Semi-Cryogenic Engine

The Indian Space Research Organisation (ISRO) recently successfully conducted the hot test known as the Power Head Test Article (PHTA) on a semi-cryogenic engine (SE2000).

About Power Head Test Article (PHTA)

The Power Head Test Article (PHTA) is a crucial precursor test for the semi-cryogenic engine (SE2000) development.
It helps validate the integrated performance of key subsystems, including the gas generator, turbo pumps, pre-burner, and control components.
The test involved a hot firing for 4.5 seconds to assess the engine’s functionality.
The first successful test follows a previous failed attempt in July 2023 due to a technical issue.
PHTA plays a key role in the development of ISRO’s next-generation launch vehicles for future space missions.

About Semi-Cryogenic Engine and Its Significance

Semi-Cryogenic Engine

A semi-cryogenic engine uses a Liquid Oxygen (LOX) and kerosene (RP-1) combination as propellants.
It offers higher thrust (2,000 kN) compared to conventional cryogenic engines giving it its name SE2000.
The use of kerosene makes it more storable, cost-effective, and less complex than fully cryogenic engines.
It has a higher thrust-to-weight ratio due to the higher density of kerosene, requiring smaller fuel tanks.

Significance of the SE2000

These engines are suitable for first-stage boosters in heavy-lift launch vehicles, including ISRO’s upcoming Next Generation Launch Vehicle (NGLV).
The development of semi-cryogenic propulsion systems will enhance India’s capability in cost-effective and efficient space launches.

Difference Between Cryogenic and Semi-Cryogenic Engines

Feature	Cryogenic Engine	Semi-Cryogenic Engine
Propellant Used	Uses Liquid Hydrogen (LH2) as fuel and Liquid Oxygen (LOX) as an oxidizer.	Uses Kerosene (RP-1) as fuel and Liquid Oxygen (LOX) as an oxidizer.
Temperature Requirement	Operates at extremely low temperatures, with LH2 stored at -253°C.	Requires moderate cooling, with LOX stored at -183°C, while kerosene is stored at room temperature.
Thrust Generation	Provides high thrust but requires large fuel tanks due to the low density of hydrogen.	Offers a higher thrust-to-weight ratio as kerosene is denser, requiring smaller fuel tanks.
Complexity	Very complex due to extreme cooling requirements and handling of highly volatile liquid hydrogen.	Less complex as kerosene is easier to store and handle.
Usage	Used in upper stages of heavy-lift launch vehicles (e.g., GSLV, LVM3).	Suitable for first-stage boosters in heavy-lift launch vehicles (e.g., NGLV).
Efficiency	Very high efficiency due to the high specific impulse of Liquid Hydrogen.	Slightly lower efficiency than cryogenic engines but better than conventional solid or liquid engines.

Also Read
UPSC Daily Editorials	UPSC Daily Current Affairs
Daily Current Affairs Quiz	Daily Main Answer Writing
Check Out Previous Years Papers From PW Store	UPSC Test Series
Check Out UPSC NCERT Textbooks From PW Store	Check Out UPSC Modules From PW Store