The Indian Space Research Organisation’s (ISRO) heaviest rocket – the GSLV MKIII, will launch 36 satellites of the OneWeb communication constellation from the country’s only space port in Sriharikota, Andhra Pradesh, soon. With this launch, the GSLV MKIII will enter the global commercial launch service market.



  • Earlier, NewSpace India Limited (NSIL) – a central public sector enterprise (CPSE) under the Department of Space and the commercial arm of the ISRO, has signed two launch service contracts with M/s OneWeb, United Kingdom.
    • OneWeb is a global communications network, powered from space, enabling connectivity for governments, businesses, and communities.
    • Bharti group-backed OneWeb is implementing a constellation of LEO satellites.
  • As part of the contract, 36 communication satellites will be placed into orbit by one LVM3 – ISRO’s heaviest launcher, from Satish Dhawan Space Centre, under the OneWeb India-1 Mission.
  • It will be the first LVM3 dedicated commercial launch and through this launch LVM3 is making its entry into the Global commercial launch service market.
  • This will be the second flight of the GSLV MKIII, since it carried India’s second lunar mission Chandrayaan-2.
  • Also, this will be the first time a rocket other than India’s workhorse – PSLV, is being used to carry out a commercial launch.
    • Since its first operational flight, the PSLV has launched at least 345 foreign satellites from 36 countries (PSLV-C37 – the most notable, that put 104 satellites (of which 101 were foreign commercial satellites) in orbits in 2017).
  • India currently has three operational launch vehicles – the PSLV, GSLV and GSLV Mk III.
  • In 2020, the government opened the space sector to the private sector with the goal of allowing private players to provide routine space services while ISRO focuses on scientific missions.


What is a ‘Geosynchronous Satellite Launch Vehicle’?

  • It is a space launch vehicle designed, developed and operated by the ISRO to launch satellites and other space objects into Geosynchronous Transfer Orbits (GTO).
    • A satellite in the GTO, orbits (at an altitude of 37,000 km) the Earth once per day, keeping the satellite in roughly the same area over the ground.
  • GSLV has the capability to put a heavier payload (up to 5,000 kg up to 37,000 km) in orbit than the Polar Satellite Launch Vehicle (PSLV can carry up to 2000 kg into space up to 600-900 km).
    • PSLV is designed mainly to deliver earth observation or remote sensing satellites, whereas GSLV has been designed for launching communication satellites.
    • GSLV delivers satellites into a higher elliptical orbit – GTO.
  • GSLV is a 3-stage launcher with strap-on motors.
    • The first stage – uses the solid rocket motor with four liquid engine strap-on motors. This stage generates maximum thrust.
    • The second stage uses a liquid rocket engine which is known as Vikas engine.
    • The third stage uses a Cryogenic engine, which uses liquefied oxygen and hydrogen as fuel.
  • GSLV-D5 – launched in 2014 – was the first successful flight of the GSLV using the indigenous cryogenic engine (CE-7.5).



  • GSLV MKIII Project was approved in 2002, with a mandate of achieving the capability to launch a 4-ton (4000 kg) class satellite to Geo-Synchronous orbit, by realising an indigenously developed launch vehicle.
  • GSLV MKIII is configured as a 3-stage vehicle with two solid strap-on motors (S200, among the largest in the world), one liquid core stage and a high thrust Cryogenic Upper Stage (CUS).
  • Characteristics of GSLV MKIII —
    • Performance capability of 4.3 ton to GTO
    • Payload capability to support 10 ton to LEO missions
    • Cost effective
    • Improved reliability, operability and redundancy management
    • Future growth potential of payload with minimal design changes
    • To support manned missions (like Gaganyaan mission) of Indian Space Programme
  • The maiden operational flight of GSLV MKIII has successfully launched Chandrayaan-2 spacecraft into the Super Geo-Synchronous Transfer Orbit in 2019.