Maarg Manthan · Topic 12.2

Categories of Launch Vehicles and Their Uses

Science & Technology › Space Technology and ISRO · Topic 12.2

A launch vehicle, or rocket, is a machine that lifts a payload such as a satellite from the ground to space by burning propellant and throwing hot gas backwards. Launch vehicles are grouped by the mass they can lift to low Earth orbit: small-lift vehicles carry up to about 2 tonnes, medium-lift 2 to 20 tonnes, heavy-lift 20 to 50 tonnes and super-heavy-lift more than 50 tonnes. They are also grouped as expendable, which are used once, and reusable, which return and fly again. Indian launch vehicles are the Small Satellite Launch Vehicle, the Polar Satellite Launch Vehicle, the Geosynchronous Satellite Launch Vehicle and the Launch Vehicle Mark 3. Sounding rockets are smaller rockets that make short flights to the upper atmosphere for experiments.

5 min read · UPSC Prelims · Science & Technology · Space Technology and ISRO

At a Glance

Small-lift Up to about 2 tonnes to LEO
Indian small launcher SSLV
Workhorse PSLV
Heaviest Indian LVM3
Reusable Falcon 9, RLV tests
Exam link UPSC Prelims, Science & Technology: Space Technology and ISRO

Where Does It Fit?

This topic follows the types of orbits. Each orbit needs a launch vehicle of suitable power, so the categories of rockets are explained next, before the detailed look at PSLV and GSLV. Previous topic: Types of Orbits (LEO, MEO, GEO, Polar, Sun-Synchronous). Next topic: ISRO’s Space Research Programme and ANTRIX Corporation.

How Are Launch Vehicles Classified?

Category	Details and examples
Small-lift	Up to about 2 tonnes to LEO. SSLV of India, Electron of Rocket Lab
Medium-lift	2 to 20 tonnes. PSLV, GSLV Mk II, Soyuz, Falcon 9 in expendable mode, Ariane 6
Heavy-lift	20 to 50 tonnes. Falcon 9 reusable, Delta IV Heavy, Long March 5, Ariane 5
Super heavy-lift	More than 50 tonnes. Saturn V, Space Launch System, Falcon Heavy, Starship
Expendable	Used once and discarded, as with most Indian rockets
Reusable	Stages return to Earth to fly again. SpaceX Falcon 9 boosters land and re-fly. India tests a Reusable Launch Vehicle technology demonstrator
Sounding rocket	Short suborbital flights for atmosphere and ionosphere studies. ISRO’s Rohini series

Which Indian Launch Vehicles Exist and What Do They Carry?

SSLV: Small Satellite Launch Vehicle, three solid stages and a liquid velocity trimming module. Carries up to about 500 kg to low Earth orbit and is meant for on-demand launches of small satellites
PSLV: Polar Satellite Launch Vehicle, four stages, alternating solid and liquid. Carries about 1,750 kg to sun-synchronous orbit or about 3,800 kg to low Earth orbit. First flew in 1993
GSLV Mk II: Three stages with an indigenous cryogenic upper stage. About 2,500 kg to geosynchronous transfer orbit
LVM3: Launch Vehicle Mark 3, earlier called GSLV Mk III. Three stages. About 4,000 kg to geosynchronous transfer orbit and about 8,000 kg to low Earth orbit. Used for Chandrayaan-3 and for Gaganyaan
Human-rated LVM3: A version made safer for crew with a crew escape system for the Gaganyaan programme
ASLV: Augmented Satellite Launch Vehicle, an early experimental rocket of the 1980s and 1990s
SLV-3: India’s first satellite launch vehicle, which put Rohini in orbit in 1980
Private rockets: Skyroot’s Vikram series and Agnikul’s Agnibaan are small launchers under development

What Else Should You Remember?

Stages: rockets are built in stages, and a stage is dropped when its fuel is used up, so the remaining rocket is lighter and faster
Strap-on boosters: extra rockets attached to the first stage to raise lift-off thrust
Payload fairing: a nose cone that protects the satellite through the atmosphere and then splits away
Solid propellant: simple, storable and gives high thrust, used in boosters, but cannot be shut off once lit
Liquid propellant: controllable and can be restarted, but needs pumps and tanks. India’s Vikas engine burns unsymmetrical dimethylhydrazine and nitrogen tetroxide
Cryogenic propellant: liquid hydrogen and liquid oxygen, with the highest efficiency among chemical fuels, as in GSLV Engine Variants and Cryogenic Rocket Technology
Specific impulse: a measure of how efficiently a rocket uses fuel, higher for cryogenic stages
Payload fraction: the share of lift-off mass that is useful payload, usually small, about 1 to 4 per cent
Reusable Launch Vehicle: ISRO carried out autonomous landing experiments with the RLV-LEX series between 2023 and 2024, using a winged test vehicle dropped from a helicopter
SSLV transfer: the Government has moved to transfer SSLV technology to industry, with a company chosen in 2025. Check the latest status
Launch pads: Sriharikota has launch pads for PSLV, GSLV and LVM3, and a new launch complex is being set up at Kulasekarapattinam in Tamil Nadu for small rockets
Cost: reusability aims to cut cost per kilogram to orbit, which is why it is a main trend

Why Does It Matter for the Exam?

Lift classes: small to super heavy
Indian vehicles: payload capacities of SSLV, PSLV, GSLV and LVM3
Concepts: stages, propellant types, reusability
Current affairs link: private launchers and reusable tests
Common errors: confusing PSLV orbit with GSLV orbit or placing LVM3 as a medium vehicle

As an analytical point, India has a range of launch vehicles that suit different payloads. The new emphasis on small launchers, private rockets and reusability is meant to lower cost and raise launch frequency.

Why Is This Topic Important?

Classes Lift categories
India SSLV to LVM3
Trend Reusability

What Came Next?

The next topic covers ISRO’s research programme and its commercial arm Antrix Corporation. Next topic: ISRO’s Space Research Programme and ANTRIX Corporation.

Key People and Terms

Payload What the rocket carries
Stage Rocket section dropped after use
Fairing Nose cone cover
Thrust Force pushing the rocket
Expendable Single use
Suborbital Does not complete an orbit

Exam Corner

Points to Remember

PSLV: about 1,750 kg to SSO.
GSLV Mk II: about 2,500 kg to GTO.
LVM3: about 4,000 kg to GTO.
SLV-3 flew in 1980.
SSLV carries up to about 500 kg.

Do Not Confuse With

PSLV and GSLV Polar sun-synchronous vehicle versus geosynchronous vehicle
LVM3 and GSLV Mk II Heavier three-stage rocket versus smaller cryogenic upper stage rocket
Sounding rocket and launch vehicle Suborbital versus orbital

Memory Hook

SSLV small, PSLV workhorse, GSLV for the high, LVM3 for the heavy.

Mains Angle

Questions ask for capacities and use of each Indian rocket. These points help.

Range Four launchers
Cost Reusability
Industry Private role

A Question You May Face

An original practice question, not a past paper question.

“Describe the categories of launch vehicles and discuss the role of India’s launch vehicles in meeting national and commercial space needs.”

How to Answer

Classes By lift.
India SSLV, PSLV, GSLV, LVM3.
Trends Reusable, private.
Way Launch frequency.

GS Relevance

Prelims: lift categories, Indian launchers and capacities, reusable rockets. GS Paper 3: science and technology, space technology.

Frequently Asked Questions

How are launch vehicles classified?

Launch vehicles are classified by the mass they can lift to low Earth orbit: small-lift up to about 2 tonnes, medium-lift 2 to 20 tonnes, heavy-lift 20 to 50 tonnes and super-heavy-lift above 50 tonnes. They are also classed as expendable if used once or reusable if parts can return and fly again.

Which are the launch vehicles of ISRO?

ISRO operates the Small Satellite Launch Vehicle, the Polar Satellite Launch Vehicle, the Geosynchronous Satellite Launch Vehicle Mark II and the Launch Vehicle Mark 3, called LVM3. Earlier vehicles included SLV-3 and ASLV. Each has a different payload capacity and is designed for a different orbit.

What is the payload capacity of LVM3?

LVM3 can carry about 4,000 kilograms to geosynchronous transfer orbit and about 8,000 kilograms to low Earth orbit. It is the heaviest launcher of India and was used for Chandrayaan-3. A human-rated version will be used to carry crew in the Gaganyaan programme.

What is a sounding rocket?

A sounding rocket is a small rocket that makes a short suborbital flight into the upper atmosphere to carry out experiments, such as measuring winds, ionosphere properties or cosmic rays, and then falls back. The first rocket launched from Thumba in 1963 was a sounding rocket, and ISRO's Rohini series continues this work.

What is a reusable launch vehicle?

A reusable launch vehicle is a rocket whose parts can return to Earth and be flown again, which lowers the cost of access to space. SpaceX lands and re-flies Falcon 9 boosters. ISRO has tested a winged Reusable Launch Vehicle demonstrator by autonomous landing experiments between 2023 and 2024.

PYQ Practice — Statement Analysis

1 The Polar Satellite Launch Vehicle is designed mainly for sun-synchronous orbits.

True

Its main design target.

2 SLV-3 was the first launch vehicle to carry a satellite to geostationary orbit.

False

It placed Rohini in low orbit.

3 LVM3 was used for Chandrayaan-3.