Gaganyaan Crew Module

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
  1. The Crew Module Uprighting System (CMUS).
  2. The separation of the Crew-Service Umbilical mechanism (CSU-2).
  3. 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

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