[Tecdavid]

Hi there, Tom.
I'm still not so confident in my ability to critique, and this was a rather long excerpt, so I apologise if what I say isn't precisely clear or particularly helpful, but I'll try.

I like the overall setting. As far as I'm aware, a specifically icy setting within a space exploration story hasn't really been done before. And I think the second paragraph you mentioned is actually a good inclusion. I feel it helps clarify the setting and atmosphere rather well.

I have to agree with Strings in that some sentences can run on a little, and lack a smooth flow. An example would be "its washed out colored bands and storms clearly visible in Europa’s nearly atmosphere-free sky" - That extra detail seems a little cumbersome. It disrupts things.
I understand that this is difficult to avoid when you want to convey the details and specifics, and depending on what kind of narrative you want to display, I suppose it’s up to you whether you want to tone it down at all.

The characters appear a little grouchy for my tastes, but that's purely my opinion. Some might be put off by their manner, however, unless there's a reason behind their starkness.