GSLV-F01 is the third flight of ISRO’s Geosynchronous Satellite Launch Vehicle
and this is the first operational flight. In its two developmental test flights
conducted in April 2001 and May 2003 respectively, GSLV successfully launched
GSAT-1 and GSAT-2 satellites into Geosynchronous Transfer Orbits (GTOs).
In the first developmental test flight (GSLV-D1), the vehicle
placed 1530 kg GSAT-1 into GTO and in the second developmental test flight
(GSLV-D2), it placed 1825 kg GSAT-2 into GTO. In its first operational flight
(GSLV-F01), GSLV will launch the 1950 kg EDUSAT.
The 49 metre tall 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 40 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 12.5 tonne of Liquid Oxygen and
The Aluminum alloy GSLV payload fairing is 3.4 m in diameter and
is 7.8 m long. 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. The three-axis attitude 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.
Satish Dhawan Space Centre (SDSC) SHAR, the launch station for
GSLV, is located at 80 km north of Chennai on the east coast of India.