WindBorne Global Sounding Balloons: Technological Advances and Dropsondes

WindBorne Systems has developed a novel balloon-based observation system, enabling constellations of balloons to be flown throughout the troposphere for extended periods of time. Each balloon, known as a Global Sounding Balloon (GSB), can fly for weeks at a time while being remotely directed to ascend and descend from a few hundred meters above the earth surface to the lower stratosphere. GSBs collect tens of vertical profiles of wind speed and direction, pressure, temperature, and humidity per flight.

During the first 4 years of operations, the GSB was developed, demonstrated and refined during large-scale intermittent field campaigns with hundreds of GSBs being flown throughout much of the Northern Hemisphere. In early 2023 WindBorne began operating a persistent constellation of GSBs, and by mid 2024 the constellation averaged 24 GSBs aloft supported by 100 GSBs launches per month. By early 2025, plans are to average 100 GSBs aloft at any given time, collecting many hundreds of vertical profiles of atmospheric data each day. Beyond 2025, a continuous constellation numbering in the thousands of balloons aloft is envisioned.

The constellation size is growing not only due to higher frequency of launches, but also because the duration of each GSB flight is increasing with technological advances. During 2024, the flight controller electronics and balloon envelope were redesigned yielding a smaller and more performant GSB which led to a 25% increase in data collection and duration and a 23% decrease in system weight. These updates, along with additional improvements over the next 1-2 years, are expected to lead to at least a doubling of the GSB lifetime and data collection, resulting in fewer launched GSBs for larger constellation sizes.

Additionally, a capability to drop lightweight sondes from GSBs is under development. The sondes will enhance data collection capabilities by enabling atmospheric observations in regions where GSBs currently don’t fly optimally, such as in areas of precipitation and icing. GSBs will be able to fly at high levels and drop sondes into the inclement weather below, collecting profiles of temperature, wind and humidity from flight level (often > 10km above ground level) all the way to the surface. While initial testing has been completed with only a single sonde per GSB, multiple sondes will be dropped from each GSB in the future.