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GSLV and Various Engine- Science & Technology Notes

GSLV AND VARIOUS ENGINE

 
 
 
The Geosynchronous Satellite Launch Vehicle (GSLV) is a rocket system developed by the Indian Space Research Organisation (ISRO) primarily designed to launch satellites into geosynchronous transfer orbits (GTO) and geostationary orbits (GEO). These orbits are highly desirable for communication and weather satellites because they allow the satellite to maintain a fixed position relative to the Earth\'s surface.
 
What is a Geosynchronous Satellite Launch Vehicle (GSLV)?

The Geosynchronous Satellite Launch Vehicle (GSLV) is an essential rocket system developed by the Indian Space Research Organisation (ISRO) to launch satellites into geosynchronous transfer orbits (GTO). These orbits are used for placing satellites in positions where they match the Earth\'s rotation, effectively staying fixed relative to a point on the Earth\'s surface.

The GSLV has been crucial for India\'s space missions, especially for launching communication satellites and weather satellites into geostationary orbits. It has undergone several developmental phases, with different iterations incorporating various improvements in technology and efficiency.

Key features and components of GSLV:

Core Stages:

  • S1 Stage: This stage uses solid fuel and provides the initial thrust during the launch phase.
  • L110 Stage: It is a liquid-fueled stage used as the second stage of GSLV, employing Vikas engines.

Cryogenic Upper Stage (CUS):

  • This stage uses cryogenic fuel (liquid oxygen and liquid hydrogen) for propulsion. The CUS significantly enhances the payload capacity and efficiency of the GSLV.

Advancements and Variants:

  • GSLV Mk I: Earlier versions had mixed success rates due to challenges in perfecting the cryogenic stage.
  • GSLV Mk II: This version featured improvements and successfully launched multiple satellites.
  • GSLV Mk III: Often referred to as LVM-3, it\'s an upgraded version with a higher payload capacity, making it suitable for heavier satellite launches. It\'s notable for its use in Chandrayaan-2, India\'s lunar mission
 
Stages of GSLV

The GSLV (Geosynchronous Satellite Launch Vehicle) typically consists of multiple stages, each contributing to the rocket\'s propulsion and payload delivery into the desired orbit. Here\'s a breakdown of the stages commonly found in GSLV:

Core Stages:

    • S1 Stage: The first stage of the GSLV is often powered by a solid rocket motor. It generates the initial thrust required for liftoff and ascends the rocket beyond Earth\'s atmosphere.

    • L110 Stage: Following the S1 stage, the GSLV typically incorporates a liquid-fueled stage called the L110 stage. This stage uses Vikas engines, which are liquid propulsion engines that operate using a combination of liquid propellants.

Cryogenic Upper Stage (CUS):

    • One of the distinguishing features of GSLV is its cryogenic upper stage. This stage utilizes cryogenic propulsion technology that involves the use of liquid oxygen (LOX) and liquid hydrogen (LH2) as propellants. The use of cryogenic fuel significantly enhances the rocket\'s efficiency and payload capacity.

Payload Fairing:

    • Above the upper stages, the GSLV incorporates a payload fairing. This protective casing shields the payload (satellite or satellites) during the launch ascent through Earth\'s atmosphere. Once the rocket reaches space, the fairing separates to expose the payload to space.

Each stage in the GSLV plays a crucial role in achieving the desired orbit for satellite deployment. The combination of solid, liquid, and cryogenic propulsion stages allows the GSLV to carry various payloads into geosynchronous transfer orbits (GTO) or geostationary orbits (GEO), which are often utilised for communication, weather, and scientific satellites

 
Types of Engines

Rocket engines used in space exploration can be broadly classified into several types based on their propulsion mechanisms and fuel sources. Here are some of the main types:

Liquid Rocket Engines:

    • These engines use liquid propellants, typically liquid oxygen (LOX) as the oxidizer and a liquid fuel, such as liquid hydrogen (LH2), RP-1 (a highly refined form of kerosene), or other hydrocarbons. They offer good efficiency and controllability.

Solid Rocket Motors:

    • Solid rocket motors use solid propellant, which is a mixture of fuel and oxidizer. Once ignited, they burn until the solid propellant is depleted. They\'re relatively simple, reliable, and offer high thrust but have limited controllability once ignited.

Cryogenic Rocket Engines:

    • These engines use cryogenic propellants like liquid hydrogen and liquid oxygen stored at extremely low temperatures. They provide high specific impulse (efficiency) but require complex and insulated systems due to the low temperatures.

Hybrid Rocket Engines:

    • Hybrid engines use a combination of liquid and solid propellants. For example, a liquid oxidizer could be combined with a solid fuel. They aim to combine the advantages of both liquid and solid propulsion systems.

Ion Engines:

    • Ion engines are a type of electric propulsion that uses electrical energy to accelerate ions to generate thrust. They are highly efficient but provide low thrust, making them suitable for long-duration missions like deep space exploration.

Nuclear Thermal Rocket Engines:

    • These engines utilize nuclear reactions to heat propellant, usually hydrogen, which is then expelled to generate thrust. They offer potentially high efficiency but are currently at an experimental stage.

Air-Breathing Engines (Hypersonic Engines):

    • These engines are designed to operate in the atmosphere at hypersonic speeds. They typically use atmospheric oxygen as part of their combustion process to reduce the amount of onboard oxidizer required
 
 
 
Previous Year Questions

1.Consider the following statements: (UPSC CSE 2007)

1) In the year 2006, India successfully tested a full-fledged cryogenic stage in rocketry.

2) After USA, Russia and China, India is the only country to have acquired the capability for use of cryogenic stage in rocketry.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: (a)

2.Cryogenic engines find applications in: (UPSC CSE 1995)

(a) sub-marine propulsion

(b) frost-free refrigerators

(c) rocket technology

(d) research in superconductivity

Answer: (c)

3.ISRO successfully conducted a rocket test using cryogenic engines in the year 2007. Where is the test stand used for the purpose, located? (UPSC CSE 2008)

(a) Balasore

(b) Thiruvananthapuram

(c) Mahendragiri

(d) Karwar

Answer: (c)

 
 
Frequently Asked Questions on GSLV
 

What is GSLV?

GSLV stands for Geosynchronous Satellite Launch Vehicle. It is a series of Indian rockets developed by the Indian Space Research Organisation (ISRO) to launch communication satellites into Geosynchronous Transfer Orbit (GTO).

What are the different versions of GSLV?

There are four main versions of GSLV:

  • GSLV Mk I: The first version, used cryogenic engines but was not very successful.
  • GSLV Mk II: Used a mix of solid and liquid engines, achieving more success than Mk I.
  • GSLV Mk III: The current operational version, uses an indigenous cryogenic upper stage and is India\'s most powerful rocket.
  • GSLV Mk IIE: Under development, aims to reduce dependence on foreign components and improve cost-effectiveness.

What is the capacity of GSLV?

The capacity of GSLV varies depending on the version and the specific mission. Generally, GSLV Mk II can launch up to 500 kg satellites, while GSLV Mk III can launch up to 4 ton satellites.

What are the successes of GSLV?

  • GSLV Mk III successfully launched Chandrayaan-2 mission to the Moon in 2019.
  • GSLV Mk II has launched several successful communication satellites like GSAT-12 and INSAT-3C.
  • India achieved self-reliance in cryogenic engine technology, a critical milestone for space capabilities.

What are the challenges of GSLV?

  • High dependence on imported components, especially for earlier versions.
  • Complex cryogenic technology leading to some initial failures.
  • Competition from more established launch vehicles like Ariane 5 and Falcon 9.

What are the future plans for GSLV?

  • Continued development of GSLV Mk III for heavier payloads.
  • Development of GSLV Mk IIE for cost-effective launches.
  • Exploring reusability technologies for future versions