WASHINGTON — The U.S. Army has for years experimented with high-altitude balloons and long-endurance, fixed-wing, solar-powered platforms capable of operating in the stratosphere. Now the service is pursuing prototyping efforts that could lead to programs of record, including one able to deploy launched effects.
The Army has come a long way from experimenting in the desert of White Sands Missile Range, New Mexico, in 2020, according to Space and Missile Defense Command chief Lt. Gen. Daniel Karbler, who observed that testing firsthand. Balloons have found their way into operational exercises with units, and the Army is in the process of developing requirements for eventual approval in order to progress programs for a series of high-altitude capabilities.
The Army Requirements Oversight Council in December greenlighted the pursuit of high-altitude balloons and fixed-wing, solar-powered platforms along with payloads capable of deep sensing, per an abbreviated capabilities development document, according to Col. Dave Mulack, Army Space and Missile Defense Command’s space and high-altitude capabilities manager.
Next, the service will seek requirements approval for four other different payloads. The council has not yet validated a navigation warfare payload, Mulack told Defense News in a recent interview, but it’s going through the process. Navigation warfare sensors help spot, locate and identify possible interference with position, navigation and timing reception.
Another three payloads will follow, potentially giving high-altitude platforms assured positioning, navigation and timing; network extension; and launched effects capability, Mulack added. He did not provide details regarding planned or completed experimentation for launching other sensor-equipped unmanned aircraft from high-altitude platforms.
For the deep-sensing capability, “think [intelligence, surveillance and reconnaissance] payloads [in the] stratosphere that provide the capability to extend into longer, deeper areas to provide situational understanding,” Mulack said.
The Army has tested a deep-sensing capability through theater-level exercises in the Indo-Pacific Command and European Command areas of operations with a focus on pairing the right sensor or payload with the right high-altitude platform — whether that is a small, medium or large balloon, or a fixed-wing, solar-powered platform flying between 60,000 and 100,000 feet.
The Army’s multidomain task forces are involved in the experimentations. For example, the group in Europe used three high-altitude balloons as targeting sensors in the 2021 exercise Thunder Cloud in Norway. The Pacific-based task force experimented with a deep-sensing, high-altitude capability at even greater ranges in naval exercises like Vanguard in 2023.
The Army’s newly formed space, cyber and special operations triad is also experimenting with the capability, Karbler noted.
But these high-altitude platforms and payloads are “not meant to replace any other type of sensor,” Mulack stressed; rather, they will supplement existing capabilities. These capabilities can easily deploy with smaller units, providing troops with well-beyond-line-of-sight sensing rapidly and inexpensively. One high-altitude balloon, for example, can fit inside a backpack. Balloons can range in size from a small sport utility vehicle when inflated to around the size of two buses.
As the Army continues to develop these capabilities, it is testing how to recover payloads from high-altitude platforms. Balloons are “an attritable platform” — disposable to a certain degree — but the Army would like to recover payloads that include more exquisite technology, Mulack said. The payload community is working on this, he added.
The bench is deep with industry members developing high-altitude platforms, Mulack noted. There are at least half a dozen companies in the space for balloons. And while Airbus’ fixed-wing, solar-powered Zephyr aircraft gets most of the attention because it broke the world record for flight duration (64 days) and will attempt to break that record soon, there are another half a dozen companies with fixed wing, solar-powered capabilities.
Additionally, the Army is working on mission-planning software to deploy high-altitude balloons, taking advantage of work performed outside of the defense sector, such as weather modeling for the stratosphere.
“Based on latitude and season of the year, we know generally what the stratospheric weather conditions are,” Mulack said, “and mission planning for balloons has matured to the point where we’re getting close to station-keeping” — the ability to prevent drifting.
Jen Judson is an award-winning journalist covering land warfare for Defense News. She has also worked for Politico and Inside Defense. She holds a Master of Science degree in journalism from Boston University and a Bachelor of Arts degree from Kenyon College.