ISRO Demonstrates Bootstrap Mode Start on CE20 Cryogenic Engine
Context
ISRO successfully demonstrated the bootstrap mode start test on the CE20 cryogenic engine.
The CE20 engine powers the upper stage of the LAUNCH VEHICLE MARK-3 (LVM3).
Test conducted on November 7 at the High-Altitude Test (HAT) facility, ISRO Propulsion Complex, Mahendragiri.
Test duration: 10 seconds under vacuum conditions.
Significance of the Test
Crucial milestone toward achieving multiple in-flight restarts of the CE20 engine.
Enhances mission flexibility, especially for:
Multi-orbit insertion missions
Complex satellite deployments
Deep-space or human-spaceflight–related missions
Current CE20 Engine Capabilities
Already qualified for:
Thrust levels between 19 to 22 tonnes.
Single-start operation during flight.
Use in GAGANYAAN missions.
Present ignition sequence:
Ignition initiated under tank-head conditions.
Turbo-pumps start using a stored-gas start-up system.
Limitation of Current System
For every restart, the engine needs:
An additional start-up gas bottle
Extra plumbing and support systems
Adds mass, complexity, and limits number of restarts.
What is Bootstrap Mode Start?
Bootstrap mode start allows the engine to:
Start and build up to steady-state operation without any external start-up assistance.
Use internal performance of the engine to spin up turbo-pumps and stabilize combustion.
Once mastered, this mode:
Eliminates need for multiple start-up gas bottles
Enables multi-restart capability
Increases efficiency of upper-stage missions
Why Multi-Restart Capability Matters
Essential for:
Multi-orbit deployments
Missions requiring precise orbital insertion
Interplanetary trajectories needing course corrections
Future human-spaceflight manoeuvres
Payloads requiring phasing or orbit-raising steps
Prelims Practice MCQs
Q. Which of the following engines recently achieved a successful bootstrap mode start test under vacuum conditions at ISRO’s High-Altitude Test facility?
[A] CE7.5
[B] CE20
[C] VIKAS
[D] SCE200
Correct Answer: [B] CE20
Explanation:
ISRO demonstrated the bootstrap mode start on the CE20 cryogenic engine, used in the LVM3 upper stage.
Q. The CE20 cryogenic engine is used in which of the following launch vehicles?
[A] PSLV
[B] GSLV-F10
[C] LVM3
[D] SSLV
Correct Answer: [C] LVM3
Explanation:
The CE20 engine powers the upper stage of LAUNCH VEHICLE MARK-3 (LVM3).
Q. What is the main benefit of the bootstrap mode start demonstrated on the CE20 engine?
[A] It increases engine thrust beyond 30 tonnes
[B] It enables multiple in-flight restarts without external start-up assistance
[C] It reduces cryogenic fuel temperature to increase efficiency
[D] It allows reuse of the LVM3 upper stage
Correct Answer: [B]
Explanation:
Bootstrap start lets the engine reach stable operation without external stored-gas systems, enabling multi-restart capability.