Stratospheric Balloons As Remote Sensing Platforms
Our guest today is Anthony Antonio, CEO and cofounder of UrbanSky, based out of Denver, CO. UrbanSky is a remote sensing startup with a primary focus on the use of zero pressure stratospheric balloons as the UAS/UAV for sensor payloads. Anthony’s background is in business, obtaining his degree in Business Management from Washington College before he joined the StratEx project. After helping to facilitate the world record setting space dive from an stratospheric balloon, he and his partner, Jared Leidich, set out to present the “cubesat of the stratosphere” to the world.
The Rise of Stratospheric Balloons
Balloons are not generally the first thing that comes to mind when considering the cutting edge, in fact, the earliest remote sensing projects were conducted with balloons. The real excitement comes from thinking outside the traditional sphere of uses of balloons, and of the stratosphere itself.
Atmospheric balloons have already carried weather sensors to great heights for data collection. It is a relatively simple process, using small latex balloons which will pop when they hit a certain altitude, dropping their data payload back to Earth to begin a proverbial Easter egg hunt for scientists on the ground.
Larger stratospheric balloons have been used to carry much heavier payloads, including the former Senior Vice President of Google who set a world record jumping from one at 136,000 feet.
The presence of only very large, or very small balloons on the market is being challenged by the advent of mid-sized zero pressure balloons.
The balloons can be launched from the back of a pickup truck.
This is a huge improvement from the previous need to launch large balloons from airports, or even space ports due to the need for special infrastructure.
Zero pressure balloons are made from a thin plastic bubble that opens at the bottom, and is partially filled with helium at launch. As the balloon rises, the helium expands and fills the balloon.
Once it reaches between 60,000 and 70,000 feet, excess helium will leak out from vents, keeping the balloon at a very stable altitude.
Zero pressure balloons can maintain this altitude for about 6 to 10 hours, as colder temperatures associated with nighttime will compress the helium in the balloon, triggering its descent. This can be combated to a degree by strategically dropping ballasts (generally sandbags) to reduce weight, and gain more airtime.
Balloons are significantly cheaper than traditional remote sensing vehicles, but they do still face limitations. The FAR 101 rules of the FAA apply to High Altitude Balloons with payloads above 6lbs. If a balloon keeps its payload under this limitation, they are subject to far fewer FAA regulations, and gain a lot of flexibility with their flights.
Balloons as an Earth Observation System
The low cost and high flexibility of stratospheric balloons is enticing enough, but learning how stable these balloons can be at high altitudes unlocks a lot of doors in remote sensing. Furthermore,
the stratosphere is an untapped “market” as generally the only aircraft found there are weather balloons, or the occasional spy plane.
Stability of the balloon may not be an obstacle anymore, but there is still a great deal of thought put into how to steer the balloon to ensure it collects the target mission. Traditionally with large balloons, this involved navigating layers of wind in the atmosphere in very much the same way you would steer a sailboat. This left pilots very dependent on the weather and winds near their launch infrastructure.
Smaller balloons, like those produced by UrbanSky, can be transported and launched from a pickup truck in about 10 minutes, allowing them to travel to ideal conditions. Once a targeted area for collection is planned, atmospheric modeling algorithms can be run which output the ideal launch location for the desired flight plan.
Each balloon can collect 20-22km of imagery
, and can be launched in close proximity to widen the collection area. This wide range means there is a very safe margin of error (1-2km) for balloon missions. When collection is complete, the balloon and its camera can be disengaged, and recovered in a predictable location.
Currently, due to the 6lb limits, only one sensor is generally attached to a balloon at a time. The most commonly used sensor is an RGB, 3-band camera.
Flying significantly closer to the Earth than a satellite means equally improved image resolution.
UrbanSky’s system allows for a 10cm ground sampling distance (GSD) with their RGB camera, and 3.5m for their infrared sensor. The future likely holds continued innovation as high resolution sensors are made smaller and smaller.
Future and Uses of Remote Sensing Balloons
The reimagining and miniaturization of low cost stratospheric balloons has the potential to change the landscape of the aerial imagery market. The significantly lower costs mean it becomes much more feasible to collect imagery at smaller intervals. Instead of waiting every 3 months, 6 months, or even a full year for collection by a competing UAV, balloons can be flown as often as daily over areas of interest, yielding huge amounts of high resolution data.
The unprecedented amount of data that could be made available by balloons has some applications right out of the gate,
but many have historically considered this resolution out of range, leaving a lot of space open for brainstorming new, innovative uses.
Some of the best known applications are for the insurance industry, and creating input data for deep learning extraction. Benefits such as ease of deployment, cost unlocked opportunities for collection of lesser natural disasters in localized areas. The market for large natural disasters is currently pretty well covered by a variety of market players and governments, so expanding the scale of collectable events is groundbreaking.
One especially engaging use case for balloons is imaging wildfires.
Infrared cameras can be flown over areas of interest without interfering with aircraft fighting the fire below in lower airspace. Currently, balloon data is not downlinked, meaning it must be collected with the flight system once it has landed. UrbanSky, however, foresees real time data streaming where onboard photogrammetry software, paired with infrared, can broadcast data directly to firefighters on the scene, allowing them to respond more effectively to emergencies.
Other potential uses for stratospheric balloons are not limited to imagery workflows, but can encompass communications, and emergency applications. As time goes on, even more uses will be innovated and implemented. As we have seen, the ceiling is rising for the widening range of balloon and remote sensing technologies, and the sky is no longer the limit.