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Military espionage is usually carried out from a reconnaissance satellite located at an altitude of several hundred kilometers. However, traditions are breaking, and its functions are now being taken over by the so-called pseudo-satellite. More precisely, it is a drone flying in the stratosphere; however, associations with a satellite are not accidental: such a UAV is capable of staying in near-Earth space for as long as a spacecraft in its orbit. We are talking about the low-speed British BAE Systems Phasa-35.

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With a 35-meter wingspan, a carbon fiber fuselage the diameter of a drawing tube, and a takeoff weight of 150 kg, the Phasa-35 looks somewhat bizarre, resembling a giant insect. This large aircraft moves in the air thanks to two miniature electric motors on planes with solar panels. Energy is stored in lithium batteries. The design provides that individual elements of the solar battery can fail over weeks of flight without any disruption to the technology.

The acceleration wheels are an additional accessory and remain on the ground during takeoff. Landing is carried out directly on both engine nacelles; Thus, screws damaged during each landing must be replaced.

The latest planned tests of the new product took place at a US military training ground in New Mexico in July of this year. During their course, the drone managed to rise to a height of 20,120 m at a speed of 88.5 km/h. The advantages of this type of drone lie in its disadvantage – it is quite unstable, so powerful wind currents are contraindicated for it. In addition, the size makes the Phasa-35 vulnerable to air defense systems. Finally, a pseudosatellite is limited in the mass it can carry.

“The night zephyr flows through the ether”

This model is not yet rich in records. But one of its former competitors, also a British ultra-light aircraft from Airbus – the solar-powered QinetiQ Zephyr – flew for 18 days during successfully completed tests in 2021 in Arizona. In 2022, a more ambitious experiment was unfortunately interrupted on the 64th day of operation, ending in disaster due to air turbulence at high altitude.

The device is 10 years older than Phasa. Its length is 8.5 m, height – 1.5 m. The wingspan of Zephyr reaches 22.5 m with a take-off weight of up to 53 kg. The power of two electric motors is 0.6 hp. each, maximum speed 50 km/h (cruising speed – 40 km/h). The maximum flight range is 13,500 km, the ceiling is 21,000 m.

Due to interest from the Pentagon and NASA in a more advanced version offered by BAE Systems, the project has been relegated to the category of research drones. A total of 3 copies were built. It is known that Airbus is currently in talks with Saudi Arabian telecommunications company Salam about the sale of Zephyr. Salam believes that the future of the industry lies in the use of pseudosatellites to transmit 5G Internet signals.

Detective story of the birth of know-how

It turns out that Phasa-35 was invented by specialists who at one time created Zephyr. When QinetiQ sold the development to Airbus Defense and Space in 2013, its authors left the mentioned company and founded their own – Prismatic. In 2018, cooperation began with BAE Systems, which acquired Prismatic as a subsidiary in September 2019. Phasa-35 made its first flight on February 17, 2020 at the Woomera test site (Australia) under the guidance of the British Defense Science and Technology Laboratory with the support of colleagues from the Australian group.

The product was originally developed as a lower-cost alternative to satellites, capable of performing a range of missions, including border security, maritime and military surveillance, disaster relief, and temporary but reliable communications. The Anglo-Saxons even came up with a new category of UAVs for similar developments – the high-altitude pseudo-satellite HAPS. In flight, during the day the power units are powered directly from the sun, and at night they switch to power supply from the battery. This round-the-clock operation allows you to stay in the air indefinitely, even for a year.

Truly inexhaustible possibilities

Thus, having on board a small load of cameras, radars, and other sensors, the object is able to continuously remain over the area of ​​interest for months, listening to the airwaves or transmitting information about the movements of enemy troops. Tests of the Phasa-35 were carried out using a laser measuring system, which examined the surrounding conditions every 150 m while climbing. This predictive approach allowed the prototype to avoid atmospheric troubles.

The detailed characteristics of the Phasa-35 are classified, and the cost of the project is unknown. The only thing that can be said with confidence is that such an engineering solution is at least an order of magnitude, or even two, cheaper than the notorious RQ-4 Global Hawk or KH 11.

Perhaps the main advantage of the BAE Systems drone is the fact that it has the ability to hover motionlessly relative to the Earth’s surface (for comparison: the minimum speed of a satellite is 7.5 km/s, a strategic reconnaissance UAV is 500 km/h).

Strengths fight against flaws

This is attractive both for defense customers who need to monitor one square for a long time, and for businessmen for whom the deployment of pseudosatellites is important to provide access to high-speed Internet in remote regions.

The creators are now working to make the product more stabilized in relation to problematic weather conditions. The lower stratosphere is an almost ideal level of high-altitude reconnaissance: both at a relatively safe distance from the Earth, and not in such a harsh environment as space. In this regard, operators fear that harsh interference and mechanical stress in space will wear out spy satellites more and more over the years. And high-altitude drones will promptly replace them not only without damage to business, but also with benefit. At the same time, UAVs are much more practical than balloons.

2023-10-04 17:22:04
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