Skyborg UAV aims to join frontline US fighter aircraft

It’s only a few weeks into the new year, yet there’s plenty happening in “UAV land” already. I expect another year of innovations, novel developments and groundbreaking firsts in unmanned aircraft.

This month’s question: What’s a Skyborg? The U.S. Air Force (USAF) has awarded contracts to Kratos, Boeing and General Atomics to prove their approaches to the UAV program.

All three have fielded existing, company-developed drones which are intended to fly alongside and be controlled by the latest frontline U.S. fighter aircraft. The idea is to have expendable force-multiplier unmanned aircraft support the capabilities of high tech, hugely expensive aircraft in order to undertake perhaps more risky missions, with the potential improvement acceptable versus unacceptable losses.

Flying alongside frontline fighter aircraft, these jet-powered unmanned aircraft could undertake more risky close support parts of the mission, where loss of the UAV might be more likely, while the manned aircraft remains outside the high-risk envelope. Hence the term attritable is now being applied to these unmanned accompanying vehicles, which are intended to have a reduced cost profile so that loss of the UAV might be more tolerable.

The Air Force Life Cycle Management Center (AFLCMC) has awarded Skyborg Vanguard Program contract amounts to Boeing ($25.7 million), General Atomics ($14.3 million) and Kratos ($37.8 million) for initial prototyping. All appear to have Skyborg prototypes in development.

Kratos has subsequently announced other contract modifications related to the U.S. Air Force Research Laboratory (AFRL) Low Cost Attritable Aircraft Technology (LCAAT) program.

Boeing will offer a variant of the Airpower Teaming System (ATS) drone being developed in Australia for the Australian Air Force. Engine runs and initial taxi tests were recently completed, however the program went into a short hiatus at the end of 2020 because of high COVID-19 infection rates in and around Sydney.

Boeing will offer a variant of the ATS drone being developed for the Australian Air Force. (Photo: Boeing)

General Atomics Aeronautical Systems Inc. (GA-ASI) is in the process of modifying two company-owned Avenger UAVs to incorporate upgraded datalinks and the Skyborg System Design Agent (SDA) software. Flight trials will investigate Artificial Intelligence capability for autonomous control of the UAVs while operating alongside manned aircraft – with the object of demonstrating that “a mix of manned and unmanned aircraft can communicate, collaborate, and operate together,” said David R. Alexander, president of GA-ASI.

General Atomics Avenger unmanned aircraft. (Photo: GA-ASI)

The jet-powered Avenger aircraft has been under development and evaluation for more than 10 years so it is well characterized, and its performance as a UAV is already understood.

The XQ-58A Valkyrie UAV has benefited from earlier generations of Kratos high-speed jet-powered target systems — something none of the other Skyborg competitors have in their bag of tricks. Kratos has been providing high-speed target drones to the military for a number of years, so jet powered drones are something they have been developing and fielding for a long time.

Kratos aerial target drone. (Photo: Kratos)

XQ-58A Valkyrie UAV. (Photo: Kratos)

The Valkyrie UAV was developed under the LCAAT program to demonstrate unmanned low-cost capabilities, and to fly as a stealthy companion to manned aircraft. It is intended to carry internal and wing mounted weapons. The turbine division of Kratos is also investigating lower cost jet engine options for attritable UAVs.

Meanwhile, continuing developments in detect and avoid (DAA) are progressing, moving towards a solution for one of the main problems holding back integration of unmanned aircraft into controlled airspace.

A number of these solutions are based on ADS-B or Automatic Dependent Surveillance Broadcast, whereby the UAV location – usually position provided by onboard GPS — is transmitted at a regular interval by an equipped UAV. So any similarly equipped manned or unmanned aircraft can receive the ADS-B signal, has knowledge of where such flying obstacles might be and is therefore able to avoid a potential collision.

And for pseudo-satellite applications like the Airbus Zephyr which must transition between low-level airspace and the stratosphere, having on-board certified ADS-B is essential so that other aircraft and FAA air-traffic control have full visibility of such a delicate airframe which is lacking great maneuverability during climb-out, on station at altitude and during descent.

Zephyr pseudo-satellite UAV with uAvionix ADS-B transponder and GPS. (Photo: uAvionics)

Since Zephyr transitions through Class A airspace, the manufacturer Airbus decided that it should be equipped with an ADS-B transponder and GPS source which had undergone FAA recognized qualification testing and which meets known Technical Standard Order (TSO) requirements.

The equipment also needed to be small and use little power — at 70 grams and using only 2 watts, the uAvionix ping 200X transponder and truFYX GPS provide high power (54 dBm), high integrity transmissions of ADS-B and transponder mode data to Air Traffic Control (ATC) and other suitably equipped aircraft.

Zephyr is an all-electric vehicle, using sunlight to derive power from large photo-voltaic arrays which cover its upper surfaces. Batteries store surplus energy which is not consumed during daylight and provide power in order to maintain aircraft station through the night hours. From a perch at around 70,000ft, Zephyr is apparently focused on Earth-observation capability with payloads envisaged to include Electro Optical, Infrared, Hyper spectral, Passive Radio Frequency (RF) Radar, Synthetic Aperture Radar (SAR), plus Early Warning, Lidar and Automatic Identification System (AIS).

The Hover DAA solution. (Photo: Sagetech)

“Sagetech is another DAA supplier which is currently working with both fixed and rotary wing UAS customers who are incorporating DAA systems in their design and type certification projects,” said Tom Furey, CEO of Sagetech. “Sagetech is providing regulatory guidance, transponders and interrogators, and system design to ensure these UAV systems in development will satisfy the anticipated certification requirements. Sagetech itself, through technology development and partnerships with companies including Hover Inc., expects to offer a complete DAA prototype system by the end of this year.”

So, lots of progress towards Skyborg drone teaming systems with $78min awards by the Air Force Life Cycle Management Center from an anticipated budget of around $400m, while certified Detect and Avoid solutions help move commercial drones towards potential regular flight in controlled airspace.