What would happen to your body if you got lost in space

Soyuz MS-22

Fear became reality for cosmonauts Sergey Prokopyev, Dmitri Petelin, and Frank Rubio, who were on a six-month space mission aboard the Soyuz MS-22 in 2022. They became stranded in orbit when the Soyuz MS-22 capsule was hit by a meteor and developed a leak.

Has anyone ever gotten lost in space?

Thankfully, there has never been an astronaut irretrievably stranded in space before. Bruce McCandless was the first astronaut to make an untethered spacewalk on February 7, 1984.

Deaths above the Kármán line

Most fatal accidents involving astronauts have occurred during launch, return to Earth, or other phases of space missions in the Earth atmosphere. There have only been three deaths that have happened in space above the Kármán line. 

Soyuz 11

 In 1971, Soviet cosmonauts Georgy Dobrovolsky, Viktor Patsayev, and Vladislav Volkov died when Soyuz 11 malfunctioned upon undocking from Salyut 1 while in space above the Kármán line. A valve opened, exposing them to space's vacuum and lack of oxygen. Their bodies were recovered from the spacecraft after landing.

Spacesuits

Spacesuits provide the astronaut's body with proper pressure, oxygen, and warmth. The oxygen tanks allow for a maximum of between 6.5 and 8.5 hours before they need refilling. 

How would you die if you weren't wearing a suit?

If an astronaut was lost in space with no way to return and wasn't wearing a spacesuit, death would occur within a minute, about 50 seconds after loss of consciousness.

The liquid in the body would boil

At lower pressures, liquids boil at much lower temperatures than on Earth. Since 60% of the human body is made up of water, this would have dire consequences for an astronaut lost in space.

Air in the lungs

All of the air would be sucked out of the lungs. While it might seem best to hold onto the remaining air as long as possible, it would quickly expand and cause the lungs to rupture.

How would your body decompose in space?

On Earth, decomposition after death begins almost immediately. Blood pools due to gravity in a process called livor mortis, the muscles stiffen in a process known as rigor mortis, and bacteria and enzymes begin to digest the body's soft tissues.

The body won't explode

Space movies often depict a body exploding due to the lack of pressure in a vacuum, but in a series of experiments conducted by NASA in the 1960s with dogs, chimpanzees, and squirrels, none of them exploded.

Hit by micrometeoroids

An astronaut lost in space could be struck by high-speed micrometeoroids—tiny particles of dust or rock—or by debris from satellites or spacecraft.

Would the body eventually leave the solar system?

If the body was sealed in a space suit, decomposition would only last for as long as the oxygen lasted. Ultimately, the body could drift in the endless expanse of the universe for millions of years.

What would happen if someone died on the International Space Station?

While there's no official protocol to handle a sudden death on the ISS, keeping the body inside a spacesuit somewhere cool eliminates the risk of a biohazard.