Advancements in Indian Space Technology: ISRO's Semicryogenic Engine Test

ISRO's Recent Milestone in Engine Development

The Indian Space Research Organisation (ISRO) has achieved a significant milestone by successfully conducting a hot test of a semicryogenic engine component, known as the Power Head Test Article (PHTA), at its Propulsion Complex in Mahendragiri, Tamil Nadu. This innovative engine employs a combination of liquid oxygen and kerosene, delivering an impressive thrust of 2,000 kN (kilonewtons), and is specifically designed to power the booster stage of the Launch Vehicle Mark-3 (LVM3).

Importance of the Test

This test is particularly crucial for several reasons:

• First Major Step: This marks ISRO's first successful hot test in its semicryogenic engine development programme.
• Strategic Milestone: It enhances India's capability in developing high-thrust engines that utilize more cost-effective and efficient fuels compared to traditional cryogenic engines.
• Technology Demonstration: The test successfully validated key components such as the pre-burner, turbo pumps, start system, and control mechanisms.

Details of the Hot Test

The hot test was carried out on March 28 and lasted for 2.5 seconds. The mode of the test involved hot firing, which utilized real-fuel combustion to observe the engine's actual behavior. The purpose was to verify the performance of critical subsystems in an integrated environment under real conditions. The outcome was promising, with smooth ignition and functioning observed, all engine parameters aligning with expectations.

Understanding Semicryogenic Engines

• Semicryogenic engines utilize liquid oxygen (cryogenic) and kerosene (at ambient temperature) as propellants.
• Unlike cryogenic engines that use liquid hydrogen, semicryogenic engines are easier to handle, more cost-effective, and can be stored for longer durations.
• These engines provide a high thrust-to-weight ratio, making them ideal for heavy-lift launch vehicles.

Benefits for India

The advancements in semicryogenic technology will provide numerous advantages:

• Boost to LVM3: The LVM3 will be equipped with a more powerful and efficient booster stage, enhancing its payload capacity to low Earth orbit (LEO) and geostationary transfer orbit (GTO).
• Indigenous Capability: This development reduces India's dependence on imported engines and fuels.
• Cost-Effective Launches: Kerosene is a cheaper and safer alternative to liquid hydrogen.
• Frequent Missions: The technology enables quicker turnaround for launches due to easier fuel handling.
• Commercial Launch Market: Strengthens India's position in offering affordable launch services on a global scale.

Future Steps

Following this successful test, ISRO plans to conduct a series of further tests aimed at:

• Fine-tuning the design and integration of the engine components.
• Improving the efficiency and reliability of the engine.
• Eventually moving towards the full-scale realization of the complete engine.

Understanding Kilonewtons

A kilonewton (kN) represents a unit of force commonly used in engineering, space science, and physics:

• Definition: 1 kilonewton equals 1,000 newtons (N), where 1 newton is the force required to accelerate a 1 kg mass by 1 meter per second squared (1 m/s²).
• In Simple Terms: On Earth, 1 kilonewton is approximately the force needed to lift a mass of about 100 kilograms.
• Use in Rockets: In the context of rocketry, thrust is measured in kilonewtons, where a higher number indicates greater thrust for lifting heavier payloads into space.
• Example from ISRO Test: The tested semicryogenic engine produces a remarkable thrust of 2,000 kN, sufficient to lift approximately 200 tonnes against Earth's gravity.