Adding a Space Context Condition
If you can figure out the name of the contexts made available from spaces, you can use the condition that is triggered by other active contexts.  I personally have not heard of spaces creating context on their own however.  You may also consider writing your own plugin/module as this is relatively simple to do.  I myself used the path condition files to create the context keywords module(http://drupal.org/project/context_keywords).  You could honestly probably reuse 90% of the code from mine, and just change the part that returns true or false.