How Astronauts Survive in Space: Life Support Systems Explained
An astronaut in a spacesuit orbiting Earth faces four immediate threats: the vacuum of space (zero pressure, instant death in seconds without suit), extreme temperature swings (−150°C in shadow, 150°C in sunlight), intense radiation (solar wind, cosmic rays), and hypoxia (lack of oxygen). The Environmental Control and Life Support System (ECLSS) on spacecraft manages all four through oxygen generation, carbon dioxide removal, water recycling, temperature regulation, and pressure maintenance. The International Space Station recycles 90 percent of water and generates oxygen through electrolysis. Deep-space missions to Mars will require even more sophisticated recycling: current ECLSS efficiency is insufficient for 2-year Mars transit. This article examines how astronauts survive in space, the engineering of life support, and the challenges of keeping humans alive in the harshest environment.