Personally I don't use Inventor, but 3D CAD is 3D CAD so.. I would start by meshing together random dome shapes until it looked good enough for a nice shell shape, and then performing a shell feature (no relation

) option when my shell-shaped "blob" was all done.
Got MatLab available on your campus? This is a cool thing I found.
http://www.mathworks.com/matlabcentr...bjectType=file
Also, from an engineering perspective, check out the cool way these people made a shell shape on this page:
http://management.cadalyst.com/cadma....jsp?id=380964
This sounds like a cool project. Good luck with it.
Btw, what kind of Rapid-Prototype machine do you have? Z-Corp?