1. Write a note on Geosynchronous Satellite Launch Vehicle (GSLV)? What are it’s significance for India and how is it different from Polar Satellite Launch Vehicle (PSLV)?

GSLV is a launch vehicle used to launch INSAT class of satellites (GSAT series) into Geosynchronous Transfer Orbits. It is a three-stage launcher with one solid rocket motor stage, liquid stage and one cryogenic stage. With its efficient cryogenic engine it could lift greater loads into space.

Significance of GSLV:

  • Mastering space technology: Despite restrictions on dual use technologies, India has built & validated fully working highly complex cryogenic rocket propulsion system. Eg: GSLV-Mk II can launch much heavier satellites which weigh around 5000 kg.
  • Space Research:  Enables to launch space stations to much higher altitudes
  • Commercial launch market: Compared to launch vehicles of other countries, it costs almost half to launch satellites with GSLV
  • Self reliant in vehicle launch: With successful launch of GSLV-MKIII India could achieve complete self-reliance and with cheaper launches help the Indian exchequer.
  • Good governance: Tele-education, tele-medicine, village resource centre, remote banking disaster management system etc. would benefit and in turn help provide efficient basic services to even remote parts of the country.
  • Strategic significance: Will help insulate India from whims & uncertainties of global space launch market which is changing with shifting geo-political priorities.  

Difference between GSLV & PSLV




  • Communication satellites
  • Higher lift off mass (2500kg)
  • & higher altitudes (36000 km)
  • Earth observation or remote-sensing satellites.
  • Satellites of lower lift off mass to Geosynchronous Transfer Orbits
  • Low lift off mass (upto 1750kg), lesser altitude (600-900km)
  • Initially to Geosynchronous Transfer Orbits (GTO) and further raised to  Geosynchronous  Earth Orbits (GEO)
  • Sun synchronous circular polar orbits (Low Earth orbits)
Stages 3 stages :

  • 1: solid
  • 2: liquid
  • 3: cryogenic
4 stages :

  • 1&3 stages: solid propellant
  • 2&4 stages: liquid propellant
Recent developments GSLV-Mk II (indigenous cryogenic upper stage) Launched many successful missions like Mars Orbiter Mission (MOM), IRNSS.
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