It’s summer here in the Northern hemisphere, and that means the solar-based industry in the US is in top experimental gear (to clarify: the company in question is British but the test flight is in the Arizona Desert). A few more months and they’ll hibernating or relocating to their Australian headquarters, but in the meantime, we’re getting a lot of solar-related news. It wasn’t long ago that the Solar Impulse proved it could stay in the air for 24 hours (26, in fact), and now we’re hearing that Qinetiq’s much-smaller craft, the Zephyr, will be going for a world-record 14 days. Of course, it already holds the world record, since it’s been in the air a good week or so already. It’s kind of like when you set the high score but the points are still rolling in.
Unlike the Solar Impulse, the Zephyr is intended to be a long-flight, low-payload craft, meaning you won’t be strapping yourself into one any time soon. At 50kg/110lb gross weight, the Zephyr is about as light as a functioning solar craft of that size can be; its construction is carbon fiber and the paper-thin solar cells are connected to a handful of Li-S batteries. Despite its growth in the latest version, the Zephyr still is essentially just a frame with a control module attached to operate the rudders, prop speed, and so on.
The goal of these things, other than to advance the state of the art, is ultimately military. While no ultralight solar craft will ever be able to create any serious destruction, the “eye in the sky” is becoming an increasingly valuable tactical asset, this type of design could easily carry a lightweight camera array or a few units to improve units’ communications. The military and green interests don’t often align, but reducing fuel usage will simplify the supply chain and decrease costs in a big way. Ultra-lightweight construction and efficient solar architecture are also, of course, extremely marketable and essential to other green technology.
The craft was launched some time ago and is still aloft; if all goes well, it’ll fly around above Yuma for another couple days, or, if the weather is fine, even longer. We’ll update once it sets down and the record is official.