Do you have to submit drawings? This kind of sounds more like they might be referring to having the drawings fully dimensioned, which would be a lot different from fully defined sketches. When I'm reviewing drawings, the things I mostly look out for are drawings being over-dimensioned (usually due to tolerance stack-ups) and features not having dimensions from two reference planes. A fully dimensioned drawing is one that allows someone else to remake the part identical to your model (or at least with all of the important features matching), so that a vendor or machinist can make a part that doesn't have to be scrapped when it doesn't fit your assembly.
As for the actual project, I would agree with tahu505 that a helmet probably isn't a great option for this kind of thing. Unless this is a fairly advanced course, I wouldn't expect them to be looking for surfacing/mesh work. You'd be putting in a lot of work on aspects that probably wouldn't be considered as part of your grade, though that's not to say that you shouldn't give it a shot.
What kind of "simulations" do you have access to? Are they looking for FEA? Just a motion simulation to show that there isn't interference?
