Hi Groovee,
You'll probably need a full day at Kennedy Space Centre, so wouldn't really plan to do anything else, unless you want to stay over a night?
Just south, is Merritt Island, where there is plenty to do. We are going kayaking with manatees this July around that area.
If you are into shopping, there are a few good areas just off the Merritt Island Causeway - The Merritt Square Mall etc.
There is also Cocoa Beach, with the famous Ron Jon surf shop, just south of Cape Canaveral
To the north, you've Daytona - where the cars go on the beach and north of that St.Augustine, the oldest city in Florida - a great place to stay over.
Not much inbetween Titusville and Orlando, though.
Hope this helps?
Tracy