Internal drive disappeared. Shows up as "Media" & 0 bytes

I recently installed a 120GB SSD drive instead of my 640GB rotational hard disk drive. I then removed my optical drive, and put the 640GB drive in its place using an internal adaptor that fits into that space. I installed OS X on the 120GB drive. Everything worked fine for a few days and all my data was intact in the older 640GB drive. I was able to copy files from it and copy files out of it without any problems.

I was copying some files over from the 640GB drive to the new SSD drive when things started to slow down. So I restared my laptop and I got an error message which said "Your disk is not initialized" When I click on Initialize it shows me disk utiility where my older 640GB drive shows up as "Media" with no partitions or data on it and a total capacity of 0 bytes.

I am unable to erase, partition or anything else on this drive. In system information I see that the Macbook pro is aware that a drive is attached to the SATA interface and also that it's rotational media. But I am unable to use the drive or access any of my data.

Anyone know what I can do? Did my HDD crash?

Attached screenshots of Disk Utility and Sytem Information