The procedure and potential issues associated with the death of an astronaut during space travel. The course of action varies depending on where the death occurs; for instance, if someone dies in low-Earth-orbit or on the Moon, the body can be returned to Earth relatively quickly. However, if death occurs during a mission to Mars, the situation becomes more complex due to the extended return time, and the body would have to be preserved for the duration of the mission.
  

Key Points: 

1. Space travel’s inherent risks make the question of astronaut death necessary to consider as missions to the Moon and Mars are planned.
2. NASA has protocols in place if an astronaut dies on a low-Earth-orbit mission or on the Moon, allowing for the relatively quick return of the body to Earth.
3. Death on a Mars mission would pose unique challenges, with the body likely having to be preserved for the couple of years remaining in the mission due to the inability to immediately return to Earth.
4. In the event of a death on Mars, cremation would not be feasible due to the energy requirements, and burial could potentially contaminate the Martian surface. Hence, the body would be preserved until it could be returned to Earth.
5. Aside from handling the body, protocols must also include measures to help the remaining crew members and the deceased astronaut’s family on Earth cope with the loss.

Source: https://theconversation.com/what-happens-if-someone-dies-in-space-193071