The National Aeronautics and Space Administration (NASA) Ultra-Long Duration Balloon development project is attempting to extend the potential flight durations for large scientific balloon payloads. The culmination of each of the development steps has been the fabrication and test flight of progressively larger balloons. This new super-pressure balloon is a pumpkin balloon design. This paper concentrates on the super-pressure balloon development test flights that have been, and are currently being planned by the NASA Balloon Program Office at Goddard Space Flight Center's Wallops Flight Facility. Descriptions of two test flights from early 2001 are presented along with lessons learned. Results are also presented of a July 2002 test flight of a full-scale 610,500 m 3 balloon with a 2800 kg suspended load that incorporated the lessons learned.