Can't boot Ubuntu server with Degraded Raid5

Hello I need some help on this one. First off, Ubuntu server is NOT installed on my RAID5 array, It is on a separate stand-alone disk. I rebooted my server remotely from work today via SSH and it didn't come back up. When I got home and plugged a monitor into the server I see the following message indicating one of the 4 disks in my RAID5 array has failed and the array is degraded. The problem I have is that I am unable to answer "Y" to go ahead and start the degraded array, so my system won't boot! I need to boot normally so I can see which disk has failed in the array and get a replacement ordered ASAP. I have tried reboot several times but when I get the message:

If you abort now, you will be provided with a recovery shell.
Do you wish to start the degraded array? [y/N]:
a

it refuses to take any keyboard input from me and default to N and drops me to the recovery shell. I tried switching to a wired USB Keyboard but still nothing. How can I get back into my system to run the MDAM commands neccessary to find my failed drive? Any help is extremely appreciated. I would also like to start the degraded array so I can back up a few files, just to be safe until my replacement for the failed drive gets here.