Space HubCryogenic Upper Stage (CE-20 & CE-7.5)
India's Indigenous High-Impulse Cryogenic Rocket Propulsion
ISRO's Cryogenic Engine (CE-20 and CE-7.5) powers the upper stages of LVM3 and GSLV Mk II heavy rockets. Utilizing liquid hydrogen (LH2) at -253°C as fuel and liquid oxygen (LOX) at -183°C as oxidizer, cryogenic engines yield the highest specific impulse (thrust efficiency) required for deep-space and heavy geostationary payload deployment.
Development History & Milestones
Following foreign technology transfer denials in the 1990s, ISRO's Liquid Propulsion Systems Centre (LPSC) embarked on the Cryogenic Upper Stage Project (CUSP). The indigenous CE-7.5 engine achieved its first operational success on GSLV-D5 in January 2014. The gas-generator cycle CE-20 engine was subsequently developed for LVM3.
Core Space Applications
- 1LVM3 cryogenic upper stage (C25) for Chandrayaan and Gaganyaan
- 2GSLV Mk II cryogenic upper stage (C12/C15) for GSAT communication satellites
- 3Interplanetary trajectory injection for Mars & Venus orbiters
Frequently Asked Questions
Why are cryogenic rocket engines difficult to build?
Cryogenic engines require handling liquid hydrogen at extremely low temperatures (-253°C), managing turbopumps rotating at 30,000+ RPM, and preventing thermal contraction leaks.
Which ISRO rockets use cryogenic engines?
ISRO's LVM3 uses the CE-20 cryogenic engine in its C25 stage, while GSLV Mk II uses the CE-7.5 engine in its C15 stage.