Geosynchronous Satellite Launch Vehicle (GSLV)

The development of space technology has enabled countries to explore the vastness of the universe and enhance communication systems. One such remarkable achievement in India’s space program is the Geosynchronous Satellite Launch Vehicle (GSLV). This article dives into the specifications and technical details of GSLV, highlighting its key components and capabilities.

 Geosynchronous Satellite Launch Vehicle (GSLV)

Overview of GSLV (Geosynchronous Satellite Launch Vehicle)

GSLV is an Indian launch vehicle designed to transport communication satellites into geostationary transfer orbits (GTO). It consists of three stages and is capable of launching payloads into both geostationary and low Earth orbits. Let’s explore some of the key features and technical specifications of this impressive space vehicle.

Lift Off Mass and First Flight

The GSLV has a lift-off mass of 420 tonnes, making it a substantial launch vehicle. Its maiden flight took place on April 18, 2001. However, it wasn’t until January 5, 2014, that the indigenous cryogenic stage was successfully integrated into the GSLV, marking a significant milestone in India’s space program.

Technical Specifications

First Stage: GS1

The first stage of GSLV, known as GS1, is derived from the Polar Satellite Launch Vehicle’s (PSLV) PS1. It features a 138-tonne solid rocket motor augmented by four liquid strap-ons. The primary fuel used in the GS1 stage is HTPB, providing a maximum thrust of 4800 kN. The burn-time of this stage is approximately 100 seconds.

Second Stage: GS2

The second stage, GS2, utilizes the reliable Vikas engine, which has been extensively used in the PS2 stage of the PSLV. The Vikas engine employs a combination of UH25 fuel and N2O4 oxidizer. With a nominal thrust of 846 kN, the GS2 stage provides crucial propulsion during the ascent phase. The burn-time of the second stage is around 150 seconds.

Third Stage: CUS

The Cryogenic Upper Stage (CUS) is the third stage of GSLV and was developed under the Cryogenic Upper Stage Project (CUSP). The CUS features the CE-7.5 cryogenic engine, which operates on a staged combustion cycle. The fuel combination used in the CUS is LOX (Liquid Oxygen) and LH2 (Liquid Hydrogen). The CE-7.5 engine provides a nominal thrust of 75 kN and has a burn-time of 814 seconds.

Payload Capacity of GSLV

GSLV has the capability to transport payloads to both Geostationary Transfer Orbit (GTO) and Low Earth Orbit (LEO). Its payload capacity to GTO is 2,250 kg, primarily intended for INSAT class communication satellites. These satellites operate from geostationary orbits, allowing them to remain fixed relative to the Earth’s surface. GSLV’s capacity to place up to 6,000 kg in LEO enables the launch of multiple smaller satellites, expanding the scope of missions.

GSLV Mk II: Launch Vehicle Details

The Geosynchronous Satellite Launch Vehicle Mark II (GSLV Mk II) is a fourth-generation launch vehicle developed by India. Initially, Russian-supplied cryogenic stages were used in GSLV launches. However, since January 2014 (starting with GSLV D5), the indigenously developed Cryogenic Upper Stage (CUS) has been successfully utilized. GSLV Mk II follows a three-stage configuration and features four liquid strap-ons. This launch vehicle has achieved six consecutive successful launches, highlighting its reliability and effectiveness.


The Geosynchronous Satellite Launch Vehicle (GSLV) is an exceptional accomplishment in India’s space program. With its impressive lift-off mass, technical specifications, and payload capacity, GSLV has become a reliable launch vehicle for communication satellites. The integration of indigenous cryogenic stages further strengthens India’s self-reliance in space technology. The GSLV Mk II’s continuous successes underscore the country’s commitment to advancing its space exploration capabilities.

List of GSLV Launches

To know about the list of GSLV Launches, Click here.


Also read I Chandrayaan 3.

Also read I Gaganyaan.

Also see I  GSLVF12/ NVS01 Launch.


What is the lift-off mass of GSLV?

The lift-off mass of GSLV is 420 tonnes.

When was the first flight of GSLV with an indigenous cryo stage?

The first flight of GSLV with an indigenous cryogenic stage took place on January 5, 2014.

What are the technical specifications of the GSLV?

The GSLV features three stages: GS1, GS2, and CUS. The GS1 stage has a max thrust of 4800 kN and a burn-time of 100 seconds. The GS2 stage has a max thrust of 846 kN and a burn-time of 150 seconds. The CUS stage, utilizing the CE-7.5 cryogenic engine, has a nominal thrust of 75 kN and a burn-time of 814 seconds.

Which engine is used in the second stage of GSLV?

The second stage of GSLV employs the Vikas engine.

What is the payload capacity of GSLV to GTO?

The payload capacity of GSLV to GTO is 2,250 kg.

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