You should be able to simply reassemble the array manually. You know which devices comprise the array, right? If they were /dev/sda, /dev/sdb, and /dev/sdc for the RAID5 at /dev/md0, for example, I think this'll work:
mdadm --assemble /dev/md0 /dev/sda /dev/sdb /dev/sdc
You can go ahead and try that. To the best of my knowledge, you can't actually damage an array with a simple assemble. The rest of the information that mdadm needs it should be able to find in the RAID superblock on one of the disks. I'm a novice when it comes to Linux software RAIDs but I just put my second one together a couple weeks ago and I had to do that at one point.