Key Enablers to Station Keeping High Altitude Long Endurance Balloons in Service to Society

Technology development and maturation for space or near-space applications requires large investments, in terms of both cost and schedule, to cultivate new and revolutionary technologies for space exploration and earth observing. A considerable component of technology development, optimization, and maturation, involves iterative design cycles consisting of flight testing systems in relevant environments to gather crucial performance data used to improve successive designs. Unfortunately, orbital and suborbital flights have relatively short durations, are costly and limited by the amount of launch vehicles, and launch opportunities available. Due to these and other challenges posed by design constraints for rocket launches, prolonged flights utilizing high altitude balloons at altitudes in excess of 30 km offer a compelling alternative to sub orbital flights to test technologies for space and near-space applications. The environment above 30 km AMSL provides an excellent proxy for long duration testing of earth observing payload functions, new materials, power collection / generation technologies and general experimental payloads. Furthermore the ability to loiter in a specified domain provides new capabilities. To this end, Northrop Grumman has invested into the development of stratospheric wind forecasting models and a station keeping optimization capability to provide flight profiles, with altitude change directives and times, to maximize the duration that a balloon platform will remain within a 200 mi. diameter operational domain. To reach this goal we have refined the Weather Research and Forecasting (WRF) model in the stratosphere and conducted a set of basic weather balloon flights to compare the predicted ascent, flight, and descent profiles against real world flights and refined the accuracy and precision of the model and software. In addition an operational decision support system has been developed to provide forecast flight durations and trajectories based on high resolution WRF modeling as well as ensemble forecasts from the GFS ensemble forecast system. Examples of how this emerging technology benefits society will be demonstrated at the conference.