Semi Cryogenic Engine

• 14 May 2025

Source: ISRO 

Indian Space Research Organisation (ISRO) successfully conducted a short-duration hot test of its semi cryogenic engine at the ISRO Propulsion Complex (IPRC), Mahendragiri.  

• A short-duration hot test involves briefly firing the engine using actual fuel to verify its ignition and performance under real operating conditions. This test marks the 2nd milestone, following the first successful hot test conducted in March 2025. 
• Semi Cryogenic Engine: It is a liquid rocket engine that uses liquid oxygen (LOX) as an oxidizer and refined kerosene (RP-1) as fuel.  
  • Designed to power the booster stages of future heavy-lift launch vehicles, semi-cryogenic engine's LOX-kerosene combination offers higher density impulse than cryogenic systems, enhancing propulsion performance. 
  • Additionally, kerosene is cheaper and easier to handle than liquid hydrogen, reducing costs and simplifying operations. 
  • The successful development of this semi-cryogenic engine will boost ISRO’s payload capacity and support future launch vehicles like the  Next Generation Launch Vehicle (NGLV). 
• NGLV : It is a cost-efficient, reusable heavy-lift rocket being developed by ISRO, designed to carry up to 30 tonnes to Low Earth Orbit, with a reusable first stage. 
  • It features a 3-stage design with LOX engines for the first two stages and a cryogenic upper stage. 
  • NGLV aims to support communication satellite launches, deep space missions, and future human spaceflight and cargo missions. 

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