how do i back up my time capsule?
You can open up your Time Capsule from the Finder. In the left hand panel it ought to be under the Shared section.

Connect to it and you'll find a sparse bundle file for each computer you're backing up.

Those can then be copied off to another location, eg. another hand drive either attached to the Time Capsule, or attached to your computer.

If you want to automate this you can write a script to automatically mount the TimeCapsule then copy of the files using something like Unison. That's how I have it setup.

To mount it:

mount_afp afp://$USER@$CAP_IP/$CAP_NAME "/Volumes/$MOUNT_NAME"


To sync to another location with Unison:

unison -batch -logfile /PATH/TO/LOGFILE -perms 0 "DESTINATION" "SOURCE"


Unison is available in HomeBrew, mount_afp is built in.