ISRO has successfully demonstrated the bootstrap mode start test on the CE20 cryogenic engine, which powers the upper stage of the Launch Vehicle Mark-3 (LVM3).

• The test duration was 10 seconds, conducted under vacuum conditions at the High-Altitude Test (HAT) facility.

Strategic Significance of the Test

• The Test enables multiple in-flight engine restarts, essential for placing satellites into different orbits in a single mission.
• It increases India’s competitiveness in the global commercial launch market.
• The test strengthens preparedness for Gaganyaan and future deep-space missions.
• It also reduces dependence on external technologies, advancing Atmanirbhar Bharat in high-end space propulsion.

About Cryogenic Engine 

• A cryogenic engine is a type of rocket engine that uses super-cooled liquid propellants, typically Liquid Oxygen (LOX) (at -183°C) and Liquid Hydrogen (LH₂) (at – 253°C), stored at extremely low temperatures.

• CE-20 Cryogenic Engine: The CE-20 is India’s most powerful cryogenic rocket engine, developed by ISRO, and it powers the cryogenic upper stage of the LVM3 (GSLV Mk-III) launch vehicle.
• Development: The CE20 engine has been developed by the Liquid Propulsion Systems Centre (LPSC), Valiamala, Kerala.
• Mission Performance: The engine has proven its reliability by operating successfully in six consecutive LVM3 launches, including landmark missions such as Chandrayaan-2, Chandrayaan-3, and two commercial OneWeb satellite missions.
• Current Capabilities: Qualified for thrust levels of 19–22 tonnes with a single start, using a stored gas start-up system.
• Limitations of Current Start System:
  • Each in-flight restart currently requires additional start-up gas bottles and systems which leads to increased structural weight.
  • Additional hardware reduces vehicle payload capacity.

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About Launch Vehicle Mark-3 (LVM3)

• Overview: LVM3, nicknamed “Bahubali”, is India’s most powerful operational rocket, developed by ISRO for launching heavy communication satellites and interplanetary missions.
• Formerly Known As: Geosynchronous Satellite Launch Vehicle Mark-III (GSLV Mk-III).
• Capability: Designed to carry communication, navigation, and deep-space missions (like Chandrayaan & Gaganyaan).
• Type: Three-stage rocket using solid, liquid, and cryogenic fuel engines.
• Stages:
  • Stage 1 – Solid Propellant – Two large strap-on boosters for liftoff
  • Stage 2 – Liquid Propellant – Provides initial thrust after boosters separate
  • Stage 3 – Cryogenic (Liquid Hydrogen + Liquid Oxygen) – Final stage which injects satellite into orbit
• Payload Capacity:
  • Up to 8,000 kg to Low Earth Orbit (LEO) (~2,000 km altitude).
  • Up to 4,000 kg to Geosynchronous Orbit (GEO) (~36,000 km altitude).
• Major Achievements:
  • Successfully launched Chandrayaan-2 (2019) and Chandrayaan-3 (2023).
  • Conducted Crew Module Atmospheric Re-entry Test (2014) — key for Gaganyaan.
  • Carried out OneWeb missions (2022–23) to LEO after the Russia–Ukraine war halted OneWeb’s international launch options.
• Rebranding: Renamed as LVM3 after demonstrating versatility beyond GEO missions (e.g., 5,700 kg payload for OneWeb to 450 km orbit).

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