Indian Space Research Organization (ISRO) is set for the launch of “THE FAT BOY” aka Geosynchronous Satellite Launch Vehicle (GSLV) -Mark III- D1, on June 5 at 17:28. India’s heaviest but smallest rocket is going to be ISRO’s next step to put a man in space after the remarkable success of Mars Orbiter Mission (MOM). This rocket is 43 meters in height and 4 meters wide and it’s being called “Fat Boy” because it has a lift-off mass of 640 tonnes, equal to the weight of 200 Elephants! It is a three-stage vehicle with world’s heaviest two solid motor strap-on boosters, a liquid propellant core stage and a Cryogenic Upper Stage (CUS). The new Cryogenic engine uses liquid oxygen and liquid hydrogen as propellants. It is incorporated with advanced spacecraft technologies including indigenous Lithium (Li) ion battery and bus subsystem. This rocket is much more maneuverable than other rockets launched in this feature.
Development of the GSLV MK III began in early 2000s, with the first launch planned for 2009-2010. Several factors had delayed the program, including the April 15, 2010 failure of the ISRO-developed cryogenic upper stage test on the GSLV MK II. This is the second mission of the GSLV rocket during the last four years after two such launches failed in 2010. Finally, ISRO got the much awaited success launching a sub-orbital flight test of the GSLV MK III launcher, with a passive cryogenic third stage, in 2014. It took ISRO’s scientist 15 years to master the cryogenic engine technology. Only three countries- US, Russia and China have this technology.
GSLV MK-III is better than GSLV MK-II as it will place 4 tonne class satellites into Geosynchronous Transfer Orbits in comparison to GSLV MK-II which could place only 2 tonne class of satellites in space. Thus the launch vehicle will increase India’s capability to carry payloads from the current cap of 2 tonne. It is the heaviest next generation rocket, conceived and designed to make ISRO self-reliant in launching heavier communication satellites of INSAT-4 class.
UITS Educator | SPACE