PSLV Launches
METSAT

ISRO's Polar Satellite Launch Vehicle (PSLV), successfully launched India's first exclusive meteorological satellite, METSAT, into a
Geo-synchronous Transfer Orbit (GTO)

PSLV-C4 lifted off from Sriharikota at 3.53 pm with the ignition of the first stage and four strap-on motors. The major phases of the flight included the ignition of the second, third and fourth stages and their smooth separation after burn-out, separation of payload fairing and the injection of METSAT into GTO. The total flight duration from PSLV-C4 lift-off to METSAT separation from the fourth stage of PSLV in GTO was 1211 seconds (about 20 minutes).

PSLV was initially designed for launching 900 kg Indian Remote Sensing satellites (IRS) into a 900 km polar sun synchronous orbit. Since its first launch in 1993, it has been successively improved to enhance its capability. The major changes made in PSLV since its previous launch in October 2001 included the improvements in the performance of the third stage solid propellant motor by optimising the motor case and propellant loading. Also, the propellant in the fourth stage liquid propellant motor had been increased from 2 tonne to 2.5 tonne. Besides, PSLV-C4 employed a carbon fibre composite payload adopter. All these resulted in substantial payload advantage. The vehicle trajectory was modified for the flight of PSLV-C4 to inject the METSAT into a Geo-synchronous Transfer Orbit.

In its PSLV-C4 configuration, the 44.4 metre tall, 295 tonne PSLV has four stages using solid and liquid propulsion systems alternately. The first stage is one of the largest solid propellant boosters in the world and carries 138 tonne of Hydroxyl Terminated
Poly Butadiene (HTPB) based propellant. It has a diameter of 2.8 m. The motor case is made of