India prepares to launch its heaviest space rocket GSLV Mk3

GSLV Mk III on Launch pad Image Credit ISRO Indian Space Research Organisation is preparing to launch its heaviest satellite la...

GSLV Mk III on Launch pad Image Credit ISRO

Indian Space Research Organisation is preparing to launch its heaviest satellite launch vehicle, the GSLV Mk III on Monday June 5.

GSLV Mk III-D1 mission will orbit a 3136 kg GSAT-19 communication satellite to a Geosynchronous Transfer Orbit (GTO) and is scheduled to be launched at 17:28 Hrs (IST) from the Second Launch Pad at Satish Dhawan Space Centre, Sriharikota.

The D1 is the first developmental flight of the rocket which have a lift off mass of 640 tonnes. It is a three stage launch vehicle with a height of 43.43 m and is capable of launching payloads upto 4 ton in to GTO or upto 10 tons into Low Earth Orbit (600 km).

The mission will have an perigee of 170 km and apogee of 35795 km.

The twin Vikas engines form the L110 second stage Image Credit ISRO

The first stage comprise two S200 strap-on motors, located on either side of its core liquid booster. Each S200 carries 205 tons of composite solid propellant and their ignition results in vehicle lift -off and functions for 140 seconds.

During strap-ons functioning phase, the two clustered Vikas liquid Engines of L110 liquid core booster will ignite 114 sec after lift -off to further augment the thrust of the vehicle. These two engines continue to function after the separation of the strap-ons at about 140 seconds after lift -off.

The indigenously developed C25 cryogenic third stage will function for 643 seconds to place the satellite in the intended GTO orbit.

C25 Cryogenic Stage Image Credit ISRO

The 20 tonne thrust cryogenic stage is loaded with 28 tons of propellants (LOX & LH2) and has an overall diameter of 4 m and length of 13.5 m. The ignition of C25 stage takes place 2 seconds after the separation of the L110 stage about 322 seconds after lift-off.

The vehicle is configured with a 5 m dia Ogive payload fairing and slanted strap-on nose cone to provide aerodynamic robustness.

Currently ISRO operates GSLV Mk II rocket with a 2,500 kg capacity to GTO and its workhorse PSLV, with a 1750 kg capacity to LEO.

The S200 strap-on motors are derived from the S139 core booster engines of the PSLV and GSLV Mk II, while the Vikas engine forms the second stage of both. The Vikas was developed with French assistance and is based on the Viking 4A engine.

In December 2014, the GSLV Mk3 flew an experimental flight without its cryogenic third stage.