At the moment, GreenHopper currently support up to 30 characters in the sprint name.

One of the key points of planning a sprint is the SPRINT GOAL. As the name of the sprint contains the number and the goal, the number (Sprint 30 ) already takes up 10 position, leaving only 20 characters, which is much too less to provide a meaningful description.
Please extend that field to at least 80 charecters.