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GSLV MK-III (LVM3)

The GSLV-III (LVM3) or Geosynchronous Satellite Launch Vehicle Mark III, is a launch vehicle currently under development by the Indian Space Research Organization. GSLV Mk III is conceived and designed to make ISRO fully self reliant in launching heavier communication satellites of INSAT-4 class, which weigh 4500 to 5000 kg. It would also enhance the capability of the country to be a competitive player in the multimillion dollar commercial launch market. The vehicle envisages multi-mission launch capability for GTO, LEO, Polar and intermediate circular orbits. The launcher is not a derivative of GSLV. It is a completely new design.

GSLV-Mk III is designed to be a three stage vehicle, with 42.4 m tall 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 m in diameter and can accommodate a payload volume of 100 cu m.

The Cryogenic Upper Stage of GSLV features a propellant loading of 12.5 tons and that of GSLV Mk II, 15 tons. The Mk III, as indicated above, carries 25 tons of LOX/LH2. The LVM3 designation refers to the configuration of the launcher, which can be easily upgraded.

The launcher is under development with a $500 million budget and a Russian cryogenic stage, which will eventually be replaced with an Indian Cryogenic Engine (ICE). Both the variants are expected to be ready in 2009 for first flight. The development work on Mk III is progressing as per schedule for a launch in 2011.

Vehicle Description

• Boosters

  The boosters used on the GSLV-III will be the S200, which is also designated Large Solid Booster, or LSB, which is a solid propellant stage with a mass of 200 tonnes. Two boosters will be used. Each has a diameter of 3.4 metres and a length of 25 metres. Each booster generates 517 tonnes-force (5.15 MN) of thrust at lift-off.

• Core stage

  The core stage will be the L110 restartable liquid stage which has 110 tonnes of liquid propellant and a diameter of 4-metres. It will be the first Indian liquid engine cluster design, and will use two improved Vikas engines, each producing 75 tonnes (735 kN) of thrust. The improved Vikas engine will use regenerative cooling, providing improved weight and specific impulse, compared to earlier rockets.

• Upper stage

  The upper stage will be the C25, which is a cryogenic stage fuelled by 25 tonnes of liquid oxygen and liquid hydrogen. It has a 4-metre diameter and is 8.2 metres long. The stage will produce 20 tonnes (197 kN) of thrust.

• Payload fairing

  The payload fairing will have a diameter of 5 metre and a payload volume of 100 cubic metre.

Current status

In 2007, the wind tunnel tests were completed and vehicle aero-elastic test activities commenced. The vehicle configuration update was completed. All major facilities including propellant plant, vehicle assembly and integration building, mobile launch pedestal and facilities at work centers have reached the final phase of completion. The L110 engine has been qualified with successful completion of 240 seconds hot tests.

First batch of light alloy structure and motor case segments were realized at work centers. The avionics system designs have been completed and first batch of packages are being realized for qualification. Avionics assemblies layout has been finalized and integration trials for package assembly are being carried out. The Solid booster S-200 was successfully tested in January 2010.

Typical Parameters

• Lift-off weight: 629 tonnes
• Pay Load: 4 Tonne in to GTO
• Height: 42.4 metre