Soyuz-2.1b/Fregat - Kosmos-2595 (Glonass-K 18) - 13 September 2025 (02:10 UTC)

[zubenelgenubi]

Launch thread for the sixth Glonass-K satellite.

This should be satellite No. 18, launching from either Plesetsk LC 43/3 or 43/4.

If launch is successful, the satellite will receive a Kosmos designation.

[B. Hendrickx]

R0201/25   Effective Date: 2025-09-13 02:30:00
R0201/25 NOTAMN
Q) SCIZ/QRDCA/IV/BO/W/000/999/6005S12723W160
A) SCIZ B) 2509130230 C) 2509140330
D) 13 SEP 0230-0330, 14 SEP 0230-0330
E) ZONE ...D... SECT WEST PACIFIC DUE TO RUSSIAN LAUNCH MISILE IN THE
AREA IS BOUNDED BY GEO COORD:

602324S / 1220448W
631300S / 1310000W
585800S / 1310000W
572848S / 1260112W
602324S / 1220448W

INSTRUCTIONS: SANTIAGO OCEANIC CONTROL 10024KHZ
FANS 1A EQUIPPED ACFT LOGON SCEZ
INFO PROVIDED BY MAIN ATM CENTER OF RUSIA
FSUE STATE ATM CORPORATION
F) SFC G) UNL

Similar coordinates were announced for the launch of Glonass-K N°15L in October 2020 and Glonass-M N°61 in November 2022.

These could be for Glonass-K N°18L. The launch was expected this year.

[B. Hendrickx]

Local authorities of the Tyumen region in Western Siberia have issued a rocket stage impact warning for September 13 and confirmed that the payload is Glonass-K N°18L.
https://tumentoday.ru/2025/09/05/chast_raketynositelya_prizemlitsya_pod_uvatom_13_sentyabrya/

The payload's name is not likely to appear in the Ministry of Defense's press releases on this launch. The same happened with the Glonass-K2 launch last March: local authorities identified the payload, but the MoD did not.

And here's another NOTAM for 3rd stage impact in the Pacific Ocean. This is the western area of the impact zone (closer to New Zealand). The back-up launch date (September 14) is not mentioned here for some reason.

B6838/25   
Effective Date: 2025-09-13 02:30:00
B6838/25 NOTAMN
Q) NZZO/QRDCA/IV/BO /W /000/999/6106S16115W999
A) NZZO B) 2509130230 C) 2509130330
E) TEMPO DANGER AREA NZD096 (SOUTH AUCKLAND OCEANIC FIR) IS
PRESCRIBED AS FLW:
ALL THAT AIRSPACE BOUNDED BY A LINE JOINING:
59 42 36 S 165 49 12 E
58 58 00 S 131 00 00 W
63 13 00 S 131 00 00 W
62 42 00 S 163 00 00 E
62 09 00 S 163 00 00 E
59 42 36 S 165 49 12 E
ACTIVITY: MISSILE LAUNCH AND DEBRIS RETURN
USER AGENCY: FOREIGN AEROSPACE FORCE
PRESCRIBED PURSUANT TO CIVIL AVIATION RULE PART 71 UNDER A DELEGATED
AUTHORITY ISSUED BY THE DIRECTOR OF CIVIL AVIATION
F) SFC G) UNL

[Alter Sachse]

Soyuz 2.1b/Fregat

[Bean Kenobi]

Launch thread for the sixth Glonass-K satellite.

This should be satellite No. 18, launching from either Plesetsk LC 43/3 or 43/4.

If launch is successful, the satellite will receive a Kosmos designation.

Shouldn't it be the contrary : if unsuccessful, it will only have a Kosmos designation and if successful, it will have a Glonass designation ?

[Satori]

Launch thread for the sixth Glonass-K satellite.

This should be satellite No. 18, launching from either Plesetsk LC 43/3 or 43/4.

If launch is successful, the satellite will receive a Kosmos designation.

Shouldn't it be the contrary : if unsuccessful, it will only have a Kosmos designation and if successful, it will have a Glonass designation ?

It is a military satellite, so it will have a Kosmos designation (and a GLONASS designation).

[B. Hendrickx]

It is a military satellite, so it will have a Kosmos designation (and a GLONASS designation).

That's right, all Glonass satellites have received Kosmos numbers, which are considered the official names.
However, the Russians stopped announcing Kosmos numbers after the launch of the Kosmos-2585/2586/2587 trio last March. We can't tell for sure how far in the numbering they are now. Did they give Kosmos numbers to the subsatellites deployed from Kosmos-2558 and (what we think is) Kosmos-2589 in late June? Hopefully, we'll get an answer to this in their satellite filings with the UN, but this can take months.

[Galactic Penguin SST]

https://forum.novosti-kosmonavtiki.ru/index.php?msg=2763157
Google translate:

September 13 - Kosmos-2596 (Glonass-K №18L / Block K7) – Soyuz-2-1b/Fregat – Plesetsk, 43/x - 05:10

05:10 DMT = 02:10 UTC

The timing is allowed since the NOTAMs are for the 3rd stage drop zone in the southern Pacific, well after launch. In particular the evacuation notices for drop zones inside Russia are for 01:00-04:00 UTC.

[B. Hendrickx]

https://tass.ru/kosmos/25044581

The Ministry of Defense has confirmed the launch of a Soyuz-2.1b rocket with "a satellite in the interests of the Ministry of Defense" (Glonass not mentioned, as expected) as well as Mozhayets-6, a small experimental satellite built by the Mozhaiskiy Military Space Academy in St.-Petersburg.

The MOD had already issued a statement earlier this month saying that Mozhayets-6 had been developed by the Academy in co-operation with "enterprises of the rocket and space industry" and had finished ground testing.

https://tass.ru/armiya-i-opk/24937235

Earlier Mozhayets satellites were launched between 1997 and 2005 (Mozhayets-5 failed to separate from its launch vehicle)
https://space.skyrocket.de/doc_sdat/mozhayets.htm
https://space.skyrocket.de/doc_sdat/mozhayets-5.htm

[Alter Sachse]

02:10 confirmed
Kosmos 2595 and 2596!

[B. Hendrickx]

https://tass.ru/armiya-i-opk/25045529

The MoD reports that the satellites have been placed into the intended orbits by the Fregat upper stage. It has also returned to its old tradition of giving the satellites Kosmos numbers, namely Kosmos-2595 (that should be Glonass) and Kosmos-2596 (that should be Mozhayets-6). This confirms that the subsatellite deployed from Kosmos-2558 in June did not get a Kosmos number (see the "Russian launch schedule discussion" thread). So we now have:
-June 19 Angara-A5 launch: Kosmos-2589, 2590
-August 21 Angara-1.2 launch: Kosmos-2591, 2592, 2593, 2594
-September 13 Soyuz-2.1b launch: Kosmos-2595, 2596

Mozhayets-6 was designed to test various navigation technologies, so it could be in an orbit similar to that of Glonass.

The first video of the launch is here:
https://rutube.ru/video/982cf3357bce47f23e6f08d48842c8be/

[Alter Sachse]

LC 43/3

[Galactic Penguin SST]

https://twitter.com/Cosmic_Penguin/status/1966858030378873231

[B. Hendrickx]

USSPACECOM gives the following preliminary data:

2025-206A : unknown  / no orbit parameters
2025-206B:  Kosmos-2590 (Glonass) /  19,136x19,156 km, 64.79°
2025-206C: Fregat R/B / 18,823x19,147 km, 64.79°

The name Kosmos-2590 is, of course, wrong (this is the subsatellite deployed from Kosmos-2589 last June).

No orbit parameters are given so far for Object A, which must be Mozhayets-6. However, based on a recent article in the journal of the Mozhaiskiy Military Space Academy, it is probably in a highly elliptical 2000x20,000 km orbit. The article describes its objectives as follows:

-developing and testing new algorithms for astronavigation
-studying the parameters of the navigation field in medium Earth-orbits (2000-20,000 km).
-introducing new flight control methods using artificial intelligence as well as new methods to process navigation data
-studying the reliability of on-board electronic systems when exposed to “negative space factors”

The second objective is described as the most ambitious one.  The idea is to determine how the navigation field at these altitudes affects the precision of maneuvers that the satellite carries out to maintain the correct orbit parameters. The navigation field at these altitudes is said to have “gaps” and it is important to understand how these affect satellite operations.

All this indicates that the idea was to place Mozhayets-6 into a highly elliptical 2000x20,000 km orbit. This would see it make multiple passes through the Van Allen radiation belts, which would explain the need to study its exposure to “negative space factors”. The idea behind these experiments is not quite clear because there are no known plans to place Glonass satellites into these kind of orbits.

The article includes two illustrations of Mozhayets-6 and a drawing seemingly showing how it is supposed to interact with Glonass satellites.   

[GWR64]

Glonass-K 18 is in plane 3 between slots 20 (719) and 21 (755).

[B. Hendrickx]

The Swiss space situational awareness company S2A Systems has posted a picture on X that shows the newly launched Glonass flying in formation with a fainter object that it says is tumbling. The distance between the two was roughly 60 km. Unless there was yet another passenger satellite on this launch, this should be Mozhayets-6. USSPACECOM has still not published orbital elements for what it has labeled 2025-206A (Glonass is labeled 2025-206B).

Several questions remaining at this point:
-why was the "A" index not given to Glonass, the main payload?
-the Mozhaiskiy Academy reported on its Telegram channel shortly after the launch that it had taken control of Mozhayets-6. If Mozhayets-6 is indeed the tumbling object imaged by S2A Systems, does that mean it is has gone out of control?
-if this is Mozhayets-6, why is it in a circular 20,000 km orbit if one of its objectives was to study "the navigation field" between 2000 and 20,000 km (see my previous post)? 

[GWR64]

...
-if this is Mozhayets-6, why is it in a circular 20,000 km orbit if one of its objectives was to study "the navigation field" between 2000 and 20,000 km (see my previous post)?

Is a 2,000x20,000 km orbit possible with Fregat's standard GLONASS flight profile? I don't think so. The profile would have had to be modified, and it would have taken longer. How likely is that?

[B. Hendrickx]

...
-if this is Mozhayets-6, why is it in a circular 20,000 km orbit if one of its objectives was to study "the navigation field" between 2000 and 20,000 km (see my previous post)?

Is a 2,000x20,000 km orbit possible with Fregat's standard GLONASS flight profile? I don't think so. The profile would have had to be modified, and it would have taken longer. How likely is that?

Yes, good point. Should have given more thought to that. The standard Glonass launch profile is attached. It would probably have required them to do an additional intermediate burn. Not sure if that is possible at all.

It's just not clear how they want to achieve that particular mission objective from the standard Glonass orbit.

[jcm]

...
-if this is Mozhayets-6, why is it in a circular 20,000 km orbit if one of its objectives was to study "the navigation field" between 2000 and 20,000 km (see my previous post)?

Is a 2,000x20,000 km orbit possible with Fregat's standard GLONASS flight profile? I don't think so. The profile would have had to be modified, and it would have taken longer. How likely is that?

Yes, good point. Should have given more thought to that. The standard Glonass launch profile is attached. It would probably have required them to do an additional intermediate burn. Not sure if that is possible at all.

It's just not clear how they want to achieve that particular mission objective from the standard Glonass orbit.

I read "between 2000 and 20000" as  "between the top of LEO and the Glonass orbit". I was expecting it to be in the 273 x 19038 km transfer orbit, and they just don't care about measurements in the 273 to 2000 km
range.

However, maybe they changed the mission and it's now just a 19000 km measurement.

If Mozhaets-6 is of a similar Strela-1M type design to the earlier Mozhaets, it would use a gravity boom to stabilize, and might well be tumbling for the first few weeks until that is fully deployed.

[B. Hendrickx]

If Mozhaets-6 is of a similar Strela-1M type design to the earlier Mozhaets, it would use a gravity boom to stabilize, and might well be tumbling for the first few weeks until that is fully deployed.

There are illustrations of Mozhayets-6 in Reply 13. No sign of a gravity boom. It doesn't look there is any commonality with the earlier satellites, which were launched more than 20 years ago and built in cooperation with PO Polyot in Omsk. It's not yet clear who the Mozhaiskiy Academy's industrial partner for this one is.