This paper presents the concept, design, and development of a novel type combination fast-rising, high-altitude meteorological balloon. The design consists of an inner high-altitude balloon and an outer streamline balloon. The assembly is so designed that it will ascend rapidly to approximately 50,000 ft. At this altitude, the streamline balloon bursts and falls away from the inner balloon. The inner balloon now, by virtue of its increased free lift, proceeds to accelerate at the upper level of flight, providing a faster ascent rate throughout most of the flight than that attainable by individual component balloons. The balloon provides an ascent rate in excess of 1700 ft min−1 in the daytime and 1600 ft min-1 at night to altitudes in excess of 100,000 ft.