Indian Launch Vehicles and Their Typical Payloads

India’s space transportation system has evolved from early sounding rockets to heavy-lift vehicles and private launch systems, enabling autonomous access to space. The Indian Space Research Organisation (ISRO) develops and operates these launch vehicles from the Satish Dhawan Space Centre (SDSC) in Sriharikota, Andhra Pradesh. Each vehicle is engineered for specific orbital regimes—including Low Earth Orbit (LEO), Sun-Synchronous Polar Orbit (SSPO), Geosynchronous Transfer Orbit (GTO), and interplanetary trajectories—carrying diverse payloads such as Earth observation, communication, navigation, and scientific satellites.

Historical Evolution of Indian Launch Vehicles

Sounding Rockets and Early Experimental Vehicles

India began its rocketry journey with the Nike-Apache sounding rocket launch from Thumba in 1963. The Rohini Sounding Rocket (RSR) series, including RH-200, RH-300, and RH-560, provided the foundation for indigenous solid propellant technology.

Satellite Launch Vehicle-3 (SLV-3)

• Configuration: India’s first experimental four-stage, all-solid propellant satellite launch vehicle.
• Payload Capacity: Capable of placing 40 kg payloads into Low Earth Orbit (LEO).
• Historical Milestone: Successfully launched the 35 kg Rohini satellite (RS-1) into orbit on July 18, 1980, making India the eighth nation with indigenous space launch capability.
• Project Leadership: Developed under the leadership of Dr. A.P.J. Abdul Kalam as the Project Director.

Augmented Satellite Launch Vehicle (ASLV)

• Configuration: A five-stage, all-solid propellant vehicle augmented by two strap-on boosters to test technologies needed for polar launch vehicles.
• Payload Capacity: Designed to carry 150 kg class satellites into LEO.
• Key Payloads: Successfully launched the Stretched Rohini Satellite Series (SROSS-C and SROSS-C2) carrying gamma-ray burst and ionospheric payload instruments.

Operational Workhorse Launch Vehicles

Polar Satellite Launch Vehicle (PSLV)

Known as the workhorse of ISRO, the PSLV is a four-stage vehicle utilizing alternating solid and liquid propulsion systems.

• Stage Configuration: First Stage (PS1 – Solid), Second Stage (PS2 – Liquid Vikas engine using UH25 and N_{2O_4}), Third Stage (PS3 – Solid), Fourth Stage (PS4 – Twin liquid engine using MMH and MON-3).
• Variants: PSLV-CA (Core Alone), PSLV-DL (2 strap-ons), PSLV-QL (4 strap-ons), and PSLV-XL (6 strap-ons).
• Payload Capacity: Transports up to 1,750 kg to Sun-Synchronous Polar Orbit (600 km) and 1,425 kg to Geosynchronous Transfer Orbit.
• Orbital Experimental Module (POEM): Uses the spent PS4 stage as a stabilized orbital platform for space-borne scientific experiments.
• Key Missions: Launched Chandrayaan-1 (2008), Mars Orbiter Mission / Mangalyaan (2013), Astrosat (2015), Aditya-L1 (2023), and set a world record by deploying 104 satellites in a single flight (PSLV-C37) in February 2017.

Geosynchronous Satellite Launch Vehicle (GSLV Mk II)

GSLV Mk II is a three-stage heavy launch vehicle equipped with an indigenous cryogenic upper stage.

• Stage Configuration: First stage (GS1 – Solid core with 4 liquid Vikas engine strap-ons), Second stage (GS2 – Liquid Vikas engine), Third stage (C12.5/C15 – Indigenous Cryogenic Upper Stage using liquid hydrogen and liquid oxygen).
• Payload Capacity: Delivers 2,250 kg payloads to Geosynchronous Transfer Orbit (GTO) and up to 6,000 kg to Low Earth Orbit.
• Key Payloads: Frequently deploys GSAT series communication satellites and the NVS series navigation satellites for the NavIC constellation.

Heavy-Lift and Next-Generation Vehicles

Launch Vehicle Mark-3 (LVM3 / GSLV Mk III)

LVM3 is India’s most powerful active operational launch vehicle, designed for heavy communication payloads and human spaceflight missions.

• Stage Configuration: Two S200 solid rocket boosters, a L110 core liquid stage (twin Vikas engines), and a high-thrust C25 Cryogenic Upper Stage (CE-20 engine).
• Payload Capacity: Transports up to 4,000 kg class payloads to GTO and 8,000 kg class payloads to LEO.
• Commercial and Exploration Achievements: Injected Chandrayaan-2 (2019) and Chandrayaan-3 (2023) into lunar transfer orbits. Successfully completed commercial deployments for OneWeb, placing 72 satellites into LEO across two dedicated missions.
• Human Spaceflight Integration: Modified as the Human-Rated LVM3 (HLVM3) to carry the Crew Module and Orbital Module for the Gaganyaan mission.

Small Satellite Launch Vehicle (SSLV)

Developed to address the growing global demand for small and micro-satellite launches on quick turnaround times.

• Stage Configuration: Three solid propulsion stages followed by a liquid-velocity trimming module (VTM) for precise orbital insertion.
• Payload Capacity: Places 500 kg payloads into Low Earth Orbit (500 km) and 300 kg to Sun-Synchronous Orbit.
• Key Features: Requires minimal launch infrastructure, capable of assembly within 72 hours by a small team compared to 40 days for a PSLV.

Next Generation Launch Vehicle (NGLV)

Currently under development to replace existing operational launch vehicles with cost-effective, reusable capabilities.

• Configuration: Three-stage vehicle utilizing eco-friendly semi-cryogenic propulsion (refined kerosene/RP-1 and liquid oxygen) for core stages.
• Payload Capacity: Targets 10,000 kg to GTO and 20,000 kg to LEO in its expendable configuration.
• Feature: Designed with a reusable first stage to reduce space access costs.

Comparison of Primary Indian Launch Vehicles

Commercial Operations and Private Sector Emergence

NewSpace India Limited (NSIL) and Antrix Corporation

• Antrix Corporation Limited: Established in 1992 as the commercial arm of ISRO to handle international satellite launches and technology transfers.
• NewSpace India Limited (NSIL): Incorporated in March 2019 under the administrative control of the Department of Space (DOS). NSIL owns, operates, and commercially executes launch services using PSLV, SSLV, and LVM3.

Private Indian Launch Vehicle Developers

Following space sector reforms managed by IN-SPACe (Indian National Space Promotion and Authorization Centre), private aerospace companies have developed launch capabilities:

• Skyroot Aerospace: Successfully launched India’s first privately built sub-orbital rocket, Vikram-S, under Mission Prarambh in November 2022. Developing the Vikram series of orbital launchers.
• Agnikul Cosmos: Successfully flight-tested Agnibaan SOrTeD in May 2024, powered by the Agnilet engine—world’s first single-piece 3D-printed semi-cryogenic rocket engine launched from a private launchpad (Agnikul Launchpad at Sriharikota).

Key Facts and Trivia for Quick Revision

• The Thumba Equatorial Rocket Launching Station (TERLS) was established in Thiruvananthapuram, Kerala, in 1963 due to its proximity to the Earth’s magnetic equator.
• India became the eighth nation in the world to acquire indigenous satellite launch capability on July 18, 1980, with the launch of SLV-3.
• The Liquid Propulsion Systems Centre (LPSC) developed the Vikas engine, the liquid-fuel engine powering the PSLV second stage, GSLV core stage, and LVM3 core stage.
• The CE-20 engine, developed by ISRO for the upper stage of LVM3, is India’s largest indigenously developed cryogenic engine.
• PSLV uses a combination of hydroxyl-terminated polybutadiene (HTPB) solid propellant and liquid fuels like Unsymmetrical Dimethylhydrazine (UDMH) with Nitrogen Tetroxide (N_{2O_4}).
• Liquid Oxygen (LOX) and Liquid Hydrogen LH₂ serve as oxidizer and fuel respectively in ISRO cryogenic rocket stages.
• Satish Dhawan Space Centre (SDSC) SHAR in Sriharikota, Andhra Pradesh, functions as the primary spaceport for all Indian satellite launch operations.
• The SSLV operates from a dedicated Small Satellite Launch Complex (SSLC) being set up at Kulasekarapattinam in Tamil Nadu, which offers a direct southward launch trajectory without needing to maneuver around Sri Lanka.
• Vikram Sarabhai Space Centre (VSSC) in Thiruvananthapuram functions as the primary lead facility for the design and development of launch vehicle technology in India.