Auto wallet-backup is currently being worked on by my partner. When opening the wallet for the first time. You will be asked to select a folder (could be any folder/USB/HD) where you want the SpaceCoin-qt to back-up your wallet.dat. It will backup the wallet.dat at start and exit.

Example: 10-09-2015 11:52 - spacecoin wallet.dat
             10-09-2015 18:58 - spacecoin wallet.dat

Note: QT only - not for daemon
I expect this to be done within 2 weeks from now