Angara-A5/Briz-M - Kosmos-2589 [14F166A] - Plesetsk - June 19, 2025 (03:45 UTC)

[Galactic Penguin SST]

Two objects finally found out of 3 expected, for now:
2025-131A/64467: 20268 x 51110 km x 1.10°
2025-131B/64468: 18775 x 50536 km x 1.43°

[B. Hendrickx]

Two objects finally found out of 3 expected, for now:
2025-131A/64467: 20268 x 51110 km x 1.10°
2025-131B/64468: 18775 x 50536 km x 1.43°

Object A is the payload and Object B is the Briz-M upper stage. The Briz-M auxiliary propellant tank (what should become Object C) has not yet been catalogued.

The orbit parameters leave almost no doubt that the payload is 14F166A. They are close to those given for 14F166A and its Briz-M stage in the environmental impact report:

14F166A: 18,858 x 52,728 km
Briz-M: 17,047.1 x 52,264.7 km, 1.655°

An insider on the NK forum has noted that the orbit given in the report was calculated based on the maximum mass of the payload. In the end, it was decided to launch a lighter version of the payload, resulting in a higher perigee and a lower apogee.

There is also another verison of the satellite (designated 14F166) which is supposed to reach a transfer orbit of 25,206 x 46,380 km. The report only reveals that the two versions of the satellite have "different payload modules" and that 14F166A will carry 60 kg less hydrazine than 14F166 (100 kg vs. 160 kg). At the time of writing (early 2023), 14F166A was scheduled for launch before the end of 2023 and 14F166 in 2025. Something that caught my attention in the report only recently is that another environmental impact study for launches of these satellites was conducted in 2021. This was based on the assumption that they would use the 14S48/Persei (Blok-DM type) upper stage. Possibly, it was decided to switch to Briz-M after the failure of  Persei on the December 2021 Angara-A5 test flight.

The Ministry of Defense's launch announcement said the mission carried "satellites", but only one payload has been detected. This supports earlier speculation that 14F166A is carrying one or more CNIIHM passenger satellites that will be released from it after it reaches GEO. Amid all the secrecy surrounding this launch, this is a remarkable instance of openness on the part of the MoD. The presence of the additional payload(s) could just as well have been covered up. The MoD followed the same policy for the launch of subsatellites on two Lotos-S missions.

It now remains to be seen how long it will take the satellite to reach GEO. Two earlier Russian missions have followed this particular insertion profile via a supersynchronous transfer orbit, namely Express-80/103 in 2020 and Express-AMU3/AMU7 in 2021. Both pairs of satellites were based on the lighter Express-1000 platform. The first pair needed about six months to reach GEO (using only SPD-100V electric thrusters) and the second pair about three months (using SDP-100V thrusters and an additional SPD-140D thruster). 14F166A, using the heavier Express-2000 platform, has only SPD-100V engines for this purpose. It is known to have a high-pressure xenon tank (KBVD) with a capacity of 350 kg (image attached).

[GWR64]

The goal for Russian satellite launches of this type, if the GEO cannot be reached directly, was always a 24-hour orbit.
So that the satellite remains visible to Russian ground stations on its way to the GEO. The first was Express-AM5, I think.
The orbital period here is 23 hours 50 minutes, so it's probably within tolerance.

[smoliarm]

Do we know the mass of Kosmos-2589? Or, do we have an estimate for it?

[russianhalo117]

Do we know the mass of Kosmos-2589? Or, do we have an estimate for it?

For 14F166A their is 100Kgs of fuel components plus the baseline mass of Ekspress-2000 bus service module very similar to that of the Blagovest series. The payload module mass is known to be different for 14F166 and 14F166A. As for total combined processed and launched dry mass/wet mass including potential undeployed rideshares i don't know.

[Alter Sachse]

Do we know the mass of Kosmos-2589? Or, do we have an estimate for it?

According to Wikipedia, the Angara 5 can transport 5400 kg in the GTO.
The weight of the Briz stage must be deducted from this
(dry mass over 2300 kg) Mass of fuel unknown.
The Blagovest mentioned had a weight of ~3100 kg.

[B. Hendrickx]

Sources differ on the mass of the Express-2000 platform. The total satellite mass is given between 3250 kg and 3550 kg and the payload mass between 1079 and 1300 kg. Attached is a detailed mass breakdown from one source, where Express-2000 is compared with the Eurostar 3000 platform of Airbus Defence & Space. A few key figures from this are:

-total satellite mass: 3325.9 kg
-payload mass: 1079 kg
-satellite dry mass: 2986.4 kg
-platform dry mass: 1907.4 kg
-fuel mass: 339.5 kg

But, again, there is contradictory information. For instance, one source gives 60 kg of hydrazine and up to 350 kg of xenon, resulting in a total fuel mass of 410 kg. There can, of course, be significant differences between individual satellites.

All we know about the mass breakdown of these specific satellites is that they have a xenon load of 350 kg and a hydrazine mass of either 100 kg (for 14F166A) or 160 kg (for 14F166). This is significantly more than what would appear to be the standard hydrazine mass for these platforms, perhaps suggesting that they have higher attitude control requirements. We should also take into account that the insertion into GEO via a supersynchronous transfer orbit allows for a higher mass than when the satellite is inserted directly into GEO by the launch vehicle.   

[B. Hendrickx]

I've written more on ISS Reshetnev's 14F166(A) satellites and the CNIIHM passenger satellites in two posts in the program thread:

https://forum.nasaspaceflight.com/index.php?topic=60120.0

[Alter Sachse]

Launch time 03:45 UTC I don't think.
03:49 the successful launch was reported.

https://www.militarynews.ru/story.asp?rid=1&nid=647515&lang=RU

The message usually always appears later after a launch.

Edit: The successful launch was reported at 03:49.
It is not the launch time !

[smoliarm]

Thanks a lot for answers.
One more question:
So, Kosmos-2589 was deployed into super-synchronous transfer orbit -
20268 x 51110 km x 1.10°
- How to calculate delta V required to GEO from this specific orbit?

I vaguely remember that there was something like "delta V calculator", but I can't figure where to look for it

[russianhalo117]

I've written more on ISS Reshetnev's 14F166(A) satellites and the CNIIHM passenger satellites in two posts in the program thread:

https://forum.nasaspaceflight.com/index.php?topic=60120.0

An update on Russianspaceweb.com:
Angara-5 carries its first payloads

On June 26, 2025, the third object was catalogued in an orbit close to the original payload, indicating that the expected "inspector" satellite might have separated from the mother spacecraft.

[B. Hendrickx]

An update on Russianspaceweb.com:
Angara-5 carries its first payloads

On June 26, 2025, the third object was catalogued in an orbit close to the original payload, indicating that the expected "inspector" satellite might have separated from the mother spacecraft.

Yes, we now have the following three objects:

2025-131A (Kosmos-2589): 20270 x 51109 km
2025-131B (Briz-M) : 18758 x 50566 km
2025-131C  (?) : 20265 x 51088 km

It is not the discarded Briz-M propellant tank, which should be in a much lower orbit and has not been detected yet. SpaceTrack so far lists it only as "Object C" and the type as "unknown". No radar cross section is given yet. Based on the orbit, it would seem to be a second payload. In itself this is not surprising given the Ministry of Defense's statement that multiple satellites were on board. What is surprising is that it appears now rather than being released from Object A after that reaches GEO. So do we have two payloads that will independently maneuver to GEO? In that case, the second payload must have a significant mass itself. We'll have to wait and see what happens the coming days.

[B. Hendrickx]

Object C is definitely an active payload. It has raised both its perigee and apogee.

This was the altitude of the two satellites yesterday:
Kosmos-2589:  20270 х 51109
Object C:  20265 х 51088 км

And these are the orbits today:
Kosmos-2589 : 20270 х 51109
Object C:  20271 х 51200

At this point, it looks like Object C is not headed for GEO. In that case, it would have to lower its apogee rather than increase it. Also, if it is a relatively small satellite, it will most likely not have the fuel reserves to reach GEO. The fairly significant apogee raising burn may point to the use of a liquid-fuel propellant system rather than electric propulsion.

One possibility is that Object C is an inspector satellite that will be tested in a geostationary transfer orbit, using Kosmos-2589 as a target. But we'll have to wait and see what happens next.

Right now, Object C is flying almost directly above Kosmos-2589. The screenshot below was made around 12.00 UTC today, when the distance between the two objects was roughly 170 km.

[Alter Sachse]

It is not known what task object C has.
It now needs 1433.5 minutes for one orbit
when it reaches 1436 minutes, it will orbit above a certain position.

The Canyon satellites had an orbit of 30000x40000 km.

[owais.usmani]

At this point, it looks like Object C is not headed for GEO.

Can you please elaborate how you came to this conclusion?

Also, what is the possibility of this "Object C" being the primary payload of this launch instead of the object currently labelled as "Kosmos-2589"?

[Alter Sachse]

At this point, it looks like Object C is not headed for GEO.

Can you please elaborate how you came to this conclusion?

Also, what is the possibility of this "Object C" being the primary payload of this launch instead of the object currently labelled as "Kosmos-2589"?

The orbit becomes more elliptical rather than circular.

[B. Hendrickx]

For comparison, I've added tables showing how Express-103 and Express-AMU7 moved from very similar supersynchronous transfer orbits to GEO in 2020/2021 and 2021/2022 (taken from Robert Christy's "Orbital Focus" website).  For Express-103 this took about six months and for Express-AM7 about three months. As is to be expected, there was a gradual increase in perigee and a gradual decrease in apogee. One exception was an apogee raising burn by Express-AM7 on or before January 6, 2022, so drawing any conclusions from a single apogee raising burn by Object C is probably premature. We'll just have to wait and see.

[B. Hendrickx]

Things are becoming ever weirder. Now not only Object C has again raised its perigee and apogee, but so has Kosmos-2589.
Latest parameters:
Kosmos-2589 :  20,359 x 51,223 km
Object C : 20,279 x 51,291 km

Orbital periods are 1,436.33 and 1,436.01 minutes, so they're now in highly elliptical synchronous orbits.

[GWR64]

I tried to explain:
https://forum.nasaspaceflight.com/index.php?topic=60779.msg2696226#msg2696226
The procedure for four Proton missions was similar:
Express-AM5, AM6, Express-80+103 and Express-AMU3+7.
On AM6 and AMU3+7, the Briz-M did not reach the correct orbit.
AMU3 and 7 had SPD-140 on board for acceleration.

[B. Hendrickx]

I tried to explain:
https://forum.nasaspaceflight.com/index.php?topic=60779.msg2696226#msg2696226
The procedure for four Proton missions was similar:
Express-AM5, AM6, Express-80+103 and Express-AMU3+7.

Yes, as you pointed out, the orbit allows them to stay within constant range of Russian ground stations, as can be seen in the ground track of Kosmos-2589 below. We should soon see them begin to lower their apogees as the perigees climb.

So far the apogees are still rising, with the current orbits being:

Kosmos-2589 : 20381 х 51231 km (period 1437.08 minutes)
Object C : 20282 х 51292 km (period 1436.12 minutes)

It turns out that the Swiss space situational awareness company S2A Systems detected an unidentified object in the vicinity of Kosmos-2589 early on June 22.
https://web-cdn.bsky.app/profile/s2a-systems.bsky.social/post/3lsk37tgkr22d

A few images of COSMOS 2589 and the UNID that is moving away from it, which we noticed for the first time in the night from June 21 to 22.

The question is if this is Object C (before it was catalogued by USSPACECOM) or something else. It seems to have caught up with and then overtaken Kosmos-2589 between the first set of images (taken between 0.33 and 1.25 UTC) and the second series of images (taken between 9.15 and 11.18 UTC).