problem raid 5

Version : 1.2
Creation Time : Mon Feb 18 22:33:14 2013
Raid Level : raid5
Array Size : 5860530176 (5589.04 GiB 6001.18 GB)
Used Dev Size : 2930265088 (2794.52 GiB 3000.59 GB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent

Update Time : Sat Aug 30 07:51:42 2014
State : clean, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 1
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Name : openmediavault:disconasdepedro (local to host openmediavault)
UUID : 5b642643:9d296581:9d7df945:8de64731
Events : 1010

Number Major Minor RaidDevice State
0 8 32 0 active sync /dev/sdc
1 8 16 1 active sync /dev/sdb
2 0 0 2 removed

2 8 0 - faulty spare /dev/sda

what steps should I follow now ?, can now access the information after having my software working for a day to recover.
Thank you

all gone. I erased the drive and I added the raid and I have given to repair, result: bye raid 5 all my information. I will not make a raid 5, at least not with this software

thanks, but useless, I gave rebuild and raid and lost data ... I'm back to make a new raid 1 think it will be safer, I hope.