Geosynchronous Satellite Launch Vehicle

The Geosynchronous Satellite Launch Vehicle (GSLV) has been in the spotlight recently as ISRO prepares for the launch of the NASA-ISRO NISAR satellite. This significant milestone showcases the vehicle’s readiness to carry out complex space missions, especially involving high payloads to Geosynchronous Transfer Orbits (GTOs).

Key Details about GSLV:

1. What is GSLV?

   • The GSLV is an Indian-made space launch vehicle developed and operated by the Indian Space Research Organisation (ISRO). It is designed primarily to launch satellites and other space objects into Geosynchronous Transfer Orbits (GTOs).

   • GSLV is crucial for launching heavier payloads compared to the Polar Satellite Launch Vehicle (PSLV), giving ISRO greater flexibility in its satellite deployment and space exploration missions.

   Specifications of GSLV:

   • Height: 49.13 meters, making it the tallest rocket in ISRO’s fleet.

   • Lift-off Mass: 420 tonnes.

   • Stages:

     • First Stage: The S139 solid booster with 138 tonnes of solid propellant, augmented by four liquid strap-on boosters with 40 tonnes of liquid propellant.

     • Second Stage: A liquid engine carrying 40 tonnes of liquid propellant.

     • Third Stage: Cryogenic Upper Stage (CUS), carrying 15 tonnes of cryogenic propellants. This stage is crucial for providing the final boost to get the satellite into its intended orbit.

   Why is GSLV Important?

   • Heavier Payloads: GSLV has a higher payload capacity compared to PSLV, allowing ISRO to launch larger and heavier satellites.

   • Advanced Cryogenic Technology: The cryogenic upper stage provides better efficiency and greater thrust, enhancing the vehicle’s performance, especially for missions requiring precision and longer orbital insertions.

   • Versatility: GSLV is capable of launching a wide range of satellites, including communication satellites like INSAT and GSAT, as well as other payloads for navigation and scientific missions.

Variants of GSLV:

1. GSLV Mk I:

   • Payload Capacity: 2-2.5 tons to GTO.

   • Cryogenic Stage: Initially used Russian-supplied cryogenic upper stage due to early challenges with indigenous cryogenic technology.

   • Flight History: 5 flights between 2001-2010, including suborbital tests, with the last launch in 2010.

   GSLV Mk II:

   • Enhanced Capacity: An improved version with an indigenously developed cryogenic upper-stage engine.

   • Payload Capacity: Capable of carrying payloads up to the 2.5-ton class to GTO.

   • First Successful Launch: Occurred in 2014.

   GSLV Mk III (LVM-3):

   • Most Advanced Variant: Known for its significant advancements in terms of size, capacity, and technological sophistication.

   • Payload Capacity: Up to 4 tons to GTO.

   • This variant is critical for large-scale missions, including those involving heavy payloads and ambitious space exploration objectives.

Notable GSLV Missions:

• South Asia Satellite (2017): A communication satellite aimed at providing telecommunication services to neighboring countries in South Asia.

• Chandrayaan-2 (2019): A crucial mission to the Moon, aiming to study the lunar surface, including its poles, and deploy a lander and rover.

Significance of NISAR Launch:

The NASA-ISRO NISAR (NASA-ISRO Synthetic Aperture Radar) mission is set to be launched aboard the GSLV. This satellite is part of a collaborative effort between NASA and ISRO, and will play a critical role in monitoring and understanding changes in Earth's land surface, with applications ranging from climate change studies to disaster management.

• NISAR will map the Earth's surface with high precision, using radar technology to monitor subtle changes, such as the movement of glaciers, tectonic shifts, and deforestation. The mission has the potential to provide valuable data for monitoring environmental changes and supporting sustainable development.