- Purpose: To counter the absence of atmospheric pressure in space that otherwise causes ebullism (boiling of body fluids), hypoxia, and tissue expansion.
- Function:
- Maintains internal body pressure.
- Supplies oxygen and removes CO₂.
- Provides thermal regulation and micrometeoroid protection.
- Prevents rapid decompression injuries.
Relevance:
GS 3 – Science & Technology (Space Technology)
• Human spaceflight safety systems – pressure, oxygen, and temperature regulation
• Gaganyaan mission and indigenous crew module development
• Collaboration with Russia (Sokol KV-2 suit technology)
• Physics behind decompression, Boyle’s law, and vacuum effects on human body
• Space suit design as application of materials and life-support engineering
Why is wearing IVA suits mandatory during ascent and descent?
- Ascent & Descent = Critical Phases
- Highest risk of cabin depressurisation, high G-forces, vibration, and thermal stress.
- In 1971, Soyuz 11 tragedy: A cabin vent valve opened prematurely at 168 km altitude → pressure loss → 3 cosmonauts suffocated.
- Post-Soyuz Safety Reform:
- Mandatory IVA (Intra-Vehicular Activity) suits during these phases.
- Serves as a personal life-support backup in emergencies.
Types of Suits:
| Type | Purpose | Key Features | Weight |
| EVA (Extra-Vehicular Activity) | Spacewalks / external repairs | Miniature spacecraft; 12–14 layers; protection from vacuum, radiation, micrometeoroids | 100–130 kg |
| IVA (Intra-Vehicular Activity) | Inside spacecraft; during launch/re-entry | Pressure maintenance, oxygen backup, temperature control | 8–10 kg |
Which IVA suit does Gaganyaan use?
- Model: Sokol KV-2 suit (Russian, by Zvezda).
- Features:
- Two layers:
- Inner pressure bladder: Rubberised polycaprolactam — airtight barrier.
- Outer restraint layer: White nylon canvas — mechanical strength.
- Heritage: Used in 128+ Soyuz missions.
- Functionality: Ensures survival in case of cabin pressure loss during launch/re-entry.
- Two layers:
- Significance: Symbolises India’s step in indigenous human spaceflight capability while leveraging international collaboration.
Key Concept — Atmospheric Pressure
- At sea level: ~1 atm (~101.3 kPa) = ~20 tonnes of force on human body.
- Human physiology is tuned to this pressure; any sudden drop (e.g., vacuum) leads to lethal decompression effects within seconds.
The Gist
- Earth’s atmosphere ensures pressure balance vital for life.
- In vacuum, body fluids boil and oxygen deprivation occurs instantly.
- Pressure suits = lifesaving interface between biology and vacuum.
- Gaganyaan adopts the globally proven Sokol KV-2 IVA suit for crew safety during critical mission phases.
