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CONTENTS
Introduction
Organisation
Geostationary Satellite Services
Earth Observations System
Space Sciences
Sponsored Research
Space-Industry Partnership
International Cooperation
Space Programme Publicity
‘Space’ in Parliament
Human Resources
General
Milestones
Acronyms
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Space
Transportation
Space Transportation
system includes the satellite launch vehicles to place satellites
like INSAT and IRS and scientific satellites in the requisite orbits
as well as the sounding rockets for carrying out short duration scientific
experiments. India made a modest beginning in this area with the launch
of a 75 mm diameter sounding rocket in 1963 for investigation of ionosphere
over the geo-magnetic equator over Thumba, near Thiruvananthapuram.
Since then, India has established a substantial capability in the
design, development and operationalisation of a series of sounding
rockets for scientific investigations, Polar Satellite Launch Vehicle,
PSLV, for launching Indian remote sensing satellites and Geo-synchronous
Satellite Launch Vehicle, GSLV, for launching geo-stationary communication
satellites.
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Geo-synchronous
Satellite Launch
Vehicle (GSLV)
In its maiden test
flight, GSLV placed a 1540 kg experimental satellite, GSAT-1,
in an orbit of 182.4 km perigee and an apogee 32140.6 km with
an orbit inclination of 19.3 degree. The analysis of the flight
data has indicated that GSLV performed well in flight validating
the design and functioning of all the vehicle subsystems, the
integration procedures including the safe handling of liquid
and cryogenic propellants, the navigation and control, the flight
sequence including ignition of various stages, separation of
spent stages and the heat-shield besides the co-ordinated working of a network of
ground stations to track and monitor the vehicle in flight.
Performance of GSLV-D1 was very close to target.
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GSLV-D1 ready for lift-off
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The first launch attempt of GSLV on March
28, 2001, was aborted by the timely detection of under performance
in one of the four liquid propulsion strap-on stages which are ignited
four seconds before the ignition of the main solid propellant core
stage. The under performance was traced to a partial blockage in a
propellant plumb-line. After replacement of the defective engine,
the flight was successfully conducted within 20 days of the first
attempt. The timely abort of the first flight attempt validated the
safety systems incorporated in the vehicle to detect even a minor
anomaly and abort the launch thus protecting the vehicle system.
GSLV will be commissioned
into service after another one or two developmental flights. The mechanical
hardware and a majority of the electronic packages have already been
realised during the year for the second developmental test flight
of GSLV.
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Vehicle Description:GSLV
is a three-stage vehicle, 49 m tall and weighing 401 tonne at
lift-off. The vehicle uses some of the systems that have been
flight proven in ISRO’s Polar Satellite Launch Vehicle, PSLV;
the solid propellant first stage motor and the liquid propellant
second stage motors of PSLV are employed in the GSLV core first
and second stages respectively. The four liquid strap-on motors
are also derived from the PSLV second stage.
The first stage of GSLV comprises
a solid propellant motor (S125) and four liquid propellant strap-on
motors (L40). S125 stage is 20.3 m long and 2.8 m in diameter.
Its motor case is made of high strength steel. It carries 129
tonne of Hydroxyl Terminated Poly Butadiene (HTPB) based solid propellant. The stage develops about
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GSLV-D1 Lift Off
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4700 kilo
Newton thrust
and burns for 100 seconds. The four strap-on (L40) stages are
19.70
m long and 2.1 m in diameter and they are
fabricated using aluminum alloy.
Each of them is loaded with
40 tonne of hypergolic propellants, namely, Unsymmetrical
Di-Methyl Hydrazine (UDMH) as fuel and Nitrogen Tetroxide (N2O4)
as oxidiser, stored in two tanks mounted in tandem.
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The
second stage of GSLV is 11.6 m long and 2.8 m diameter. It is
loaded with 37.5 tonne of UDMH and N2O4
in two compartments of an aluminum alloy tank separated by a thin
metal sheet known as common bulkhead. The engines used for the
strap-on motors and the second stage aresimilar and employ a turbo-pump
fed engine producing a thrust of about 700 kilo Newton in vacuum.
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One of the
Liquid propellant
strap-on stages of GSLV
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The third stage of GSLV
uses a Cryogenic Stage (CS) which is procured from Glavkosmos, Russia.
The stage, that employs liquid hydrogen and liquid oxygen as fuel
and oxidizer respectively, is 8.7 m long and 2.9 m in diameter. Liquid
hydrogen (LH) and liquid oxygen (LOX) are stored in two separate aluminum
alloy tanks connected by an inter-stage structure. With a propellant
loading of 12.5 tonne, the stage can burn for duration of about 750
second producing a nominal thrust of 75 kilo Newton.
Interstage structures, which
connect the different stages of GSLV, also houses the avionics and
control systems of the lower stage. The ventedinter-stage between
the first and second stage enables the firing of the second stage
even while the first stage has just completed its thrusting action.
This design avoids use of additional systems needed to provide sufficient
acceleration
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betweenthe time before the ignition
of second stage takes place and sufficient reduction in velocity
of the first stage. The core first stage, along with the four
strap on motors, is separated from the rest of the vehicle using
a flexible linear shaped charge (FLSC) that severs the connection
between first and second stages.
The vehicle equipment
bay which houses the vehicle electronic systems like processors,
navigation system, control system, guidance system, telemetry
system, telecommand system, The heat-shield, which is 7.8 m
long and 3.4 m in diameter, protects the vehicle electronics
and the spacecraft during the flight through the atmosphere.
The heat-shield is discarded at about 110 km during the second
stage thrust phase. The spacecraft is separated by opening the band-clamp joint
and the springs attached within the separation system that provides
the required separation velocity to the satellite. The system is
designed
to ensure that
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Integration
of Cryogenic
stage of GSLV
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no collision occurs between the spent third stage and
the spacecraft.
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The Redundant Strap
Down Inertial Navigation System/Inertial Guidance System (RESINS/(IGS),
which is housed in the equipment bay computes the inertial position
and velocity and guides the vehicle from lift-off to spacecraft
injection. The digital auto-pilot and closed-loop guidance scheme
resident in the on-board computer ensures the required attitude
manoeuvre and guided injection of the spacecraft into the specified
orbit.
The vehicle performance
is monitored with extensive instrumentation. The performance
data is transmitted via telemetry systems to the ground station.
In addition to the performance parameters, the inertial position
of the vehicle and its orientation are computed by the vehicle inertial system and computers,
which are also transmitted via the telemetry to the ground stations.
A telecommand system is used to terminate the flight in case the vehicle
deviates from its flight path beyond the specified safety limits.
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Testing
of high-pressure Vikas engine
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A C-band transponder on board the
vehicle helps in tracking it from ground based radars. The complete
telemetry and tracking coverage of the vehicle from lift-off
to satellite injection will be provided by four ground stations
located at SHAR Centre, Sriharikota, the down range stations
at Port Blair, Brunei and Biak in Indonesia. All these stations
are networked with the SHAR Centre during launch to provide
data in real time.
Improvements to GSLV: Studies
have been undertaken to design and develop variants of GSLV
with increased payload capabilities. Studies for larger cryogenic
stages namely C-25 with 20 tonne thrust to be used for the GSLV-MKIII
version is continuing. Detailed studies for L-110 stage, using
liquid propellant for the core stage of GSLV-MKIII vehicle have
been made.
A major milestone during the year
towards the improvement of GSLV capability was the successful
testing of the up-rated version of the liquid propellant Vikas
engine. The up-rated version develops a chamber pressure of 58.5 bar against
52.5 bar in the current version.
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This new engine uses UH25 (a mixture
of Unsymmetrical Di-methyl Hydrazine and hydrazine hydrate) as fuel
and nitrogen tetroxide as oxidizer.
The new engine has the potential to increase the payload capability
of GSLV by about 150 kg in the Geo-synchronous Transfer Orbit (GTO).
GSLV Lift-off sequence
Cryogenic
Upper Stage Project (CUSP)
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CUSP envisages design and development
of an indigenous cryogenic upper stage to replace the Russian-supplied
cryogenic stage in the GSLV. CUS will have a thrust of 7.5 tonne
and carry 12.5 tonne propellant (liquid oxygen and liquid hydrogen),
which burns for about
800 seconds.
During
the year, ground testing of the second engine has commenced.
Subsystems for the third engine have also been
realised. Thrust chamber assembly consisting of combustion chamber
and divergent has been successfully brazed in a rotary vacuum
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Wind
Tunnel Tests for GSLV-MK-III
configuration studies
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brazing
during the year. Studies for an uprated CUS engine with 9.5 t thrust
has also been undertaken during the year.
Polar Satellite
Launch Vehicle (PSLV)
A major event under the PSLV
project during the year was the sixth flight (PSLV-C3) conducted on
October 22, 2001 from SHAR Centre, Sriharikota. In this flight, PSLV-C3,
successfully launched three satellites — Technology Experiment Satellite
(TES) of ISRO, BIRD of Germany and PROBA of Belgium – into their intended
multiple orbits. It was for the second time that PSLV launched three
satellites simultaneously; in the previous launch in May 1999 PSLV
had launched India’s IRS-P4 along with German DLR-TUBSAT and Korean
KITSAT-3.
While TES and BIRD (Bispectral and Infrared Remote
Detection) satellites were placed in the 568 km sun-synchronous orbit,
PROBA (Project for On Board Autonomy) was placed in an elliptical orbit
with a perigee (nearest to earth) of 568 km and anapogee (farthest to the
earth) of 638 km. The higher orbit for PROBA was achieved by firing the
reaction control thrusters of PSLV-C3 fourth stage.
Both BIRD and PROBA were launched under commercial agreements entered into
by the Antrix Corporation, the commercial agency under Department of
Space.
In its present configuration, the 44.4 m
tall, 294 tonne PSLV has four stages using solid and liquid propulsion
systems alternately. The first stage is one of the large solid
propellant boosters in the world and carries 138 tonne of
Hydroxyl Terminated Poly Butadiene (HTPB) propellant. It has a diameter of
2.8 m. The motor case is made of maraging steel. The booster develops a
maximum thrust of about 4,430 kN. Six strap-on motors, four of which are
ignited on the ground, augment the first stage thrust. Each of these solid
propellant strap-on motors, carries nine tonne of HTPB propellant and
produces 667 kN thrust.
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The second stage employs indigenously
manufactured Vikas engine and carries 40 tonne of liquid propellant
— Unsymmetrical Di-Methyl Hydrazine (UDMH) as fuel and
Nitrogen tetroxide (N2O4)
as oxidizer. It generates a maximum thrust of about
724 kN.
The third stage uses 7 tonne of
HTPB-based solid propellant and produces a maximum thrust of
324 kN. Its motor case is made of polyaramide fibre. The fourth
and the terminal stage of PSLV has a twin engine configuration
using liquid propellant. With a propellant loading of 2 tonne
(Mono-methyl hydrazine and Mixed Oxides of Nitrogen), each of
these engines generates a maximum thrust of 7.4 kN.
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PSLV-C3
ready for lift-off
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The
3.2 m diameter metallic bulbous heat-shield of PSLV, is of isogrid
construction and protects the spacecraft during the atmospheric
regime of the flight. PSLV control system includes: a) First
stage; Secondary Injection Thrust Vector Control (SITVC) for pitch
and yaw, reaction control thrusters for roll and SITVC in two strap-on
motors for roll control augmentation, b) Second stage; Engine gimbal
for pitch and yaw and, hot gas reaction control for roll, c) Third
stage; flex nozzle for pitch and yaw and PS-4 RCS for roll and d)
Fourth stage; Engine gimbal for pitch, yaw and roll and, on-off RCS
for control during the coast phase.
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The inertial navigation
system in the equipment bay, which is located on top of the fourth
stage, guides the vehicle from lift-off to spacecraft injection
into orbit. The vehicle is provided with instrumentation to monitor
the vehicle performance during the flight. S-band PCM telemetry
and C-band transponders cater to this requirement. The tracking
system provides real-time information for flight safety and for
preliminary orbit determination once the satellite is injected
into orbit.
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TES (Centre),
PROBA (Left) and BIRD Satellite mounted over the equipment bay
of PSLV
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PSLV employs a large number of stage
auxiliary systems for stage separation, heat-shield separation and
jettisoning, etc.
A few improvements had been
carried out in the PSLV-C3 compared to PSLV-C2. They included optimisation
in the weight of fourth stage (PS4) tank, and ball-lock separation
system for the separation of auxiliary satellite that has an interface
compatible with the European Ariane vehicle.
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The flight
profile for PSLV-C3 mission had been modified to place the three
satellites in their specified orbits — the Indian satellite, TES
and the German satellite, BIRD, in a 568 km sun-synchronous orbit
and the third satellite, the Belgian PROBA in a 568 x 638 km elliptical
orbit – which require firing the reaction control thrusters
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of PSLV fourth stage for about 500 seconds
after the separation of first two satellites. A Data Storage Unit
(DSU), which stores the telemetry parameters and transmits in delayed
mode had been introduced to take care of any break in the radio visibility
between the vehicle and the ground stations located at Thiruvananthapuram
and Mauritius as well as recording of the PROBA separation event.
The PROBA separation related parameters
were transmitted when the stage passed over the Lucknow ground station
of ISRO.
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With the successful launch of three
satellites simultaneously for the second time, PSLV has proved
itself as a promising vehicle with prospects for commercial
launching of satellites even while serving its primary goal
of launching Indian remote sensing satellites. Efforts are continuing
to further improve the payload capability of PSLV. It is also
proposed to be used for a geo-synchronous mission for launching
the ISRO’s METSAT.
During the year, a high-performance
composite solid propellant motor for the third stage of PSLV
has been successfully tested. The improvements in the motor
performance have been achieved by reducing the inert mass of
motor case and nozzle and optimising the design parameters. This is a significant
technological improvement involving analytical and experimental
evaluation of critical interfaces among motor
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case, insulation and
propellant. The high-performance third stage motor could enhance the
payload capability of PSLV by 100 kg for polar sun-synchronous missions.
Launch vehicle assembly building under
construction at SHAR Centre.
Fabrication of various systems
for the next flight, PSLV-C4, has been initiated. The vehicle structures
has been realised. Procurement of materials and components for the
PSLV flights, PSLV-C5 to PSLV-C9 has been taken up.
Sounding Rockets
ISRO has developed a series of sounding rockets known
as Rohini Sounding Rockets for conducting atmospheric research and other
scientific investigations. Development of a single stage stretched version
of Rohini Sounding Rocket, RH-200SV, which can carry 8.5 kg, payload to
110 km, has been initiated during the year and two developmental test
flights have been conducted. Development of low cost avionics packages for
sounding rocket payloads has also been initiated. Studies have been made
for upgrading the present RH-560 MK-II to RH-560 MK-III which will be able
to carry a payload of 60 kg to 1000 km altitude.
During the year, three flights of RH-200 were conducted
from Balasore for meteorological purposes.
Other Developments
in Space
Transportation System
Technology developments
in the areas of avionics, aeronautics, mechanical engineering, propellants,
polymers, chemicals and materials, aerospace mechanisms, have continued
during the year which are aimed at improving the space transportation
capabilities. Experimental and theoretical studies for air-breathing
propulsion is also continuing.
Launch Vehicle
Infrastructure
The launch infrastructure
at SHAR Centre, Sriharikota supported the launch of GSLV-D1 and PSLV-C3
during the year. The first developmental test of GSLV has completely
validated the modified mobile service tower along with the propellant
service facilities including the cryogenic propellants.
The second launch
pad establishment has made further progress during the year with the
design and engineering activities for all the subsystems having been
completed. Turnkey contracts have already been awarded and the majority
of the civil works have been completed. Vehicle assembly building
and jet deflector duct construction is in advanced stages. Fabrication
of major structures like umbilical tower, lightening protection tower
and mobile launch pedestal has been completed during the year and
erection work is in progress.
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