If that is your boot drive, it seems like it's gone. You might want to disconnect all other drives, have the culprit SSD plugged in and then use a bootable installer to try and install your OS on it(again) and see if that brings back the SSD.
What is the make and model of the missing SSD? Are you on the latest BIOS update for your platform?
All you can do is test and see what happens.Just wish I knew if the SSD was going bad or not so I can just move to my 240g SSD and save a head ache
I wasn't expecting it either.I'd have had held out very little hope of that occurring, you dodged a little bullet there....!