RPO Galore: the complex proximity operations of Kosmos 2581, Kosmos 2582, Kosmos 2583 and 'Object F'

click image to enlarge

Some 590 km above our heads, a complex series of multiple Rendezvous and Proximity Manoevers (RPO) by multiple Russian military spacecraft has been going on the past months, weeks and days.

On 5 February 2025, Russia launched three satellites from Plesetsk, into a 82 degree inclined orbit: Kosmos 2581, Kosmos 2582 and Kosmos 2583 (2025-026A, B and C). Kosmos 2581 was initially placed in a 595 x 578 km orbit; Kosmos 2582 in a 597 x 576 km orbit; and Kosmos 2583 in a 597 x 580 km orbit.

The diagram below sums up what has unfolded over the past few months: a complex series of manoeuvers and approaches to each other.

Click diagram to enlarge

 

About two weeks after the launch, both Kosmos 2581 and Kosmos 2582 were manoeuvered to a slightly higher orbit: Kosmos 2582 did so on 15 February and Kosmos 2581 on 19 February. 

On 24 February, Kosmos 2582 manoeuvered again, this time slightly lowering its orbit to the same orbital altitude as Kosmos 2581, for the initiation of first of a long series of complex proximity manoeuvers. They made a very close approach (1 km or less) on 24 February around 21:44 UTC. They stayed in each others close vicinity for the next three months, manoeuvering to and fro, with Kosmos 2582 doing the manoeuvering and Kosmos 2581 acting as the target..

Meanwhile, on 18 March 2025, the third satellite from the launch, Kosmos 2583, surprised by releasing a fourth object, 'Object F' (2025-026F). This object appears to be passive (i.e. it does not appear to be manoeuvering), but starting in April, Kosmos 2583 has subsequently been doing RPO manoeuvers with it, manoeuvering to and from it repeatedly, untill late May, so perhaps it is not merely debris. 

On 26 May, Kosmos 2583 manoeuvered away from 'Object F' to a higher orbit. It subsequently made a series of manoeuvers that made it closely approach Kosmos 2581 to a few hundred meters or less on June 10 near 9:42 UTC. It next stayed in the close vicinity of Kosmos 2581, approaching it again very closely in the days around June 19.

While Kosmos 2582 meanwhile had stayed in the wider vicinity of the other two, following them at a  distance of several hundreds of kilometers, it manoeuvered on June 23 in order to get close, within kilometers, to the by then close pair of Kosmos 2581 and Kosmos 2583. As a result, all three objects were now orbiting closely together.

 

click image to enlarge

The framestack above is from video footage I shot from Leiden, the Netherlands a few nights later during a near-zenith pass in twilight on 28 June 2025, when the three objects were still in close vicinity, albeit less close than the days before (during the days before, they were so close that I generally could not resolve them). Kosmos 2581, 2582 and 2583 are all visible in the framestack, the latter however being very faint.  

Kosmos 2581 and Kosmos 2582 were at about 1.2 km from each other at the time of observation. Kosmos 2583 was at about 3.6 km from Kosmos 2581.

Below is the actual video footage the framestack was derived from: the two brighter objects are Kosmos 2581 and 2582 (Kosmos 2581 leading), and just in front of them is Kosmos 2583, barely visible (look closely at full screen during the first 4 seconds of visibility). It was shot from my home in Leiden, the Netherlands, with a WATEC 902H2 Supreme and Samyang 1.2/85 mm lens.

'Object F' meanwhile, has drifted to quite a distance from the other three objects. Below is a framestack showing it, from video observations obtained on 17 June 2025: it was faint and might show some brightness variation.

Click image to enlarge

 

This is one of the most complex RPO exercises Russia has been conducting in LEO in decades. The RPO appears to be ongoing, and it will be interesting to follow it: for example, will we see that at one point 'Object F' is becomes the subject of an RPO again or not?

 

Post scriptum: more on another recent event with another Russian satellite, Kosmos 2558, releasing an object in another blogpost from today. 

Kosmos 2558 released an object on orbit on June 26 [UPDATED]

Object C (click image to enlarge)

 

Kosmos 2558 (2022-089A, cat nr. 53323) is a Russian military satellite that was launched from Plesetsk three years ago, on 1 August 2022. It was launched into the orbital plane of an American ADVANCED CRYSTAL spy satellite, USA 326. It is therefore believed to be a 'Nivelir' type 'inspection satellite' (see also this earlier discussion of several of such missions, and Bart Hendrickx' Space Review article on the Nivelir program  here).

As I recently wrote, there have now been four of these missions in a five-year timespan. Apart from Kosmos 2558 discussed here, these are: Kosmos 2542/2543 launched in the orbital plane of USA 245 in 2020;  Kosmos 2576 placed in the orbital plane of USA 314 in 2024 (see this earlier blogpost); and very recently, Kosmos 2588 placed in the orbital plane of USA 338 (see this earlier blogpost). 

With the exception of Kosmos 2542/2543, which have been deorbitted, all three remaining missions are still dedicatedly shadowing their American targets, keeping their orbital altitude and inclination difference such that the rate of RAAN (node) precession matches that of their target. This ensures that the orbital planes do not drift apart.

While mostly seen as 'inspection missions', I have repeatedly voiced a concern that these missions might be the positioning of 'dormant' on-orbit Anti-Satellite (ASAT) weapons. To me, the long, ongoing shadowing of what are some of the most prized US military space assets, their KH-11 Advanced Enhanced Crystal high-resolution optical IMINT satellites, is odd for 'just' an inspection mission. What is there still left to inspect after 3+ years? The satellites make only periodic close approaches (every few days) so monitoring of attitude (pointing) or radio signals is not an explanation.

Understandibly, the 'stalking' behaviour of these Kosmos satellites on their satellites makes the US military nervous. And now they have yet another reason to get even more nervous: on 26 June 2025 near 12:03 UTC (according to my analysis), Kosmos 2558 released  a second object, currently designated as 'Object C' (2022-089C, cat nr. 64627). 

The release is actually visible in the orbital elements for kosmos 2558, as a sudden slight lowering of the orbit:
 

Click diagram to enlarge

 

This is the third time we see this kind of 'Matrushka Doll' behaviour from Russian military satellites in five years time. 

Shortly after reaching orbit in 2020, Kosmos 2542 released a sub-satellite too, Kosmos 2543, which next in turn fired what is interpreted as a projectile, 'object E' (the latter was widely seen as an ASAT technology test at the time). 

In addition, more recently, Kosmos 2583 released an object, 'Object F' (2025-026F), on 18 March this year, as part of a complex series of RPO's (Rendezvous- and Proximity Operations) between Kosmos 2581, Kosmos 2582, Kosmos 2583 and said 'Object F'. I will publish a separate blogpost on these later [edit: separate post now available here].

In 2020 and more recently with Kosmos 2583 and 'Object F', this spawning of other objects happened within weeks after the launch of the parent satellite. But this time with Kosmos 2558 and 'Object C', the release of a second object happened almost three years after launch.

I observed Kosmos 2558 and the newly released 'Object C' last night. 'Object C' reached magnitude +8. The images below are 1-second frame stacks from video observations I made from Leiden, the Netherlands, on the night of 28-29 June 2025, two-and-a-half days after 'Object C' was released. At the time of observation, 'Object C' was some 143 km distant from Kosmos 2558, passing the camera FOV some 16-seconds after it. The first framestack shows 'Object C'; the second shows Kosmos 2558.

 

Object C (click image to enlarge)

 

Kosmos 2558 (click image to enlarge)

Below is the video footage of the pass in question. The first to pass through the FOV is Kosmos 2558 as a bright object: then, some 16 seconds later, 'Object C' passes through the FOV as a fainter object. The footage was shot from Leiden, the Netherlands, with a WATEC 902H2 Supreme camera and Samyang 1.2/85 mm lens.

 

 

It will be interesting to see whether any manoeuvering between the two objects is happening over the coming weeks.

 

UPDATE 4 July 2025:

Since release, Object C has been manouevering with respect to Kosmos 2558. While initially manouevering back to Kosmos 2558, it lowered its orbit significantly (by 15 km) on July 3 near 18:42 UTC. See diagram below.

Click diagram to enlarge

Kosmos 2588 has been placed in the same orbital plane as the US spy satellite USA 338: another RPO?

click image to enlarge

 

Russia launched a new military satellite from Plesetsk today (23 May 2025), Kosmos 2588 (cat nr. 64095, COSPAR 2025-109A). It was placed in a 73-degree inclined, approximately 464 x 481 km orbit.

As first noted by Bart Hendrickx, the orbital plane is very close to that of a US military optical reconnaissance satellite, USA 338 (2022-117A). This can be seen in the diagram above. 

The difference in RAAN is only 0.11 degrees, the difference in inclination is a mere 0.6 degrees. Kosmos 2588 orbits just above USA 338. They can come to within 100 km of each other in this orbital configuration.

This is the fourth time in the last five years that Russia has placed a military satellite in the same orbital plane as and very close in orbital altitude to that of a US military optical reconnaissance satellite. 

The first time was in 2020 when they placed Kosmos 2542/2543 in the orbital plane of USA 245. That had the appearance of an 'inspector satellite' mission (although Kosmos 2543 later fired a projectile). The second time was in 2022 when Kosmos 2558 was placed in the orbital plane of USA 326. The third time was in 2024, when Kosmos 2576 was placed in the orbital plane of USA 314 (see my earlier blogpost here). 

The latter two occasions were different from the first, in that the Russian satellites in question stayed co-planar with the US satellites, rather than paying a relatively brief visit as Kosmos 2542/2543 had done. Rather than being inspector satellites, we might perhaps be seeing a counterspace capacity (a sleeping co-orbital ASAT capacity) being positioned in the latter two cases.

Which makes the current fourth instance highly interesting: the plot thickens. It will be interesting to see whether they keep this one co-planar as well.

It is possible that, as was the case with the launch of Kosmos 2576 a year ago, multiple payloads have been put in space. So far (less than a day after launch) only one has been catalogued.

We are seeing more and more of these RPO activities (in LEO as well as GEO) lately. Things in space are clearly getting more confrontational and passive-aggresive. A very worrying trend.

The Russian eavesdropping satellite LUCH (OLYMP-K) 2 has moved significantly

click diagram to enlarge

I have written before on this blog about the Russian military SIGINT satellite LUCH (OLYMP-K) 2 (2023-031A). It was launched  on 12 March 2023, and like its predecessor LUCH (OLYMP-K) 1, it has since moved about along the geostationary belt, doing proximity operations near western commercial geostationary satellites. 

Each two to four months, it is moved to a new target, where it stays in close proximity until moved to a new target again, behaviour in a similar fashion to the US satellite PAN/NEMESIS-1 in the past. It is probably clandestinely accessing and monitoring communication streams of the target satellites, and perhaps mapping contact networks. It can sometimes come very close to its target, to within a few to a few tens of kilometers (that is very close in space).

From September 2024 onwards it was positioned at 0.93 W close to Intelsat 1002, but on February 7, 2025, it started a drift eastwards. After a significant one-month drift over 62 degrees in longitude, it settled again on March 7 near 62 E, its new eavesdropping target being Intelsat 39 (2029-049B). This latest move is the largest since it was launched.

Due to a combination of flu, moonlight and the fact that the new position is barely above the eastern horizon for me, I have not been able to image it in its new position yet.

The diagram above shows the various repositionings of LUCH (OLYMP-K) 2 since it was launched. Since launch, it has taken up the following positions:

PERIOD                     LONG.      NEAR
21-03-2023  24-03-2023     78.00 E    (checkout) 
07-04-2023  02-05-2023     58.00 E    (checkout) 
22-05-2023  25-09-2023      9.00 E    EUTELSAT (KA SAT) 9A, EUTELSAT 9B
04-10-2023  04-12-2023      3.20 E    EUTELSATt 3B
05-12-2023  26-03-2024      2.60 E    EUTELSAT KONNECT VHTS
01-04-2024  22-06-2024      4.75 E    ASTRA 4A
01-07-2024  16-09-2024      0.54 W    THOR 7
18-09-2024  07-02-2025      0.92 W    INTELSAT 1002
07-03-2025                 62.02 E    INTELSAT 39

The Russian KOSMOS 2576 launch of May 16, and USA 314: another 'inspector satellite'? [UPDATED]

click to enlarge

 

 (this blogpost reflects discussions with and information provided by Bart Hendrickx, Bob Christy and Jonathan McDowell)

In a previous blogpost I wrote about a Russian launch into SSO from Plesetsk on May 16. According to Roscosmos, the launch was at 21:21:29 UTC.

Based on the Sun-Synchronous orbit indicated by the launch azimuth I initially suspected this to be a new IMINT mission, but now I am not so sure. 

IMINT is part of it, but not all, and the primary payload, KOSMOS 2576, might actually be another inspector satellite, this time targetting the American KH-11 ADVANCED CRYSTAL spy satellite USA 314 (2021-032A), as suggested by Bob Christy.

The launch inserted at least 9 objects into space (2024-092A to J), and possibly more: all in basically the same orbital plane (with small subgroups), but at different orbital altitudes. Based on the nine objects catalogued so far (status 20 May 2024), four groups can be discerned, based on orbital period and inclination:

GROUP     ORBIT (km)  INC     PERIOD   OBJECT(S) possible ID
I         451 x 435   97.25   93.45    A         KOSMOS 2576
II        796 x 780   98.59   100.62   G,H,J     Rassvet
IIIa      552 x 532   97.59   95.52    D,E,F,K   SITRO-AIS
IIIb      548 x 531   97.59   95.45    B,C       Zorkiy 2M

As expected, Roscosmos has announced the primary military payload to be designated KOSMOS 2576. It is likely object A (see below) that stands out as a lone object in orbital altitude and inclination. 

Also part of this launch, according to sources, are three civilian Rassvet satellites that provide high speed internet connectivity; and (as announced by Sputnix) two civil Zorkiy 2M earth observation satellites, and four civil SITRO-AIS satellites (the latter six all cubesats). This means that at least one satellite has not been catalogued yet, if these numbers are correct. [edit: this fourth satellite has now also been catalogued, as object K]

To make it even more complex, some analysts believed the launch to have included three military Razbeg Optical reconnaissance satellites as well. But this now seems less likely.

The orbital plane that the primary payload, Kosmos 2576 was launched into, might not be random. As was first pointed out by Bob Christy, the orbital plane closely matches that of the American KH-11 ADVANCED CRYSTAL spy satellite USA 314 (2021-032A).

In the past, we have seen this happen before. In August 2022, Kosmos 2558 was inserted into the orbital plane of the American KH-11 spy satellite  USA 326 (see this earlier blogpost), making close approaches each 5 days. Earlier, in 2020, Kosmos 2542 and its spawn Kosmos 2543 were inserted into the orbital plane of the American KH-11 spy satellite USA 245, also making close approaches.

Object A, the primary candidate for Kosmos 2576, differs in RAAN with USA 314 by only 0.02 degrees, and in inclination by only 0.8 degrees. Its current orbital altitude (451 x 436 km) is lower than that of USA 314 (769 x 548 km), but both orbital altitude and inclination are the same as that of a previous 'inspector satellite', Kosmos 2558 (see earlier blogpost). Object A might raise its orbit in the future or, like Kosmos 2542 did in 2020, spawn a second satellite that moves upwards in orbit. It will be interesting to see what object A will or will not do in the near future.

click to enlarge

The reason to see the lone group I object, object A as the primary payload (Kosmos 2576) is the following: 

First, as already mentioned, its orbital plane closely matched that of USA 314, and as Bob Christy noted,  its orbit in terms of altitude and inclination closely matches that of a previous 'inspector satellite' that targetted a US KH-11 satellite, Kosmos 2558. 

Second: when propagated backwards to the time of launch, the object is placed close to Plesetsk; and its orbital plane passes right over the stage deorbit area from Navigational Warning NAVAREA XII 330/24 in the Pacific Ocean (see map below, and see also previous post for maps and discussion), related to the initial launch phase. This indicates that object A is the primary payload and the first of the objects to be released into orbit. 

click m ap to enlarge

 

By contrast, the three group II objects (G, H, J) at ~780 km do not match the deorbit area in the Pacific well at all (as can be seen in the map above), and back-propagated to the launch time they do not come out near Plesetsk. This indicates manoeuvers before their orbit insertion.

The orbital insertion sequence of the various objects from this launch was probably as follows:

(1) launch into 97.24 inclined, 435 x 451 km orbit, insertion of object A (primary payload);
(2) manoeuver up into 98.59 inclined, 780 x 796 km orbit, insertion of objects G,H,J (secondary payloads);
(3) manoever down into 97.59 inclined, 535 x 552 km orbit, insertion of objects D,E,F,K;
(4) slightly lower apogee, no inclination change, 531 x 548 km orbit, insertion of objects B,C;
(5) Fregat stage deorbit reentry ~10h 20m after launch.

The reasoning behind this sequence is the following:

In addition to the Navigational Warnings which I discussed above and in a previous post, Bob Christy found a NOTAM in the Indian Ocean which is likely for the Fregat stage deorbit, with a time window starting some 10 hours after launch (suggesting a prolonged coast phase and/or multiple manoeuvers):

F1791/24 NOTAMN
Q) YMMM/QWMLW/IV/BO/W/000/999/2815S07736E500
A) YMMM
B) 2405170700 C) 2405220900
D) DAILY 0700-0900
E) ROCKET LAUNCH FROM RUSSIA WILL TAKE PLACE
FLW RECEIVED FROM GOVERNMENT OF RUSSIA:
THE MINISTRY OF DEFENSE OF RUSSIA PLANS TO LAUNCH MISSILE IN THE
SPACE AND TO SINK ITS FRAGMENTS IN THE WATERS OF THE OCEAN.
CHARACTERISTICS OF IMPACT AREA:
3521S07521E
2100S07900E
2109S07936E
3530S07603E
3521S07521E
F) SFC G) UNL
CREATED: 14 May 2024 12:33:00
SOURCE: YBBBZEZX

The orbital plane of the group III objects (see table earlier in this post) B, C, D, E,  F and K passes over this area, 10h 20m after launch (i.e. near 7:40 UTC, May 17).This could indicate that these objects were the last to be released, before deorbit of the Fregat stage. The orbital planes of group I and II do not match this deorbit area that well, passing somewhat east and west of it. 

click map to enlarge

 

This leaves group II objects G, H J, the ones in the highest orbit (~780 km), whose orbital plane matches neither the Pacific Ocean nor Indian Ocean deorbit areas particularly well. This indicates manoeuvers both before and after their release, suggesting their orbital insertion was between that of group I and group III.

As to the possible identities of the objects from group II, IIIa and IIIb:

The orbital inclination and period (95.45 minutes and 97.6 degrees) of the two group IIIb objects (B, C) match those of two objects (2024-092B and C) from a previous launch that included Zorkiy 2M satellites. So objects B and C of the current launch are probably the two Zorkiy 2M payloads.

The orbital inclination and period  (95.52 minutes and 97.6 degrees) of the three group IIIa objects (D, E, F, K) match those of both earlier Rassvet and SITRO-AIS launches, but their number matches the number of SITRO-AIS payloads announced in this launch.

The three group II objects (G, H, J) in the higher ~780 km orbit match neither previous Rassvet, SITRO-AIS or Zorkiy 2M launches. But by a process of ellimination they must be the three Rassvet payloads announced - if there are no other objects catalogued in the future.

The picture presented here might be revised if more objects are catalogued. For now, this is my best interpretation. It will be particularly interesting to see what object A will do.

 

UPDATE 22 May 2024:

US United Nations ambassadeur Robert Wood has, in a May 20 UN Security Council debate, accused Russia of launching a 'counterspace weapon' into Low earth Orbit on May 16. The claim was later repeated, including a mention of it being in "the same orbit" as a US Government satellite, by Pentagon spokesman Brig. General Pat Ryder.

This clearly refers to Kosmos 2576 (object A) - the US military evidently also thinks the co-orbital character of Kosmos 2576 with USA 314 is no coincidence. 

Russia flatly dismisses the suggestion, calling it "fake news".

Currently, there are two Russian satellites in LEO that are suspiciously co-planar with an American KH-11 ADVANCED CRYSTAL electro-optical reconnaissance satellite: Kosmos 2558 (2022-089A) co-planar with USA 326 (2022-009A); and now Kosmos 2576 (2024-092A) co-planar with USA 314 (2021-032A). Kosmos 2558 currently makes approaches to ~50 km to USA 326 each 7 days.

click image to enlarge

For those who want to compare, here are two recent orbits for USA 314 and USA 326 based on amateur tracking data:

USA 314
1 48247U 21032A   24141.96990730 0.00002000  00000-0  27073-3 0    05
2 48247  98.0438 254.1015 0157205 111.3087 248.6912 14.70745533    09
USA 326
1 51445U 22009A   24141.98253796 0.00017500  00000-0  79138-3 0    00
2 51445  97.4250 239.7279 0011614 145.1315 214.8683 15.20909891    06