GSLV-F01 Launch Successful – Places EDUSAT in Orbit

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 second.

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 operations.

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 INSAT-3C.

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.