On Friday, July 3, 2015 at 1:52:29 PM UTC-4, Ed Huntress wrote:

I guess you are. Doing it on sunlight alone is a remarkable technical
achievement.

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Ed Huntress

So what are the technical advances? A new type of solar cell? A new type of battery? A new material used in the frame or covering of the aircraft?

The TV program I saw said it was a publicity stunt to promote solar cell useage. The big technical advance according to the TV was a seat with a built in toilet.

I thought we already had solar powered drones that could remain aloft for days.

Dan