The water in their skin and blood would vaporize within about 10 seconds, causing their body to swell, resembling a balloon inflating with air, which would lead to the collapse of their lungs.
By the 30-second mark, paralysis would set in, ultimately leading to the astronaut's death.
The choice to hold one's breath would also make a difference in how quickly one perishes.
Opting to hold your breath would lead to death more quickly, as the air within your lungs would expand, rupture your lungs, and cause rapid death.
On the other hand, not holding your breath could prolong consciousness for up to two minutes.
In the vacuum of space, heat loss relies solely on fluid evaporation or radiation, especially for cooler entities like the human body. Over time, the body would transition into a frozen, mummified state, drifting through space for countless millennia until a potential encounter with another celestial body, where it could be destroyed by heat or radiation.
In the scenario of recovering a body, what would happen?
According to experts, if a death occurs on a brief mission to places like the ISS or the moon, the body is more likely to be brought back to Earth promptly.
However, for a Mars voyage, an immediate return might not be feasible due to the vast distance involved - millions of miles away.
In this case, the body could possibly be frozen in the cold of space to reduce its mass, facilitating storage for eventual return. Professors Christopher Newman and Nick Caplan from Northumbria University suggest this approach.
According to Professor Urquieta, preservation might require the use of a specialized body bag.
He said that cremation could be impractical on the Red Planet due to the fact that it 'requires too much energy, that the surviving crew needs for other purposes.'
Interment, too, remains unfeasible due to the potential for human remains to harbor bacteria and other microorganisms that could contaminate Mars.
NASA enforces stringent regulations to prevent the introduction of Earth microbes to other planets, as explained by Catherine Conley of NASA's Office of Planetary Protection.
Conley stated that all microbes must be eliminated, which could potentially reinstate cremation as an option. Nevertheless, the prevailing probability would involve preserving the deceased's body aboard the spacecraft until it could be brought back to Earth.
