Article Posted on : - Sep 25, 2009

GSLV-F04 prior to launch. Image credit: ISRO

The Geosynchronous Satellite Launch Vehicle (GSLV) is a communication satellite launcher operated by the Indian Space Research Organisation (ISRO). It was developed to enable India to launch its INSAT-type satellites into geostationary orbit.

Geosynchronous Satellite Launch Vehicle (GSLV) Mark I & II are capable of placing INSAT–II class of satellites (2000 kg to 2,500 kg) into Geosynchronous Transfer Orbit (GTO).

The three-stage GSLV vehicle is 49 meter tall with a lift off weight of 414 tones. It has a maximum diameter of 3.4 meter at the payload fairing. First stage comprises S125 solid booster with four liquid (L40) strap-ons. Second stage (GS2) is liquid engine and the third stage (GS3) is a cryo stage. The vehicle develops a lift off thrust of 6573 kn.

The first flight of GSLV took off from Sri Harikota space centre on April 18, 2001 by launching 1540 kg GSAT-1. It was followed by four more launches – GSLV-D2 on May 8, 2003 (1825 kg), GSLV-F01 on September 20, 2004 (EDUSAT 1950 kg), GSLV-F02 on July 10, 2006 and GSLV-F04 on September 2, 2007 (INSAT-4CR 2130 kg).

GSLV-III.

The GSLV-III or Geosynchronous Satellite Launch Vehicle Mark III is a launch vehicle currently under development by ISRO. The latest version of the launch vehicle is being designed to make ISRO fully self-reliant in launching heavier communication satellites of INSAT-4 class, which weigh 4500 kg to 5000 kg. The vehicle envisages multi-mission launch capability for GTO, LEO, Polar and intermediate circular orbits.

The 42.2 meter tall GSLV-Mk III is being designed to be a three stage vehicle, with a lift off weight of 630 tonnes. First stage comprises two identical S200 Large Solid Booster (LSB) with 200 tonne solid propellant, that are strapped on to the second stage – the L110 re-startable liquid stage.

The third stage is the C25 LOX/LH2 cryo stage. The large payload fairing measures 5 meter in diameter and can accommodate a payload volume of 100 cu m. The development work on Mk III is progressing as per schedule for a launch in 2011.

ISRO is also planning to launch the country's communication satellite GSAT-4 with its Geo-synchronous Satellite Launch Vehicle – GSLV-D3, by December 2009.

- Courtesy:
                  ISRO