Space Suits and Human Survival in Outer Space

Space is a hostile environment without air or atmospheric pressure. This absence creates severe challenges for human survival. Recent space missions, including India’s Gaganyaan, show the importance of specialised suits that protect astronauts from vacuum and extreme conditions.

Atmospheric Pressure and Its Importance

Earth’s atmosphere is a thick layer of gases held by gravity. It protects life by blocking harmful radiation, stabilising temperature, and providing breathable air. Atmospheric pressure presses on the human body with about 20 tonnes of force. Our bodies counterbalance this pressure, so we do not feel it. As altitude increases, atmospheric pressure drops. In space, there is near vacuum with no pressure, making it deadly for humans.

Effects of Vacuum on the Human Body

Sudden exposure to vacuum causes rapid boiling of bodily fluids (ebullism), decompression, and lack of oxygen (hypoxia). Gases in lungs and tissues expand quickly, leading to unconsciousness within seconds and death in minutes. Without protection, humans cannot survive even brief exposure to space.

Types of Space Suits

Astronauts wear two main types of suits. Extra-vehicular activity (EVA) suits are for outside spacecraft work. They have 12-14 layers and act as personal spacecraft. EVA suits protect against vacuum, radiation, extreme temperatures, and debris. They weigh 100-130 kg. Intra-vehicular activity (IVA) suits are worn inside spacecraft. They include flight suits for fire and environmental protection and pressure suits that provide full-body pressurisation, oxygen, and thermal regulation. Pressure suits weigh 8-10 kg and have fewer layers than EVA suits.

Historical Incidents and Safety Improvements

In 1961, Yuri Gagarin wore an IVA suit called SK-1 during his historic spaceflight. The Soviet Union and the USA developed several IVA suit designs over time. A tragic event occurred in 1971 during Soyuz 11 when three cosmonauts died due to cabin depressurisation. This incident led to mandatory use of IVA suits during launch and re-entry to protect against pressure loss, high G-forces, heat, and vibrations.

India’s Gaganyaan Mission and Suit Technology

India’s Gaganyaan mission uses the Russian Sokol KV2 IVA suit. This suit has two layers – an inner airtight rubberised polycaprolactam bladder and an outer white nylon canvas restraint layer. The Sokol suit has been used in over 128 Soyuz missions. It represents India’s strategy of combining global expertise with ambitions for indigenous human spaceflight capability.

Questions for UPSC:

1. Point out the significance of atmospheric pressure for human survival and explain the physiological effects of its sudden loss in space.
2. Critically analyse the evolution of space suit technology and its role in ensuring astronaut safety during different mission phases.
3. Estimate the challenges faced by human spaceflight missions in terms of environmental hazards and how international cooperation has addressed these.
4. With suitable examples, underline the impact of space exploration on technological advancements and their applications on Earth.

Answer Hints:

1. Point out the significance of atmospheric pressure for human survival and explain the physiological effects of its sudden loss in space.

1. Atmospheric pressure maintains bodily fluid balance and supports normal physiological functions on Earth.
2. It protects from harmful solar radiation and stabilises temperature, enabling life-supporting conditions.
3. Sudden loss of pressure (vacuum exposure) causes ebullism – boiling of bodily fluids at low pressure.
4. Rapid decompression leads to expansion of gases in lungs and tissues, causing tissue damage and hypoxia.
5. Loss of oxygen supply results in unconsciousness within seconds and death in minutes without protection.
6. Human bodies evolved to balance Earth’s atmospheric pressure; loss disrupts this equilibrium critically.

2. Critically analyse the evolution of space suit technology and its role in ensuring astronaut safety during different mission phases.

1. Early IVA suits like Yuri Gagarin’s SK-1 provided basic pressurisation and protection inside spacecraft.
2. EVA suits evolved into complex multi-layered garments (12-14 layers) acting as personal spacecraft for external spacewalks.
3. IVA suits include flight suits for fire and temperature protection and pressure suits for low-pressure environments.
4. Post-Soyuz 11 disaster, IVA suits became mandatory during launch and re-entry to protect against sudden depressurisation and G-forces.
5. Modern suits provide oxygen supply, thermal regulation, radiation shielding, and micrometeoroid protection.
6. Weight and mobility improvements balance protection with astronaut comfort and mission efficiency.

3. Estimate the challenges faced by human spaceflight missions in terms of environmental hazards and how international cooperation has addressed these.

1. Space environment is hostile – vacuum, extreme temperatures, radiation, and micrometeoroid impacts threaten human survival.
2. Sudden loss of cabin pressure and high G-forces during launch/re-entry pose critical risks.
3. Technological complexity requires advanced life-support and protective systems like space suits and pressurised cabins.
4. International collaboration (e.g., use of Russian Sokol suits by India) shares expertise and enhances mission safety.
5. Joint missions and shared research accelerate development of safer, more reliable space technologies.
6. Global standards and protocols (e.g., mandatory IVA suits) improve astronaut safety worldwide.

4. With suitable examples, underline the impact of space exploration on technological advancements and their applications on Earth.

1. Space suit technology has advanced materials science, influencing protective clothing and medical devices on Earth.
2. Life-support systems developed for space aid in medical ventilators and oxygen supply technologies.
3. Satellite technology from space exploration revolutionised global communication, weather forecasting, and navigation (GPS).
4. Thermal regulation and insulation techniques from space suits inform building and textile industries.
5. International space missions encourage global scientific cooperation and innovation spillovers benefiting multiple sectors.
6. Examples – NASA’s memory foam, water purification tech, and robotics developed for space are now widely used terrestrially.