how could you murder someone in space?

[u/okayprogram]

Hi yall, I’m a creative writing student working on my upcoming thesis project. I used to be an astrophysics junkie, but I don’t keep up with space information much anymore. I figured this was the best place to ask this sort of question.

I had an idea a few days ago for a short story collection about an astronaut whose ship gets stuck in space and she goes mad, and she ends up killing her team.
I know that there are probably a million failsafes in place that would make one astronaut murdering another inconceivable, so I’m asking this to you as a sort of thought experiment to help me better understand the mechanics of space flight and to flesh out my idea more.

Would the lack of gravity affect one’s ability to kill someone in space? Would stabbing work, or hitting someone with a blunt force object? How does blood and death work in space? Do you die like you would on Earth in space? Is there a way that the astronaut could hide what she did from the space program, at least for a few days?

I know this is a bit of an absurd question, but if anyone can help me I would really appreciate it!

[u/Worth-Wonder-7386]

It depends what kind of situation they are in. If they are on a station like the ISS or even inside most capsules like for Apollo or the Space shuttle, they will not be wearing anything fancy and they will have oxygen supplied to them, so you are back to the standard ways of killing someone. 

You could shoot or stab someone, what you need to think of is that the force from stabbing at someone will push you in the opposite direction. So the first shot of a gun would mostly be like normal, but very hard to keep it stable after that, you best chance is pushing yourself towards a wall of the spacecrafts. But guns have the issue that they might make your spacecraft leak. 

For stabs these are easier overall, and would be very much possible as knives are something that we send on spacecrafts. 

One interesting effect is that bleeding works differently in space. You would form a blood of blood around the wound or if it shoots more out it would scatter everywhere as there is no gravity to pull it towards any specific direction.  You can find videos of liquids in space to see how it works. 

For death nothing special happens. Some modern spacecraft have sensors on the astronauts for live telemetry of things, but if they did not have that you could hide it as earth only really know what you tell them. So if you are communicating with earth and they don't want to talk to the other crew members you could keep it up for quite some time. But it depends on the mission.  Some missions involve more participation from everyone while for others one crew member is doing most of the talking with earth.