Military Review

Pseudo-satellites for pseudo-space: in anticipation of a high-altitude revolution


Pathfinder Plus. Source:

Favorable observation angle

Stratospheric heights of about 18-30 kilometers are poorly mastered by humans. In this kind of "near space" planes are taken infrequently, and there are no spacecraft. But such a layer in the Earth's air layer is very convenient for covert observation. Firstly, aircraft at such altitudes can survey an area comparable to the territories of Afghanistan or Syria, and at the same time patrol over one territory for a long time. At the same time, an orbiting satellite skips the terrain rather quickly, often not having time to capture important objects and processes. Secondly, ground-based air defense systems are not yet designed to search for and destroy such small-sized and high-altitude reconnaissance aircraft. According to calculations, the effective scattering area can reach 0,01 m2... Of course, with the massive appearance of such pseudo-satellites in the sky, the air defense will find solutions for interception, but the cost of destruction can be prohibitive. In addition to reconnaissance, high-altitude drones can provide communications and navigation.

Most of the drones developed so far, designed for such heights, are built on the basis of solar cells and batteries. At altitudes of several tens of kilometers, solar energy is "absorbed" much more efficiently, which allows the winged machine not only to power electric motors, but also to store energy in batteries. At night, the drones use what they store during the day; at dawn, the cycle repeats. It turns out a kind of perpetual motion machine that allows machines to fly from several days to several years at altitudes up to 30 kilometers. For example, if one such pseudo-satellite replaces the famous Global Hawk, then the operator will save about 2000 tons of fuel per year. This is not taking into account the lower cost and much longer operational time. However, all this information is theoretical: until now, the record for the duration of the flight of such equipment is 26 days. This was achieved in 2018 by the European pseudo-satellite Airbus Zephyr.

Illustration of the Airbus Zephyr pseudo-satellite application. Source: NPO Lavochkina JSC

Compared to classical satellites, high-altitude drones are naturally much cheaper and are closer to the Earth, which ensures high quality shooting and observation. The mentioned Airbus Zephyr is 10 times cheaper than Global Hawk and 100 times cheaper than World View satellites. In this case, the pseudosatellites are located below the ionosphere, which increases the accuracy of navigation and the determination of the location of radio emission sources. Unlike a satellite, an aircraft is capable of hovering over the object of observation for a long time, like an eagle, tracking all the changes taking place below.

One of the prototypes of the Helios drone. Source:

What is the concept of a pseudo-satellite for stratospheric flight? It is a lightweight composite airframe with good aerodynamic characteristics, equipped with highly efficient solar panels, batteries and fuel cells. In addition, highly efficient electric motors, lightweight control devices with low energy consumption, capable of promptly and independently reacting to emergency situations in flight are required. Such high-altitude vehicles are distinguished by their low carrying capacity (up to 100-200 kilograms) and extreme slowness - up to several tens of kilometers per hour. The first of these appeared in the 1980s in the United States.

Flying solar panels

Experimental pseudo-satellites of the HALSOL program were the first among such devices in the USA. Nothing sensible came of them due to the elementary lag in technology: there were no capacious batteries or efficient solar cells. The project was closed, but the appearance of the prototypes was not declassified, and the initiative passed to NASA. In 1994, its specialists presented their Pathfinder, which became, in fact, the gold standard for future pseudo-satellites. The device had a wingspan of 29,5 meters, a take-off weight of 252 kilograms and an altitude of 22,5 kilometers. Over the course of several years, the project has been repeatedly modernized; the last in the series was the Helios HP, whose wings were stretched to 75 meters, and the takeoff weight was caught up to 2,3 tons. This device in one of the generations was able to climb to 29 meters - a record for horizontally flying aircraft without jet engines. Due to the imperfect hydrogen fuel cells, Helios HP collapsed in the air during the second flight. The idea of ​​its restoration was not returned.

The second known model of a dual-use pseudo-satellite can be called the Zephyr family from the British QinetiQ, which appeared on the artificial horizon in 2003. After extensive testing and design improvements, the project was bought by Airbus Defense and Space in 2013 and developed into two main models. The first has a wingspan of 25 m and includes: a glider made of ultra-light carbon fiber, solar panels made of amorphous silicon from United Solar Ovonic, lithium-sulfur batteries (3 kWh) from Sion Power, an autopilot and a charger from QinetiQ. Solar panels generate up to 1,5 kW of electricity, which is enough for a round-the-clock flight at an altitude of 18 km. The second, larger pseudo-satellite was the Zephyr T with two tail booms and an increased wingspan (from 25 m to 33 m). This design allows lifting four times the payload (weighing 20 kg, sufficient to accommodate a radar station at an altitude of 19500 m).

Zephyr has already been contracted by the armies of Great Britain and the United States in single quantities. They had not yet had time to fully get used to the troops, when in March 2019 one of them crashed near an assembly plant in Farnborough, Hampshire. In this accident, the main drawback of such aircraft was revealed in full glory - high sensitivity to meteorological conditions during takeoff and landing. At working heights of many kilometers, precipitation and wind are not terrible for pseudo-satellites, but at the ground they feel uncomfortable.

Solar Eagle. Source:

DARPA also did not stay away from such a promising topic and in the late 2000s initiated the VULTURE program (Very-high Altitude, Ultraendurance, Loitering Theater Element - a super-high-altitude surveillance system with ultra-long loitering over a theater of operations). The firstborn was the Solar Eagle pseudo satellite, created by Boeing Phantom Works in conjunction with QinetiQ and Venza Power Systems. This giant has a wingspan of 120 meters, lithium-sulfur batteries, and eight motors powered by both solar panels and hydrogen cells. Currently, the Americans have classified the project and, most likely, are already testing the Solar Eagle in the form of pre-production prototypes.

PHASA-35 Source:

The most modern of the unclassified prototypes is a pseudo-satellite jointly developed by BAE and Prismatic Ltd - PHASA-35 (Persistent High Altitude Solar Aircraft, long-term high-altitude solar aircraft). In February 2020, it was launched into the air for the first time at the RAF airbase in South Australia. The flying solar panel with wings is capable of climbing 21 kilometers and carrying a payload weighing up to 15 kilograms. By the standards of high-altitude drones, the PHASA-35 has a small 35-meter wingspan and is designed, as the developers themselves write, for monitoring, communication and security. However, the initial and main path of the pseudo-satellite will be combat work. In this regard, following the results of the first flight, Ian Muldoney, Technical Director of BAE Systems, commented:

This is an outstanding early result and demonstrates the pace that can be achieved when we combine the best of British capabilities. Moving from design to flying in less than two years (20 months) shows that we can rise to the challenge the UK government has put before the industry to build the future air combat system over the next decade.

By the end of this year, it was planned to complete the tests and, after 12 months, transfer the first production vehicles to the customer. But the pandemic, of course, will make its own adjustments within the specified time frame.

Domestic LA-251 "Aist". Source:

The second pseudo-satellite, LA-252 "Aist", is still under development. Source: NPO Lavochkina JSC

Now there is a steady growth in interest in such high-altitude drones, and the expansion of the development area is proof of this. In addition to the successes of China, India, Taiwan and South Korea, Russian design bureaus are involved in the design of pseudo-satellites. The first domestic experimental high-altitude drone was developed at the S.A. Lavochkin and named LA-251 "Aist". It was presented for the first time at the Army-2016 forum. The drone is made according to the normal aerodynamic design and is a free carrying monoplane with a wingspan of 16 m and a mass of about 145 kg. The monoplane has two tail booms, four 3 kW engines, and is equipped with a 240 Ah battery. Flight altitude up to 12 thousand meters, duration up to 72 hours. A larger "Aist" with a wingspan of 23 meters and a payload of 25 kg is now being developed. Such a pseudo-satellite already rises 18 kilometers and can be in the air for several days. For the sake of lightening the design, the aircraft was left with one beam and the number of motors was reduced from four to two. The further development of the domestic theme of pseudo-satellites is hindered by the lack of technologies for the production of lithium-sulfur batteries with a specific energy output of 400–600 Wh / kg. In addition, solar panels with a specific gravity of 0,32 kg / m are needed.2 with an efficiency of at least 20%. In many respects, it depends on this whether Russia will be able to reduce the existing gap with world leaders. With such a gigantic territory, our country simply cannot do without such pseudo-satellites in the future.
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  1. The leader of the Redskins
    The leader of the Redskins 10 September 2020 06: 08 New
    Funny flying machines.
    In our age of jet engines and hyperspeeds, they look anachronistic, like the first airplanes. And they come up with the use of them, like the same "whatnots".
    But we know what step the world aviation has taken in just a hundred years. Who knows, maybe in half a century our children will not be able to imagine their life without pseudo-satellites hanging at 30 km height?
    1. Civil
      Civil 10 September 2020 07: 35 New
      In 2018, the Albatross project was presented at Skolkovo. On a grand scale and a super site. On that and finished.
      1. Aviator_
        Aviator_ 10 September 2020 07: 50 New
        In 2018, the Albatross project was presented at Skolkovo. On a grand scale and a super site. On that and finished.

        They have mastered the money, the target function has been fulfilled. What kind of Albatross?
        1. Lopatov
          Lopatov 10 September 2020 15: 47 New
          Quote: Aviator_
          The money mastered

          Did he agree? laughing laughing laughing

          Quote: Aviator_
          What kind of Albatross?

          Konyukhov stated that they would start building the plane at the end of 2019, and it would take 20-24 months.
          It is still very early to shout "everything is lost, sawed off"
          1. Aviator_
            Aviator_ 10 September 2020 19: 41 New

            This "worker" now dreams of a bridge across the Tatar Strait, why does he need a high-altitude airplane?
            1. Lopatov
              Lopatov 10 September 2020 22: 11 New
              Quote: Aviator_
              This "worker" now dreams of a bridge across the Tatar Strait, why does he need a high-altitude airplane?

              There is his firm working with energy storage. Supercapacitors and the like. But so far this is being used by force in order to start trucks in frosts, although the prospects are great. For example, research work "Krymsk"

              We need advertising. Stock. An idea appears: a non-stop flight around Sharik under the wise guidance of Konyukhov.
              But it is not profitable to conduct it as an advertisement. Therefore, it passes as patronage on the part of Vekselberg

              If you do not understand, "Albatross" is an airplane that must catch up and overtake "Voyager" Steve Fossett
              1. Aviator_
                Aviator_ 11 September 2020 07: 55 New
                Clear. Under the wise patronage of Vekselberg, Konyukhov will conquer space. Only aircraft control is not balloon control, will our traveler be able to master it?
                1. Lopatov
                  Lopatov 11 September 2020 10: 55 New
                  Quote: Aviator_
                  will our traveler be able to master?

                  1. Aviator_
                    Aviator_ 11 September 2020 18: 14 New
                    A glider and an airplane in the stratosphere are fundamentally different piloting techniques. Our first stratospheric aircraft M-50 (the second was later called "Geophysics") was ditched by an honored test pilot. I understand Fedya is a brave man, but there are objective laws.
      2. Sidor Amenpodestovich
        Sidor Amenpodestovich 10 September 2020 09: 35 New
        Quote: Civil
        In 2018, the Albatross project was presented at Skolkovo. On a grand scale and a super site. On that and finished.

        Wow! In Russia, at least something is being done for real, and not with the aim of powdering the brain and plundering? How, then, does the state still manage to exist, if only they do what they saw and take out?
  2. Kote Pan Kokhanka
    Kote Pan Kokhanka 10 September 2020 06: 14 New
    I waved, something from childhood. Although I understand that children's airlines are made of wood and paper !!!!
  3. Uncle lee
    Uncle lee 10 September 2020 06: 45 New
    Pseudo-satellites for pseudo-space
    An interesting twist in technology!
  4. Free wind
    Free wind 10 September 2020 07: 14 New
    We have the S-300, the system is just getting ready for launch, everyone is falling from the sky, even shot sparrows.
  5. Reviews
    Reviews 10 September 2020 07: 21 New
    Another round of the spiral.
    Americans have already implemented on more traditional platforms. "Stratovision".

    And the plane with a hundred-meter span appeared on drawing boards back in the 1930s.

    1. John jons
      John jons 10 September 2020 20: 51 New
      U-2 reminds ...
  6. Aviator_
    Aviator_ 10 September 2020 07: 52 New
    An interesting niche for aircraft. In fact, the stratospheric altitude region is now not used at all, but should be.
  7. Mountain shooter
    Mountain shooter 10 September 2020 08: 19 New
    There was an idea to hang airships. But the higher the airship, the lower the carrying capacity.
    And such an application drives the technology of solar batteries, batteries, and electric motors ... makes it possible to reduce the weight of equipment and its energy consumption ... Any developments that drive progress in related areas are extremely useful. Synergy is the name of this phenomenon. Everyone needs high efficiency solar panels and capacious lightweight batteries.
  8. thinker
    thinker 10 September 2020 08: 29 New
    I wonder when and in general whether the project will be implemented - a stratospheric airship
    "Berkut" is an airship powered by solar panels. It is able to maintain a constant geographic position at altitude 20-23 km... The payload, which includes surveillance and tracking equipment, is 1200 kg and is supplied with electricity.
    1. Disant
      Disant 10 September 2020 15: 10 New
      if it were true, they would have done it long ago. It is unlikely that any airship is able to stay in place at those heights - it will be blown to hell
  9. Eskobar
    Eskobar 10 September 2020 10: 09 New
    If Rusnano had not squandered our hard-earned billions under the leadership of Chubais, but brought it to mind and worked for the result, we would have our own production of lithium batteries and solar cells
  10. Trapp1st
    Trapp1st 10 September 2020 11: 36 New
    heights of the order of 18-30 kilometers
    This will not be considered entry into foreign airspace, i.e. a legitimate purpose, and will any international flight rules apply to such devices?
    1. Jacket in stock
      Jacket in stock 10 September 2020 11: 55 New
      If the device hangs over the theater of military operations, then no one will remember the international flight rules.
      1. Trapp1st
        Trapp1st 10 September 2020 12: 00 New
        If the apparatus is hanging over a theater of operations
        That is, this device will not be able to replace satellites, to conduct reconnaissance of a technologically advanced enemy, especially when there is no open military action.
  11. Jacket in stock
    Jacket in stock 10 September 2020 11: 58 New
    Especially hung up the comparison of value with the global hawk.
    There's equipment on board ...
    She's just worth millions.
  12. Jacket in stock
    Jacket in stock 10 September 2020 12: 01 New
    Again, looking at these fragile shelves, the first thing that comes to mind is an air launch. To avoid the adverse effects of atmospheric phenomena in dense layers,
    He folded his wings, loaded them into a container on the back of a normal plane, raised them to a height, brought them back to working condition and released them ...
    1. prior
      prior 10 September 2020 12: 21 New
      There is a simpler option - he climbed higher on balloons, accumulated the "sun" in the batteries, and then "sama".
    2. Proctologist
      Proctologist 10 September 2020 13: 41 New
      I thought so too. "Folding" will probably not work - the folding mechanisms will make the device heavier, and you will not be able to transfer them to the carrier by 100%. But it is possible to rigidly secure, dividing takeoff and acceleration safe. And it is convenient for transportation, its own speed is small. True, it is possible to transport them disassembled, and then assemble them by hand at the launch airfield.
  13. Pavel57
    Pavel57 10 September 2020 12: 24 New
    At what height does outer space begin, where you can fly without demand?
    1. certero
      certero 10 September 2020 12: 30 New
      Usually space is considered from 100 km
    2. voyaka uh
      voyaka uh 10 September 2020 13: 54 New
      ABOUT! This is a question of questions.
      Not a single international treaty prescribes any specific figure
      Usually, they write "aircraft altitude".
      Until recently, it was 21 km.
      But there were: 1) these new super-high planes - about 30 km.
      2) hypersonic winged glider missiles appeared. Heights 30-80 km
      And this is a big problem with air sovereignty.
      It is clear that such an ultra-high plane must be shot down. This can be the S-500 or the Israeli Hatz, or the Aegis missiles.
      And gliders also need to be knocked down. Difficult to get into, but they will learn over time.
      In any case, the country's airspace must officially include the stratosphere and above - semi-space.
      Up to 100 km.
      1. Zementbomber
        Zementbomber 14 September 2020 11: 58 New
        In fact - the internationally recognized upper limit of the national airspace - runs at an altitude of 100 km above the level of the World Ocean. Anything below you can shoot down if it flew unauthorized. Well, if you can shoot down, of course.
  14. voyaka uh
    voyaka uh 10 September 2020 12: 34 New
    I would still call them "super-high light aircraft" and not pseudo-satellites.
    They have nothing to do with companions,
    and the long wings clearly classify these vehicles as airplanes. Airplanes
    1. Proctologist
      Proctologist 10 September 2020 13: 38 New
      True in essence, but pseudo-satellites sound shorter and more beautiful, while fair enough, since by design (and not by design) these aircraft replace satellites.
  15. APASUS
    APASUS 10 September 2020 13: 58 New
    Attached a container with equipment to the balloon and let it hang for months
    1. Reviews
      Reviews 10 September 2020 21: 06 New
      Quote: APASUS
      Attached a container with equipment to the balloon and let it hang for months

      Calculate the weight of the cable.
      1. APASUS
        APASUS 11 September 2020 14: 09 New
        Quote: Avis
        Calculate the weight of the cable.

        Can you calculate the weight of the anchor chain better?
        1. Reviews
          Reviews 11 September 2020 14: 17 New
          Quote: APASUS

          Can you calculate the weight of the anchor chain better?

          Have you seen her anywhere on a balloon? Well, count, if you have nothing to do ...
  16. eklmn
    eklmn 10 September 2020 17: 45 New
    For those curious about Helios (translated by Google):
    “The electrically driven Helios is made primarily of composite materials such as carbon fiber, graphite epoxy, Kevlar, expanded polystyrene and a thin transparent plastic shell. The main tubular wing spar is made of carbon fiber. The spar, which is thicker at the top and bottom to absorb the constant bending movements that occur during flight, is also wrapped in Nomex and Kevlar for added strength. The fins are also made of epoxy and carbon fiber. Profiled polystyrene foam is used for the leading edge of the wing, and a strong transparent plastic film covers the entire wing. ”
    “The only flight control surfaces used on the Helios prototype are 72 elevators on the trailing edge, which provide pitch control. They span the entire wing and are powered by tiny servo motors linked to the aircraft's flight control computer. To turn the aircraft in flight, yaw control is applied by applying differential power to the engines — accelerating the engines on one outer wing panel and decelerating the engines on the other outer panel. The main test during the first series of flights was to evaluate the differential engine power as a pitch control. During normal cruise flight, the outer wing panels of the Helios are curved upward and give the aircraft the shape of a shallow crescent when viewed from the front or rear. This configuration places the engines on the outer wing panels higher than the engines on the center panels. The increase in the speed of the outer panel engines caused the aircraft to descend and begin to descend. Conversely, the addition of power to the motors in the center panels made Helios tilt and climb. "
    Electric motor - 2hp (1,5 kW)
    Solar panels - 18,5 kW
    Weight - from 800kg to 1000kg
    Speed ​​- 30km / h to 43km / h (approx.)
    1. Viktor Sergeev
      Viktor Sergeev 11 September 2020 07: 59 New
      That is, it can hardly keep itself in the air, and any improvement in order to obtain equipment will lead to a sharp increase in mass (engine, batteries, number of batteries) and the inability to fly. So far, this is an empty experiment.
      1. eklmn
        eklmn 11 September 2020 19: 13 New
        "That is, it can barely keep itself in the air, and any improvement in order to obtain equipment ..."
        You are right if this equipment is made with r / lamps or transistors. But now the equipment for observation (and the apparatus will not do anything else) is so miniature and energy-consuming that it will not feel this weight.
  17. fa2998
    fa2998 10 September 2020 18: 35 New
    Quote: Trapp1st
    This will not count as entering foreign airspace.

    It will be, space is considered to be pr. 100 km. - I don't want to fly. Everything below is the airspace over a sovereign country.
  18. Hog
    Hog 10 September 2020 22: 15 New
    It's a good thing, they are perfect for monitoring fires in Siberia, and, in principle, for the Emergencies Ministry.
    1. Viktor Sergeev
      Viktor Sergeev 11 September 2020 07: 57 New
      Are you missing the usual satellites? Can you imagine how many airplanes are needed flying 20 km. height to control the taiga and how much will such a system cost?
  19. Viktor Sergeev
    Viktor Sergeev 11 September 2020 07: 54 New
    I represent the power of a radar weighing 20 kg. Height 20 km. this is great for air defense, target. Interestingly, how can a low ESR be achieved with devices of this size? Will the coating be applied in five coats? In reality, it will go against the barmolees (although why bother to fence a garden if there are much cheaper methods of observation), but no one will let this hang over its territory, if there is air defense, they will be shot down immediately. A rocket for such, for example, launched from a MiG31 or other fighter, will cost a penny in comparison with this miracle.
    Well, what 30 km can we talk about when using non-jet engines? Well, maybe they will pull themselves somehow, but the load is unlikely.
  20. Chia1917
    Chia1917 11 September 2020 18: 37 New
    0 - "Проект завершен в сентябре 2017 году. В ходе его реализации ... Построена масштабная модель высотного БЛА на солнечных батареях с размахом крыла 9.5 м. Достигнута продолжительность беспосадочного полета в течении 50 часов на высоте до 8 км. Разработана и испытана летающая лаборатория беспилотного высотного комплекса свехдлительного функционирования с размахом крыла 28.5 м. Максимальная высота полета составила 19 км."
  21. Ervin
    Ervin 15 September 2020 15: 53 New
    It would not be bad at all if such a “birdie” went astray and made an emergency landing somewhere in the Astrakhan region. Without the "tsap-tsarap" - and the S-70 "Hunter" - there would not have been, and a lot of other things. Although it is not a fact that it will turn out to be done, technology has lagged behind since the last century.