Soyuz-2.1v/Volga - Plesetsk 43/4 - Kosmos 2535/6/7/8 - July 10, 2019 (17:14 UTC)

[B. Hendrickx]

Object D (Kosmos 2538)
July 12          97.89° 97.10 min 616-623 km
current data   97.88° 96.63 min 594-601 km

now               97.88° 97.02 min 609-622 km

- the numbering is not known
- which is Kosmos 2535 which is Kosmos 2536 ?
Object D one of the two ?

Good questions. Based on yesterday's Ministry of Defense statement, the inspector satellite is either Kosmos-2535 or Kosmos-2536. Based on the currently available tracking data, the inspector satellite would appear to be Object D (the only one making significant maneuvers), but NORAD identifies that as Kosmos-2538. How can we know for sure that Object D is what the Russians call Kosmos-2538?

Also note that the Ministry of Defense said that the inspector did not only inspect the "registering satellite", but also "serviced" it. The most logical interpretation of that is that there was some kind of physical contact between the two satellites.

[Alter Sachse]

Object D was registered last, but that doesn't mean he was the last one to be separated.
Object A and D have similar orbit elements.
These are probably the two satellites.

[jcm]

Agreed. Here is the semimajor axis height of the satellites versus time, A in red and D in cyan.
B and C in blue seem to be passive (maybe SKRL-type calib spheres perhaps?)

[Alter Sachse]

B and C in blue seem to be passive (maybe SKRL-type calib spheres perhaps?)

I believe, calibration was cited as one of the tasks.

[jcm]

Here is the separation of A and D versus time (quick and dirty estimate, there is some noise in my calculation at the 2 km level)

[satwatcher]

Some observational data on the objects from the 2019-039 launch.

COSMOS 2535 [44421/19039A] is transmitting on S-band at 2280MHz. It was heard during scans of that frequency on July 12, 16 and today, August 4. Though COSMOS 2535 has been close to COSMOS 2538 [44424/19039D] over the last few days, the identification is secure, as on July 12 and 16 they were much farther apart and COSMOS 2535 was the best fit of the Doppler curves.

In the past, the following COSMOS objects have also transmitted on 2280MHz:
COSMOS 2491 [39497/13076E]
COSMOS 2499 [39765/14028E]
COSMOS 2504 [40555/15020D]
COSMOS 2521 [42919/17037D]

All these satellites share similar behaviour in that their radio transmitter is only active when in range of Russian ground stations. However, COSMOS 2535 is the first to show ground locks, in which the spacecraft radio locks to a ground station, which is visible as an additional Doppler shift (ground station to spacecraft plus spacecraft to my location). As far as I can recall, the other 4 COSMOS satellites transmitting at this frequency have not shown ground locks (and I do not recall having seen this for any previous Russian satellite).

Video observations were obtained of all five 2019-039 objects between 20:43 and 20:57UTC this evening at distances of 1100 to 1300 km for COSMOS 2535/6/7/8 and 870 km for the Volga upper stage [44425/19039E]. The Volga upper stage [44425/19039E] was brightest due to the smaller range.

Both COSMOS 2536 [44422/19039B] and COSMOS 2537 [44423/19039C] were seen and were steady and of equal brightness.

According to the latest CSpOC TLEs, which are unfortunately already 3 days old, COSMOS 2535 [44421/19039A] and COSMOS 2538 [44424/19039D] were still close together. Only a single object was seen, but due to the old TLEs, it is unclear which of the two was visible. Once updated TLEs become available I can hopefully identify which object was visible. Unless both objects were very close (angular separation of an less than 2 arcminutes), this means the other object is considerably fainter. This object was stable in brightness and about as bright, maybe a bit brighter, as COSMOS 2536 and 2537.

[jcm]

Another rendezvous appears to have been carried out on Aug 7

[B. Hendrickx]

Note that Objects A and D were separated by between 20 and 30 km on August 4 (day 216 in Jonathan McDowell's graph), which I suppose should have been far enough for Cees Bassa to see them separately when he made his visual observations on that day (see post 65),  yet he saw only one of the two objects. This could mean that one of the two objects is much smaller than the other, but another intriguing possibility is that one of them uses stealth technology to reduce its visibility. As I have mentioned before, TsNIIKhM and NII Ferrit Domen signed a contract in November 2016 for what almost certainly is radar absorbing material for the Nivelir satellites. According to Ferrit Domen's website, the stealthy material it is developing (among other things for satellites) can also absorb radiation in the optical and infrared parts of the spectrum. More details in post 325 in the Kosmos-2519/2521/2523 thread:

https://forum.nasaspaceflight.com/index.php?topic=43064.320

It will be interesting to see if further visual observations confirm the stealthy nature of either Object A or D.

             

[satwatcher]

Video observations from August 10 around 20:45UTC of the pass of COSMOS 2535 and COSMOS 2538 again show a single object. The CSpOC orbital elements suggest that COSMOS 2535 fit the observations best.

[B. Hendrickx]

One more visual observer reporting that he saw just one object when he was expecting to see two:

http://www.satobs.org/seesat/Aug-2019/0058.html

From: JAY RESPLER via Seesat-l <seesat-l_at_satobs.org>
Date: Mon, 12 Aug 2019 03:30:31 -0400
On Aug 5, Cosmos 2535 and Cosmos 2538 were predicted as 2 seconds apart.
Only one object was seen.

Note that he is actually talking about Kosmos-2535 and 2536, the two satellites of the quartet launched on July 10 that according to a statement from the Ministry of Defense on August 1 are involved in rendezvous and proximity operations. Kosmos-2535 and 2536 must be Objects A and D or vice versa and Kosmos-2537 and 2538 must be Objects B and C or vice versa. The latter two have not shown any activity to date.

[Alter Sachse]

Docked or invisible ("Stealth") ?

[B. Hendrickx]

From Jonathan McDowell:

https://twitter.com/planet4589

The Kosmos-2535 and 2536 spacecraft (44421 and 44424)  continue rendezvous experiments with close approaches on Aug 7, Aug 11, Aug 12, Aug 16, Aug 18 and Aug 19. In between the sats mostly stay within 30 km or so but on Aug 16 and 18 did a retreat to 400 and 180 km separation

[Rondaz]

The Russian satellites Kosmos-2535 and Kosmos-2536, launched in July, continue proximity operations experiments. Here is the orbital height versus time and a (+/- several km) estimate of the relative separation versus time..

https://twitter.com/planet4589/status/1179524169123454976

[Rondaz]

A new object cataloged from the Kosmos-2535/2536 launch. Doesn't seem to be recently ejected. It's in the catalog as debris from the Volga stage - if that's correct, it must have separated on launch day. The object was very close to Kosmos-2535/36 on Aug 3  by my calcs..

https://twitter.com/planet4589/status/1180621717112328194

[jcm]

A new object cataloged from the Kosmos-2535/2536 launch. Doesn't seem to be recently ejected. It's in the catalog as debris from the Volga stage - if that's correct, it must have separated on launch day. The object was very close to Kosmos-2535/36 on Aug 3  by my calcs..

https://twitter.com/planet4589/status/1180621717112328194

I wish someone would check my sums on this. Seems like I am the only one paying attention to this mission at the moment!

[B. Hendrickx]

According to a post on the "Novosti kosmonavtiki" forum, four more objects have been catalogued (Objects G, H, J, K), all identified as "Cosmos-2535 debris". I understand these have appeared in addition to the "Volga debris" mentioned by Jonathan McDowell in his latest post here. Is that Object I?

http://novosti-kosmonavtiki.ru/forum/forum12/topic16791/?PAGEN_1=5

The new objects are in significantly different orbits. One wonders if they may have resulted from some type of interaction between Cosmos-2535 and 2536 during one of their recent encounters.   

[gwiz]

"Volga Debris" is Object F/44621

[B. Hendrickx]

Several Russian media have picked up this story, some of them jumping the gun and speculating that Cosmos-2535 may have broken up in orbit.

An English-language report is here:

https://www.mbs.news/2019/10/the-us-says-it-detected-foreign-objects-in-space-after-the-approach-of-russian-satellites.html

The US says it detected foreign objects in space after the approach of Russian satellites

Space13:48 17.10.2019(updated at 13:51 17.10.2019) Short URL

MOSCOW (Sputnik) – The US military claims that they have found in space four unknown objects that appeared after several approaches of two Russian satellites launched last July, according to the space-track.org website of the US Air Force.

On July 10, the Soyuz-2.1V rocket orbited four Russian military satellites, including Cosmos 2535 and Cosmos 2536.
The Americans say that the four new objects were separated from Cosmos 2535 and that they fly at a height of 600 kilometers.

The US Air Force did not communicate the dimensions of the devices or their possible missions.

According to information from the Russian Ministry of Defense, Cosmos 2535 and Cosmos 2536 were designed to investigate the effects of cosmic radiation on active satellites and test technologies to protect and maintain these space devices.

In June 2017, Russia launched an orbital platform into space with an inspector satellite inside, capable of analyzing the technical state of satellites from a safe distance. Four months later, the inspection device separated from the platform.

Meanwhile, Igor Lisov writes on the NK forum that the US orbital data actually indicate that the newly catalogued objects did not separate from either Objects A or D (the two objects involved in the rendezvous and proximity operations, which are Cosmos-2535 and 2536 or vice versa), but from Objects B and C (Cosmos-2537 and 2538 or vice versa), which so far have not maneuvered. He says Objects H and J separated from Object C and Object G separated from Object B, adding that the source of Object K cannot be determined with certainty, but most likely is Object B.

 

[jcm]

Interesting. Makes one wonder if B and C are Romb/Koltso type satellites (a successor generation, though) releasing ESO calibration objects

[B. Hendrickx]

In my preliminary analysis of this mission in July (see Reply 48) I speculated that the four satellites might be of the following types:

- a 14F150 satellite of NPO Lavochkin (same type as Kosmos-2519) (part of the Nivelir project)
- a 14F153 inspector satellite of the Central Scientific Research Institute of Chemistry and Mechanics (TsNIIKhM or CNIIHM) (same type as Kosmos-2491, 2499, 2504 and 2521) (also part of the Nivelir project)
- another, unidentified CNIIHM satellite, possibly intended to study effects of artificial and natural space factors on other satellites
- a radar calibration sphere of the KYuA type built by NPTs KB RPS, a small design bureau belonging to the Moscow Power Engineering Institute 

 This was mainly based on the following information available at the time:

- insurance documentation released in December 2018 for the shipment of NPO Lavochkin satellites and Fregat upper stages to Russian cosmodromes in 2019 mentioned a 14F150 satellite to be transported to Plesetsk in the first half of the year
- Dutch satellite watcher Cees Bassa picked up signals from one of the satellites that were on the same frequency as those transmitted by Kosmos-2491, 2499, 2504 and 2521
- the Ministry of Defense launch announcement gave "studies of artificial and natural effects on satellites" and radar calibration as one of the mission objectives
- all four satellites were reported to have been built by companies based in Moscow

Enough time has now passed since launch to see how much of this preliminary analysis holds true, although everything remains very much in the realm of speculation (and will undoubtedly continue to do so for the remainder of this mission).   

Analysis of orbital elements by Jonathan McDowell shows that two of the objects from this launch (A and D) have regularly performed maneuvers and that the other two (B and C) have so far remained passive, gradually decaying from the deployment orbit. The two maneuverable satellites were identified in an August 1 statement of the Ministry of Defense as Kosmos-2535 and 2536, which means that the two passive ones must be Kosmos-2537 and 2538. It is still unclear exactly which objects correspond to which Kosmos numbers. However, NORAD’s identification of Object D as Kosmos-2538 is clearly wrong. 

The lack of maneuvers is exactly what can be expected from radar calibration satellites, so there is a possibility that objects B and C are both radar calibration spheres. One potential problem with that is that four new objects catalogued by NORAD last week seem to have originated from B and C. NORAD identified them as “Kosmos-2535 debris”, but analysis of orbital data by Igor Lisov indicates they came from B and C (see the first attachment for a full list of objects from the July 10 launch). Radar calibration spheres are unlikely to release other objects. Jonathan McDowell has speculated here that the radar calibration spheres may be the newly catalogued objects and that B and C are platforms from which they were deployed. The Soviet Union flew platforms (called Taifun-2 and Koltso) carrying multiple radar calibration spheres in the 1970s and 1980s, but these weighed over 1 ton. Clearly, if B and C are similar platforms, they would have to be much smaller given the mass constraints imposed by the Soyuz-2-1v launch vehicle. One also wonders why it would have taken three months for the spheres to be released from the platforms. In short, the nature of the newly catalogued objects remains a mystery.


Of the two maneuvering objects, “D” has been the most active one. It has been playing “yo-yo” with Object A, alternately coming very close to it and then moving away to distances of up to 400 km. The first of these close encounters was reported by the Ministry of Defense on August 1:

https://function.mil.ru/news_page/country/more.htm?id=12244103@egNews

The announcement described one of the satellites as an “inspector satellite” and the other as a “registering satellite”. It said their mission was to study the effects of “artificial and natural space factors” on satellites and also to test technology to protect (another possible translation would be “defend”) satellites and service them in orbit. More specifically, the equipment on the inspector satellite was designed to study the effects on the registering satellite of “space debris, electron and proton radiation of the Earth’s outer natural radiation belt, protons and heavy charged particles, solar and galactic cosmic rays”.

One puzzling aspect about these two satellites is that only one of them has been spotted by satellite observers even when they were far enough apart to be seen individually. One observer has told me that he estimated the magnitude of the observed object at a faint +8/8.5.

It still cannot be ruled out that Kosmos-2535 and 2536 are of the same type as Kosmos-2519 and 2521, which also performed rendezvous and proximity operations. However, there are differences between the missions as well. One obvious one is that Kosmos-2535 and 2356 were deployed individually from the Volga upper stage, whereas Kosmos-2521 was separated from Kosmos-2519 about two months after launch. Why would that configuration be changed for this mission if exactly the same satellites were involved?  Also, while it is still too early to draw any definitive conclusions, the “yo-yo” maneuvering pattern seen until now is not quite what was observed on the Kosmos-2519/2521 mission, which saw two prolonged periods of formation flying (one lasting two weeks and another about a month) and several fast and slow flybys. See Jonathan McDowell’s description of that mission here:
https://www.planet4589.org/pipermail/jsr/2018-August/000127.html
In addition to that, 14F150 is likely to be a relatively large satellite (+100kg) that should be easily spotted by satellite observers. The visual observations would indicate that the satellites are smaller than that and one may even be using stealth technology.


One alternative explanation for the nature of Kosmos-2535/2536 is that they are the first satellites flown as part of Burevestnik, another project run by CNIIHM. Burevestnik has been described in procurement documentation as a “space security system” and is likely to be intended for anti-satellite operations. As is known from a presentation of solar panel/battery manufacturer PAO Saturn earlier this year, two types of satellites are being developed under this project which were identified as Burevestnik-M and Burevestnik-KA-M.  See reply nr. 14  in the Burevestnik thread:

https://forum.nasaspaceflight.com/index.php?topic=45734.0

One explanation for this is that one is an interceptor and the other a target satellite (the “M” in one of the names could stand for mishen’, Russian for “target”). Kosmos-2535 and 2536 could possibly be those two types of satellites.

Any test flight of this system would probably not be intended to physically destroy the target since the vast amounts of space debris generated by such an event would spark worldwide condemnation (last year’s Indian ASAT test being a case in point).   However, what could be tested are such things as the propulsion system and sensors needed to approach target satellites as well as non-destructive technology that could be used for both offensive and defensive purposes. There actually is some evidence that one such type of technology has been studied as part of Burevestnik.

In 2015 the Scientific Research Institute of Applied Chemistry (NIIPKh) (based in Sergiev Posad some 70 km north of Moscow) signed a contract with a company called SKBT Tekhnolog on what were described as “recommendations on the choice of chlorine-free oxidizers for gas generating substances”. The research project was named Burevestnik-SP. Although Burevestnik is a name used for a variety of projects, there can be little doubt that this contract was related to the Burevestnik space project because around the same time NIIPKh was also awarded a contract for a research project named Burevestnik-Pr-KBTM-NIIPKh in which it acted as a subcontractor to KB Tochmash (the “Nudelman design bureau”), which seems to be another leading player in Burevestnik (the purpose of that research is not clear from the available documentation). The documentation for Burevestnik-SP is here:

http://zakupki.gov.ru/223/purchase/public/purchase/info/common-info.html?regNumber=31502227950

A possible clue as to what Burevestnik-SP was all about came in an article written by NIIPKh specialists in 2016 (two of them being Sergei N. Vagonov and Igor V. Tartynov, the two  NIIPKh representatives who signed the Burevestnik-SP contract).

https://cyberleninka.ru/article/n/istoriya-i-perspektivy-razvitiya-nizkotemperaturnyh-pirotehnicheskih-generatorov

The article explored various possible applications of “low-temperature pyrotechnic gas generators”, more specifically solid-fuel generators that produce nitrogen gas. These can be used for a wide variety of purposes (such as the inflation of airbags), but one more unusual function of such generators described in the article was to “defend spacecraft from attacks by enemy assets equipped with detection, homing and negation systems” by producing “aerosol formations in the [upper] layers of the atmosphere”. These aerosol particles were described as having both a “masking” and “damaging” effect, probably meaning that they could be used not only to conceal the satellite under attack from the interceptor, but also to disable some of the interceptor’s systems (such as optical devices). The authors noted that such gas generators could be made small and light enough to be installed aboard satellites and at the end of the article singled out “spacecraft defense” as one of the most important future applications of such gas generators.

А NIIPKh patent filed in October 2016 (among others by Vagonov and Tartynov) seems to describe exactly such a space-based gas generator.

https://patents.s3.yandex.net/RU2627416C1_20170808.pdf
English machine translation:
https://patents.google.com/patent/RU2627416C1/en
(note that the word “aircraft” seen here is an inaccurate translation of the Russian word meaning “flying apparatus”, which is used in this patent to refer to space-based objects)

The device is called a “generator of finely dispersed formations” (see the drawing in the attachment) and is said to be intended to place “targets consisting of equally distributed finely dispersed formations on the trajectory of space bodies”. More specifically, it could be used for “research of fireballs in the upper atmosphere”, but that very much looks like a cover for its real purpose. The research drew upon work done at the Russian space agency’s TsNIIMash research institute last decade and described in this patent filed in 2006:

https://patentimages.storage.googleapis.com/00/b8/2e/1ef4a9f9813105/RU2332264C2.pdf
(Russian version)
https://patents.google.com/patent/RU2332264C2/en
(English version)

Unlike the gas generator proposed by TsNIIMash, the one conceived by NIIPKh would remain fixed to the satellite rather than separate from it in order not to create any unnecessary space debris. According to the patent holders, experiments with a prototype version of the generator in a vacuum chamber had given promising results, making it possible for them to recommend it for serial production.

Similar satellite defense technology was developed by the Central Scientific Research Institute of Radio Engineering (TsNIRTI), a Moscow-based company best known in the space community for producing electronic intelligence payloads for satellites. The work was done in cooperation with a Siberian research institute (IPPU SO RAN) under a research project called “Vual” (“veil”) initiated by the Russian space agency in late 2011. It involves the use of nanosized carbon black particles to conceal satellites from attacking ASATs. I described Vual in some detail in an article for “The Space Review” last year (see the final part of the article):

http://www.thespacereview.com/article/3536/1

Attached is a drawing from a 2014 TsNIRTI patent describing the use of this technology to defend a satellite from an approaching interceptor. By 2015 TsNIRTI and IPPU SO RAN had tested an installation that could produce the carbon black particles on an industrial scale, as is clear from this TsNIRTI paper:
https://studylib.ru/doc/2273828/bol._shakov-d.a.--ershov-g.v.--murlaga-a.r.-sravnitel._noe

There clearly has been co-operation between NIIPKh and TsNIRTI in developing this type of technology, as is obvious from these three patents (all filed in 2014) (available only in Russian):

https://patents.s3.yandex.net/RU143274U1_20140720.pdf
https://patents.s3.yandex.net/RU149628U1_20150110.pdf
https://patents.s3.yandex.net/RU143883U1_20140810.pdf

Among the patent holders are NIIPKh’s Vagonov and Tartynov and TsNIRTI’s  Sergei N. Druzhko, who is known to have been involved in Vual.  Although none of these patents mention space-related uses of the gas generators, it is definitely possible that the two institutes have co-operated in that area as well.   

Roscosmos’ TsNIIMash research institute also has continued research into this type of technology, as is clear from this patent filed in April 2018 (available only in Russian):
 
https://patents.s3.yandex.net/RU2678759C1_20190131.pdf

It describes a way of concealing and defending satellites from “actively approaching objects” by ejecting a “finely dispersed fraction of metal-coated polymer particles which reflect radiation”.  The lead author, Mikhail V. Yakovlev, also holds several other patents that seem to be related to satellite defense from ASAT attacks.

Also noteworthy in this respect is a patent that appeared online earlier this month and belongs to CNIIHM. It is available through both of these links (in Russian only):

https://edrid.ru/en/rid/219.017.d3ec.html
https://findpatent.ru/patent/270/2702478.html

One of the patent holders is Vladimir Verkhoturov, the head of CNIIHM’s space department (called “Design Bureau of Applied Mechanics” (KBPM)), and also identified in procurement documentation as chief designer of Burevestnik.  Another one is Sergei Khramov, who co-authored a patent on ground-based test firings of satellite thrusters that can be linked to Nivelir and Burevestnik (the evidence for that is given in Reply 12 in the Burevestnik thread).
   
The patent involves the use of electrostatically charged “finely dispersed particles” to destroy space debris with an opposite electrostatic charge. The authors explain how this technique could be used to deal with space junk in geostationary orbit, which after some time in space gets a negative electrostatic charge. The interceptor would eject a cloud of lithium-coated particles which would become positively charged through interactions with the surrounding plasma as well as solar and cosmic radiation. Even if the particles are not aimed at the target and, say, released in the opposite direction, they would still be attracted by the negatively charged target. This places less stringent design requirements on the interceptor’s orientation systems and reduces the number of particles that need to be released. The particles would spread over all surfaces of the target, not just the side facing the interceptor, and, according to the authors, would destroy it, sending the resulting debris particles “on other trajectories”.

In other words, the net result of the interaction between the particles and the target would be the production of even more space debris. This would suggest that the research was not so much focused on cleaning up space debris, but on ASAT applications instead (which would also be more in line with CNIIHM’s background). One also wonders if the charged particles wouldn’t be more likely to affect on-board electronic systems rather than physically destroy the target, in which case this should be seen as non-destructive ASAT technology. The patent also lends some support to the idea that the main goal of Burevestnik may be to test technology that will ultimately be needed for ASAT operations in geostationary orbit (see the Burevestnik thread)     


In short, there is ample evidence that Russia has been studying technology enabling satellites to eject clouds of finely dispersed particles that could be used for both defensive and offensive purposes (the line between offensive and defensive technology is not always easy to draw). There is also some evidence that at least part of this work took place in the framework of Burevestnik and reached the stage of laboratory testing several years ago.

The big question, however, is if this technology has matured to the level that it can be tested in space. Any documentation that may prove this is not likely to be publicly accessible. All one can say is that tests of this type of technology would be consistent with one of the mission objectives for Kosmos-2535/2536 given in the August 1 MoD statement, namely “satellite protection/defense” (same word in Russian). They might even explain one of the other goals mentioned in the statement, namely to study the effects of “artificial and natural space factors” on satellites. This may not have to be interpreted literally. It usually takes months or years for such effects to become clearly visible, so is this really a realistic mission objective and why would it be of such particular interest to the military? Possibly, this was just a veiled way of saying that the “inspector satellite” was designed to study its own effects on the “registering satellite”.
 
Another objective given in the August 1 MoD report is “satellite servicing” (although it was not in the MoD launch announcement). This would imply that there has to be some sort of physical contact between the two satellites. The orbital data don’t rule out that Kosmos-2535 and 2536 have periodically docked, but the encounters between the two satellites have so far have been brief. If they were to test satellite servicing technology, one would expect them to stay docked for longer periods of time unless the purpose is to test only the docking procedure itself.  Satellite servicing has definitely been the subject of various Russian paper studies (as evidenced, for instance, by numerous patents recently produced by NPO Mashinostroyeniya, the former Chelomei bureau), but there is no documentary evidence for an approved military satellite servicing project (which, admittedly, is no conclusive proof of its non-existence).  Roscosmos did recently include servicing of geostationary satellites in a tender for a broader R&D program called Partitura-3, but this clearly is still far from implementation, if it ever gets approved. 

While it is impossible to provide conclusive evidence for a link between Kosmos-2535/2536 and Burevestnik, the project has definitely been underway long enough to have reached the test flight stage. Indications are that it started in September 2011, the same month that the Nivelir project was approved. Moreover, Burevestnik seems to use the same bus as the flight-proven Nivelir satellites (see several posts in the Burevestnik thread for the evidence). This also means that a Burevestnik test flight would still be consistent with Cees Bassa’s reception of Nivelir type radio signals. If Burevestnik has the same bus as Nivelir, it is also likely to have the same communications systems.

Finally, if NPO Lavochkin’s 14F150 nr. 2 is not part of this mission, why was it planned to be shipped to Plesetsk in the first half of this year? First, we don’t know for sure if it was delivered to Plesetsk during that period and, second, a recent statement by the general director of RKTs Progress indicates that another Soyuz-2-1v is currently being readied for launch at the Plesetsk cosmodrome. According to the Russian launch schedule on the “Novosti kosmonavtiki” forum, it is due for launch before the end of the year. Possibly, 14F150 nr. 2 is scheduled to go up on that flight.

Again, the link between Cosmos-2535/2536 and Burevestnik is highly speculative, but not at all unlikely based on orbital behavior, official Russian statements and a handful of Russian procurement documents, patents and articles. It will be interesting to see if further events during this flight support this hypothesis or not.