Major milestone for India’s cryogenic technology
ISRO advances CE20 cryogenic engine with boot-strap mode start test: The CE20 cryogenic engine underwent a successful boot-strap mode start test under vacuum conditions. This new start sequence did not require the traditional auxiliary start-up gas bottle.
This breakthrough supports in-flight restart capability, which enhances mission flexibility for future LVM3 launch operations and crewed missions.
What boot-strap mode start means
Boot-strap start enables the cryogenic engine to ignite using only its internal propellants and system pressure.
Eliminating external start systems reduces weight and increases payload capacity.
It allows multiple re-starts in space for orbital changes, satellite deployment sequences, and human-spaceflight safety.
Cryogenic engine fundamentals
Cryogenics deals with the behavior of materials at extremely low temperatures below –150°C.
Cryogenic engines use Liquid Hydrogen (LH₂) as fuel and Liquid Oxygen (LOX) as oxidizer.
They offer higher specific impulse, meaning more thrust for every kilogram of propellant compared to solid or earth-storable liquid propellants.
Static GK fact: Hydrogen remains the lightest and most efficient rocket fuel ever used in space launch vehicles.
CE20 engine profile
The CE20 is India’s largest cryogenic engine developed by the Liquid Propulsion Systems Centre (LPSC) at Valiamala, Kerala.
It powers the C-25 cryogenic stage of the LVM3.
Static GK fact: CE20 is capable of generating around 200 kN (20-tonne-class) thrust in vacuum.
It has been qualified for human-rated missions, including the ambitious Gaganyaan programme.
Importance for LVM3
The LVM3, also known as Launch Vehicle Mark-III, is India’s heavy-lift launch vehicle.
It consists of three stages:
- Two S200 solid strap-ons
- One L110 liquid core stage powered by twin Vikas engines
- One C25 cryogenic upper stage powered by CE20
This configuration enables 4-tonne payload delivery to GTO (Geosynchronous Transfer Orbit).
Static GK fact: LVM3 launched India’s lunar lander Chandrayaan-3 in 2023.
Mission flexibility and future use
With the new start technique, multiple orbital deployments in a single mission become easier.
It improves safety redundancy for crew module re-orbiting during Gaganyaan flights.
It also supports commercial satellite launches demanding precise orbital insertions.
This advancement helps India move closer to reusable launch vehicle ambitions and advanced interplanetary missions.
India’s strengthening space leadership
The successful test places India among the limited global group capable of restartable cryogenic technology.
The achievement expands launch service competitiveness, boosts national capability in satellite outreach, and strengthens future human-space exploration.
Static Usthadian Current Affairs Table
ISRO advances CE20 cryogenic engine with boot-strap mode start test:
| Topic | Detail |
| Engine tested | CE20 cryogenic engine |
| Achievement | Boot-strap mode start under vacuum |
| Key benefit | Restart capability without auxiliary systems |
| Launch vehicle | LVM3 (Launch Vehicle Mark-III) |
| Propellants used | Liquid Hydrogen and Liquid Oxygen |
| Temperature domain | Below –150°C (cryogenic range) |
| CE20 development centre | Liquid Propulsion Systems Centre, Kerala |
| Mission relevance | Gaganyaan and multi-orbit satellite deployment |
| Upper stage using CE20 | C-25 cryogenic stage |
| Payload impact | Higher payload capacity due to system mass reduction |
