Five-year-mission solar stratocruiser prototype is a go

$155m 'Vulture II' robosunbird gets off drawing board

By Lewis Page - Posted in Science - The Register

The famous Pentagon tech wildcards at DARPA have announced plans to move forward with a flying, full-size prototype "Vulture" strato-wingship able to cruise the upper atmosphere for 5 years without landing.
 
The Vulture programme got underway last year with three competing industry teams carrying out development work on their different concepts. In essence all the designs offered vast, feather-light - yet strong - electrically propelled aircraft able to charge up onboard energy-storage systems using solar power. During the hours of darkness, the ships would rely entirely on stored juice to hold station regardless of powerful stratospheric winds, and to power their payload systems - probably military comms/surveillance kit.

The original phase one effort was intended to deliver nothing more than design studies. Now, however, DARPA has issued a statement saying that it expects to proceed with "Vulture II" next month. This is to involve "manufacturing and flight test of a full scale platform to demonstrate... critical function and capability of all elements of the Vulture II program."

The tech-head agency expects this to be done within a budget of "$155m total". The winning contractor will almost certainly be one of the three consortia which worked on the initial Vulture I design studies.

We here on the Reg stratocruiser desk will be cheering for the innovative "Z-wing" triad ship from Aurora Flight Sciences, BAE Systems and partners. This would see three wing sections take off independently and dock together 17 miles up. The resulting Z-wing would be able to cunningly tilt parts of itself in flight so as to align its solar cells with a sun low on the horizon, as it would be much of the time when flying at high northern or southern latitudes in winter.

Frankly though, any day a $155m deal is awarded for someone to build a five-year upper-atmos wingship is a pretty good day for the stratocruiser desk, so we won't complain whoever gets the job.

But it'll be a big job. At the moment the sunbird flight record is just two nights, held by the Qinetiq "Zephyr", and even that was achieved with the midsummer sun passing almost directly overhead the flight test area. Still, if the Vulture II doesn't work, perhaps DARPA's $400m solar-powered blimp - flight demonstrator now building - will do better.