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Astronaut Robert Stewart Floating Above Earth During a Mission in 1984. Photo: HUM Images
Space travel is associated with numerous challenges and harsh conditions, making it crucial to simulate Earth-like conditions for life to evolve and develop. The space suit enables astronauts to venture outside the spacecraft briefly by providing air, water, pressure, and protection for the body. What happens if humans don’t wear this advanced suit? How long can humans survive in the vacuum of space?
According to Stefaan de Mey, a strategic officer at the European Space Agency (ESA), within a very short time, about 10 to 15 seconds, humans would lose consciousness due to lack of oxygen. In the darkness of space, oxygen becomes a serious concern. “Oxygen begins to expand and rupture the lungs, causing them to burst, boil, and foam blood, immediately causing vascular obstruction and life-threatening effects on the body,” Mey explained.
Divers face a similar risk when water pressure decreases as they ascend from great depths. Prior to entering space without protective suits, one would need to exhale as much air from the lungs as possible. Complete absence of pressure also poses various life-threatening issues, though not immediate. The body fluids like saliva and tears would start to boil. The human body would swell, but the elastic skin can withstand pressure changes. In the best case, you would have a few seconds before running out of oxygen in the bloodstream, rendering you unconscious. As the situation cannot be altered, brain death will occur within a few minutes, unless you are rescued and brought back to the oxygen-rich environment of the spacecraft and revived.
Apart from providing vital oxygen and pressure regulation, the space suit also shields astronauts from various threats and hazards. “There are issues with temperature, radiation, and the threat of meteorites,” Mey explained. “Hence, the space suit is designed to protect the astronaut’s body in outer space.” Whether an astronaut is under the sun or in shadow, they will experience extreme temperatures, ranging from -150 to 120 degrees Celsius in low Earth orbit (LEO). These conditions can cause severe burns or intense cold.
The space suit also prevents exposure to various types of radiation. Prolonged exposure to electromagnetic radiation from the Sun in LEO can result in health issues such as radiation poisoning and an increased risk of cancer. Ultraviolet (UV) rays also cause skin burns. Furthermore, particles from solar storms reaching astronauts in outer space exacerbate the problem.
Near-Earth asteroids and space debris pose another threat. Moving at speeds of tens of kilometers per second, they threaten satellites, spacecraft, and spacewalk activities. While they have limited potential to impact human survival, multi-layered protective suits are designed to shield astronauts from any asteroids or space debris orbiting around Earth.