Project Razbeg

[B. Hendrickx]

The All-Russian Scientific Research Institute of Electromechanics (VNIIEM) is working on a new military satellite project called Razbeg (“run-up”, “running start”). This is clear from the following procurement documentation on zakupki.gov.ru:

http://zakupki.gov.ru/223/purchase/public/purchase/info/common-info.html?regNumber=31705789387
(published in November 2017)

http://zakupki.gov.ru/223/purchase/public/purchase/info/common-info.html?regNumber=31807328993
(published in December 2018)

The first series of documents says that the “government customer” for the project is the Ministry of Defense and that it began with a contract signed on 1 November 2016 (number 6/Ts-2016, Cyrillic: 6/Ц-2016) between VNIIEM and an organization called “Center of Special Technical Assets”, which I will come back to in a moment. The documents include
 a draft contract between OKB Fakel (a manufacturer of satellite propulsion systems) and NPO IT (Scientific Production Association of Measuring Technology) for the delivery of 170 temperature sensors called TM293-05. OKB Fakel acts as a subcontractor to VNIIEM. The contract name is Razbeg-MK-DU, with DU standing for “propulsion unit” (the meaning of MK is not clear). This shows that Razbeg will carry a propulsion system made by OKB Fakel, which specializes in thermal catalytic engines and stationary plasma thrusters.

The second series of documents does not mention the name “Razbeg”, but does refer to contract 6/Ts-2016, showing it is related to this project. It contains a contract signed on 22 October 2018 between VNIIEM and the Moscow Factory of Electromechanical Equipment (AO MZEMA) for the delivery of components for a reaction wheel called DM-10-1000. Reaction wheels are used to maintain attitude control without the consumption of propellant. VNIIEM pioneered electromechanical attitude control systems with its Omega and Meteor satellites back in the 1960s and has since produced numerous reaction wheels for its own satellites and satellites built by other companies. The DM-10-1000 reaction wheel is not mentioned on VNIIEM’s website or by other sources. The VNIIEM website does list a reaction wheel called DM-10-25, which probably has similar characteristics:

http://www.vniiem.ru/ru/index.php?view=article&id=288:2010-02-17-21-42-21

No payloads have been identified for Razbeg yet, but the fact that VNIIEM has so far only built Earth observation satellites (weather satellites called Meteor and Elektro and remote sensing satellites called Meteor-Priroda, Resurs-O and Kanopus) strongly suggests that this is some type of Earth imaging satellite, most probably a photographic reconnaissance satellite. It could well be the operational successor of VNIIEM’s experimental photographic reconnaissance satellite Cosmos-2525 (launched in March 2018), which was identified in VNIIEM documentation as EMKA (Experimental Small Satellite). At least one element that EMKA and Razbeg share is a propulsion system of OKB Fakel, although it cannot be determined at this point if it is identical.

As explained in the Cosmos-2525 thread, EMKA likely started out as a proposed civilian or dual civilian/military remote sensing satellite called Zvezda (“star”), which is mentioned in a handful of VNIIEM articles in 2014/2015.  One of those, published in VNIIEM’s in-house journal “Voprosy Elektromekhaniki” in 2014, described Zvezda as an experimental precursor of a small high-resolution imaging satellite called MKA-V  (MKA standing for “Small Satellite” and “V” for “high resolution”).

http://jurnal.vniiem.ru/text/141/17-22.pdf

As can be seen in the attached table from the article, MKA-V is somewhat larger and heavier than Zvezda (
90x100x160 cm vs. 90x70x140 cm and 250 kg vs. 150 kg),  but seems to have the same optical system (presumably produced by the Belarusian company OAO Peleng). MKA-V is also supposed to fly in a higher orbit than Zvezda (450 km vs. 300 km), which could at least partially explain the longer operational lifetime given in the table (5 years for MKA-V vs. 1 year for Zvezda). MKA-V is the box-shaped satellite seen below the table. It closely resembles the privately built US remote sensing satellite SkySat-1, data for which are also included in the table for comparison.

Indications are that EMKA became a dedicated military project in 2015, resulting in the signing of a contract between the Ministry of Defense and VNIIEM on 23 October 2015. It is therefore reasonable to speculate that the November 2016 contract is for the operational version of this satellite, originally designated MKA-V and now called Razbeg. If this is indeed the case, the project is likely to see the launch of several satellites, complementing the imagery currently provided by the two operational Persona satellites and by their successors called Razdan, which are yet to be launched. 

One argument against Razbeg being MKA-V is that it would have made more sense for the Ministry of Defense to await the results of the Cosmos-2525/EMKA mission to press ahead with the development of its operational successor. It is also strange that unlike the October 2015 EMKA contract, which was a “direct” contract between the Ministry of Defense and VNIIEM, the November 2016 Razbeg contract was awarded to VNIIEM through an organization subordinate to the Ministry of Defense, namely the Center of Special Technical Assets. Little can be learned about this from online sources other than that it is based in Voronezh and is a branch of the State Scientific Research and Test Institute for Problems of the Technical Protection of Information (GNIII PTZI), also located in Voronezh. This in turn is the research arm of the Federal Service for Technical and Export Control (FSTEK), a Ministry of Defense agency tasked with “protecting state secrets and countering cyber espionage”. 

Most of the papers emanating from GNIII PTZI are about countering cyber espionage and it is totally unclear what role it or the Center of Special Technical Assets plays in the space program. The Center of Special Technical Assets also signed a contract with NPK KBM (Design Bureau of Machine Building in Kolomna) on 1 December 2015 as part of Burevestnik, likely a co-orbital anti-satellite system (see the Burevestnik thread). Another organization under FSTEK, the Central Scientific Research Institute of Chemistry and Mechanics (TsNIIKhM or CNIIHM), is known to play a leading role in Burevestnik, Nivelir (satellite inspectors) and Numizmat (purpose unknown, but clearly intended for rendezvous and proximity operations in orbit). There are also similarities in the contract numbers for Numizmat (3/Ts-2014), Burevestnik (20/Ts-2015) and Razbeg (6/Ts-2016). Possibly, these are used for projects involving FSTEK.

This organizational background could point to another role for Razbeg than photoreconnaissance, but this will only become clear if more information becomes available. An Internet search does turn up a couple of projects named Razbeg, but none of them seem to be related to the space program. It is customary in the Russian designation system to use the same name for totally unrelated projects.

[B. Hendrickx]

In the first post here it was speculated that Razbeg is a 250 kg high-resolution photoreconnaissance satellite referred to in one VNIIEM publication as MKA-V. Another possibility is that is a much heavier satellite (more than 1.5 tons) based on a new VNIIEM bus that will also be used by the Russian-Belarusian high-resolution remote sensing satellite called RBKA. See the RBKA thread:

https://forum.nasaspaceflight.com/index.php?topic=48765.0

[B. Hendrickx]

http://zakupki.gov.ru/223/purchase/public/purchase/info/common-info.html?regNumber=31908153653

This is documentation for a tender by ISS Reshetnev called "Development of communications equipment" as part of a theme called Razbeg-NK-NS. The contract was awarded in late August to a company called OOO BIT in Yekaterinburg.

Presumably, ISS Reshetnev is responsible for the development of the ground segment for Razbeg ("NK" likely stands for "ground complex" and "NS" may stand for "ground station").  ISS Reshetnev (together with its daughter company NPO PM Razvitiye) fulfills a similar role in the Nivelir project.

Also online until recently was information about a contract called Razbeg-NS-SZ signed with a company named ZAO Akuta in St.-Petersburg in October 2018. This was for the development of a system to prevent unauthorized access to information ("SZ" stands for "protection system"). This is likely also related to the ground segment for Razbeg.

[B. Hendrickx]

Another contract for VNIIEM’s Razbeg project turned up last week on Russia’s government procurement website:

https://zakupki.gov.ru/223/contract/public/contract/view/general-information.html?id=8188281

The contract is called “Razbeg-MK-ETR1” and is related to the satellite’s thermal control system (“ETR” stands for “elements of the thermal control system”). More specifically, it is for “metrological examination of design documentation” for this equipment.

The contract was awarded by the Scientific Research Institute of Electromechanics (NIIEM). Based in the Moscow suburb of Istra, this is a former affiliate of VNIIEM that gained independence in 1992. However, the two institutes maintain close ties, with NIIEM supplying numerous subsystems for satellites built by VNIIEM (although it also does work for other satellite manufacturers). In the field of thermal control, NIIEM builds controllers for electric heaters and cryogenic cooling systems for infrared detectors. According to the documentation, VNIIEM and NIIEM signed a contract for the Razbeg project on 25 June 2019. 

The documentation describes Razbeg as a “small spacecraft” (Russian acronym MKA), a term usually used in Russian literature to refer to satellites weighing less than 500 kg. That would rule out the possibility that Razbeg uses the same bus as a Russian-Belarusian high-resolution remote sensing satellite (RBKA) currently under development at VNIIEM (this weighs more than 1.5 tons) (see post 2 here). It does support speculation that Razbeg is a 250 kg class satellite earlier described in VNIIEM literature as MKA-V, the operational successor of the “experimental small satellite” (EMKA) launched last year under the name Kosmos-2525 (see post 1).


A code-name for Razbeg may be “Project 505”, which almost certainly is a satellite project run by VNIIEM. The name is seen in at least three sources:

http://www.novator-istra.ru/images/Docs/Godovoi-otchet-2018.pdf

This is the annual report for 2018 of AO Novator, another company in Istra that supplies subsystems for VNIIEM satellites. Among the activities planned for 2019 is work on Meteor-M and “(a) satellite(s) of Project 505” (because of the use of the acronym KA for “satellite” it is impossible to determine whether this is singular or plural). More specifically, AO Novator is to supply “the separation system” and “antennas of the modified telecommand system” (AFU TKS-M). The “separation system” would appear to be the system that separates the satellite from the launch vehicle. However, back in the 1990s AO Novator also developed a “universal separation system” (USO) to separate subsatellites from the Meteor satellites. This might be an indication that Razbeg will fly to space piggyback with a larger satellite. 


https://mo.superjob.ru/resume/inzhener-1-kategorii-24132604.html

This is the CV of a specialist who worked for VNIIEM from October 2017 until August 2019. He took part in the development of Kanopus-V nr. 3-6 and “the spacecraft (of) Project 505”.

https://zakupki.gov.ru/223/purchase/public/purchase/info/common-info.html?regNumber=31908684797

This is procurement documentation released by NIIEM last week for (a) spacecraft developed under Project 505. It is for the delivery of a German-built “stepper motor” to be used in “the manufacture of protection equipment for OEM TsA”. “OEM” is an acronym often used for “electro-optical module” and “TsA” usually stands for “payload”. The least one can deduce from this is that the Project 505 satellites will have an optical payload.

It is not yet possible to definitively link Project 505 to Razbeg, but there seem to be few other candidates. It is clearly not Meteor or Kanopus-V and the only other satellites known to be under development at VNIIEM (RBKA and Ionozond) are also civilian satellites that would not seem to require the use of a cover name. VNIIEM is also reported to have been working on a Kanopus-based satellite for Iran, but the status of that project is unclear.

[B. Hendrickx]

Razbeg will carry a star tracker called mBOKZ-2R, which is one in a line of BOKZ star trackers built by the Optico-Physical Department (OFO) of the Institute of Space Research (IKI). This is known from three contracts signed in July and November 2019 year between IKI and IRZ Test (part of the Izhevsk Radio Factory) for the delivery and testing of electronic components of the star tracker.

https://zakupki.gov.ru/223/contract/public/contract/view/general-information.html?id=7288378
https://zakupki.gov.ru/223/contract/public/contract/view/general-information.html?id=7288579
https://zakupki.gov.ru/223/contract/public/contract/view/general-information.html?id=8036392

The contracts do not mention the name Razbeg, but refer back to the contract (nr. 6/Ts-2016) that started the project on 1 November 2016. This was signed between VNIIEM and a mysterious organization called the Center of Special Technical Assets (part of the Ministry of Defense’s Federal Service for Technical and Export Control or FSTEK), which also acts as the customer for the latest phase of the Burevestnik project. 

 "mBOKZ" stands for "Small Unit to Determine Star Coordinates" (star trackers help a satellite find its proper orientation by comparing its view of stars in space against a star map stored in onboard computer memory). The star tracker was earlier flown on the AIST-2D remote sensing satellite of RKTs Progress, launched on the first mission from Vostochnyy in April 2016, and on VNIIEM’s experimental photoreconnaissance satellite Kosmos-2525/EMKA, launched in March 2018. See this list of satellites carrying BOKZ type star trackers on the IKI website:

http://ofo.ikiweb.ru/razrabotki/bokz.html

In the list, AIST-2D’s star tracker is called mBOKZ-2 and that of Kosmos-2525 mBOKZ-2V, but it is not clear if there is a major difference between these and the mBOKZ-2R star tracker for Razbeg.

More details on mBOKZ-2 are here:

http://ofo.ikiweb.ru/razrabotki/mbokz-2.html

The star tracker consists of two optical units and a data processing box (see the attached picture). The data processing box has two independent circuits for the two optical units. Using a 2048x2048 pixel CMOS array, mBOKZ-2 is four times lighter, two times smaller and twice as accurate as earlier star trackers in this series (most of which have used CCD sensors instead). OFO IKI's website says contracts have been signed for the delivery of more than 25 mBOKZ-2 star trackers for future missions.

The presence of similar star trackers on Kosmos-2525/EMKA and Razbeg could be further evidence that Razbeg is the operational successor of EMKA, a possibility discussed in earlier posts here.

The mBOKZ-2R star tracker as well as a Sun tracker called OSD-V were also the subject of four contracts signed between September and December 2019 between IKI and IRZ Test for what is identified as “Project 505”.

https://zakupki.gov.ru/223/contract/public/contract/view/general-information.html?id=7578109
https://zakupki.gov.ru/223/contract/public/contract/view/general-information.html?id=7763238
https://zakupki.gov.ru/223/contract/public/contract/view/general-information.html?id=7939220
https://zakupki.gov.ru/223/contract/public/contract/view/general-information.html?id=8140591

More specifically, IRZ Test was to supply and test components for one test unit of both mBOKZ-2R and OSD-V and two flight units of both mBOKZ-2R and OSD-V.

I mentioned Project 505 in the previous post and speculated it could be a code-name for Razbeg. The newly found documentation confirms that Project 505 is run by VNIIEM and is intended for remote sensing. However, it refers back to other contracts between VNIIEM and IKI than the one signed between the two organizations for Razbeg. Therefore, Project 505 could be another project than Razbeg. One possibility is that it is Sapsan, a remote sensing satellite revealed by Roscosmos at the Paris Air Show last year but not linked to any satellite manufacturer. See this thread:

https://forum.nasaspaceflight.com/index.php?topic=48486.0

[B. Hendrickx]

Court documents published earlier this year show that two subcontractors for Razbeg are NPK Barl and the Research Institute of Radio Communications in Rostov-na-Donu (RNIIRS).

https://kad.arbitr.ru/Card/56d2d86c-aa17-4a4c-a984-f550732cc2e1

NPK Barl awarded a contract to RNIIRS on July 3, 2017 for work called Razbeg-NS-SPI-APK. Considering the background of the two companies, this is almost certainly related to Razbeg’s ground support systems. NPK Barl builds both mobile and fixed ground stations for remote sensing satellites and has co-operated with RNIIRS on such systems in the past. The abbreviations may stand for:
NS: ground segment
SPI: information reception system
APK: rotatable antenna complex (this is the system that appears to be provided by RNIIRS)

RNIIRS sued NPK Barl for not having been paid for phase 2 of Razbeg-NS-SPI-APK, which was completed in early 2020. However, NPK Barl was in the same situation, not having received the necessary payments from the prime contractor (VNIIEM) despite having finished its part of the work as well. VNIIEM in turn attributed this to delays in payments from the Ministry of Defense.

It’s noteworthy that NPK Barl also provides ground support systems to VNIIEM in the project to develop a remote sensing satellite for Iran (Project 505). That does not necessarily mean that the satellites themselves have a common design, although that possibility certainly exists. For one, Razbeg and the Project 505 satellite are known to use the same type of star sensor, provided by the Institute of Space Research. It is also possible that both use a lightweight remote sensing telescope built by NPK Barl, which branched out into such systems several years ago. More on that in this article on the Russian-Iranian remote sensing satellite:
https://www.thespacereview.com/article/4199/1

[B. Hendrickx]

Documentation appeared online recently on environmental impact studies of Razbeg launches from Plesetsk. The studies were announced here:
https://o-v-o-s.ru/29/33427

They were to be conducted from January 15 to June 1 and public hearings were scheduled between April 16 and May 15.
Documentation containing the results of preliminary environmental studies is here:
https://mirniy.ru/info/ads/23826-uvedomlenie-o-provedenii-obschestvennyh-obsuzhdeniy.html

The name Razbeg itself is not used in the documentation, only the index for the individual satellites (14F169) and for the so-called  “space system” (14K051). This is an overall program designator covering the satellites, the launch vehicles, the cosmodrome infrastructure and the ground segment to control the satellites and receive data from them.

Little is revealed about the satellites themselves, except that they are built by VNIIEM, consist of a service module and a payload module and will carry up to 8 kg of hydrazine and between 80 and 110 kg of xenon. This shows they will use both monopropellant hydrazine thrusters and an electric propulsion system. Both are likely provided by OKB Fakel, which is known to be involved in Razbeg (see the first post in the thread). As is known from procurement documentation, Razbeg will also have reaction wheels (DM-10-1000) for attitude control (see post 1).

The 14F169 satellites are compatible with a variety of launch vehicles and can be launched individually or in groups. The possible launch vehicles are the Soyuz-2.1v, Soyuz-2.1a, Soyuz-2.1b and Angara-1.2 (with Angara-A5 given as a possible alternative “if required”). If necessary, the Soyuz-2.1a and 2.1b can be outfitted with a Fregat upper stage. The Volga upper stage is not mentioned. Angara-1.2 will use its so-called “aggregate module” (AM) to place the satellites into orbit.
According to the documentation, the modernized Rokot-2 with the Briz-KM-2 upper stage could also be considered as a launch vehicle for 14F149, but since this relies on toxic propellants, the use of the other launch vehicles is preferable from an ecological standpoint of view.
 
Three types of payload fairings are given, designated GO81KS, SZB14744 and 98KS. 81KS is the big 4.11x11.4m fairing for Soyuz-2.1a and 2.1b.  14744 is most likely 14S744, a smaller fairing used for Soyuz-2.1a and 2.1b (for instance, for the launch of Bars-M satellites). 98KS is the fairing for the Soyuz-2.1v. For some reason, the payload fairing for Angara-1.2 (14S733) is not included.

The satellites can be delivered to Plesetsk by road, rail or air. Launch preparations are described in detail, but look fairly standard.  What does seem unusual is the fact that one of the tanks will be removed from the satellite for loading in the fueling station and will then be returned to the assembly building for re-integration with the satellite. It is not clear if this is the hydrazine or the xenon tank.

Launches of Razbeg satellites will use only the standard drop zones in the White Sea and Barents Sea, indicating that only northbound launches into polar orbits are planned.  Several years ago environmental impact studies were conducted of Soyuz-2.1v launches from Plesetsk into 73° inclination orbits, but these will evidently carry other payloads than Razbeg.

The 14F169 satellites will not contribute to the space debris population. Nothing will be ejected from the satellites after they separate from the launch vehicle, nor are they designed to be detonated in orbit (like some Soviet-era photoreconnaissance satellites).  After fulfilling their missions, they will slowly decay before re-entering and burning up in the atmosphere. It is not planned to de-orbit them because their “ballistic lifetime” will not exceed 25 years, which by Russian standards is the maximum time that a defunct satellite can remain in orbit and still comply with space debris regulations.
 
The third stage of the Soyuz-2.1a and 2.1b and the second stage of the Soyuz-2.1v and Angara-1.2 will enter orbit. This is a different profile than seen during the Angara-1.2 launches in April and October 2022, when the 2nd stage was suborbital and the AM insertion stage delivered the payload to its intended orbit. The AM insertion stage will be de-orbited following the release of the satellites (as it was after the April and October 2022 launches), but what is called only “the upper stage” (presumably Fregat) will be moved to a storage orbit. This is hard to explain, because even if the satellites are delivered to relatively high orbits, the Fregat should be capable of de-orbiting itself. 

Some more tidbits of information on Razbeg have leaked out via court documents:
https://kad.arbitr.ru/Card/a8c6f38f-376f-4f86-b40d-89e416a7043b

These ones, published in 2022-2023,  refer a contract for Razbeg signed on June 27, 2018 between VNIIEM and NPK SPP. Again, Razbeg is not mentioned by name, but the documents do give the number of the government contract that is known to have started the project in November 2016. Although no details are given on the nature of the work, the documents mention PNBO, a division of NPK SPP that specializes in ballistic support of space missions.  Possibly, the work had something to do with operating several of the satellites in the same orbital plane, something which is obviously being considered.   For some reason, the contract between the companies was annulled in early 2020, by which time only part of the work had been completed.

https://kad.arbitr.ru/Card/e6a7d508-c0a0-40b3-82c6-34d3f5f824c2

One of the documents here is the only one so far that links the 14K051 program designator to the name Razbeg. It mentions two contracts signed on February 3, 2017 between VNIIEM and a company called STT Grup. One (called Razbeg-IO) was for “information support” and the other (Razbeg-NS-TO) was for the development of a so-called “mobile test object”. This is Russian terminology for ground-based optical calibration targets that can be used to determine the resolving power of remote sensing instruments. Similar calibration targets were made for the mission of Kosmos-2525 (EMKA), probably an experimental precursor of Razbeg launched in 2018. These were foldable polymer sheets with various patterns painted on them to help calibrate the satellite’s optical payload. Another contract between VNIIEM and STT Grup on April 27, 2020 covered the delivery of hardware and software to assist in mission planning. STT Grup was declared bankrupt in early 2023, but it is not clear how this affected the work.


As I have explained in other threads, there are several reasons to believe that the Razbeg satellites are similar in design to Khayyam, the remote sensing satellite that VNIIEM built for Iran and which was launched from Baikonur in August 2022. Also see this article on The Space Review:
https://www.thespacereview.com/article/4475/1
Much of the information came from a patent related to Khayyam filed by a company called NPK Barl:
https://patents.s3.yandex.net/RU2753201C1_20210812.pdf

NPK Barl is involved in building the ground segment for both Khayyam and Razbeg and may also provide their optical payloads. Three different types of payloads are described in the patent (with apertures of 0.535, 0.75 and 1.1 m). Khayyam, a 650 kg satellite, was orbited by a Soyuz-2.1b with a Fregat upper stage, even though the Soyuz should have been capable of launching the satellite without the upper stage. Also seen in the patent is a configuration with three of the same satellites under the payload shroud.  This may be the configuration planned for the first launch. According to a VNIIEM presentation in mid-2022, the company expected to launch three small satellites (“MKA nr. 1, 2 and 3”) in the second half of the year, something which ultimately didn’t happen.

Razbeg has been linked to a number of Russian military satellite launches in the past years. While that seemed like reasonable speculation at the time of these launches, subsequent mission operations made this interpretation unlikely.  The fact that the environmental impact study of Razbeg launches from Plesetsk was not supposed to be finished until this June is another sign that these satellites are yet to fly, not taking into account the possibility that Khayyam may be acting as a trailblazer.  Since the satellites are designed to be launched by a variety of launch vehicles, one can assume that a considerable amount of them are expected to be placed into orbit. This should at least partially compensate for the apparent cancelation of one of the bigger and more capable Razdan (14F156) optical reconnaissance satellites, only one of which now remains scheduled for launch.

[Ludovic Monnerat]

Little is revealed about the satellites themselves, except that they are built by VNIIEM, consist of a service module and a payload module and will carry up to 8 kg of hydrazine and between 80 and 110 kg of xenon. This shows they will use both monopropellant hydrazine thrusters and an electric propulsion system. Both are likely provided by OKB Fakel, which is known to be involved in Razbeg (see the first post in the thread). As is known from procurement documentation, Razbeg will also have reaction wheels (DM-10-1000) for attitude control (see post 1).

Shouldn't it be the opposite, with 8 kg of xenon and between 80 and 110 kg of hydrazine? With a wet mass of 650 kg and normal assumptions (isp 220 s for hydrazine and 1500 s for xenon), such a spacecraft would have a delta-v of 466 m/s (283.4 for the chemical propulsion and 182.2 for the electric one), which seems reasonable. Not taking into account the huge price of such a quantity of xenon.

[B. Hendrickx]

Shouldn't it be the opposite, with 8 kg of xenon and between 80 and 110 kg of hydrazine? With a wet mass of 650 kg and normal assumptions (isp 220 s for hydrazine and 1500 s for xenon), such a spacecraft would have a delta-v of 466 m/s (283.4 for the chemical propulsion and 182.2 for the electric one), which seems reasonable. Not taking into account the huge price of such a quantity of xenon.

The documentation does give the values I mentioned in my post (up to 8 kg of hydrazine and between 80 and 110 kg of xenon). These are given in three different passages in the text, so it doesn't look like a typo.

But you're right, the amount of xenon does seem to be disproportional to the satellite's mass (assuming that is indeed roughly the same as that of Khayyam, namely 650 kg). By comparison, VNIIEM's Kanopus-V remote sensing satellites, which weigh around 450 kg, have a xenon load of just 5.2 kg and RKTs Progress' Aist-2T satellites, which weigh 670 kg, have a maximum xenon mass of 19.4 kg. Both are designed to operate at an altitude of about 400-500 km and have no chemical propulsion system in addition to the electric propulsion system.

Also, there are no Russian-built xenon tanks that I know of that have a capacity of between 80 and 110 kg. The one that comes closest is the MVSK50 tank of NIIMash, which has a maximum capacity of 71 kg (it is used by several of ISS Reshetnev's geostationary communications satellites). There does seem to be a good candidate for the hydrazine tank, namely the MVSK84 of NIIMash with a capacity of 8.1 liters (this is used by some of the inspector satellites). Another one may be the S5.155 of KB Khimmash, which was flown on Kosmos-2525, the experimental precursor of Razbeg. Its capacity, however, is unknown.

Anyway, you've made an excellent point and this is another mystery to unravel.

[zubenelgenubi]

Wonderful first post! Welcome aboard!

<snip>

Anyway, you've made an excellent point and this is another mystery to unravel.