GSLV Mk III enters operational service on record-breaking flight.
India’s mammoth third-generation Geosynchronous Satellite Launch Vehicle, known as GSLV Mk III, made its first operational flight early Monday morning, June 5. Riding the booster into orbit was the GSAT-19 communications satellite weighing in at 6,913 pounds - the heaviest payload ever launched by India and over double the lifting capacity of the previous GSLV vehicle. GSLV Mk 3 made its debut on December 18, 2014, launching a scale version of a potential crew vehicle into a ballistic trajectory while testing out the rocket’s side booster and core stage. However, that flight only carried a mass simulator for the cryogenic upper stage which was still undergoing development. After undergoing initial ground testing in early 2017, the upper stage was finally ready for an orbital flight.
Liftoff occurred at 5:28pm local time, or 7:58am EDT, from the Satish Dahwan Space Center. The rocket’s twin 86-foot tall solid rocket boosters provided all the lifting power to send the vehicle into flight with its twin-engined core stage igniting almost two minutes later. Five minutes after liftoff, with both strap-on boosters and the payload fairing already jettisoned, the cryogenic upper stage separated from the core stage and ignited on its first-ever in space firing. The stage performed flawlessly for the ten minutes it fired, placing the GSAT-19 satellite into orbit 15 minutes and 45 seconds after launch.
Numerous changes were made to the GSLV Mk III vehicle following its December 2014 test flight based on data gathered during that flight. To give the rocket better aerodynamic qualities, the solid rocket booster’s nosecones were tapered in towards the core stage and the payload fairing was changed from a cylindrical shape to that of an ogive - similar to the American Atlas V 500 series.
P/c: ISRO.
