American military and civilian agencies have flown balloons over the U.S. for a growing range of national-security applications, scientific research, intelligence collection and commercial uses… Less known is the extent to which the U.S. has floated balloons over foreign countries, though there are examples in history. In the 1950s during the Cold War, the U.S. flew balloons outfitted with cameras over Soviet airspace, an operation sometimes referred to as Project Moby Dick, before later switching to U-2 spy planes…

The diplomatic confrontation with China over the alleged spy balloon the U.S. shot down off the South Carolina coast in February 2022 is likely to fuel greater interest from government and the private sector in surveillance balloon manufacturing and detection, analysts said. “We’re seeing the exploitation of near space,” said retired Gen. John Jumper…

World View Enterprises Inc., a Tucson, Arizona company that says it has launched more than 120 high-altitude balloon missions in the last decade, rigs balloons with cameras to inspect natural-gas and oil pipelines and sensors to sniff the atmosphere for traces of gases like methane. Balloons hover far closer to earth than satellites’ orbits, enabling them to gather higher quality data…The company says it has provided its remote sensing services to civilian and government agencies and private companies…

Twice a day, meteorologists across the world launch weather balloons to collect information about the atmosphere’s temperature, pressure and humidity to feed short-term weather forecasts as well as longer-term seasonal climate predictions. These simple latex balloons carry a device called a radiosonde that weighs a few ounces and transmits the data back to ground stations as they float up to 115,000 feet before popping after a two-hour flight… 

NASA and research agencies from several other Western nations also operate massive research balloons that spend several weeks circling the globe in the stratosphere at altitudes of up to 120,000 feet. Since these balloons travel beyond the limit of a traditional commercial aircraft—which travel generally between 30,000 and 40,000 feet—they can give vital information about atmospheric conditions and chemistry, as well as astronomical observations, that drones or high-altitude aircraft can’t obtain… 

The Pentagon’s Defense Innovation Unit has contracted Aerostar to explore military applications. Aerostar has said its balloons can loiter for weeks or even months in position, using solar panels to recharge onboard batteries.

“Now the stratosphere is very clearly a new and contested domain,” says Mr. Hartman, referring to the region of the atmosphere that runs roughly from four to 30 miles in altitude. “We call it the stratosphere economy.”

Excerpts from Dustin Volz et al., What Does the U.S. Do With Its Own Balloons?, WSJ, Feb. 14, 2023