Giant surveillance balloons are lurking at the edge of space
It’s a brisk December morning at Spaceport Tucson, America’s premiere (only?) dedicated launch pad for stratospheric balloons, and a small army of technicians in reflective vests is milling around on the concrete and thawing out after a long, cold night. Nearby, a white metal tripod the size of a smart car is tethered to two dozen solar panels and hundreds of feet of clear plastic that stretches across the pad.
This alien-looking contraption is referred to as a “stratollite,” a portmanteau of “stratospheric satellite,” operated by a company called World View Enterprises. It’s a finely honed surveillance device outfitted with a suite of sensors and a camera sensitive enough to detect people standing on the ground from the edge of space. The stratollite travels by virtue of two balloons, one filled with helium to provide lift, and the other with pressurized air, which functions as a steering system. By the time the contraption reaches peak altitude about 14 miles above sea level, the helium balloon will have grown large enough to comfortably encompass a football field. But in its deflated state, the expanse of plastic brings to mind the sloughed-off skin of the rattlesnakes that call the surrounding Arizona desert home.
Most of the crew has been on site at Spaceport Tucson since 2am preparing for World View’s twelfth and final launch of the year. Things are looking good: The sun and a waning gibbous moon compete for attention in a nearly cloudless sky, and an aerostat tethered close to the pad registers almost no wind. You could hardly ask for better conditions to launch the thousand-pound stratollite on a month-and-a-half sojourn at the edge of space. Mission control gives the green light to start inflation, a process that takes just a few minutes but uses enough helium to fill more than one million party balloons.
Once the stratollite rises to its peak altitude, it rides the wind for weeks on end, tracing spaghetti-like patterns over the American southwest. A condenser in the stratollite sucks in the sparse air in the upper atmosphere and pumps it into the second, “superpressure” balloon attached beneath the helium balloon. The pressurized air is denser than the helium, so the superpressure balloon acts as a weight. To lower the stratollite’s altitude, you increase the pressure, and vice versa to climb higher.
Because the stratollite is at the mercy of the wind, the ability to change altitude at will is critical for navigation. Winds move in different directions and at different speeds depending on the altitude, so stratollite’s minders can steer it by drifting up or down. On any given day, the altitude of the stratollite might change by as much as 25,000 feet depending on the wind patterns.
Founded in 2012 by Taber MacCallum and Jane Poynter of Biosphere 2 fame, World View was originally conceived as a platform for human journeys to the upper stratosphere. Given that only a handful of people have piloted stratospheric balloons and lived to tell the tale, it was an ambitious goal—but the company had the technical chops to back it up. In 2014, MacCallum and Poynter worked together on a mission to send Google executive Alan Eustace on a record-breaking space-diving journey to 136,000 feet suspended beneath a stratospheric balloon.
But it wasn’t at all clear there was enough demand for ferrying humans to the upper stratosphere, so in February, World View tapped Ryan Hartman, the former president and CEO of the drone company Insitu, to retool the company as a data services platform. The idea is to use long-lasting stratospheric balloons to collect high-resolution images of Earth and sell this data to the government and private companies.
Given his background in drones, Hartman is intimately familiar with the concept of Earth surveillance as a service. He says World View aims to fill a niche that can’t be met by more conventional technologies like drones and satellites, which involve compromises in the quality of images, the area these images cover, and the frequency with which images are collected. Stratospheric balloons promise cheap access to incredibly high-resolution images that can be collected anywhere on Earth. Using off-the-shelf imaging hardware, World View can take photos with 15-centimeter resolution from 75,000 feet, and its custom-made cameras will soon be capable of 5 centimeters.
According to Hartman, World View’s system is sensitive enough to tell whether a person on the ground is “holding a shovel or a gun.” Unsurprisingly, perhaps, World View has attracted the interest of the US Department of Defense, which Hartman says will be one of the company’s first customers when it starts selling its data next year. He says the company has also received a lot of attention from the energy sector, which is interested in using the image data to monitor its oil and gas wells, transmission lines, and other critical assets.
https://arstechnica.com/?p=1635963