Make sure to replace the IP with the IP from your time capsule. You can find that with the airport utility on your mac.
Step 1 install cifs utils
sudo apt-get update
sudo apt-get isntall cifs-utils
Step 2 make mount point
sudo mkdir /mnt/capsule
Step 3 mount time capsule
sudo mount.cifs //192.168.1.3/Data/ /mnt/capsule -o pass=YOURPASS
That's it. I found tutorials on the web earlier talking about how you have to add the name of your time capsule between the IP address and the Folder. That just didn't work for me. I always got the mount error(6) shown below.
mount error(6): No such device or address
Also make sure you have the right password set and that the folder Data (or whatever you specify) exists on your capsule as a folder.