China just flew a 250-foot airship to near the top of the Earth’s atmosphere. The solar-powered behemoth can stay airborne for half a year and requires no fuel to get it more than 12 miles into the air–just fill it with helium and let it go; the sun powers it once it reaches its cruising altitude.
Airships predate airplanes, but have been largely supplanted by them. However, they remain superior for pretty much anything that doesn’t require the speed of a jet engine. They can hang around for months, they can carry large payloads, and they can fly way higher than most planes, because an airplane’s wing runs out of air to support it at such high altitudes.
This last property might be the reason China is testing the Yuanmeng airship. During its estimated two-day trial, the airship launched from Xilinhot, Inner Mongolia, bristling with communications gear–“data relays, high-definition observation and spatial imaging” equipment–says the Chinese People’s Daily. The sedentary nature of the airship allows it to sit up at the edge of space and watch. It can surveil the ground, and it can also act as a base station to command fleets of military planes. In a pinch, the Yuanmeng airship could act as a stand-in for communications satellites.
Popular Science speculates on China’s plans for the technology:
Operating higher in near space means that the Yuanmeng would have constant line of sight over a hundred thousand square miles–an important requirement for radar and imaging. Increased sensor coverage means increased warning time against stealthy threats such as cruise missiles, giving Chinese forces a greater opportunity to detect and shoot down such threats. It would also be harder for fighters and surface-to-air missiles to attack near space objects.
They’re not perfect though. The People’s Daily spoke to Yu Quan of the Chinese Academy of Engineering, who told them that “The biggest challenge for the near-space airship is the big temperature difference in the day and night.” Because the airship is so close to space, it experiences space-like extremes of weather as it is baked by the sun and then frozen by the night.
Airships can solve many problems. In much the same way that regular oceangoing ships carry huge loads of goods from continent to continent, airships are also good for transporting goods. Even smaller airships can carry loads of 50 tons. And perhaps they could even replace passenger airplanes as providers of low-cost air travel. They might not be as fast, but they could be a lot more comfortable.