Science & TechnologyImportant2025-04-24

ISRO Successfully Tests Semicryogenic Engine At IPRC

Q: Which of the following statements is/are correct regarding ISRO's Semicryogenic Engine (SCE-200)? 1. It uses liquid hydrogen as fuel and liquid oxygen as the oxidizer. 2. It is designed to replace the core liquid stage of the Launch Vehicle Mark-3 (LVM3) to enhance its payload capacity.

2 only — Statement 1 is incorrect because the semi-cryogenic engine uses Isrosene (refined kerosene) as fuel, not liquid hydrogen (which is used in fully cryogenic engines). Statement 2 is correct as the SCE-200 will replace the L110 core liquid stage of the LVM3 rocket.

Why focus: Fact-dense Sci-Tech update; 'Isrosene' vs hypergolic fuels comparison is prime material for GS3 Space tech Assertion-Reason formats.

In News

What Happened

On April 24, 2025, ISRO successfully conducted a short-duration hot test of its Semicryogenic Engine at the ISRO Propulsion Complex (IPRC) in Mahendragiri, Tamil Nadu. The engine, known as SCE-200, uses a combination of liquid oxygen and 'Isrosene', a specially refined space-grade kerosene. This test is a critical milestone in validating the engine's start-up sequence and overall performance.

Why It Matters

The development of a semi-cryogenic engine is crucial for India's heavy-lift space missions. By replacing the current core stage of the Launch Vehicle Mark-3 (LVM3), this new engine will increase the rocket's payload capacity to the Geostationary Transfer Orbit (GTO) from 4 tonnes to over 5 tonnes, significantly reducing India's reliance on foreign spaceports for launching heavy satellites.

Background

History & Context

ISRO's journey toward semi-cryogenic technology began more than a decade ago, with the government approving the project in December 2008 at an estimated cost of Rs 1,798 crore. Designed by the Liquid Propulsion Systems Centre (LPSC), the SCE-200 project aims to develop an oxidizer-rich staged combustion cycle engine. The technology bridges the gap between traditional solid/liquid hypergolic stages and complex cryogenic stages, offering a balance of high thrust, cost-effectiveness, and ease of storage.

What Changed

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Propellant Type: BEFORE, the LVM3 core stage (L110) used two Vikas engines relying on toxic hypergolic fuels (UH25 and N2O4). NOW, the engine uses Isrosene and Liquid Oxygen, which are eco-friendly and cheaper.
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Payload Capacity: BEFORE, the LVM3 could carry approximately 4 tonnes to GTO. NOW, the integration of the semi-cryogenic stage (SC120) is expected to increase the payload capacity to over 5 tonnes.
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Engine Configuration: BEFORE, the core stage required a cluster of two Vikas engines to achieve necessary thrust. NOW, a single 2000 kN SCE-200 engine will replace them, offering more thrust from a single powerhead.

Prelims Angle

NCERT Connection

This relates to Class 11 Physics Chapter 5 - 'Laws of Motion', specifically the principles of rocket propulsion based on Newton's Third Law of Motion and the law of conservation of momentum. The engine's 'Specific Impulse' measures how efficiently it converts propellant mass into thrust, demonstrating how optimizing fuel types (like Isrosene) improves the momentum imparted to the launch vehicle.

Practice Questions

Q1

Correct Statement(s)

Which of the following statements is/are correct regarding ISRO's Semicryogenic Engine (SCE-200)? 1. It uses liquid hydrogen as fuel and liquid oxygen as the oxidizer. 2. It is designed to replace the core liquid stage of the Launch Vehicle Mark-3 (LVM3) to enhance its payload capacity.

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