New Record For Solar-Powered Autonomous Flight: 28 Hours Without Refueling

Hallie Siegel describes a new and impressive achievement for solar-powered flight: keeping a drone aloft for more than a full day. From the article: To actually pull it off has required a fair bit of innovation in flexible solar cells, high energy density batteries, miniaturized MEMS and CMOS sensors, and powerful processors ... but researchers at ETH Zurich have just recently managed to keep their unmanned UAV aloft for 28 hours without any fuel, building on their previous record by over an hour. Having more than 24 hours of endurance is important because overcast skies can inhibit recharging and poor weather or high winds can affect power consumption.

Comments

Re:Good achievement, but

[fnj]

But why not just use a lighter-than-air vehicle and stay aloft for months?

Airships only exceed optimized airplanes in transport efficiency for extremely large sizes and severely limited speeds. Solar/battery airplanes can already exceed one diurnal cycle, so there is no reason in principle why they themselves cannot stay aloft for months.

Airships are subject to problems that do not apply at all to airplanes. A major one is that they are subject to serious lift variations due to varying degrees of heating differential to the surrounding atmosphere. This can only be countered via engine power or by expenditure of ballast and valving of gas. This has traditionally been the ultimate limit to their endurance, which has never exceeded 11 days in practice.

Not a record, not even close

[Anonymous Coward]

Qinetiq Zephyr flew for "336 hours and 22 minutes (2 weeks / 14 days)".

I'm pretty sure I remember a similar but much longer flight, but I can't find the details. Regardless, 28 hours isn't very impressive compared to 336.