabrication/testing activities of
the on-going projects are undertaken through contracts with external agencies.
Arrangements are in place to broaden the scope of this partnership with the Indian
industry in days to come.

ROAD MAP –Satellites & Technologies -A glimpse:
Over the years, ISAC has planned and executed several satellite missions of ISRO. These
missions represent a broad spectrum of satellite technology. Beginning with scientific
and application experiments, these have culminated in operational space systems. The
primary development of satellite technology in India at (ISAC) has evolved through the
building and launching of six satellites both experimental and technological, in a phased
manner over the decade (1972-82).

This has resulted in ISRO establishing capability in the design and development of simple
spinners and a more complex, three/axis stabilized satellite for near earth orbit as well
as geo-stationary applications.

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Till date, ISAC has successfully planned and executed 47 satellite missions representing

broad spectrum of satellite technology. After the developmental efforts, projects were
also undertaken starting from mid-Eighties to establish operational Space-based services
through satellite systems in the areas of communication, meteorology and remote
sensing through the INSAT and IRS series of satellites.

In 1988, these efforts led to the launch of operational I generation Remote Sensing
Satellites. IRS-1A (1988) followed by IRS-1B (1991) with multi-spectral cameras having
spatial resolution of 72.5 m and 36 m respectively. The second generation remote
sensing satellites IRS-1C (1988) and IRS-1D (1990) with improved spatial resolutions of
70 m multi-spectral, 5.8m in Panchromatic bands, a wide field sensors with 188m
resolution and 800 Km swath were developed and successfully operationalised in 1995
and 1997 respectively.

As a follow on to IRS-1C/1D spacecraft, the third generation remote sensing satellite
RESOURCESAT-1 was launched in 2003 with improved spatial resolution in all three
bands (23m) for Linear Imaging Self Scanner (LISS-III) camera, advanced wide field
sensor (AWIFS) with 56 m resolution and 740 Km swath and LISS-IV camera with 5.8 m
resolution and selectable panchromatic or multi-spectral imaging modes. Subsequent
developments in the launch vehicle front-Polar Satellite Launch Vehicle (PSLV) by ISRO
paved the way for the launch of 5 spacecraft in IRS-P series.

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Technology Experiment Satellite (TES) launched in October 2001 is intended to

demonstrate and validate technologies that could be used in the future cartographic
satellite missions.

In order to maintain a lead in the remote sensing area and provide data to the Indian
and global users of Geographic Information System (GIS), CARTOSAT-1 (IRS-P5) and

CARTOSAT-2 series of satellites with improved spatial resolution and imaging capabilities
have been taken up. CARTOSAT-1 was launched in May 2005 and it has two
panchromatic cameras (Fore and Aft) with spatial resolution better than 2.5 M.
CARTOSAT-2 series of satellites with spatial resolution better than 1 m and around 10
KM swath in panchromatic band are planned and in that series, the first one in this series
namely CARTOSAT-2, a high agile platform, with a panchromatic camera to provide ‘spot
images’ was launched on 10th January 2007 by PSLV C7. Due to high agility, the
platform can be steered to any orientation to cover any user specific needs on the
ground. This mission is meant to meet the ever increasing user demands for
cartographic applications at cadastral level, urban and rural infrastructure development
and management and various land information system (LIS) and Geographical
information system (GIS) applications.

Cartosat-2A is an advanced remote sensing satellite carrying onboard a single
panchromatic camera capable of providing scene specific spot imageries for cartographic

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and a host of other civilian applications. The spacecraft weighs around 686 Kgs. The
satellite has high agility and capability of steering along and across the track up to + 450.
The nominal altitude of the satellite is 630 Kms in sun synchronous polar orbit. There is
a provision to bring the satellite to a special orbit of 560 Kms with a revisit period of 4
days.The panchromatic camera is designed to provide better than 1 meter spatial
resolution imageries with a swath of around 10 Km. The satellite is configured to provide
multi-scene imaging capability during a pass. The satellite is designed for an operational
life of 5 years. The Cartosat-2A was successfully launched on 28th April 2008 onboard
PSLV-C9. The satellite is performing satisfactorily in orbit.

The Cartosat-2B satellite, a follow on of Cartosat-2A weighing around 690 kgs is
configured to provide multi-scene imaging capability during a pass. The advanced
remote sensing satellite will be carrying onboard a single panchromatic camera providing
scene specific spot imageries for cartographic and a host of other civilian applications.
The satellite is highly agile having a capability of steering along and across the track up
to + 450. It will be placed in a sun synchronous polar orbit of a nominal altitude of 630
kms. There is a provision to bring the satellite to a special orbit of 560 kms with a revisit
period of 4 days and 1 day respectively. The panchromatic camera is designed to provide
better than 1 meter spatial resolution imageries with a swath of around 10 km. The
satellite designed is for an operational life of 5 years. The Cartosat-2B is in realisation
phase and is planned to be launched onboard PSLV in the first half of 2010.

Resourcesat-2 is a follow on mission to Resourcesat-1 to provide continuity of data. The
configuration is similar to Resourcesat-1, except that, LISS-4 multi-spectral swath has
been enhanced from 23 km to 70 km based on user needs. Suitable changes including
miniaturization in payload electronics have been incorporated in Resourcesat-2. The
spacecraft mass is around 1220 Kg with a power generation capacity of 1250W. The
spacecraft is scheduled for launch before 2010.

Oceansat-2 mission is envisaged as the continuity service provider to OCEANSAT-1 (IRS-
P4) data users. Oceansat-2 satellite carries two main payloads for ocean related studies,
namely, Ocean Colour Monitor (OCM) and Ku-band Pencil
Beam Scatterometer. An additional piggy-back payload
called ROSA (Radio Occultation Sounder for Atmospheric
studies) developed by the Italian Space Agency (ASI) is
also a part mission. Oceansat-2 will be in a near polar
sun-synchronous orbit of 720 Kms altitude with an
equatorial crossing time of 12 noon. This orbit combined with the wide swath of both
payloads will provide an observational receptivity of 2 days. The spacecraft weighs
around 956 Kg with a power generation of 1360W and mission life of 5 years.

OCM is a 8-band multi-spectral camera operating in the Visible – Near IR spectral range.
This camera provides an instantaneous geometric field of view of 360 meters and swath
of 1420 Kms. To avoid sun glint due to specular reflection from ocean surface, there is a
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provision to tilt the OCM by + 200 in the along the track direction.
The configuration of OCM payload is identical to the one flown in
IRS-P4 but for the spectral band which is modified for Band-6 and
Band-7 based on the experience from IRS-P4.

The Ku-band Pencil beam Scatterometer is an active microwave
radar and operates at 13.515 GHz providing a ground resolution
cell of size 50 Kms x 50 Kms. Basically, it consists of a parabolic
dish antenna of 1 meter diameter which is offset mounted with a
cant angle of about 460 with respect to the yaw axis (earth viewing
axis) This antenna is continuously rotated at 20.5 rpm using a scan
mechanism with the scan axis along the +ve yaw axis. By using
two offset feeds at the focal plane of the antenna, two beams
(inner beam and outer beam) are generated which will conically
scan the ground surface. The back scattered power in each beam
from the ocean surface is measured from which the wind vector is
derived. ROSA payload is a dual channel GPS receiver with two
antenna and receiver package. ROSA will be providing of vertical
profiles of atmospheric density, refractivity, pressure, temperature and humidity to a
height of about 30 kms. The radio Occultation antenna looking along the satellite
velocity vector receives signals from the rising GPS satellites neat the earth horizon.
These signals get refracted from the atmosphere and from the bending angle, a
temperature and humidity profiles are derived. The precise orbit determination (POD)
antenna looking at the zenith of the satellite gives the precise position of the receiver.
The mainframe systems of Oceansat-2 are derived from the heritage of previous
missions like IRS-P6/P5/Cartosat-1. Oceansat-2 was launched on 23rd September 2009
onboard PSLV-C14 along with six other nano satellites. The payloads have been
commissioned and the performance of the spacecraft is normal.

Radar Imaging Satellite (RISAT), the first of its kind, is a microwave remote sensing
mission with Synthetic Aperture Radar (SAR) as a payload operating in C band. SAR is
an active imaging sensor, which operates in the microwave frequency range of the
electromagnetic spectrum. The sensor has its own illuminating source and does not
depend on sunlight for taking the imagery. The SAR payload is a planar active array
antenna based on TR (Trans-Receiver Module Architecture) and the size & weight of the
panel is 6m x 2m and 900Kg respectively. The total mass of the satellite works out to be
1780 Kg. The satellite is designed for an operational life of 5 years. The satellite is
planned to be launched onboard PSLV in 2010.

Megha-Tropiques mission aims at developing a satellite using IRS
mainframe and payload from Centre National d’Etudes Spatiales
(CNES’s-French Space Agency). The spacecraft will be placed at an
altitude of 867 Kms with an inclination of 20º. The mission life is
envisaged to be 5 years. The spacecraft will be launched onboard

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PSLV during 2010. ISRO Telemetry Tracking and Command Network (ISTRAC) ground
station at Bangalore will be used for spacecraft control and also for receiving the science
data.

IMS-1 is the first satellite in the micro satellite series envisaged to
provide satellite platform within 100 kg class including payloads, for earth
imaging, space science, atmosphere /ocean studies etc. It carries two
payloads viz., Four Band Multi Spectral Charge Coupled Device (CCD)
Camera (MxT) & Hyper Spectral Imager (HySi-T). The spacecraft is
designed such that payload will be earth pointing during imaging
operations and solar panels will be sun pointing during non-imaging
periods for maximum power generation. The Hyper-spectral Imager was first flown
onboard IMS-1 to evaluate and validate the payload similar to the one flown on
Chandrayaan-1 mission. The Solid State Recorder of 16 GB has been configured to meet
the mission requirements. The micro satellite bus provides 3-axis stabilization with a
mission life of 2 years. Indian Mini Satellite (IMS-1) was launched as co-passenger with
Cartosat-2A on 28th April 2008 onboard PSLV-C9 and is performing satisfactorily.

ANUSAT is the first microsatellite designed and fabricated in ANNA University, Chennai
supported by ISRO. This is the first effort of this kind in India to bring university based
academicians and student community, develop the micro satellite under the guidance of
ISRO. The satellite is a spinner satellite weighing ~ 40 Kg using magnetometers as sun
sensors and torquers, for spin rate and spin axis control as actuators. ANUSAT uses
extensively Very Large Scale Integrated Circuit (VLSI) technology in the form of Field
Programmable Gate Arrays (FPGAs), Hybrid Micro Circuits (HMCs), microprocessors etc.
The Very High Frequency (VHF) receivers are designed in total digital form – an all
digital Frequency Shift Keying (FSK) receiver for payload reception onboard the satellite.
The spacecraft was successfully launched onboard PSLV on 20th April 2009. It carried
onboard a digital Store & Forward payload for amateur communication in HAM band as
primary payload. In addition, technological payloads like Micro Electro-Mechanical
Systems (MEMS) magnetometer, MEMS gyro are flown. ISAC provided support such as
structure fabrication, solar panels & chemical battery in the form of subsystem
deliverables in addition to the guidance in the prior mentioned areas. Ground stations for
operating the store & forward payload is established in Pune University and Madras
Institute of Technology (MIT). The spacecraft control centre for command operations is
operated by MIT. ANUSAT will find application in amateur communication.

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SARAL (Satellite for ARGOS & ALTIKA) payloads is designed and developed for a mini
satellite series in the weight range of 400 to 450kg capable of carrying payloads up to a
weight of 200 kg. The satellite is envisaged to carry two payloads of Centre National
d’Etudes Spatiales (CNES) called ALTIKA & ARGOS. It is planned to be launched onboard
PSLV in 2010.

The IRS class of satellites typically weighs around 1000-1500 kg at launch and operates
from the polar sun-synchronous orbit of around 600-800 km.

A unique combination of communication and meteorological payloads combined in one
satellite is a marked feature of the ISRO’s first generation of indigenous geo-stationary
satellites. Five satellites in INSAT-2 series, INSAT-2A through to INSAT-2E have been
launched during the period of 1992-1999. In INSAT-3 series INSAT-3A (2950Kg), 3B

(2070 Kg), 3C (2650 Kg), 3D, 3E (2750 Kg) have been launched. The yet to be launched,
INSAT-3D is a fully meteorological satellite with Imager and Sounder payloads. INSAT-
4A (3080 Kg) was launched on December 22, 2005 carries 12 Ku band and 12 C band
transponders. INSAT-4B (3111 Kg) with 12 Ku band and 12C band transponders is
launched on 12th March 2007 from French Guyana by Ariane 5 V175 launch
vehicle.INSAT-4CR (exclusive KU band payloads) is launched by GSLV – F04 on 2nd
September 2007.

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The INSAT system is one of the largest domestic communication satellite systems with
11 live and operational spacecraft (INSAT-2E,3B,3C,3A,3E,4A,4B,4CR,GSAT-
2,3,KALPANA-1). The INSAT system totally account for about 210 transponders (includes
12 KU from INSAT-4CR) as on date. The GEOSATs under realization are GSAT-4, INSAT-
3D, INSAT-4D/GSAT-5, INSAT-4E/GSAT-6, INSAT-4F/GSAT-7, INSAT-4G/GSAT-8,
IRNNS).

The KALPANA-1 (2002) a 1,000 kg satellite dedicated to meteorological applications.
GSAT-1 flown on the first developmental test flight of Indian Geo-synchronous Launch

Vehicle (GSLV), was intended to prove new spacecraft technological elements like 10N
RCS thrusters, Fast Recovery Star Sensor, and heat pipe radiator panels. The GSAT-2
was the payload for the second development flight of GSLV. GSAT-3 (EDUSAT) is a
spacecraft dedicated to educational purpose while GSAT-4 is a technology demonstration
satellite, acting as a precursor to Advanced Communication Technology Satellite (ACTS).
It will incorporate Ka-band regenerative and bent pipe transponder payload and a
number of new bus elements. The ACTS is thought of as a pure technological satellite,
which will provide convergence of remote sensing with Information Technology and
information/knowledge/data collection and distribution with a constituent of one or two
LEO satellite. HAMSAT (40 Kg), an application specific micro-satellite designed to provide
satellite based Amateur Radio Services to Indian and international HAMs (Amateur Radio
Operators) was launched on board the PSLV in 2005 as an auxiliary payload along with
IRS-P6.

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GSAT-4 spacecraft is an experimental technology demonstrator with a lift-off mass of
2200 kg to be flown on-board developmental flight of GSLV-D3 built using indigenous
cryogenic upper stage (CUSP). GSAT-4, first Indian spacecraft in Ka band, is configured
as a forerunner to advanced communication satellite (ACS) and will be utilized for
conducting various experiments in the advanced communication payload area,
introduction of navigation payload and to prove some of the new bus subsystem
technologies & experiments. The spacecraft contains Ka-band bent pipe and regenerative
payload having eight conjugate spot beams with frequency reuse for full India coverage,
Global Positioning System (GPS) and Geo-stationary Earth Orbit (GEO) Augmented
Navigation (GAGAN) Payload in C, L1 & L5 bands and Tel Aviv University Ultra Violet
Explorer (TAUVEX), an Ultra Violet (UV) experiment conceived and developed by
University of Tel Aviv, Israel. The satellite is planned to be launched during 2009
onboard GSLV-D3.

GSAT-12 is being realized as a replacement for Extended C band services, presently
being provided by INSAT-3B at 830 E. The primary goal of the spacecraft is to provide
continued support to the Extended C band users such as National Stock Exchange, Banks
etc., as a fast track satellite. Thus the spacecraft is primarily configured to carry 12
Extended C band Solid State Power Amplifier (SSPA) based transponders with exactly
the same frequency bands and the area of coverage over India as INSAT-3B.It is
scheduled for launch during 1st half of 2010 onboard PSLV.

INSAT-3D is a state-of-art meteorological spacecraft with 6 channel Imager and 19
channel Sounder payload. The spacecraft is built around I -2K platform with dry mass of
920 Kg and lift-off mass of 2050 Kg, providing a mission life of 7 years. The spacecraft
will be located at 82º E longitude in geostationary orbit. The spacecraft has many new
elements like the star sensor which is being flown for the first time in Geo-Stationary
Earth Orbit (GEO) orbit, micro stepping Solar Array Drive (SADA) to reduce the
spacecraft disturbances and the Bus Management Unit (BMU) for control, sensor
processing & Telecommand / telemetry function of the spacecraft. The spacecraft also
incorporates new features of bi-annual rotation and Image & Mirror motion
compensations for improved performance of the meteorological payloads. The spacecraft
is scheduled for launch during 2010 onboard GSLV.

Configured as an exclusive C-band communication satellite, GSAT-5/INSAT-4D will
carry 12 normal C-band transponders and six extended C-band transponders. The 12
normal-C band transponders have global coverage whereas four ext-C band
transponders have zonal coverage. Two of the Extended C-band transponders are
allotted for covering the main land hub stations and Antarctica with a single beam using
a dedicated antenna. It will be launched on board GSLV during 2010 time frame and to
be positioned at 82º E longitude.

The primary goal of GSAT 6, a multimedia mobile S-band satellite, is to cater to the
customer requirements of providing entertainment and information services to vehicles

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through digital multimedia consoles and to the multimedia mobile phones. The
spacecraft is planned to be launched during third quarter of 2010 using GSLV. This is a
geosynchronous spacecraft to be stationed at 83º East longitude with a mission life of 12
years. The spacecraft is configured around I-2K bus with a lift-off mass of 2200 kg.

GSAT-8/INSAT-4G, is a communication satellite configured around I-3K bus with a lift
off mass of 3150Kg and 6KW (SS EOL) power generation capacity having mission life of
more than 12 years. This spacecraft carry 24 Ku band transponders and 2 channel
geostationary navigation payload – GAGAN. This will augment high power Ku band
transponder capacity over Indian main land region. The satellite will be positioned at 55º
E longitude. The spacecraft is scheduled for launch in 2010 onboard a foreign launch
vehicle.

GSAT-7/INSAT-4F (~2500 Kg) is proposed as a multi-band satellite carrying payloads
in UHF, S-band, C-band and Ku-band. It is planned to be launched during 2010-11 time
frame by GSLV.

SATELLITE BASED NAVIGATION SYSTEM:

Satellite based Positioning, Navigation and Timing (PNT) service is of vital importance to
economics and societies. It is emerging as an important space application area not only
for civil aviation but in many other areas such as mobile telephones, surface transport,
intelligent highway system, maritime transport, rail, oil and gas, precision agriculture,
fisheries, survey and marine engineering, science, electricity networks .It is one of the
main components of satellite based communication, Navigation and Surveillance
(CNS)/Air traffic management system adopted by the International Civil Aviation
Organisation (ICAO) for worldwide implementation. It will facilitate seamless navigation
across geographical boundaries and would eventually replace different types of ground-
based navigation systems providing services over different air spaces.

There are two core constellations for satellite based navigation in the world today-the US
Global Positioning System (GPS) and Russian Global Navigation Satellite System
(GLONASS).The GPS constellation consists of 29 satellites at present in the 20,000 Km
orbit. The GPS is being modernised through the addition of an L5 signal, modifications in
the satellite and control segment to offer better accuracies and ruggedness. The Russian
core constellation called GLONASS was fully operational with 24 satellites in 1995.Then
onwards, the number of satellites in the constellation steadily declined to 14 now. The
Russian Government has decided to revamp the GLONASS constellation and make it
operational with 21 satellites by 2008-09.A third core constellation (Galileo) with 30
satellites in 24000 Km orbit has been planned by the European Union Member States.
Besides civil aviation, the Galileo system is aimed at providing service to various modes
of transport, communications network, intelligent highway systems, personal mobility
and vehicle tracking. Galileo system proposes to offer a host of services; an open service
aimed at mass market applications leading to low cost receivers.
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The position accuracies provided by these global constellations are not adequate to meet
the requirements of integrity, availability, continuity and enhanced accuracy for civil
aviation during the precision approach and landing of aircraft. Augmentation systems to
GPS have been planned by US, EUROPE, JAPAN and INDIA for seamless global
navigation.

ISRO is contemplating on establishment of an Indian Regional Navigation Satellite
System (IRNSS) to provide location information to various users as an independent
system to GPS, GALILEO and GLONASS with a constellation of GEO and GSO orbits. The
constellation study conducted at ISAC has established the possibility of providing a
regional service with accuracy comparable to GPS or GALILEO.

Indian Regional Navigation
Satellite System (IRNSS) is an
independent regional navigation
satellite system. It is designed to
provide position accuracy better
than 10m over India and the
region extending about 1500Kms
around India. It is designed to
provide an accurate real time
Position, Navigation and Time
(PNT) services for users on a
variety of platforms with 24 x 7
service availability under all
weather conditions. The IRNSS
system mainly consists of three components viz; Space Segment (Constellation of
Satellites & Signal-In-Space), Ground Segment and User Segment.

IRNSS constellation consists of seven satellites. Three satellites will be placed in the
Geo-stationary orbit (GEO) at 34°E, 83°E & 131.5°E and two satellites each will be
placed in the Geo-synchronous orbit (GSO) with an equator crossing at 55°E & 111.5°E
with an inclination of 29º. Two spare satellites are also planned to be realised. IRNSS
will have two types of signals in L5 & S-Band. L5-Band centre frequency is 1176.45 MHz
& S-Band centre frequency is 2492.028 MHz. Both L5 and S-Band consists of two
downlinks. IRNSS provides two basic services such as Standard Positioning Service (SPS)
for common civilian users and Restricted Service (RS) for special authorized users.

GPS Aided GEO Augmented Navigation (GAGAN): ISRO and Airport Authority of
India (AAI) are implementing a project for the demonstration of the Satellite Based
Navigation System for the Indian Airspace. The Indian SBAS is also known as GPS Aided
GEO Augmented Navigation (GAGAN) system. ISRO and AAI have signed an MOU in

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August 2001 for implementing this
satellite based navigation over Indian
region. The demonstration of Ground
based network (GAGAN) will mark the
beginning of satellite based navigation
system, Airport Authority of India being
the user. The technology demonstration
is completed using IMMARSAT-4F1
satellite. The navigation payload for
GAGAN is to be flown onboard GSAT-4.

Space Capsule Recovery Experiment (SRE-1) is a 550
kg capsule intended to demonstrate the technology of
an orbiting platform for performing experiments in
micro gravity conditions. After completion of the
experiments, the capsule will be de-orbited and
recovered. SRE-I mission will provide valuable
experience in fields like navigation, guidance and
control during the re-entry phase, hypersonic aero
thermo dynamic, development of reusable thermal
protection System (TPS), recovery through
deceleration and flotation, besides acquisition of
basic technology for reusable launch vehicles. SRE-I

carries two experiments, an Isothermal Heating Furnace (IHF) and a Bio-mimetic
experiment.
SRE-1 was launched into a 635km Polar SSO in January 2007 as a co-passenger with
CARTOSAT-2 and stayed in orbit for 10 days during which its payloads performed the
operations they are intended to. The SRE capsule was de-boosted and recovered
successfully back to earth on 22nd January 2007.
SRE-2 is a follow on mission to SRE-1 and will provide continued platform for
microgravity experiments and is planned to be launched onboard PSLV C16. The
payload mass is increased with a total mass of 604 kg against 555kg of SRE-1. New

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payloads are proposed for SRE-2 in addition to the advanced Intermediate High
Frequency (IHF) payload with a 30kg mass allocated for all.

A scientific satellite called
“ASTROSAT” providing data on Ultra

violet monitoring of the sky and also for
monitoring X-ray source, configured using IRS type of bus is planned for launch in
2010. Astrosat has been configured to carry onboard six payloads, to meet the
mission goal. It will carry a complement of instruments sensitive over a wide spectral
region covering Visible (350-600 nm), Ultraviolet (UV in 130-300 nm), Soft X-rays
(0.3 – 10 keV) and Hard X-ray (10 – 100 keV) bands. This will enable multi-
wavelength observations of a variety of celestial objects in the different spectral bands
at the same time.
The Indian Mission to moon,
Chandrayaan-1 is an exciting mission
in space science. Chandrayaan-I, 1380

kg spacecraft (560Kg (525+35)) Kg in to 100 KM Lunar orbit) was launched from the
Satish Dhawan Space Centre, SHAR, Sriharikota by PSLV-XL (PSLV-C11) on 22 October
2008 at 06.22 hrs IST into a highly elliptical initial orbit (IO) with perigee of 255 km and
an apogee of 22,860 km, inclined at an angle of 17.9 degree to the equator. In this
initial orbit, Chandrayaan-1 orbited the Earth once in about six and a half hours.
Subsequently, the spacecraft’s Liquid Apogee Motor (LAM) firing was done on 23 October
at 09.00 hrs IST, when the spacecraft was near perigee, to raise the apogee to 37,900

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km and the perigee to 305km. The spacecraft at this stage took eleven hours to go
round the Earth once. The orbit was further raised to 336 km x 74,715 km on 25
October at 05:48 hrs IST. In this orbit, spacecraft took about twenty-five and a half
hours to orbit the Earth once. The LAM was fired again on 26 October at 07:08 hrs IST
to take the Chandrayaan-1 spacecraft to extremely high elliptical orbit with apogee
164,600 km and perigee at 348 km. Chandrayaan-1 at this stage took about 73 hours
to go round the Earth once. On 29 October, orbit rising was carried out at 07:38 hrs IST
to raise the apogee to 267,000 km and perigee to 465 km. Chandrayaan-1’s orbit at this
stage extends more than half the way to moon and took about six days to orbit the
Earth.

On 4 November at 04:56 hrs IST, Chandrayaan-1 entered the Lunar Transfer Trajectory
with an apogee of 380,000 km. On 8 November at 16:51 hrs IST, the spacecraft’s liquid
engine was fired to reduce its velocity to insert the spacecraft in the lunar orbit (LOI)
and enable lunar gravity to capture it. As a result, the spacecraft was in an elliptical orbit
with periselene (nearest point to the moon) of 504 km and aposelene (farthest point
from the moon) of 7,502 km. The first orbit reduction manoeuvre was carried out
successfully on 9 November at 20:03 hrs IST. Thus the spacecraft was in lunar orbit with
200 km periselene. The aposelene remained unchanged (i.e 7,502 km). After careful
and detailed observation, a series of three orbit reduction manoeuvres were successfully
carried out and the spacecraft’s orbit was reduced to its intended operational 100 km
circular polar orbit on November 12. On 14 November at 20:06 hrs IST, the Moon
Impact Probe (MIP) was ejected from the Chandrayaan-1 spacecraft and hard landed on
the lunar surface near the South Polar Region at 20:31 hrs IST after 25 minutes journey.
India became the fourth nation to have its flag flying on the Moon's surface when
Chandrayaan-1's MIP which has the Indian Tricolour painted on it - touched down.

The scientific instruments / payloads were commissioned and exploration of Moon with
the array of onboard instruments provided voluminous data for scientists.

After the successful completion of major mission objectives, the orbit of Chandrayaan-I
was raised to 200 km. The orbit raising maneuvers was carried out on May 19, 2009.
The spacecraft in this higher altitude enabled further studies on orbit perturbation,
gravitational field variation of the moon and also enable imaging lunar surface with a
wider swath. Due to problems in Onboard Computers the spacecraft mission was
terminated. However most of the mission objectives have been achieved.

The data collected from various payloads of Chandrayaan-1 were analysed by world wide
scientists and the final products were presented and discussed in Chandrayaan-1 Science
meets held at Bangalore on 29th January 2009 and subsequently at Goa on 7th
September 2009.

Water on moon- Path breaking discovery of Chandrayaan-1

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On 24th September, 2009, in a discovery hailed as path-breaking, Chandrayaan-1 has
found evidence of water on the moon. The data from the Moon Mineralogy Mapper (M3)
instrument of the National Aeronautics and Space Administration (NASA) had clearly
indicated the presence of water molecules on the lunar surface extending from lunar
poles to about 60 degrees latitude. Chandrayaan-1 M3 was one of the 11 scientific
instruments onboard Chandrayaan-1 that ISRO launched on October 22, 2008. The
analysis of the data from Chandrayaan-1 M3 has led to a path-breaking finding, that
hydroxyl, a molecule consisting of one oxygen atom and one hydrogen atom along with
H2O, was also found in the lunar soil. The findings from Chandrayaan-1 M3 show a
marked signature in the infrared region of 2.8-3.0 micron in the absorption spectrum,
which provided a clear indication of the presence of hydroxyl and water molecules. The
analysis of the huge volume of Chandrayaan-1 M3 data was carried out by a joint team
of scientists from the US and India.

Onboard results Laboratory results

Chandrayaan-1 M3 reflectance of ice, water and OH

The scientific team was led by Pieters, a planetary geologist at Brown University in
Rhode Island, and Principal Scientist of Chandrayaan-1 from Physical Research
Laboratory (PRL) of the Indian Department of Space, J N Goswami. The team concluded
that there were traces of hydroxyl (OH) and water (H2O) molecules on the surface of the
moon closer to the polar region. The experts also concluded that traces of OH and H2O
were in the form of a thin layer embedded in rocks and chemical compounds on the
surface of the moon and the quantity were extremely small - of the order of about 700
parts per million (ppm). These molecules could have come from the impact of comets or
radiation from the sun. But most probable source could be low energy hydrogen carried
by solar wind impacting on the minerals on lunar surface. This in turn forms OH or H2O
molecules by deriving the oxygen from metal oxide. The M3 observations are
strengthened by results obtained from the analysis of archived data of lunar observation
in 1999 by another NASA mission, Cassini, on its way to Saturn. This data set also

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revealed signatures of both OH and H2O absorption features on the lunar surface. It is
worth noting that the data from Chandryaan-1 MIP mass spectrometer found traces of
H2O during its descent to lunar surface on 14th November 2008. "Harvesting one ton of
the top layer of the moon's surface will yield as much as 32 ounces of water," scientists
involved in the discovery said.

The scientific feat has been termed a landmark event in international space cooperation
between India and other countries.

Payloads of Chandrayaan-1

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Chandrayaan-1 carries the following science instruments developed by ISRO to achieve
the science objectives,

1. Terrain Mapping stereo Camera (TMC) in the
panchromatic band, having 5m spatial resolution ( size of
the smallest object that can be seen ) and 20 km swath
( width of the picture):To prepare 3-D Atlas

2. A hyper-spectral camera (HySI) operating in 400-
900nm band with a spectral resolution of 15nm and
spatial resolution of 80m with a swath of 20km
producing data in 64 spectral bands ( colors ) VNIR
region

3. A laser ranging instrument (LLRI) with height
resolution of about 10m. :To Determine Global
Topographic Field of Moon and supplement to TMC
and HYSI

4. A high energy X-ray (30-270keV) mapping (HEX)
employing CdZnTe solid state detector with CSI
anti-coincidence system having a foot print of
approximately 40km to identify degassing faults
or zones on the moon by mapping Rn[222] and
its radioactive daughter Pb[210]. This will enable
us to understand the transport of volatiles on the
moon.

5. A Moon Impact Probe (MIP) was released to
impact the Moon’s surface on 14th November
2008 during the Mission. MIP carries three
instruments, a mass spectrometer, a C- band
altimeter and a video camera.

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6. Apart from the five payloads (TMC, HySI, LLRI, LEX and HEX) and MIP discussed
above, five additional instruments under international collaboration have been
accommodated in Chandrayaan-1. They are,

7. Miniature Imaging Radar Instrument (Mini-SAR) from Applied Physics Laboratory
USA supported by NASA: To detect Lunar polar water Ice
ANTENNA

CONNECTOR
BRACKET

FILTER
MODULE
TX MODULE

CP MODULE RX/EXMODULE

8. Sub KeV Atom Reflecting Analyser (SARA) from IRF,
Sweden, JAXA, Japan supported by ESA and VSSC,
ISRO.

9. Moon Mineralogy Mapper (M-3) from Jet Propulsion
Laboratory and Brown University, USA, supported
by NASA

10.Infra Red Spectrometer-2 ( SIR-2) from Max Plank Institute , Germany,
supported by ESA: For Mineral Mapping

11.Radiation Dose Monitor
(RADOM), Bulgarian Academy
of Science, Bulgaria.: To
measure Radiation
Environment both in Lunar
Orbit and Enroute to the moon

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Chandrayaan-1 Scientific Instruments and their configurations

DEVELOPMENT OF VARIOUS TECHNOLOGICAL ELEMENTS FOR IRS & INSAT
Spacecraft: FLASH BACK

Important and critical technologies were developed for the IRS systems. Development
of structure for the IRS Satellite has resulted in a standard 1000 kg bus platform. Use of
Multi layer insulation blankets, selective employment of optical solar reflectors, auto
controlled heaters and heat sinks represent the thermal system used in the IRS.

Accordion type, spring actuated mechanisms are used for solar panel deployment. Tilt
mechanisms and hold-down and release mechanisms are also in place for application in
payloads operation. The solar arrays used in IRS series have a total area up to 9.63 m2
employing BSR (Base surface reflecting) cells generating up to about 1 KW power. 21
AH Nickel-Cadmium batteries are supporting eclipse operations.

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As the data rates involved are from 10 to 45 Mbps/sec, the LSTTL (Low-Power Schottky
Transistor-Transistor Logic) & the FTTL (FAST Transistor-Transistor Logic) logics are
used. The X band was used to transmit the payload data the basic source of which is a
temperature controlled crystal oscillator working in VHF band and frequency multiplied to
x band with data rates up to 105 mbps . Shaped beam antennas are used in S-band and
in the x band to provide a wider coverage compensating for path loss. The S band data
transmitting antenna is a five turn conical helix mounted above a large shaped reflector.
The X band antenna commits of a circular wave guide giving circular polarization. The
base band Telemetry so far used in the PROM based, using a fusible is with about 1400
channels. The TM system makes extension with use of HMCs. From a totally hardware
based system TC systems in the latest IRS spacecraft have evolved to processor /
Application specific integrated circuits (ASIC) based systems.

The AOCE system is configured around an 80 C86/1850 processor. Sun sensors such as
4 pi fine sensor, precision yaw sensor and digital sun sensor have been developed. A
conical Earth sensor meant to generate pitch roll errors with respect to earth and a star
sensor designed around an area array ECD, optics and detector electronics are also in
use.

For the CARTOSAT – 2, a number of new technology elements have been developed.
These include a light weight structure, large size 700 mm and light weighted a zerodur
glass Mirrors, narrow beam dual gimbals antenna, High bit rate data handling system,
high rate TM (4 kbps) and TM (4kbps) system, and a Integrated Bus Management Unit
with MIL-STD – 1553 interfaces

The INSAT experience has resulted in a new optimized I-1000/I-2000/I-3000
standardized spacecraft bus with carbon composite structures with a 6% structure mass.
Development of multi-layer insulation materials, optical solar reflection, and color
anodizing processes for aluminum, heat pipes, passive radiant coolers and Cryo-
refrigerator for payloads are some of the important development in thermal
management which can handle power dissipation up to around 4 KW. Spring actuated
deployment mechanisms for solar panel deployment, motorized deployments for
controlled release of booms, Antenna pointing mechanism, coillable lattice booms, shape
memory alloy actuators are in place.

Gallium-Arsenide (Ga-As ) cell based solar panels measuring a total area of 26.5 sq.
meters and generating up to nearly 3.5 KW power are employed in INSAT-3A. 70 AH,
Ni-H2 batteries are used for energy storage.

In the INSAT Satellites in C-band, the TTC antenna commit of an omni-antenna for both
up & down link transmissions and a global beam antenna for C & Ku band down links.
Multiple spot beam antenna is used in GSAT – 3 for regional coverage. A dual gridded
antenna is used in INSAT – 4A for wider coverage. The INSAT TM system employs

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around 1000 channels for measuring health parameter, while the TC system are ASIC
based system with FPGA for on-band decision making.

The INSAT spacecraft is a 3 axis-stabilized moment biased system with 2-axis
momentum storage system using two wheels simultaneously. Observer based magnetic
torquer logic provides a very fine yaw control. The Attitude, orbit control electronics
(AOCE) system is 1750 processor based with several fault tolerant features.

INTERNATIONAL CONTRACTS:

ISRO bagged international
contract through ANTRIX
for building two
communication satellites
namely W2M/EUTELSAT
and AVANTI HYLAS to be
realized in the time frame
of 2008-2010.

W2M is the first commercial, state of art communication satellite built for Eutelsat, one
of the largest satellite fleet operators in Europe. The contract for the delivery of the W2M
spacecraft in-orbit was signed between EADS Astrium and Antrix/ISRO. Astrium will be
the prime contractor and responsible for the payloads while the platform system,
spacecraft AIT, launch base support services and the orbit raising mission operations and
delivery in the designated on-orbit slot of 16 deg E will be the responsibility of
Antrix/ISRO.

W2M can operate up to 32 Ku-Band transponders in different drive conditions from
Beginning of Life (BOL) to End of Life (EOL), displaying great flexibility to operate a wide
range of services from TV broadcasting to broad-band data networks. It has a fixed
European coverage and steerable beam which can be oriented in orbit according to
market requirements, notably over America, Africa and Central Asia. The platform
system also has several new features like CCSDS based TTC system operating in S-Band
during orbit raising and Ku-band during nominal on-orbit phase, on-board autonomy in
the form of FDIR (Fault Detection, Isolation and Reconfiguration) features in control
systems, for battery maintenance, for thermal management etc. W2M spacecraft based
on ISRO’s I-3K platform has been optimized to deliver 6.5 KW of power and handle
thermal dissipation of 3.5KW. It is the heaviest spacecraft built in ISRO weighing close to
3.5 tones. After the successful completion of all assembly, integration and testing
activities as per contract and the spacecraft was shipped to Ariane launch base at
Kuorou on 18th October 2008. It was launched onboard Ariane-5 (V186) on 20th
December 2008 and only 12 transponders are being put in to operation due to onboard
performance anomaly of S/C on orbit .

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HYLAS is being developed and built for M/s Avanti Screen media U.K., jointly with
EADS-Astrium under a contract through ANTRIX. EADS Astrium is the prime contractor
in charge of overall programme management and will build the communications payload.
ANTRIX/ISRO will build the satellite bus based on the flight proven I-2K model, with a lift
off mass around 2.5 ton and power of 3.2 KW, integration and testing of the spacecraft.
ISRO will also be in charge of low earth orbit operations. The spacecraft is planned for
launch during 2010.

FUTURE TECHNOLOGY REQUIREMENTS – BIRD’S EYE VIEW:

COMMUNICATION SATELLITES: The trend in communication satellite technology for
low cost ground terminals is to go in for increased power (up to 10 KW) with increased
band width (use of higher frequency bands like Ka-band) and heavier satellites (4 to
5T).The higher frequency bands are required in view of crowding in existing bands,
interference mitigation and to obtain larger user bandwidth. Use of multiple beam
antennae for region specific coverage with high Effective Isotopic Radiated Power (EIRP)
for cost effective terminals is needed. To provide interconnectivity as per demand, beam
to beam switching/on-board switching is necessary. For better link margins,
regenerative payloads with on - board processing may be thought of.

All these requirements call for technological elements in satellite areas. To name a few:

Space inflatable large unfurlable antenna (12 - 14 M Diameter size for multiple
beams and shaped beams) for mobile communication
For use of Ka band, improved surface accuracy of antenna/fabrication
technologies
High accuracy antenna pointing mechanisms as demanded by narrow spot
beams and Inter satellite link (ISL) antennae
Use of large scale indigenous MMIC technology
High efficiency solar cells for solar cell based solar arrays for power generation
High capacity, low mass & volume, Lithium-ion based batteries for eclipse
operations
High voltage power buses (typically 70 to 100 V) to reduce transmission losses
and improve pay load operating efficiency
Micro-stepping Solar Array Drive Mechanisms to minimize the impact on
spacecraft pointing, specifically required for the multiple spot beam antenna
Use of STAR trackers for attitude reference, CCD based active Pixel sensors,
Laser Gyros, Gimballed wheels
A mix of Chemical & Ion propulsion (PPTs/SPTs) to optimize the mission life
Use of new materials in the AOCS thrusters, to realize higher efficiency &
performance

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Use of Payload Band for TTC operations, High Bit Rate Cryptic Data Handling,
Use of SSMA (Synchronous state message algorithm) technology to provide
higher ranging accuracy, of the order of couple of meters
BMU (Bus management unit) with 1553 digital bus or 1773 optical links
Micro-processor based unattended autonomous operation of the spacecraft
Apart from micro processors, use of mix of FPGAs (Field programmable gate
array), ASICs (Application specific integrated circuit) , high density multi-layer
HMCs along with packaging technologies to minimize the volume and mass
Approach of System on Chip
Use of Adoptive Smart Structures and Space inflatable structures
Use of such materials & technologies to minimize the structure mass to keep
its ratio to S/C mass at lift off, around 5%
Use of flexible heat pipes, deployable radiator panels and micro heat pipes for
high dissipating devices right below them

REMOTE SENSING SATELLITES: Few of the emerging technologies required to meet
earth observation programmes in future are:

High resolution multi spectral imaging (~2.5 m resolution)
High resolution panchromatic imaging (~0.5 m resolution)
Advanced Synthetic Aperture Radar (ASAR) C/X/L Band (multi-frequency),L &
Multi polarization with 1 m resolution
Scatterometer and improved Radiometer
Hyper spectral imaging spectrometer
Sensors coated with different spectral bands for hyper spectral application,
High resolution smaller pixel size (< 7 micron) Linear Array CCDs (Charge
coupled device) up to 15 K array length
Light weighted (up to 80%) zerodur mirrors and bonded mirrors
Ion polishing/Ion figuring techniques to achieve / 80 to 100
CFRP structures with moisture ingression protection techniques
Carbon-Carbon materials for highly stable structures
On board data processing techniques- Radiometric compensation onboard,
vector quantisation and wavelet quantisation for compression ratios 20:1 to
40:1,onboard storage techniques using SDRAMs (Synchronous Dynamic access
memory) up to 200-300GB capacities with data rates 320 MBPS (mega bits per
second)
Data transmission techniques using electronically steered multi-beam phased
array antenna (for high data rate handling) in X band and Ka band and using
MMIC technologies and using SSPAs (Solid state power amplifiers)
To go in for high stability spacecraft main frame making use of high accuracy
(~1 arc sec) wide angle star tracker capable of meeting to higher spacecraft

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rates and using high accuracy GPS receivers. This provides location accuracies
of the order of few meters directly from the images.

ISRO’S 11TH FIVE YEAR PLAN (SPACECRAFT):

Future projects in Earth Observations area are targeted towards imaging in 0.25m
resolution, imaging in hyper spectral bands, geo imaging, microwave imaging (fine
resolution) etc. Similarly in the area of communication programme the forth coming
projects envisaged are aiming at augmenting the transponder growth to 500 in various
bands, spacecraft capable of handling more than 12KW power and carrying more than
52 Ku band transponders, navigation payloads, etc. Space Science projects are also
becoming more popular. Future missions like moon landing, exploration of space in UV
and X- ray bands, Adithya-1 a solar mission, Mars orbiter, Small satellite for
environmental observations etc. will bring many challenging technologies.

CHALLENGES

Scientific:
State-of-the-art technology, Standardization, Miniaturization, Highly reliable
systems (International Standards), Indiginisation, Technology Transfer,
Technology Forecasting etc.

Managerial:
Multi - Project management, Scheduling : Timely realisation of Projects, Crisis
management, Team building,Optimum utilization of Resources, Cost effective
Systems, Vision : Future requirements, new applications, advance planning etc,
Intellectual Property Rights ….

TO SUMMARISE

With a series of state of art remote sensing, communication and satellite mission serving
a heritage to its ambitious plans of building and launching 25 + satellites in the next
decade. This world class status of ISRO Satellite Centre only stands to be enhanced
further.

Synergy with user needs… Closing the gap between the ‘Data availability’ and ‘service
demand’ … new avenues of space exploration… these are the dictates of the overall
space program of the next 10 to 15 years.

In space, sky is not the limit. As ISAC braces itself for the future, it can look back with
humble pride and satisfaction, at the milestones passed by, in its journey from the
meadow status, 35 + years back. Space offers lot more potential and there is enough

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space at ISAC to do lot more. It is this spirit of innovation that is driving force behind
this world class space organization.

ACKNOWLEDGEMENTS:

The author would like to express and acknowledge with thanks the support extended by
Group Director, PPEG and other colleagues Mr.Rajendrasingh P.Byali,Mr.Santosh Hebbar
in PPEG for the preparation and structuring of the manuscript.

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Overview-ISAC

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