Proof Of Concept
I'd say that 64 days constitutes adequate proof of concept. Good for them.
An unmanned, solar-powered drone was hours from breaking the world record for the longest-duration flight before it suddenly crashed. Armed with solar panels, weighing less than 75 kilograms and with a wingspan of 25 meters, the Zephyr 8 model, developed by Airbus, is designed to fly for long periods of time with no crew. A …
The conspiracy theories have entered the chat… Must. Not. Feed. The. Troll….. Aaaahhhh too late…
It’s not like the US DoD hasn’t been doing this ever since they could make things fly…
https://en.m.wikipedia.org/wiki/Casa_Grande_Photogrammetric_Test_Range
https://northomahahistory.com/2016/11/21/fort-omaha-balloon-school/
And as for secret reconnaissance accidents, there have been been a couple of Blackbird accidents flying over the US…
https://www.sr-71.org/blackbird/losses.php
So as for the US military using military equipment over US soil, what are you expecting? How else are you going to train? How do you test? How do you experiment?
Troll fed.
This drone is really a high performance sailplane with electric propulsion and solar charging. Staying up for a long time isn't the problem, its just a matter of finding minimal lift. Albatrosses, for example, rarely land, they just float on air currents using the action of wind on the sea's waves to generate enough lift to fly for as long as they want to (they have to land to feed). The only issue is that those controlling the plane need to watch out for changes in the atmosphere. The 'S' maneuver, for example, might have been to try to get away from unexpected turbulence, the sort of thing that could literally tear the wings off a plane like this.
It would have been prudent to carry some kind of parachute so that if there was a mishap the carcass could be recovered to figure out what when wrong. As it is they're going to be stuck with a pile of debris and a lot of questions.
It is a salutary lesson about the actual limitations of automation, drones, AI etc, that all the resources, and countless years of work of Airbus etc, didn't beat two guys with a Cessna, 60 years ago.
My pick is that they were using a Google IOT cloud service, and they incorrectly assumed that even GG wouldn't kill it in 64 days.
It was absolutely mad and the reason the FAA then stopped recognizing duration records. Those crazy guys had shown what could be done and everyone could see what that could lead to. Similar to glider duration records (set by Geza Vass and Guy Davis in 1961 with a flight time of 71 hours and 5 minutes. The single seat flight-endurance was set by Charles Atger in 1952 with a flight time of 56 hours and 15 minutes), with the right conditions those could theoretically go for months, but resupply is a problem and pilot fatigue a very real risk.
The NASA Helios crash comes to mind, I wouldn't be surprised if it turns out to be a similar problem. Windshear or turbulence can do funky things to an airplane
My first thought was to ask if the authorities have checked on the current locations of Robert Timm and John Cook, but it looks like Timm left this world in 1976 and Cook followed in 2012, so the odds of either of them being involved in the drone's downing to protect their record are very slim, unless one believes in things like ghostly intervention.