Fragment revision: could and would

[Jeroen1000]

I feel that based on the context and the message the writer would like to convey to the reader, would OR could should be used (depending on the writer's message). I've given it so much thought I've gotten confused now . Here goes:

But, does ( or would) a stay in space have any consequences for our body? The living conditions are so different out there that it would be almost impossible for it not to have any effects on the body. The (or no 'the'?) NASA carried out a research to find out what the possible consequences of a stay in space could (or would) be.

Now for my thoughts:

1. It's fairly sure a stay in space will have consequences. Therefore, I would choose the word would in the first sentence. If hadn't a clue, I would use the word does instead.
2. Same goes for the could/would in the 3rd sentence.

What should I do?

[Mister Micawber]

.
This is what I would do:

But would a stay in space have any consequences for our body? The living conditions are so different out there that it would be almost impossible for it not to have any effects on the body. NASA carried out research to find out what the possible consequences of a stay in space could/would be.

First: 'would' because 'we' are not likely to stay in space.
Second: would/could offer the same probabilities; I would call them optional synonyms here.
.
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Native English teacher at Mister Micawber's