Posted on Leave a comment

Drone On A Leash: Orion 2 Tethered Mini-Drones Can Fly 24-Hour Shifts

Spread the love

Electrically-propelled mini-drones are increasingly popular means of obtaining a bird’s eye view of an area, or establishing communication relays in remote places. But such small unmanned aerial systems (sUAS) can’t carry much in the way of batteries.

That limits most mini-drones to flying times of 20 to 30 minutes, hardly convenient if you need that eye-in-the-sky or impromptu communications station online for long stretches of time.

Tethered drones offer a solution for tasks where endurance is important—and roving over wide areas is not. Such drones are literally tied to a power station on the ground by a cable which may also double as a high-speed datalink for the drone’s sensors. As a bonus, tethered drones tend to be simpler to deploy and require less training to operate.

Static long-endurance flight is attractive to all sorts of users. Military units guarding isolated Forward Operating Bases want drones watching from on high for possible assailants, as do police and private companies providing security for large events. Film crews too appreciate cameras that can remain airborne for hours at a time. And park services, firefighters and disaster relief teams are interested in ways to establish communication links deep in wilderness or rural areas.

Nonetheless, while a tethered drone in theory could remain airborne as long there’s power left in its ground-based generator, in practice a typical small drone’s motors and other components are prone to overheating and/or vibration damage after enough hours of continuous flight. Those problems grow more acute for drones designed to carry heavier payloads up to higher altitudes.

Elistair, a leading tethered drone manufacturer, claims to have made a breakthrough with its Orion 2 drone, increasing endurance to a full 24 hours, up from 10 hours for the first-generation model.

MORE FOR YOU

The French company, which has over 300 clients across the globe, kicked off its business in 2015 with sales of kits to convert conventional drones for operation with its Safe-T tether and power station, followed by a smaller Light-T kit aimed at civilian and police clients. These kits have been used by military operators like the UK Special Forces, United Nations emergency relief agencies seeking to set up telemedicine links at disaster sites, and media to record footage of the Super Bowl and Formula One Grand Prix.

By contrast, the Orion is a “complete” unmanned aerial system (drone, tether and tether station, and laptop-based control station) optimized for maximal flight endurance. The first-generation model is already in service with operators in Greece, Singapore and the United States.

The 20-pound Orion 2 can carry up to 4.4 pounds of payload, by default a 30X magnification electrooptical sensor (including an uncooled infrared channel) with two or three axes of stabilization that can detect vehicles from 3 to 6 miles away in daylight.

The drone’s modular bay allows alternate payloads—which can include a laser illuminator or more powerful 36x magnification lenses—to be “hot-swapped” in less than a minute.


Rigor and redundancy

I asked Elistair co-founder Guilhem De Marliave, what secret formula lay behind the second-generation model’s more than doubled endurance.

“The big challenge is the lifespan of the components: bearings, motors, electronics and so forth,” De Marliave explained. “There are a lot of vibrations going on that you have to take into account. We also worked on the single points of failure—ie. communications and power—to ensure we have redundancies.”

This redundant architecture means most of the Orion 2’s vital systems, like its radios and safety battery have a backup—right down to an emergency parachute recovery option. The design is also hardened versus inclement weather, with an IP54 rating against water damage and most dust ingress.

After 24 hours, De Marliave recommends landing the drone for 10-minute inspection—after which it can be sent right back up into the air. After every 400 hours usage, the motors can be easily be swapped out with new ones.

The Orion 2 uses a Safe-T-2 micro tether that’s slightly longer than football field at 100 meters (nearly 330 feet) in length. It both transmits electrical power from the ground station and serves as a 200 megabits per second secured link. When I inquired if it was possible to lengthen the tether, De Marliave told me it was more complicated than it seemed.

“If you want to go higher, you need a bigger drone. Then you have an impact on wind resistance, you have wind drag, and then you need a bigger tether.” Their tests found there was greatly improved utility when hitting altitude between 200 and 400 feet due to surmounting obstructions created by small hills, trees and other terrain features.

“We found that we could actually do a lot more by reaching a height of 100 meters. [But] the tradeoffs were too big for longer tethers than that.”


Elistair versus the field

Elistair is by no means the only vendor of tethered drones, so I was curious to compare the Orion 2 with publicly available specifications for competing designs.

I found that while some manufacturers do give hard numbers on endurance, others advertise their drones as having “limitless” endurance while tethered. That may be true in terms of power, but leaves unclear just how long those designs can remain aloft before suffering elevated risk of component failures.

The following table is by no means comprehensive and based solely on the market based on materials released to the public by the manufacturer.

Some very small “microdrones” do specify 24-hour or indefinite capability, though these systems are inherently constrained in payload (lower magnification cameras, for example) and maximum altitude. Some of these drones also can optionally detach the cable if wider range of movement is desired and fly on batteries for up to 20 minutes. Conversely, there are also tethered UASs with greater payload and/or maximum altitude, but lower or unspecified endurance.

A market study also notes that drones using hydrogen fuel cell technology could potentially disrupt the market for tethered drone. However, a technical article suggests hydrogen fuel cells could boost endurance to “90 minutes or more” for multi-rotor drones—still well below the the many hours of endurance offered by tethered drones..

Thus, tethered drones will likely remain an attractive option to users seeking easy-to-deploy aerial observation platforms, cameras and communication relays that can remain aloft for lengthy periods of time.


Browse Drones for sale


Please note that Pricing and Availability on Drones or other products are not guaranteed and must be verified with retail seller at time of purchase. As an affiliate, we can earn from qualifying purchases, at no cost to buyer.
Stay up-to-date with new Drone blogs and new Drones - Join our Maillist

Leave a Reply

Your email address will not be published. Required fields are marked *

eleven + fourteen =