Coordinating the Sky Above: NASA’s Development and Evaluation of a Cooperative Higher Airspace Traffic Management (HATM) Concept

The proliferation of high-altitude, long-endurance (HALE) vehicles — including stratospheric balloons, lighter-than-air platforms, and fixed-wing systems — is driving a need for new traffic management paradigms above traditional controlled airspace. NASA Ames Research Center’s Airspace Operations Laboratory (AOL) has led an experimental program to define, prototype, and evaluate an Upper Class E / higher-airspace traffic management concept. The previously published work was referred to as ETM, moving forward the research will now be called Higher Airspace Traffic Management or, HATM. HATM enables cooperative operations of the diverse operators and vehicle types that will encompass the growing industry in the stratospheric altitudes. This paper details the collaboration efforts by NASA, the Federal Aviation Administration (FAA), and industry partners to refine the HATM concept, develop supporting architecture, and implement a prototype simulation environment. It also summarizes results from the industry-supported Collaborative Evaluation (CE) activities, including the initial CE-1 and the most recent CE-1.5 demonstration and evaluation. The HATM concept emphasizes (1) interoperable information sharing among heterogeneous operators, (2) strategic deconfliction for equitability across users, and (3) industry-developed Cooperative Operating Practices (COPs) that enable predictable access while maintaining safe operations. The HATM research aims to provide an amenable pathway from concept to validated operations that leverages NASA’s simulation infrastructure, flight test capabilities, and human factors expertise along with incorporating the FAA’s Concept of Operations (ConOps) work and industry’s desire to progress the cooperative service-oriented framework.