Indian Space Research Organisation (ISRO) GSLV MkIII rocket has been identified as the vehicle to launch the Gaganyaan Mission and the process for its human rating is in progress.

GSLV MkIII is a three-stage heavy lift launch vehicle developed by ISRO. It has two solid strap-ons, a core liquid booster and a cryogenic upper stage. It is designed to carry four-tonne class of satellites into geosynchronous transfer orbit (GTO) or about 10 tonnes to low earth orbit (LEO), which is about twice the capability of the GSLV Mk II.

The two strap-on motors of GSLV Mk III are located on either side of its core liquid booster. Designated ‘S200’, the high-thrust solid propellant strap-on boosters play an important role in the human-rated GSLV Mk III. Each S200 booster carries 205 tonnes of composite solid propellant and their ignition results in vehicle lift-off.

S200s function 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.

According to an ISRO statement on Monday, many new design features have been introduced in the hardware in order to human rate the S200 booster. In a fruitful industry collaboration, the first critical booster segment of the motor case with a diameter of 3.2 metre, 8.5 metre in length and weighing 5.5 tonnes has been indigenously developed and delivered by L&T.

This is the first step towards the unmanned space mission and was flagged-off by ISRO Chairman Dr K. Sivan, who is also secretary, department of space. and Jayant Damodar Patil, director and senior executive vice president, defence & smart technologies, L&T, on November 13.