What are the main types of launch vehicles used by ISRO?

ISRO primarily uses the Polar Satellite Launch Vehicle (PSLV) for polar and low-Earth orbits, the Geosynchronous Satellite Launch Vehicle (GSLV) for geosynchronous orbits, and the Small Satellite Launch Vehicle (SSLV) for small satellite missions. Each is designed for specific payload capacities and orbital requirements.

What is the significance of the PSLV for India?

The PSLV is ISRO's reliable 'workhorse' launch vehicle, known for its versatility and cost-effectiveness. It has successfully launched numerous Earth observation, remote sensing, and smaller communication satellites, including India's first lunar and Mars missions as secondary payloads, establishing India's self-reliance in space access.

Why is cryogenic technology important for launch vehicles?

Cryogenic technology, using liquid hydrogen and liquid oxygen at extremely low temperatures, is crucial because it provides significantly higher thrust efficiency (specific impulse) compared to solid or liquid propellants. This enables launch vehicles like GSLV to carry heavier payloads to higher orbits, such as Geosynchronous Transfer Orbit (GTO).

What is the difference between GSLV Mk II and LVM3 (GSLV Mk III)?

GSLV Mk II uses an indigenous CE-7.5 cryogenic engine in its upper stage and has a payload capacity of about 2.5 tonnes to GTO. LVM3 (GSLV Mk III) is a heavier vehicle with two large solid strap-ons, a liquid core stage, and a more powerful CE-20 cryogenic engine, capable of launching 4-tonne class satellites to GTO and human missions.

What is the purpose of the Small Satellite Launch Vehicle (SSLV)?

The SSLV is designed to provide cost-effective, on-demand launch services for small satellites (up to 500 kg to LEO). It offers quick turnaround time, minimal launch infrastructure requirements, and flexibility, catering to the rapidly growing global small satellite market and university missions.

What are reusable launch vehicles (RLVs) and why is ISRO developing them?

Reusable launch vehicles are designed to return to Earth and be reused, significantly reducing launch costs and increasing mission flexibility. ISRO is developing RLVs, like the RLV-TD, to enhance India's competitiveness in the global space market and make space access more affordable for future missions, including human spaceflight.

Where does ISRO launch its rockets from?

ISRO launches all its operational rockets from the Satish Dhawan Space Centre (SDSC) in Sriharikota, Andhra Pradesh. This coastal location provides advantageous launch azimuths over the Bay of Bengal for various orbital inclinations, ensuring safety and optimal mission trajectories.

What is the Vikas engine?

The Vikas engine is ISRO's workhorse liquid-propellant rocket engine, derived from the French Viking engine. It powers the second stage of the PSLV, and the liquid strap-ons and core stage of the GSLV Mk II and LVM3, demonstrating India's indigenous capabilities in liquid propulsion technology.

Launch Vehicles

Science & Technology

Constitution VerifiedUPSC Verified

Version 1Updated 10 Mar 2026

Explore This Topic

Definition Detailed Explanation Key Discoveries Scientific Principles Tech Evolutions UPSC Importance Prelims Strategy Mains Strategy Prelims MCQs Mains Questions MCQ Practice Predicted 2026 Revision Notes Current Affairs

While there isn't a single constitutional article exclusively dedicated to 'Launch Vehicles,' the Indian Constitution implicitly supports scientific and technological advancement for national development. Article 51A(h) enshrines the fundamental duty of every citizen to 'develop the scientific temper, humanism and the spirit of inquiry and reform.' This ethos underpins the nation's commitment to s…

Quick Summary

India's space program, driven by ISRO, relies on a robust fleet of launch vehicles to deploy satellites and spacecraft. The Polar Satellite Launch Vehicle (PSLV) is the versatile 'workhorse,' primarily used for placing Earth observation and remote sensing satellites into polar and low-Earth orbits.

It's known for its reliability and ability to launch multiple satellites. The Geosynchronous Satellite Launch Vehicle (GSLV) family, particularly the GSLV Mk II and the heavier LVM3 (GSLV Mk III), are crucial for launching communication satellites into Geosynchronous Transfer Orbit (GTO) and for ambitious missions like Chandrayaan and Gaganyaan.

Their key technological differentiator is the indigenous cryogenic upper stage, which uses super-cooled liquid hydrogen and oxygen for high efficiency. The newest addition, the Small Satellite Launch Vehicle (SSLV), is designed for rapid, cost-effective deployment of small satellites into Low Earth Orbit (LEO), catering to the burgeoning commercial market.

ISRO also actively researches Reusable Launch Vehicle (RLV) technology, exemplified by the RLV-TD, to reduce launch costs significantly. All launches occur from the Satish Dhawan Space Centre (SDSC) in Sriharikota.

These vehicles collectively ensure India's self-reliance in space, support national development, and enhance its commercial competitiveness in the global space sector.

Vyyuha

Your 6-Month Blueprint, Updated Nightly

AI analyses your progress every night. Wake up to a smarter plan. Every. Single.…

PSLV: Workhorse, 4 stages, solid/liquid, LEO/SSPO, ~1.75T to LEO.

GSLV Mk II: 3 stages, solid/liquid/cryo (CE-7.5), ~2.5T to GTO.

LVM3 (GSLV Mk III): Heaviest, 3 stages, solid/liquid/cryo (CE-20), ~4T to GTO, Gaganyaan.

SSLV: Small sats, 3 solid stages, quick turnaround, ~0.5T to LEO.

Cryogenic: LH2/LOX, high efficiency, GTO.

Vikas Engine: Liquid, powers PSLV 2nd stage, GSLV liquid stages.

RLV-TD: Reusable tech demonstrator, cost reduction.

SDSC: Sriharikota, India's launch site.

NSIL: ISRO's commercial arm.

National Space Policy 2023: Private sector boost.

P-S-L-V G-S-L-V S-S-L-V: Polar Satellites Lift Very Greatly, Sending Large Vehicles Straight Skyward Launching Very smalls.

Launch Vehicles

Quick Summary

Related Topics