How Long Could You Survive in Space?

How Long Could You Survive in Space? A person who ended up in outer space without any protection would probably lose consciousness in as little as 10 to 15 seconds, and death would follow without rapid repressurization. The only thing standing between an astronaut and this lethal environment is a spacesuit, a wearable life-support system often described as a personal spacecraft. In a functioning ISS spacesuit, survival would generally be limited to about six to eight hours, with roughly 30 minutes of emergency oxygen available after certain failures. Specialized survival suits can support astronauts for several days inside a spacecraft, but they cannot provide that endurance independently in open space. But even these remarkable technologies have limits. So, if an astronaut became stranded in space, it's worth wondering how long they would survive, and it's not for as long as you might think. Astronauts are on somewhat of a timer.