GSLV-F04 is the fifth flight of India's Geosynchronous Satellite
launch Vehicle (GSLV), launched INSAT-4CR satellite, into a Geosynchronous
Transfer Orbit (GTO) of 170 km perigee and 35,975 km apogee with an orbital
inclination of 21.7 degree with respect to equator on September 2, 2007.
Subsequently, the satellite was manoeuvred into geostationary orbit using its
own propulsion system.
The 49 m tall GSLV, with a lift-off mass of 415 tonne, is a
three-stage vehicle with solid, liquid and cryogenic stages. The first stage of
GSLV, one of the largest in the world, uses Hydroxyl Terminated Polybutadiene
(HTPB) based propellant. The second stage and the four strap-on motors
surrounding the first stage use liquid propellant 'Vikas' engine burning UH25
and Nitrogen Tetraoxide. The third stage is a cryogenic stage using liquid
Hydrogen as fuel and liquid Oxygen as oxidiser. GSLV employs S-band telemetry
and C-band transponders for enabling vehicle performance monitoring, tracking,
range safety / flight safety and Preliminary Orbit Determination.
The payload fairing, which is 7.8 m long and 3.4 m in diameter,
protects the vehicle electronics and the spacecraft during its ascent through
the atmosphere It is discarded when the vehicle reaches an altitude of about
The Redundant Strap Down Inertial Navigation System/Inertial
Guidance System of GSLV housed in its equipment bay guides the vehicle from
lift-off to spacecraft injection. The digital auto-pilot and closed loop
guidance scheme ensure the required attitude manoeuvre and guide injection of
the spacecraft to the specified orbit.
GSLV employs various separation systems such as Flexible linear
Shaped Charge for the first stage, Pyro Actuated Collet Release Mechanism for
the second stage and Merman Band Bolt Cutter Separation Mechanism for the third
stage. Spacecraft separation is by spring thrusters mounted at the separation
GSLV, as all other satellite launch vehicles of India, is
launched from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota, the
spaceport of India. GSLV became operational after two developmental flights
when it successfully launched GSAT-1 and GSAT-2 in 2001 and 2003 respectively.
In its first operational flight in September 2004, GSLV launched EDUSAT -
India's first dedicated satellite for educational services. However, the second
operational flight, GSlV-F02, conducted on July 10, 2006 did not succeeding
placing the satellite INSAT-4C into orbit.