but what about those collars?

They may be impractical but they sure look cool, didn't they?

What's the Spanish for drunken bum?

I think they are supposed to look like sci-fi versions of Dracula's collar. I didn't get it either, until one scene where Capt. Salas (who kind of looks like Frank Langella from the great 1979 version of Dracula) is looking right at the camera, and the collar is sort of shrouding his face. I went - aha! Dracula collars!

But forget the collars - what about that weird SS insignia on their shoulders...???

Oh my god I watched this the other night and freaking loved it! I want one of these costumes for halloween this year.

I'm sure it would help protect you incase of vampires or debree from a crash or maybe radiation. I think its pretty practical actually for flight because they are wearing weird suit and helmets to protect them from something. It must have a purpose in the plot. Regardless it is bad ass looking anyway.

Hilariously goofy costumes used to be a sci-fi staple. Sometimes I miss 'em.

I love the collars! I want one of those outfits. I am positive Michael Jackson never watched this movie because he would have used those collars...what a pity.

I actually noticed that too. Watched the movie last night in high-def, and I agree that they are ridiculous. If you notice later in the move they seem to be discarded.

I think Mario Brava should have told the wardrobe people to have another go at the design, when they were first shown to him. They look like whiplash collars and the actors move around exactly as if they were wearing whiplash collars.

(First pass Mon Aug 31 2015)
Just now watching this for the first time, and at my first glimpse of the collars I nearly lost it, they are so ridiculously hilarious! No, they don't block peripheral vision, there is a cutout on the upper forward edge nearest their eyes to enable peripheral vision. But the collars are high and tight enough to hinder neck movement, which is why they had to turn their bodies to look around. And they really don't serve a functional purpose (collars half that high would still protect the neck), other than as someone else pointed out, to look like Dracula collars and perhaps, along with the leather skull caps, to look Flash Gordonian.

*EDIT*
(Second pass Fri Apr 15 2016)
Watching this for the second time. This time, it strikes me that all the uniform collars (which are removable, BTW) are cut from the same pattern, but they fit everyone differently. So, they clearly weren't customized to fit each wearer. For some, those cut-outs almost appear to be for the ears, but for most of the crew, they cover up the ears to differing degrees. And on some, they even partially block the view. They might have been originally intended as neck braces, like a football player's neck collar, as they are flying in a spacecraft that could encounter unexpected obstacles mid-flight or even while landing. Most interesting to me was that nearly halfway through, some of the crew removed their collars, while others left not only the collars on, but also the leather helmets, which also seemed to serve no purpose other than looking "spacey". And the kicker is that the whole getup must have blocked hearing to some degree, plus vision and head mobility to a lesser degree, so aesthetics must have trumped functionality for the costume designers. Form over function.

Come see a fat old man sometime!