I got well below a 3.0 in undergrad and was accepted to a relatively okay masters program while working. Finished graduate school round one with a 3.4 in Aero Eng.
Applied for grad school round two this time with a focus on Mech Eng and going for the gold of PhD. I don't have any research papers at all, but I do have about 7 years of engineering experience working on spacecraft and now rocket engines. My biggest concern now is do I really walk away from a good paying job but in an area I absolutely loathe living in to go back to school. So far all signs point to yes.