The Liquid Propulsion Systems Centre (LPSC) Explained

The Liquid Propulsion Systems Centre (LPSC) is the Indian Space Research Organisation (ISRO) centre responsible for designing and developing liquid, semi-cryogenic and cryogenic propulsion stages and spacecraft propulsion systems, with its headquarters at Valiamala near Thiruvananthapuram and a major campus in Bengaluru. Every Indian launch vehicle that uses liquid fuel, from the Polar Satellite Launch Vehicle (PSLV) to the heavy-lift LVM3, relies on engines or stages developed at this centre.

The Liquid Propulsion Systems Centre also builds the thrusters and tanks that let satellites reach their final orbits and keep their position, and the engines that allowed Chandrayaan landers to descend towards the Moon. Together these capabilities make LPSC one of the most strategically important units in the Indian space programme.

Quick Facts: Liquid Propulsion Systems Centre

Key Takeaways

• The Liquid Propulsion Systems Centre (LPSC) is ISRO’s lead centre for liquid, semi-cryogenic and cryogenic rocket stages and for spacecraft propulsion.
• The Vikas engine, developed by LPSC from technology originally acquired from France, powers the second stage of the PSLV and the core stage of the LVM3.
• The CE-20 cryogenic engine, burning liquid hydrogen and liquid oxygen, was designed and built in India and powers the upper stage of the LVM3.
• The SCE-200 semi-cryogenic engine, using liquid oxygen and refined kerosene, is meant to give future Indian launch vehicles far more thrust per engine.
• LPSC’s thrusters, tanks and valves also support satellites, the Chandrayaan lunar landers and the service module for the Gaganyaan human spaceflight programme.
• Engine tests for LPSC are carried out at the ISRO Propulsion Complex at Mahendragiri in Tamil Nadu.

What is the Liquid Propulsion Systems Centre?

The Liquid Propulsion Systems Centre is an ISRO research and development centre that specialises in propulsion systems fed by liquid propellants. In such systems fuel and oxidiser are stored as liquids in tanks and pumped or pressure-fed into a combustion chamber, where they burn to produce thrust.

The centre’s work covers the entire chain, from conceptual design and analysis to fabrication, integration and flight qualification. LPSC designs turbopumps, thrust chambers, gas generators, valves, tanks and control electronics, and then assembles them into complete stages. It is one of the several specialised centres that ISRO operates, alongside the Vikram Sarabhai Space Centre, which develops solid rocket motors and launch vehicle structures, and the U R Rao Satellite Centre, which builds satellites.

Where is LPSC located and how is it organised?

The Liquid Propulsion Systems Centre has its headquarters at Valiamala, on the outskirts of Thiruvananthapuram in Kerala, and a second major campus in Bengaluru. The two sites have somewhat different emphases.

• Valiamala, Thiruvananthapuram: design, fabrication and integration of launch vehicle propulsion stages and engines, including the large Vikas and cryogenic systems.
• Bengaluru: development and production of propulsion systems for satellites and spacecraft, such as thrusters, tanks, valves and electronic controllers.
• Mahendragiri, Tamil Nadu: the ISRO Propulsion Complex (IPRC), a sister unit with large test stands for stage and engine testing. It was historically part of LPSC and now functions as a separate ISRO centre that supports it.

This geographical arrangement lets engineers work close to the launch vehicle programme at Thiruvananthapuram while the satellite propulsion team operates alongside the satellite programme in Bengaluru.

How did LPSC begin and develop?

The Liquid Propulsion Systems Centre began as a small group working on liquid engines in the 1960s and 1970s and became a full ISRO centre in the 1980s. The early work took place at the Space Science and Technology Centre at Thumba, which later became the Vikram Sarabhai Space Centre, and used the sounding rocket programme as a training ground.

Early milestones include the following.

Years are given at the level of decades where exact dates differ between sources.

What is the Vikas engine?

The Vikas engine is a liquid-fuelled rocket engine developed by the Liquid Propulsion Systems Centre that burns unsymmetrical dimethylhydrazine (UDMH) as fuel and nitrogen tetroxide (N2O4) as oxidiser. These propellants are called storable because they remain liquid at ordinary temperatures and can be kept in a rocket’s tanks for long periods.

The design traces back to the Viking engine, which India studied and built under a technology agreement with a French firm in the 1970s. Indian engineers then adapted and improved it, and the name Vikas honours Vikram Ambalal Sarabhai, the founder of the Indian space programme. The engine uses a pump-fed cycle, with turbopumps driven by gas from a gas generator.

Vikas engines are used in several stages:

• The second stage of the PSLV, known as PS2, which uses a single Vikas engine.
• The strap-on boosters of the GSLV Mk II and the second stage of the GSLV.
• The L110 liquid core stage of the LVM3, which has two Vikas engines.

Different versions of the engine exist, with uprated thrust and improved performance for different stages. The engine has a long and reliable record in operational service.

What are cryogenic engines and what is the CE-20?

A cryogenic engine burns propellants stored at extremely low temperatures, usually liquid hydrogen as fuel and liquid oxygen as oxidiser, and the CE-20 is India’s indigenous engine of this kind for the LVM3. Hydrogen becomes liquid only at around minus 253 degrees Celsius and oxygen at around minus 183 degrees Celsius, which makes the engines technically difficult to build.

The advantage of cryogenic propulsion is efficiency. Liquid hydrogen and liquid oxygen produce more thrust for every kilogram of propellant than storable propellants, which allows heavier satellites to be lifted to geostationary transfer orbit. For this reason the cryogenic upper stage is central to India’s ability to launch communication satellites on its own rockets.

From Russian supply to Indian engines

India’s first cryogenic stages, flown on early GSLV missions, used imported Russian engines. After international restrictions blocked further technology transfer in the 1990s, ISRO decided to develop its own. The result was the CE-7.5 engine, which has a thrust of about 7.5 tonnes and flew successfully on the GSLV-D5 mission in January 2014.

The CE-20

The CE-20 is a larger engine with about 20 tonnes of thrust, and it powers the C25 cryogenic upper stage of the LVM3. It uses a gas-generator cycle and has been qualified through extensive ground tests. It first flew in 2017 and has since been used on operational LVM3 missions, including the Chandrayaan-3 launch in July 2023.

What is the SCE-200 semi-cryogenic engine?

The SCE-200 is a semi-cryogenic rocket engine under development at the Liquid Propulsion Systems Centre that burns liquid oxygen with refined kerosene and delivers about 200 tonnes of thrust. It is called semi-cryogenic because only the oxidiser, liquid oxygen, is stored at cryogenic temperatures, while kerosene remains a normal liquid.

The engine is intended to replace the Vikas-powered core stage of future vehicles. Kerosene is denser and cheaper than hydrogen and is easier to handle than UDMH, and a single SCE-200 produces roughly the thrust of several Vikas engines. This should allow a more powerful and economical launcher, and it is also planned for a next-generation launch vehicle that ISRO has discussed publicly. Long-duration tests and integration of the stage are carried out at the Mahendragiri complex.

How does LPSC support satellites and spacecraft?

The Liquid Propulsion Systems Centre supports satellites by supplying the thrusters and tanks that raise their orbit, hold their position and control their orientation. These systems are less visible than rocket engines but are essential to every mission.

• Liquid apogee motors (LAM): bipropellant engines, with a thrust of about 440 newtons, which fire to lift a satellite from its transfer orbit to its final geostationary orbit.
• Reaction control thrusters: small thrusters with a thrust level of around 22 newtons or 1 newton that adjust attitude and keep satellites on station.
• Monopropellant and bipropellant systems: fuel tanks, pressurant tanks, lines and valves, designed to be light and leak-tight.
• Electric propulsion: LPSC has developed plasma thrusters in which electricity ionises a gas such as xenon, giving very high efficiency for long satellite lifetimes.

The Bengaluru campus produces these systems for a wide range of Indian communication, remote-sensing and navigation satellites.

What role did LPSC play in Chandrayaan and Gaganyaan?

The Liquid Propulsion Systems Centre supplied key propulsion hardware for the Chandrayaan lunar missions and is developing propulsion for the Gaganyaan human spaceflight programme. In each case, the work involved engines that must operate reliably far from Earth.

For the Chandrayaan lander, LPSC developed throttleable engines. Throttling allows the thrust to be varied during descent so that the lander can slow down smoothly and touch down gently; the Chandrayaan-3 lander soft-landed near the lunar south pole on 23 August 2023. The propulsion module, which carried the lander to lunar orbit, also used LPSC-built systems.

For Gaganyaan, the centre is responsible for the propulsion of the service module of the crew vehicle, which handles orbital manoeuvres, and for related thrusters and abort systems. Human-rated systems must meet stricter reliability standards than those for uncrewed missions.

How does LPSC compare with other ISRO propulsion units?

The Liquid Propulsion Systems Centre handles liquid propulsion, whereas other ISRO units cover solid motors, testing and launch operations. Showing the division of labour clarifies how a rocket takes shape.

The PSLV is a good example. Its first and third stages are solid motors, the second stage uses LPSC’s Vikas engine, and the fourth stage is a liquid system with small engines, again from LPSC. The PSLV is thus a hybrid of solid and liquid technology.

Why does the Liquid Propulsion Systems Centre matter?

The Liquid Propulsion Systems Centre matters because self-reliance in liquid propulsion is the foundation of India’s ability to launch heavy satellites, deep-space probes and crewed missions without foreign engines. Cryogenic technology was long restricted in the global market, so its indigenous mastery was a major strategic achievement.

The centre’s work also supports India’s commercial launch capability. Through NewSpace India Limited, the commercial arm of the space department, LVM3 launches of foreign constellation satellites have been sold. Each of these missions relies on LPSC engines. Looking ahead, higher-thrust semi-cryogenic engines and reusable technologies are among the priority areas for the centre.

What challenges does liquid propulsion development face?

Liquid propulsion development faces demanding engineering challenges because the engines combine extreme temperatures, high pressures and fast-spinning machinery in a very small, lightweight package. The Liquid Propulsion Systems Centre has to solve several such problems for every new engine.

• Turbopump design: pumps must deliver propellant at very high pressure while spinning at tens of thousands of revolutions per minute, and a single bearing or seal failure can destroy an engine.
• Combustion stability: oscillations in the combustion chamber can grow rapidly, so injector design and chamber geometry need careful testing.
• Materials: alloys must withstand both intense heat in the chamber and the extreme cold of liquid hydrogen, and they must be welded and machined to fine tolerances.
• Cryogenic handling: insulation, valves and seals have to work reliably at temperatures far below freezing, and propellant boil-off must be controlled during launch preparation.
• Qualification testing: each engine undergoes many ground firings, including long-duration runs that exceed the flight burn time, before it is cleared for flight.

Because failures during development are expensive, the centre relies heavily on computer simulation, subscale tests and incremental qualification. Industry partners also contribute, since many components such as tanks, valves and machined parts are fabricated by Indian private and public sector firms under LPSC’s specifications.

Bottom Line

The Liquid Propulsion Systems Centre is where India’s liquid rocket engines and satellite thrusters are designed. From the Vikas engine to the CE-20 and the emerging SCE-200, its work underpins most of the nation’s launches and deep-space ambitions. Last reviewed: 17 October 2026.

Frequently Asked Questions

What does the Liquid Propulsion Systems Centre do?

The Liquid Propulsion Systems Centre (LPSC) designs and develops liquid, semi-cryogenic and cryogenic propulsion systems for ISRO. This includes launch vehicle engines and stages as well as satellite thrusters, tanks and valves. It is headquartered at Valiamala near Thiruvananthapuram.

Where is LPSC located?

LPSC has its headquarters at Valiamala, Thiruvananthapuram, in Kerala, with another major campus in Bengaluru. Engine testing is performed at the ISRO Propulsion Complex at Mahendragiri in Tamil Nadu. The Bengaluru unit focuses mainly on spacecraft propulsion.

What is the Vikas engine?

The Vikas engine is a liquid-propellant rocket engine developed by LPSC that burns UDMH fuel with nitrogen tetroxide oxidiser. It is based on a French design that India acquired under a technology agreement in the 1970s and then improved. It powers the PSLV second stage and the LVM3 core stage.

What is the difference between the CE-7.5 and the CE-20?

Both are Indian cryogenic engines that burn liquid hydrogen and liquid oxygen, but the CE-20 is larger. The CE-7.5, with about 7.5 tonnes of thrust, flies on the GSLV Mk II, while the CE-20, with about 20 tonnes, powers the upper stage of the LVM3. The CE-7.5 first flew successfully in January 2014.

What is a semi-cryogenic engine?

A semi-cryogenic engine uses a cryogenic oxidiser, liquid oxygen, together with a non-cryogenic fuel such as refined kerosene. LPSC’s SCE-200 is such an engine, designed for about 200 tonnes of thrust. It is intended to power more capable future Indian launch vehicles.

Did LPSC help with Chandrayaan-3?

Yes, LPSC supplied propulsion systems used on Chandrayaan-3, including throttleable engines for the lander. The cryogenic upper stage of the LVM3 rocket that launched the mission also used the LPSC-developed CE-20 engine. The lander touched down near the Moon’s south pole on 23 August 2023.

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