Angara-A5/Briz-M - Kosmos-2589 [14F166A] - Plesetsk - June 19, 2025 (03:01:20 UTC)

[GWR64]

Hello
Celestrak now has four objects. The satellite objects A and D are slowly reducing their inclination and eccentricity.
The Breeze-M data are old. 

https://celestrak.org/NORAD/elements/table.php?INTDES=2025-131

[B. Hendrickx]

Hello
Celestrak now has four objects. The satellite objects A and D are slowly reducing their inclination and eccentricity.
https://celestrak.org/NORAD/elements/table.php?INTDES=2025-131

Note that USSPACECOM still lists the second satellite (NORAD catalog number 64527) as Object C, with Object D being the Briz tank.

Kosmos-2589 has now lowered both its perigee and apogee:
20,381 х 51,231 --> 20,370x 51,204 km

This was the first maneuver that any of the two satellites have performed in more than a week. So far nothing is indicating that the Russians are planning to place these satellites into GEO. Assuming that Object C is a relatively small satellite, it is also questionable if it has enough fuel reserves on board to reach GEO and carry out subsequent operations there.

Several American orbital mechanics experts have been looking at the possibility that the supersynchronous orbit is in fact the satellites’ final orbit and that they will be looking at the GEO belt from that vantage point. A good overview of their analysis is given in the latest issue of The Integrity Flash:

https://isruniversity.com/2025/07/06/issue-123-2/

The second satellite is referred to here as Object D, as on Celestrak.

27 Jun – 28 Jun: Both Cosmos 2589 and Object D maneuver

- Cosmos 2589 increased both its perigee and apogee over 100 km. These maneuvers decreased the orbit's 1.25° eastward progression to -0.2° west.

- Object D increased its overall average altitude over 100 km. Russia increased the apogee by over 200 km while limiting the perigee increase to <15 km. As a result of these maneuvers Object D now consistently crosses the GEO belt at -62.°0E & 147.7°E for each orbit.

I understand that after the latest maneuver Kosmos-2589 has stopped that slight drift to the west and has now stabilized the points where it crosses the GEO belt (like the second satellite). It’s worth noting that one of the crossing points (62°E) is exactly the same spot where Luch-5X is located, the satellite that is now eavesdropping on the neighboring Intelsat 39 (located at 61.9°E). But this may be entirely coincidental.

If these satellites remain in their supersynchronous orbits and are indeed 14F166A and the presumed CNIIHM subsatellite, then plans have significantly changed since the publication of the environmental impact report in 2023.   This categorically stated that 14F166A and its sister satellite 14F166 would be placed into GEO after being initially inserted into a supersynchronous transfer orbit. However, as noted in The Integrity Flash, we may currently be seeing a preliminary testing phase in supersynchronous orbit before the satellites are moved to their final orbits. Many scenarios are possible. We'll just have to wait and see.

[GWR64]

The satellite object NORAD 64527 (Celestrak says 2025-131D, other sources say 2025-131C) has now performed a significant maneuver to extend its orbital period.
The situation is unclear. There is a very slow reduction in the eccentricity and inclination of both satellites, apparently with electric thrusters. There are also some significant maneuvers with (probably) chemical thrusters from both satellites.
So far, it looks to me that the satellites (NORAD) 64467 and 64527 are moving towards GEO.

[B. Hendrickx]

The satellite object NORAD 64527 (Celestrak says 2025-131D, other sources say 2025-131C) has now performed a significant maneuver to extend its orbital period.

As a result of this the orbit is no longer synchronous and the points where it crosses the GEO belt are slowly drifting westward. This is what one would expect if the intention is to observe a wide range of GEO satellites on flyby trajectories.

The situation is unclear. There is a very slow reduction in the eccentricity and inclination of both satellites, apparently with electric thrusters. There are also some significant maneuvers with (probably) chemical thrusters from both satellites.
So far, it looks to me that the satellites (NORAD) 64467 and 64527 are moving towards GEO.

According to an orbital mechanics expert writing on the NK forum, the slow reduction in inclination is due to natural factors (such as perturbations by the Moon). The inclination decreases by 0.004° per day and it would take about 230 days for it to reach 0° if no orbit corrections were performed. So this should not be interpreted as a sign that the satellites are moving to GEO.

A picture of the two satellites has been posted on X. Kosmos-2589 is about three magnitudes brighter than the other satellite.

https://x.com/mickeywzx/status/1944391231544692832

Mysterious COSMOS 2589 launched into a kind of large-scale GEO surveillance orbit, ~20,000 x 51,000 km on 19 June. Soon after, it released a secondary object [64527], which is ~3 mag fainter, maintaining ~1700km leading co-orbit formation currently

[B. Hendrickx]

Object C/D has now maneuvered back to a synchronous orbit by reducing its perigee by 7 km and its apogee by nearly 100 km. It is returning back to the vicinity of Kosmos-2589.

Kosmos-2589: 20,375 x 51,200 km  period 1,4316.15 min.
Object C/D:     20,388 x 51,189 km  period 1,4316.20 min.

They came as close as about 30 km at about 20.00 UTC today.

[Alter Sachse]

Object C/D has now maneuvered back to a synchronous orbit by reducing its perigee by 7 km and its apogee by nearly 100 km. It is returning back to the vicinity of Kosmos-2589.

Kosmos-2589: 20,375 x 51,200 km  period 1,4316.15 min.
Object C/D:     20,388 x 51,189 km  period 1,4316.20 min.

They came as close as about 30 km at about 20.00 UTC today.

a small error in the period
1436.15 min

[B. Hendrickx]

The latest tracking data released by Celestrak now shows Kosmos-2589 and Object C/D at exactly the same altitude: 20,376 x 51,200 km.  The latter's gradual approach to Kosmos-2589 in the past two days can be seen in images released by the Swiss space situational awareness company S2A Systems. The distance between the two may have been less than 1 km earlier today. One obvious idea that comes to mind is that the two satellites will redock and then head out to GEO together, but making predictions about this mission has turned out to be very tricky.

[Galactic Penguin SST]

Apparently the exact T-0 was somewhat cryptically revealed to be 03:01:20 UTC (the words seems to be deliberately not-spaced so you won’t see it if you are using an online translator): https://forum.novosti-kosmonavtiki.ru/index.php?msg=2746519

[B. Hendrickx]

Object C has been playing yo-yo with Kosmos-2589 over the past two weeks or so. Here's an update from The Integrity Flash:

https://isruniversity.com/2025/08/04/issue-126/
 

Russia: Cosmos 2589 and Obj C 21 Jul – 1 Aug: Russia conducted several maneuvers of Object C (64527 & previously referred to in the Flash as "Object D") and continues to conduct Rendezvous & Proximity Operations (RPO) with Cosmos 2589 (64467). The last observable maneuver from Cosmos 2589 was on 7 July. Ranges between the two objects from 21 Jul – 2 Aug varied from 100km (22 July) to <1km (27 July). On 27 Jul the objects were <1km from one another for over 4 hours ~1800-2223Z.

The satellites increased their distance from one another until Object C maneuvered on 30-31 July. These maneuvers appeared to re-initiate RPO conditions and the two satellites reduced their separation from 60+km to <10km on 1 August. Without any further maneuvers, the two objects will again have <1km separation on 4 Aug at ~0300Z with lighting conditions favorable for Cosmos 2589 to image Object C. Propagating the orbits further (assumes no additional maneuvers) the two satellites will be separated by <1 to 6km through August 8. During this time period there will be ample opportunities for both satellites to image one another in various lighting conditions.

We have not yet seen any of the maneuvers necessary for either Cosmos 2589 or Object C to reduce their orbital eccentricity and join the GEO belt. It is becoming apparent that Russia is conducting initial RPO testing with the two satellites.

An update from the US space situational awareness company COMSPOC:
https://x.com/COMSPOC_OPS/status/1952830428584317204
 

COSMOS 2589 (SSC.64467) and Object C (SSC.64527) have taken the spotlight this past month with their unusually high eccentricity orbits, crossing the GEO belt twice a day. The orbital configuration offers unique opportunities for monitoring and characterizing space objects in MEO, GEO, and Graveyard orbits. Assuming no further maneuvers, Object C will come within 1,000 km of several objects over the next 2 days. The visualization shows the neighboring objects on 6-7 August during the nodal crossings.

Attached are the distant encounters during descending and ascending node crossings on August 7.

Another satellite that will be relatively close during descending node crossings in the coming days will be Luch/Olimp, the Russian eavesdropping satellite launched in 2014. It has been slowly drifting eastward at a speed of 0.5 to 0.7° for more than four months and is now close to 57°E. Its inclination has gradually increased to 1.1°. Below are the mutual positions of Kosmos-2589 and Luch/Olimp when they were at roughly the same altitude earlier today.

[B. Hendrickx]

Object C began a new series of rendezvous and proximity operations with Kosmos-2589 in late August. See new imagery from S2A Systems and a graph from The Integrity Flash.
https://isruniversity.com/2025/09/02/issue-128/
They have come closer than 10 kilometers. The active satellite would appear to be Object C. Kosmos-2589 has not made any detectable maneuvers since early July.

It's still not clear if any of the objects will move to GEO. Kosmos-2589 is the only of the two that is likely to have enough propellant to do so. Object C would probably have to redock with Kosmos-2589 to hitch a ride to GEO.

[B. Hendrickx]

Objects A and C have been officially registered with the UN as Kosmos-2589 and 2590.
https://documents.un.org/doc/undoc/gen/v25/060/05/pdf/v2506005.pdf

Kosmos-2590 seems to have separated from Kosmos-2589 as early as June 20.
Strangely enough, the orbit is given as -426.183x199.9 km, which must have been the parameters after separation of the third stage (which was suborbital). Briz-M was ignited shortly afterwards to place the payload into a low, nearly circular parking orbit.

[jcm]

Object C began a new series of rendezvous and proximity operations with Kosmos-2589 in late August. See new imagery from S2A Systems and a graph from The Integrity Flash.
https://isruniversity.com/2025/09/02/issue-128/
They have come closer than 10 kilometers. The active satellite would appear to be Object C. Kosmos-2589 has not made any detectable maneuvers since early July.

It's still not clear if any of the objects will move to GEO. Kosmos-2589 is the only of the two that is likely to have enough propellant to do so. Object C would probably have to redock with Kosmos-2589 to hitch a ride to GEO.

K2589 and K2590 remained close (within the errors?) from Sep 3 to at least Sep 7 (latest TLEs I have).
I believe they are likely now docked.

[zubenelgenubi]

It's still not clear if any of the objects will move to GEO. Kosmos-2589 is the only of the two that is likely to have enough propellant to do so. Object C would probably have to redock with Kosmos-2589 to hitch a ride to GEO.

K2589 and K2590 remained close (within the errors?) from Sep 3 to at least Sep 7 (latest TLEs I have).
I believe they are likely now docked.

Are the objects are still docked?  Any further action(s)?

[B. Hendrickx]

Are the objects are still docked?  Any further action(s)?

There have been no TLE updates for these satellites for over two weeks, so their current orbits are unknown. I don't think we can say for sure that they docked. That is just one possible interpretation of the data. There were always separate TLEs for the two objects.

[B. Hendrickx]

It looks like this mission has entered a new phase. After several months of joint operations, Kosmos-2589 and Kosmos-2590 now seem to have parted company for good. Kosmos-2590 (the presumed CNIIHM subsatellite) has significantly lowered its perigee and is no longer geosynchronous, beginning a slow drift to the east. Kosmos-2589 (most likely the first 14F166A satellite of AO Reshetnev), which remained passive during these operations, has now made its first orbit correction since early July, raising its average altitude by 18.5 km.  The current orbits are:
Kosmos-2589: 20,439 x 51,189 km  (period 1,437.50 minutes)
Kosmos-2590: 20,230 x 51,187 km  (period 1,432.11 minutes)

The original plan was for 14F166A to be moved from a supersynchronous transfer orbit to a circular geostationary orbit, but it is too early to say if this is the first move in that process.

Another indication that Kosmos-2589 is indeed likely to be the first 14F166A satellite comes from recent documentation describing a court case between the Khrunichev Center (the manufacturer of the Angara-A5 rocket) and the Pilyugin Center.
https://kad.arbitr.ru/Card/fb271802-9fd4-49c2-b242-f3dea124be1b
The two parties signed a contract on September 1, 2023 to adapt the rocket’s control system for the launch of a 14F166A satellite. That work (or at least the first stage of it) was completed by late September 2024.

[B. Hendrickx]

  The current orbits are:
Kosmos-2589: 20,439 x 51,189 km  (period 1,437.50 minutes)
Kosmos-2590: 20,230 x 51,187 km  (period 1,432.11 minutes)

The original plan was for 14F166A to be moved from a supersynchronous transfer orbit to a circular geostationary orbit, but it is too early to say if this is the first move in that process.

Things are definitely trending in that direction. Kosmos-2589 has been making regular orbit corrections to raise its perigee and lower its apogee. The orbits are now:
Kosmos-2589: 21,633 x 49,974 km (period 1,436.96 minutes)
Kosmos-2590: 20,274 x 51,184 km (period 1,433.14 minutes)

At the current pace, it will take quite some time to circularize the orbit.