Prelims: Current events of national and international importance | Science and Technology
Why in News?
The Gaganyaan Crew Module (CM) is an engineering masterpiece built to withstand the extreme, unforgiving environments of space launch, orbital flight, atmospheric re-entry, and ocean splashdown.
- The Indian Space Research Organisation (ISRO) successfully conducted 3 major qualification tests on the Crew Module systems to validate astronaut safety and system.
- Proven Subsystems
- The Crew Module Uprighting System (CMUS).
- The separation of the Crew-Service Umbilical mechanism (CSU-2).
- The structural integrity during the Apex Cover Separation.
The Architecture
- The outer shape of a spacecraft dictates how it behaves physically when hitting the atmosphere at orbital velocities.
- The Design Choice - A spherical capsule (like the Soviet Union's historical Vostok) offers the maximum internal volume for the minimum structural mass.
- However, it generates no aerodynamic lift, falling straight down and exposing astronauts to extreme, dangerous G-forces.
- A conical body provides high lift and aerodynamic stability for a controlled descent, but is less volume-efficient.
- The Gaganyaan Solution - ISRO selected a truncated sphere-cone configuration weighing approximately 5.3 tonnes.
The Survival Life-support Systems
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Subsystem
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Function & Mechanism
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Environmental Control & Life Support (ECLSS)
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- Maintains a highly conditioned, Earth-like atmosphere.
- It regulates oxygen supply, keeps cabin pressure at 0.8 atm, controls temperature at 20-26°C, and manages humidity between 30% and 70%.
- It is to prevent static discharge or microbial buildup.
- It also scrubs carbon dioxide and controls waste.
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Thermal Protection System (TPS)
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- Thermal shield on the module's exterior designed to safeguard the metallic pressure hull and the crew from re-entry heat loads exceeding thousands of degrees Celsius.
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Deceleration System
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- Consists of a highly redundant system utilizing 10 different parachutes.
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Crew Escape System (CES)
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- Acts as a high-speed "lifeboat".
- In case of a catastrophic booster failure on the launchpad or during ascent, 5 quick-firing solid fuel motors instantly pull the crew module away to safety.
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The Re-Entry & Recovery Capsule
- De-orbit & CSU-2 Separation - The Service Module fires its propulsion system to decelerate the vehicle.
- The Crew Module Umbilical (CSU-2) system executes a clean separation, detaching the Service Module, which burns up in the atmosphere while the Crew Module proceeds alone.
- Apex Cover Jettison- Before the main parachutes deploy, the protective apex cover is cleanly jettisoned.
- Parachute Deployment & Splashdown - The parachute sequence triggers, slowing the module down to terminal velocity before it splashes down in the ocean.
- Active Uprighting (CMUS)- Upon hitting the water, the module might land upside down.
- To prevent this, the Crew Module Uprighting System (CMUS) uses stored, high-pressure cold-gas to automatically inflate flotation devices, rotating the module back to an upright position to protect the crew and secure communication antennas.
Reference
The Hindu | Gaganyaan crew module
