This article continues our coverage of the Seamless Skies Awards focussing on the ‘seamless skies for all’ category which was defined as – A project or organisation which has delivered a measurable improvement to the optimisation of airspace management performance, supporting airspace users to meet their business and operational goals.
Opening Upper Class E: NASA’s High-Altitude Traffic Management Collaborative Evaluation
NASA was the winner in this category with its NASA Air Traffic Management eXploration Project. At 66,500 feet above Sioux Falls, South Dakota, a stratospheric balloon floated overhead – drifting slowly, station-keeping over a telecommunications coverage gap, invisible to radar systems designed for aircraft that travel at six hundred miles an hour.
Below, in a control room at NASA Ames Research Center in California’s Silicon Valley, researchers watched its position on a shared display alongside two other high-altitude operators in California and New Mexico, all collaborating in real-time to detect conflicts and resolve them before they happened. For the first time, the fundamental architecture of a safe, scalable high-altitude traffic management system had been demonstrated live – with real aircraft data.
For these types of operations, “station-keeping,” or remaining in the same region for extended periods of time is the norm, but this isn’t the norm for today’s Air Traffic Management capabilities.
Some background about high-altitude airspace
High-altitude airspace – roughly 50,000 feet and above, well above commercial airline cruising levels – is experiencing a surge of interest from sectors ranging from telecommunications to disaster response to scientific research. Long-endurance balloons, stratospheric airships, and high-altitude pseudo-satellites offer platforms that can deliver internet connectivity to unserved regions, provide continuous situational awareness over natural disasters, and conduct scientific missions impossible from lower altitudes or orbit. The vehicles are diverse: lighter-than-air, solar-powered, slow-moving, and designed to stay in one region for days or weeks.
Key achievements in 2025
In July 2025, NASA’s ATM-X team convened a multi-party simulation at NASA’s Airspace Operations Laboratory at Ames, bringing together researchers from three different organizations – NASA, Aerostar, and Sceye – operating from facilities in California, South Dakota, and New Mexico respectively. The exercise was the most advanced high-altitude traffic management simulation NASA had conducted, and the first to incorporate live telemetry data from an actual stratospheric vehicle in flight.
The live data feed – positional and telemetry information streamed from an Aerostar balloon operating at 66,500 feet above South Dakota – transformed the exercise from a purely synthetic scenario into a genuine mixed-environment evaluation. Participants could observe how their ground systems responded to an actual stratospheric vehicle’s behavior: its drift patterns, its trajectory intentions, its interaction with simulated neighboring operations.
Driving factors and next steps
Parimal (PK) Kopardekar, Acting Director Airspace Operations and Safety Program, NASA, spoke with Global Airspace Radar about the project and what comes next. “This project didn’t start with a view towards re-inventing what we already have. The Upper Class E concept followed what we already use and have learned from ATM and UTM.” There are a lot of different vehicles in this airspace that current radar solutions don’t reach. In addition this, these vehicles don’t act like the ones air traffic control organisations are used to managing. For example:
- High-altitude platforms (HAPS) tend to hover and not change location a lot
- Supersonic aircraft move very fast
- Balloons can be unexpectedly impacted by the wind
- Solar-powered vehicles actually sink, or decrease their altitude, overnight when there is no sunlight and then rise again in the morning.
This last one really got me thinking as this isn’t something I would even have considered.
This simulation incorporated live and virtual (digital twin) information. The next step planned is to share the results and lessons learned with the FAA to hopefully support future concepts for High-Altitude Air Traffic Management (HATM). The current thought process is to follow the UTM model of a U-Space Service Provider (USSP) who shares data to users requiring it. The next goal is to move to live trails with additional participants in early 2027.
