ISRO tests bootstrap mode start on CE20 cryogenic engine, Pg12

Key Highlights:

• ISRO successfully tested the bootstrap mode start on the CE20 cryogenic engine on November 7.
• The test was conducted in vacuum conditions at the High-Altitude Test (HAT) facility, Mahendragiri, for 10 seconds.
• The CE20 engine powers the upper stage of the Launch Vehicle Mark-3 (LVM3) rocket.
• This advancement enhances the restart capability and mission flexibility of future LVM3 flights.

Detailed Insights:

• The CE20 cryogenic engine is already qualified for operation at thrust levels ranging from 19 to 22 tonnes in flight with a single start, including for Gaganyaan missions.
• Currently, engine ignition is initiated under tank head conditions, followed by the start of turbo pumps using a stored gas start-up system.
• Future missions will require multiple in-flight restarts of the CE20 engine for flexible multi-orbit missions.
• Achieving bootstrap mode start is essential as it allows the engine to build up to steady operation without external start-up assistance, reducing the need for additional start-up gas bottles.

Scientific/Technical Concepts Involved:

• Cryogenic Engine: A rocket engine that uses cryogenic fuels, which are liquefied gases stored at extremely low temperatures.
• Bootstrap Mode Start: Engine start-up without external assistance, relying on self-generated processes to reach stable operation.
• Turbo Pumps: Pumps used to deliver fuel and oxidizer to the engine at high pressure.