Project HORUS, the Royal Navy effort to deploy persistent air-search sensors on uncrewed maritime platforms, is now under contract as the service moves ahead with a distributed system intended to detect and track airborne threats.
The status of the project was confirmed in a written parliamentary answer from Defence Readiness and Industry Minister Luke Pollard, following a question from Conservative MP Ben Obese-Jecty asking for the scope of the programme.
Pollard said: “Project HORUS is supporting urgent operational requirements for a rapidly procured, persistent air-search capability using uncrewed maritime platforms fitted with sensors to detect, track, identify and report airborne threats. The project is on contract and is intended to help the Royal Navy generate distributed sensing that reduces risk to personnel, and will inform future procurement decisions.”
The confirmation represents a step forward from the market-engagement stage reported by the UK Defence Journal in March, when the Navy was seeking mature systems that could be brought into service at pace. At that point, the requirement called for “a rapidly procured and persistent air search capability” able to detect, track, identify and report threats including drones, fast jets and cruise missiles from sensors carried aboard maritime platforms.
The original market notice envisaged moving rapidly from industry engagement to an initial capability. It stated that the intention was to select credible solutions, place contracts and deliver the first capability within four to six months, with an emphasis on mature products and suppliers able to work quickly.
HORUS is built around distributing sensors across multiple lower-cost uncrewed platforms rather than relying entirely on crewed ships or a small number of high-value assets.
The earlier requirement described a “System of System Approach” intended to introduce greater mass through numerous lower-cost sensors operating from uncrewed platforms in areas where sending personnel could carry greater risk. Persistence was also central to the concept. The March requirement sought platforms capable of remaining on station for 30 days as a threshold requirement and as long as 90 days as an objective, without in-person human intervention or maintenance.
The performance targets outlined during that earlier market engagement included the detection of NATO Class 2 uncrewed aircraft, anti-ship and land-attack cruise missiles and third and fourth-generation fighter-bombers at distances of at least 15 nautical miles.
Industry was also asked to consider how the system could eventually be expanded to detect surface threats, including fast attack craft and uncrewed vessels. The initial requirement envisaged persistent surveillance across an area of around 2,500 square kilometres, pointing towards several sensor-carrying platforms operating together rather than a single picket.
Alternative commercial approaches were also being considered, including what the Navy described as “SENSE as a service”, potentially allowing industry to provide the sensing effect rather than Defence purchasing every element outright.
Those figures and performance requirements were set out during the earlier market-engagement phase and do not necessarily describe the final contracted configuration. Pollard’s latest answer confirms, however, that HORUS has moved beyond that initial stage and is now on contract in support of an urgent operational requirement.
One of the often over looked benefits of the Royal Navy drone program and off board missiles and sensors is that it opens up the best route for air and missile defence for the British isles. The best location to intercept ballistic missiles inbound for the UK is from the North Sea.
The Army clearly doesn’t give two f**ks about defending the UK so it’s time for the navy to do the job.
Hmm, that area (2500m2) covered is tiny. We are only talking a detection range of around 28km. A small low powered X-band will easily provide that kind of range. Though it won’t give you a very high detection altitude. A lot will depend on the target you are hoping to detect and track. For a general example, if looking to detect a large commercial ship, you would need around 100W of transmitter power to detect at that range, due to the ship’s really high radar cross section (RCS). However, a stealthy plane would need over 1kw or a lot more if the RCS is very low. I’m obviously generalising as I’m not considering the antenna’s gain or the receiver sensitivity. But if the drone is going to be used to detect small drones and stealthy cruise missile, you really need to consider pumping out a lot more power, as a minimum over 1kW to detect stealthy objects at this sort of range.
For example, Leonardo don’t advertise the power output of their Osprey 30 AESA radar. Which is classed a low size, weight and power (SWaP) radar. But they say it can detect objects at 200 nautical miles, and clearly don’t state the object’s radar cross section. But we know its an X-band AESA radar, with a fairly small antenna array area. I could confidently say it would need to be pumping out over 10kW to detect an object with a RCS of 5m2 at 200km, so for 200 nautical miles it will need to be higher. However, if you increase the antenna’s overall area, the power required to detect objects drops due to the antenna’s increased gain (amplification). There are some on-line details that say it has a peak transmitter power output closer to 100kW, which then would tally up with the 200 nautical mile detection range for large RCS objects. It is supposed to draw around 500W of electrical power. Which means the craft will need a decent power set and generator. But you could easily network a number of these radars together, to give a very good low level picture of the surface and airspace.
Well that’s nice and quick. Presumably on a small USV like the Kraken boats, or possibly the K3s themselves with a Giraffe 1X type sensor. Would be useful for spotting Iran/Houthi style drone attacks early while not being a target for missiles themselves.
Alternatively could be a slightly larger set on an ACUA Pioneer/Oceanus12 type vessel that wouldn’t be so good for accompanying warships, which is what is implied by the “reduces risk to personnel”, but might make an early warning system for Akrotiri etc.