Mesh Collider stops me from controlling the object?

When I put a mesh collider or box collider on my spaceship, it stops me from controlling it. I can still move it forwards and backwards, but I can't changed the pitch/yaw/roll. I have a rigidbody attached too. The file is also like this:

Spaceship > Main Camera + (Marathon Class ship > marathon > all the meshes)

I'm not sure if you understand that, but basically all the objects for my ship are inside the folder 'Spaceship', and the rigidbody is also attached to the spaceship. My 'fly' script is attached to the main camera, and the mesh collider on the marathon folder.

If you need any additional details, just ask. Thanks for any help.