Today (September 20, 2004), India's Geosynchronous Satellite Launch Vehicle,
GSLV successfully launched EDUSAT the country's first thematic satellite
dedicated exclusively for educational services, into a Geosynchronous Transfer
Orbit (GTO) from Satish Dhawan Space Centre SHAR (SDSC SHAR), Sriharikota. This
is the first operational flight of GSLV (GSLV-F01) and the third in the GSLV
series. EDUSAT is now orbiting the Earth in GTO with a perigee (nearest point
to Earth) of 180 km and an apogee (farthest point to Earth) of 35,985 km with
an orbital inclination of 19.2 deg with respect to the equator. The orbital
period now is 10.5 hours.
The 414 tonne, 49 m tall GSLV, carrying the 1950 kg EDUSAT, lifted off from
Sriharikota at 4:01 pm. About seventeen minutes after lift off,
EDUSAT was successfully placed in GTO. At 4.8 seconds before the
countdown reached zero, the four liquid propellant strap-on stages, each
carrying 40 tonne of hypergolic liquid propellants (UH25 and N2O4), were
ignited. At count zero and after confirming the normal performance of all the
four strap-on motors, the mammoth 138 tonne solid propellant first stage core
motor was ignited and GSLV blazed into the sky. The major phases of the flight
included the first stage burn-out at 104 seconds, the strap on burn-out at 150
seconds, ignition of the second stage at 150 seconds, heat shield separation at
an altitude of 115 km and 227 seconds into the flight, second stage burn-out at
288 seconds, ignition of the 12.5 tonne cryogenic stage at 304 seconds and its
shut down at 999 seconds after attaining the required velocity of 10.2 km per
EDUSAT was put into orbit at 1014 seconds about 5000 km away from Sriharikota.
The separated cryogenic stage was subsequently reoriented and passivated.
Solar Array Deployment
Soon after its injection into to GTO, the two solar arrays of EDUSAT were
automatically deployed. The deployment of the arrays as well as the general
health of the satellite were monitored by the ground station of the ISRO
Telemetry, Tracking and Command network (ISTRAC) located in the Indonesian
island of Biak. The Master Control Facility (MCF) at Hassan in Karnataka has
since taken control of EDUSAT for all its post launch operations. Ground
stations at Lake Cowichan (Canada), Fucino (Italy) and Beijing (China) are
supporting MCF in monitoring the health of the satellite and its orbit raising
In the coming days, EDUSAT's orbit will be raised from its present elliptical
GTO to the final Geostationary Orbit (GSO) by firing the satellite's Liquid
Apogee Motor (LAM) in stages. The satellite will be commissioned into service
after the completion of orbit raising operations, checking out all its
transponders and positioning it in its designated orbital slot of 74 degree
East longitude in the GSO. There, it will be co-located with KALPANA-1 and
EDUSAT carries five Ku-band transponders providing spot beams, one Ku-band
transponder providing a national beam and six External C-band transponders with
national coverage beams. It will join the INSAT system that has already got
more than 130 transponders in C-band, Extended C-band and Ku-band providing a
variety of telecommunication and television broadcasting services.
GSLV was declared operational after its successful developmental test flights
conducted in April 2001 and May 2003. The vehicle was designed and developed by
Vikram Sarabhai Space Centre, Thiruvananthapuram. The inertial systems for the
vehicle were developed by the ISRO Inertial Systems Unit at Thiruvananthapuram.
The Liquid Propulsion Systems Centre (LPSC) also at Thiruvananthapuram
developed the Liquid propulsion stages for the Strap-ons and the second stage
of GSLV as well as the reaction control systems. While the Russian supplied
cryogenic stage is used for third stage propulsion, the guidance and control of
the stage has been implemented by ISRO. Satish Dhawan Space Centre SHAR is the
launch centre for all the launch vehicles of ISRO. ISTRAC provides Telemetry,
Tracking and Command support.
EDUSAT was developed by ISRO Satellite Centre, Bangalore. The payloads were
developed by Space Applications Centre, Ahmedabad. Master Control Facility at
Hassan is responsible for all post launch operations of the satellite.
The successful launch of EDUSAT by the first operational flight of GSLV further
demonstrates its reliability and the end-to-end capability of the country to
establish space systems to undertake large-scale application programmes for the
benefit of the society.