ISRO is preparing for its first human spaceflight mission, Gaganyaan, by implementing robust safety protocols across all mission phases. These draw from past global experiences like Apollo-1 and current best practices to ensure astronaut safety.
Overall Safety Strategy
- ISRO is drawing from global best practices, past incidents, and recent research to ensure astronaut safety.
- Safety is addressed across three phases: launch, orbit, and reentry — each with tailored protocols and systems.
Relevance : GS 3(Space ,Technology )
Launch Phase Safety
a) On the Launchpad
- Inspired by the 1967 Apollo-1 fire tragedy, ISRO has set up:
- Ziplines and fireproof bubble lift at SHAR (Sriharikota) to enable rapid crew evacuation.
b) During Lift-off
- Human-rated LVM3 (HLVM3) includes a Crew Escape System (CES):
- Tower-like structure above the crew module.
- In case of failure, CES detaches and pulls the crew module to safety using solid fuel motors.
- ISRO uses tractor-type CES (pulls the capsule); contrast: SpaceX uses pusher-type (pushes the capsule).
c) Abort Modes
- Low-altitude Escape Motor (LEM): activates shortly after ignition.
- High-altitude Escape Motor (HEM): kicks in later in flight.
- Pad abort mode: both LEM and HEM fire to distance crew rapidly from danger.
- Post-abort, crew module splashes down at sea at pre-designated recovery zones.
Orbit Phase Safety
a) Crew & Service Module Configuration
- Gaganyaan’s spacecraft has:
- Crew Module: living space for astronauts.
- Service Module: engines, fuel, life-support systems.
b) In-Orbit Emergency Protocols
- In case of malfunction, the service module’s propulsion and crew module’s thrusters can initiate controlled reentry.
- Though Gaganyaan won’t dock with ISS, astronauts are trained in docking protocols.
c) Docking & Space Station Safety (for future missions)
- Capsules used for docking serve as “lifeboats” in emergencies.
- Safe refuge zones exist within stations, with shielding against fires, debris impacts, and solar radiation.
- Redundancy in escape capsules ensures no astronaut is stranded (e.g., NASA’s spare docked capsules).
Reentry Phase Safety
a) Controlled Reentry
- Capsule fires thrusters to exit orbit and initiate descent.
- Reentry causes frictional heating up to 1,800º C.
- Ablative heat shields protect astronauts during descent.
b) Deceleration & Landing System
- Multi-phase parachute deployment ensures controlled descent:
- Apex cover separation parachutes deploy at 15.3 km.
- Drogue parachutes stabilize descent (to 70 m/s at 3 km).
- Three primary canopies reduce speed to 10–12 m/s.
- Retrograde thrusters and pyrotechnic release mechanisms assist in final touchdown and splashdown.
Case Studies & Historical Lessons Used by ISRO
- Apollo-1 (1967): Pad fire; led to modern launchpad safety upgrades.
- Soyuz T-10 (1983): Rocket fire before liftoff; CES saved crew.
- Blue Origin NS-23 (2022): In-flight engine failure; capsule escape system worked successfully.
Conclusion
- ISRO’s Gaganyaan mission is adopting a layered, redundancy-based safety approach.
- Every phase — launch, orbit, and reentry — has fail-safe mechanisms to protect astronauts.
- Learning from both historical tragedies and successful recoveries has been vital in shaping current protocols.
