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Stratospheric Balloons Take Monitoring and Surveillance to New Heights

These eyes in the sky fly above drones and below satellites

2 min read
Image of a map with highlighted markers.
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Alphabet's enthusiasm for ­balloons deflated earlier this year, when it announced that its high-altitude Internet company, Loon, could not become commercially viable.

But while the stratosphere might not be a great place to put a cellphone tower, it could be the sweet spot for cameras, argue a host of high-tech startups.

The market for Earth-observation services from satellites is expected to top US $4 billion by 2025, as orbiting cameras, radars, and other devices monitor crops, assess infrastructure, and detect greenhouse gas emissions. Low­-altitude observations from drones could be worth.

Neither platform is perfect. Satellites can cover huge swaths of the planet but remain expensive to develop, launch, and operate. Their cameras are also hundreds of kilometers from the things they are trying to see, and often moving at tens of thousands of kilometers per hour.

Drones, on the other hand, can take supersharp images, but only over a relatively small area. They also need careful human piloting to coexist with planes and helicopters.

Image of the United States Map displaying different altitudes.Click here to see larger.StoryTK

Balloons in the stratosphere, 20 kilometers above Earth (and 10 km above most jets), split the difference. They are high enough not to bother other aircraft and yet low enough to observe broad areas in plenty of detail. For a fraction of the price of a satellite, an operator can launch a balloon that lasts for weeks (even months), carrying large, capable sensors.

Unsurprisingly, perhaps, the U.S. military has funded development in stratospheric balloon tests across six Midwest states to “provide a persistent surveillance system to locate and deter narcotic trafficking and homeland security threats."

But the Pentagon is far from the only organization flying high. An IEEE Spectrum analysis of applications filed with the U.S. Federal Communications Commission reveals at least six companies conducting observation experiments in the stratosphere. Some are testing the communications, navigation, and flight infrastructure required for such balloons. Others are running trials for commercial, government, and military customers.

The illustration above depicts experimental test permits granted by the FCC from January 2020 to June 2021, together covering much of the continental United States. Some tests were for only a matter of hours; others spanned days or more.

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Economics Drives Ray-Gun Resurgence

Laser weapons, cheaper by the shot, should work well against drones and cruise missiles

4 min read
In an artist’s rendering, a truck is shown with five sets of wheels—two sets for the cab, the rest for the trailer—and a box on the top of the trailer, from which a red ray is projected on an angle, upward, ending in the silhouette of an airplane, which is being destroyed

Lockheed Martin's laser packs up to 300 kilowatts—enough to fry a drone or a plane.

Lockheed Martin

The technical challenge of missile defense has been compared with that of hitting a bullet with a bullet. Then there is the still tougher economic challenge of using an expensive interceptor to kill a cheaper target—like hitting a lead bullet with a golden one.

Maybe trouble and money could be saved by shooting down such targets with a laser. Once the system was designed, built, and paid for, the cost per shot would be low. Such considerations led planners at the Pentagon to seek a solution from Lockheed Martin, which has just delivered a 300-kilowatt laser to the U.S. Army. The new weapon combines the output of a large bundle of fiber lasers of varying frequencies to form a single beam of white light. This laser has been undergoing tests in the lab, and it should see its first field trials sometime in 2023. General Atomics, a military contractor in San Diego, is also developing a laser of this power for the Army based on what’s known as the distributed-gain design, which has a single aperture.

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