Right now, the balloons don't exactly last long -- World View's longest-lasting flight was 27 hours, which would only be useful for the briefest of uses. However, the Tucson launch lays the groundwork for much more. It's where World View will both launch and manufacture many of its balloons, and starts a new phase of refinement that could lead to balloons which stay afloat for months. That, in turn, could lead to balloons that replace satellites for long-term science experiments, weather tracking and observation (including for the military). There are even hopes for passenger pods that could enable everything from manned science missions to not-quite-space tourism.