I recently acquired a Toshiba 500GB External Hard Drive so I could back up all of my photos, videos and school work. Today I was working on a document that I'd saved to the hard drive when I had to leave the house for a bit and take the laptop with me. I saved and closed the document, safely ejected the external and headed off. When I came back and plugged my hard drive in again, my computer failed to recognize it and is saying that it is corrupted and cannot be accessed.

Is there any way to fix this, or do I need to recover my data using some sort of data recovery program and get the hard drive replaced?