looking for the name of a movie i dont remember - about space i think

okay so there is this movie about space i thought it was prometheus but after watching im not so sure,

They were on a huge space ship and i remember something that i saw and it was ppl talking about it being confusing or mysterious something like that

the name is either something kinda like prometheus or something like prometheus: blahblah to/ the blahblah, but its not prometheus 

Any help at all would be really great