Not the actual dying, but the postemergency after a life has been lost: What then? Is that an emergency? It may seem like an odd question, but it has important implications for astronauts.
The question of dying on orbit is one that we traditionally don't want to think about, but it opens a long line of questions such as, "What happens to a dead body in low Earth orbit?" Very little research has been done on this topic of space taphonomy [1], particularly regarding how long a body could wait to be returned or, possibly even more important, whether a corpse could survive the return.
Let's set a few assumptions since we know there is a big gap in our body of knowledge on the topic:
The body is contained and of no danger to the crew, and
the body must be returned to Earth as soon as possible.
These conditions set up two interesting scenarios to be considered:
Option (1) The body is returned alone via its space vehicle, and a replacement vehicle is sent up for the rest of the crew.
Option (2) The body and crew are returned via their space vehicle.
Looking at these two scenarios, until recently, option 1 would most likely have been ruled out because this would have left the remaining crew without a lifeboat. However, in mid-December 2022, the Russian Soyuz MS-22 that had docked at the International Space Station (ISS) started leaking coolant, possibly stranding astronauts Frank Rubio and cosmonauts Sergey Prokopyev and Dmitiri Petelin [2]. NASA and Roscosmos are treating this as a nonemergency and are evaluating ways in which the three passengers of MS-22 may get home.
The current risk is that, if there is an emergency on the ISS, Prokopyev, Petelin, and Rubio don't have a lifeboat. In November 2021, all seven crewmembers on the ISS were required to station in their lifeboats for a potential emergency return to Earth after the Russian military blew up one of their own satellites as a test [3].
This brings us back to my initial question: Is a death on orbit an emergency? Based on our initial condition, ie, that the body needed to be returned as soon as possible, prior to December 2022 it would most likely have been deemed an emergency and the crew would have returned with the body as soon as possible. However, the current situation playing out on the ISS seems to indicate that lifeboats are not always required for crew on the ISS, and that the body could be returned on its own as a nonemergency while the rest of the crew waited for a replacement vehicle.
Of course, this only addresses the timing of the return of the entire crew, not the many other unknowns of space taphonomy [1]. I think it's time we started asking these tough questions and planning for an eventual death on orbit. We need to know what will happen to the bodies, what we should do with the deceased to honor them and their beliefs, and, perhaps most importantly, we need to understand how to protect the rest of the crew after one is lost.
References:
[1] Damlo S. Space taphonomy: human decomposition in low Earth orbit [master's thesis]. https://ufdc.ufl.edu/UFE0059198/00001. Accessed January 2, 2023.
[2] Garcia M; NASA. Mission controllers assess Soyuz coolant leak. https://blogs.nasa.gov/spacestation/2022/12/15/mission-controllers-assess-soyuz-coolant-leak. Accessed January 2, 2023.
[3] Space Policy Online editors. Soyuz MS-22 decision delayed to January. https://spacepolicyonline.com/news/soyuz-ms-22-decision-delayed-to-january. Accessed January 2, 2023.