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GSLV to Launch INSAT- 4C on July 10, 2006
Preparations for the
launch of Geosynchronous Satellite Launch
Vehicle (GSLV-F02), with state-of-the-art
communication satellite, INSAT-4C, are
proceeding satisfactorily at Satish Dhawan Space
Centre (SDSC) SHAR, Sriharikota. As per the
present progress, the launch is expected to take
place around 4:30 pm on Monday, July 10, 2006,
from the Second Launch Pad which was
commissioned in May 2005 with the launch of PSLV.
The launch vehicle systems have been integrated
and checked out. INSAT-4C, the latest satellite
of the INSAT series, was transported from ISRO
Satellite Centre, Bangalore to SDSC SHAR in the
first week of June 2006 and since then, it has
undergone detailed checks. After propellant
filling, the spacecraft has been integrated with
GSLV.
The Mission Readiness Review is planned on July
6, 2006 followed by the meeting of Launch
Authorisation Board which will clear the launch.
In the next few days, a complete checkout of the
fully integrated launch vehicle along with
satellite will be carried out. The final
countdown and fuel filling for the liquid
propellant stages are expected to commence on
July 9, 2006 morning.
BACKGROUND
ISRO's Geosynchronous Satellite Launch Vehicle,
GSLV, in its second operational flight
(GSLV-F02) will launch INSAT-4C, India's latest
communication satellite from Satish Dhawan Space
Centre SHAR, Sriharikota about 80 km north of
Chennai. This is the first launch of GSLV from
the state-of-the-art Second Launch Pad (SLP) at
SDSC. SLP, which was commissioned in May 2005
with the successful launch of PSLV-C6, is
designed to reduce the occupancy time for the
integration and launch.
GSLV was declared operational in its present
configuration (GSLV-MK I) after two successful
developmental test flights conducted in April
2001 and May 2003 when it launched the 1,530 kg
GSAT-1 and 1,825 kg GSAT-2 satellites into
Geosynchronous Transfer Orbits (GTO). In its
first operational flight, GSLV successfully
launched the 1,950 kg EDUSAT into the
predetermined GTO. INSAT-4C weighing 2168 kg is
the heaviest satellite launched by GSLV so far.
The 49 metre tall, 414 tonne, GSLV is a three
stage vehicle. The first stage, GS1, comprises a
core motor with 138 tonne of solid propellant
and four strap-on motors each with 42 tonne of
hypergolic liquid propellants (UH25 and N204).
The second stage has 39 tonne of the same
hypergolic liquid propellants. The third stage
(GS3) is a cryogenic stage with 12.6 tonne of
Liquid Oxygen (LOX) and Liquid Hydrogen (LH2).
The Aluminum alloy GSLV payload fairing is 3.4 m
in diameter and is 7.8 m long.
The three-axis attitude (orientation)
stabilisation of GSLV is achieved by autonomous
control systems provided in each stage. Single
plane Engine Gimbal Control (EGC) of the four
strap-ons of the first stage are used for pitch,
yaw and roll control. The second stage has
Engine Gimbal Control (EGC) for pitch and yaw
and hot gas Reaction Control System (RCS) for
roll control. Two swivellable vernier engines
using LH2 and LOX provide pitch, yaw and roll
control for the third stage during thrust phase
and cold gas system during coast phase. The
Inertial Guidance System (IGS) in the Equipment
Bay (EB) housed above the third stage guides the
vehicle till spacecraft injection. The closed
loop guidance scheme resident in the on-board
computer ensures the required accuracy in the
injection conditions. GSLV employs S-band
telemetry and C-band transponders for the
vehicle performance monitoring, tracking, range
safety/flight safety and Preliminary Orbit
Determination (POD).
GSLV employs various separation systems such as
Flexible Linear Shaped Charge (FLSC) for the
first stage, pyro-actuated collet release
mechanism for second stage and Merman band bolt
cutter separation mechanism for the third stage.
Spacecraft separation is by spring thrusters
mounted at the separation interface.
Satish Dhawan Space Centre (SDSC) SHAR, located
on the east coast of India is the launch station
for all satellite launch vehicles of India.
Sriharikota was selected as the launch site to
take advantage of the earth's rotation and other
factors affecting the flight of a launch
vehicle.
Cryogenic Stage: The third stage of GSLV is
cryogenic. The cryogenic stage is much more
efficient and provides more thrust for every
kilogram of propellant it burns compared to
solid and earth-storable liquid propellants.
Specific impulse (a measure of the efficiency)
achievable with cryo fluids (liquid Hydrogen and
liquid Oxygen) is of the order of 450 sec
compared to 300 sec for earth storable and solid
fuels, giving a substantial payload advantage;
for an upper stage, with every one second
increase in the specific impulse, the payload
gain is of the order of 10 kg.
However, cryogenic stage is technically a very
complex system compared to solid or
earth-storable liquid propellant stages due to
the use of propellants at extremely low
temperatures and the associated thermal and
structural problems. Oxygen becomes a liquid at
-183 deg C and Hydrogen liquefies at -253 deg C.
The propellants, at these low temperatures, are
to be pumped using turbo pumps running at 42,000
rpm. It also entails complex ground support
systems like propellant storage and filling
systems, cryo engine and stage test facilities,
transportation and handling of the cryo fluids
and related safety aspects. While the initial
flights of GSLV are using the Russian supplied
cryogenic stage, the indigenous development of
the cryo stage has reached an advanced stage
with the engine having already been qualified
and the stage systems tests planned in the
coming months.
Satellite Launch Vehicle Development in India
The realisation of a satellite launch vehicle
involves many branches of science and
engineering, sophisticated infrastructure and
innovative management techniques. Even today,
only a few countries possess the technology of
to successfully build satellite launch vehicles.
The subsystems in a launch vehicle should
withstand hostile flight environment, should be
of light weight, cost effective and should be
realisable within a reasonable time. Years of
developmental efforts are put to test in a few
minutes of flight requiring performances with
practically no margin for error.
In India, rocket development began in 1963 with
the establishment of Thumba Equatorial Rocket
Launching Station near Thiruvananthapuram for
carrying out scientific experiments in aeronomy
and astronomy using rockets built abroad.
India's first indigenous sounding rocket was a
small 75 mm diameter Rohini, RH-75. Today, India
operates a family of sounding rockets of
diameters ranging from 200 to 560 mm and capable
of carrying upto 200 kg payload to an altitude
of 300-400 km to conduct scientific experiments.
45 sounding rockets were flown on consecutive
days during February-March 2000 for a major
scientific campaign, Equatorial Wave Campaign.
SLV-3: SLV-3, India's first experimental
satellite launch vehicle, was successfully
launched for the first time on July 18, 1980
from SHAR Centre (which was renamed as Satish
Dhavan Space Centre SHAR in 2002), Sriharikota
and it placed a Rohini Satellite, RS-1 in orbit.
The first experimental flight of SLV-3 had taken
place in July 1979 but the mission was only
partially successful due to a jammed valve in
the second stage control system resulting in the
leak of the oxidiser. After the successful
second flight, two more flights of SLV-3 were
conducted in May 1981 and April 1983 to place
Rohini satellites carrying remote sensing
cameras on board. Conceived in 1969, SLV-3 was a
22 metre long, four-stage vehicle weighing 17
tonne. All its stages used solid propellant and
it employed open loop guidance with stored pitch
programme to steer the vehicle in flight along
the pre-determined trajectory. SLV-3 provided
valuable inputs for the vehicle and mission
design, materials, hardware fabrication,
realisation of solid propellant technology,
control power plants, staging systems, inertial
sensors, electronics, testing, integration and
checkout and launch complex establishment at
Sriharikota with associated ground
instrumentation.
ASLV: Keeping in view the long term goal for
realising polar and geosynchronous launch
capability for operational class of satellites,
the development of Augmented Satellite Launch
Vehicle (ASLV) was undertaken for demonstrating
critical technologies. ASLV was configured as a
five stage solid propellant vehicle, weighing
about 40 tonne and having a length of about 23.8
m. The strap-on stage consisted of two identical
1 m diameter solid propellant motors similar to
SLV-3 first stage, other stages being the same
as in SLV-3. Closed loop guidance, active from
the ignition of the second stage motor to the
separation of the third stage, was employed in
ASLV while SLV-3 had used an open loop guidance
system.
The first developmental flight test of ASLV took
place in March 1987 but the mission did not
succeed due to non-ignition of the first stage
motor after the strap-on stage burn out. The
second flight, ASLV-D2, took place in July,
1988. This mission also did not succeed. After a
detailed failure analysis, a number of
corrective actions were taken, many of them
relating to the transition between the strap-on
stage and the first stage. With the
incorporation of all the modifications, the
third developmental flight, ASLV-D3, was
successfully conducted on May 20, 1992 when
SROSS-C satellite, carrying a Gamma- ray burst
detector and an aeronomy payload was placed in
orbit. Another flight of ASLV (ASLV-D4) was
conducted on May 4, 1994 when a 113 kg SROSS-C2
satellite was put into a low earth orbit. ASLV
provided valuable inputs to the development of
PSLV.
PSLV: The Polar Satellite Launch Vehicle (PSLV)
project was initiated in 1982. In the present
configuration (employed in PSLV-C5), the 44.4
metre tall, 295 tonne PSLV, has four stages
using solid and liquid propulsion systems
alternately. While the first developmental
launch of PSLV (PSLV-D1), on September 20, 1993
did not fulfill the mission of injecting the
IRS-1E satellite into orbit, most of the PSLV
systems performed normally. The failure of this
flight was primarily due to a software error in
the pitch control loop of the on-board guidance
and control processor, and the failure of two
small retro rockets leading to a contact between
second and third stages during the separation of
the second stage. The second developmental
flight, PSLV-D2, on October 15, 1994, was
successful when the vehicle injected the 804 kg
remote sensing satellite, IRS-P2, into the
desired orbit. During the third developmental
test flight conducted on March 21, 1996, PSLV
could place a 922 kg IRS-P3 satellite in the
intended 817 km polar orbit. With these two
consecutive successes, PSLV became operational.
Several more improvements have been incorporated
in the vehicle since then. The major
improvements include: increasing the solid
propellant in the first core stage from 128
tonne to 138 tonne; increasing the liquid
propellant loading in the second stage from 37.5
tonne to 40.6 tonne by stretching the stage
tankages; replacing the metallic payload adopter
by a CFRP adopter and; effecting weight
reduction in the vehicle equipment bay. Besides,
four of the six strap-on motors are ignited on
the ground along with the core first stage; in
the earlier flights only two were ignited on the
ground and the remaining four a few seconds
after lift-off.
In its first operational flight, PSLV
successfully placed the 1200 kg Indian Remote
Sensing satellite, IRS-1D, into a polar orbit.
Later it launched OCEANSAT-1 (IRS-P4), TES,
RESOURCESAT-1, CARTOSAT-1 and HAMSAT into the
predetermined polar orbits in 1999, 2001, 2003
and 2005 respectively. PSLV has now become a
workhorse launch vehicle for polar satellites
and it is now offered for carrying satellites of
other space agencies also. So far it had seven
successful flights. PSLV has also been used for
launching a geo-synchronous satellite - India's
first exclusive meteorological satellite,
KALPANA-1, in September 2002. It has also
launched four satellites of other space agencies
- KITSAT-3 of Korea, DLR-TUBSAT and BIRD of
Germany and PROBA of Belgium. Three more
satellites LAPAN TUBSAT of Indonesia, X-Sat of
Nanyang Technological University, Singapore and
Agile of Italy are already in the pipeline. Of
these, LAPAN TUBSAT will be flown along with
India's CARTOSAT-2 and Space Capsule Recovery
Experiment (SRE-1) on board PSLV-C7 this year.
GSLV: GSLV, in its very first developmental test
flight on April 18, 2001, succeeded in placing
an experimental communication satellite, GSAT-1,
into a Geosynchronous Transfer Orbit(GTO). It
was declared operational after its second
successful developmental test flight on May 8,
2003, when it placed GSAT-2 into its intended
GTO. During its first operational flight
(GSLV-F01) on September 20, 2004, GSLV launched
the 1950 kg EDUSAT, India's first exclusive
satellite for the educational sector.
While in the present configuration (GSLV Mk I),
GSLV is capable of placing 2,000 kg class
satellites into GTO, once its Russian supplied
upper stage is replaced by the ISRO developed
Cryogenic stage (GSLV-Mk II), it will be able to
place 2,500 kg class satellites into GTO. GSLV
Mk III will be capable of placing a 4 tonne
satellite into GTO. It will have a 110 tonne
core liquid propellant stage, two 200 tonne
solid propellant strap-on motors and a 25 tonne
cryogenic stage.
INSAT-4C
INSAT-4C is the second satellite in the INSAT-4
series. The first, INSAT-4A, was launched in
December 2005. INSAT-4C carries 12 high-power
Ku-band transponders designed to provide
Direct-To-Home (DTH) television services,
facilitate Video Picture Transmission (VPT) and
Digital Satellite News Gathering (DSNG) as well
as to serve National Informatics Centre (NIC)
for its VSAT connectivity. The 2,168 kg INSAT-4C
is launched in the second operational flight of
India's Geosynchronous Satellite Launch Vehicle,
GSLV-F02. The satellite is designed for a
mission life of ten years.
INSAT system was established in 1983. With nine
satellites - INSAT-2E, INSAT-3A, INSAT-3B,
INSAT-3C, INSAT-3E, INSAT-4A, GSAT-2, EDUSAT and
KALPANA-1 in service with a total of 175
transponders in Ku-band, C-band and Extended
C-band besides instruments for meteorological
imaging and data relay functions, INSAT is the
largest domestic communication satellite system
in the Asia-Pacific region. INSAT-4C, once
commissioned, will further augment the INSAT
system capacity.
Soon after its injection into Geosynchronous
Transfer Orbit (GTO) orbit by GSLV-F02, the
solar panels of INSAT-4C will be deployed. In
the following days, the satellite is manoeuvred
to its 36,000 km high Geo-Synchronous orbit (GSO)
by firing Liquid Apogee Motor (LAM) on board the
satellite. In GSO, INSAT-4C will be co-located
with INSAT-3C, KALPANA-1 and EDUSAT at 74 degree
East Longitude.
Salient
features:
Orbit:
Geostationary (74 degree East Longitude)
Co-located with INSAT-3C, KALPANA-1 and EDUSAT
Lift-off Mass:
2,168 kg
Dry Mass:
950 kg
Physical:
1.650 x 1.535 x
2.406 m cuboid 9.45 m long with solar panels
deployed
Propulsion and:
440 Newton Liquid Apogee Motor (LAM) with
Control Mono Methyl Hydrazine (MMH) as fuel and
Mixed Oxides of Nitrogen (MON-3) as oxidizer for
orbit raising 3-axis body stabilized in orbit
using earth sensors, momentum and reaction
wheels, magnetic torquers and
eight 10 Newton and eight 22 Newton
bi-propellant thrusters
Power:
Solar array providing 2870 W ;Two 70 Ampere-hour
Nickel-Hydrogen Batteries
Antennas:
2.2 m X 2.2 m diameter deployable reflector for
transmit functions 1.4 m diameter deployable
reflector for receive functions
Mission:
10 years
Communication
Payloads: - 12
Ku-band 36 MHz bandwidth Transponders employing
140 W Travelling Wave Tube Amplifiers (TWTAs) to
provide an Effective Isotropic Radiated Power (EIRP)
of 51.5 dBW at Edge of Coverage (EOC) with
footprint covering Indian mainland - Ku-band
Beacon as an aid to users to lock on to the
satellite signal
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