My external hard drive is suddenly not recognized.

Question

I have a thunderbolt enabled 1.5 Terabyte Seagate FreeAgent Go Drive. It was used as a simply external hard drive and then I added it to be used as a time machine location. After the first initial backup, it suddenly became no longer recognizeable. It does not apear in the finder, disk utility, or in the terminal when I ask for list of the Volumes. The drive light is on, I can hear the disk spinning, and it warms up as normal after being plugged in to the computer for a period of time. Still, I am unable to recognize the drive in any way.
Ideally, I would like to save the files if possible. If not possible, I'm happy to reformat the disk but this is not possible at this time with the drive being unrecognized by any means I am aware of.
Any help would be greatly appreciated.
I am using 2.3 GHZ i7 Retina MacBook Pro with 8GB RAM. I'm on 10.9.1.

Answer 1

Yes, exactly. It's very strange. I've never had this happen. Drives fail but then don't apear in the DiskUtility app. This drive is "there" but I cannot seem to preform any action on it. This is the type of response received (in Log) I get whenever I attempt any action:
Securely erasing data to prevent recovery failed.
2013-12-26 08:43:39 +0530: Erase complete.
2013-12-26 08:43:39 +0530:
2013-12-26 08:44:06 +0530:
          Name :           Seagate FreeAgent GoFlex Media
          Type :           Disk
          Partition Map Scheme :           Unformatted
          Disk Identifier :           disk1
          Media Name :           Seagate FreeAgent GoFlex Media
          Media Type :           Generic
          Connection Bus :           USB
          USB Serial Number :           NA0B3X6P
          Device Tree :           IODeviceTree:/PCI0@0/XHC1@14
          Writable :           Yes
          Ejectable :           Yes
          Location :           External
          Total Capacity :           1.5 TB (1,500,301,909,504 Bytes)
          Disk Number :           1
          Partition Number :           0
          S.M.A.R.T. Status :           Not Supported
2013-12-26 08:44:43 +0530: Preparing to partition disk: “Seagate FreeAgent GoFlex Media”
2013-12-26 08:44:43 +0530:           Partition Scheme: GUID Partition Table
2013-12-26 08:44:43 +0530:           1 partition will be created
2013-12-26 08:44:43 +0530:
2013-12-26 08:44:43 +0530:           Partition 1
2013-12-26 08:44:43 +0530:                     Name                    : “Untitled 1”
2013-12-26 08:44:43 +0530:                     Size                    : 1.5 TB
2013-12-26 08:44:43 +0530:                     File system          : Mac OS Extended (Journaled)
2013-12-26 08:44:43 +0530:
2013-12-26 08:44:43 +0530: Unmounting disk
2013-12-26 08:45:04 +0530: Partition failed for disk Seagate FreeAgent GoFlex Media Unable to write to the last block of the device.