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

Raiders of the Lost Venus Probe: a post-mortem of an interesting reentry and the confusion it left

On 10 May 2025, an unusual object, the Kosmos 482 Descent Craft, had an uncontrolled reentry (see this earlier post).

With my TU Delft colleague Dominic Dirkx, I have written a 'post mortem' for this reentry for The Space Review of 27 May 2025, titled:

 "Raiders of the Lost Venus Probe: a post-mortem of an interesting reentry and the confusion it left"

It can be read here.

(the Tudat script we used for our reentry analysis can be downloaded here. Tudat itself can be downloaded here). 

The tumbling behaviour of the mysterious Kosmos 2553 satellite

Framestack (530 frames) showing variable brightness of Kosmos 2553. Click image to enlarge

Over three years ago, on 5 February 2022, Russia launched a mysterious military satellite, Kosmos 2553 (2022-011A), into an unusual orbit at approximately 1995 km altitude, the outermost margin of Low Earth Orbit. Very few satellites orbit there.

Early 2024, US Congressman Michael R. Turner, chairman of the House Intelligence Committee, wrote an unprecedented public letter to House members in which said he had concerns about a "serious national security threath", urging then President Biden to declassify the information. Subsequently, various US news sources quoted various of the proverbial "anonymous sources", with often conflicting information about the nature of the threath, but all indicating some kind of Russian space weapon. And moreover: a nuclear weapon, alledgedly. See my earlier 2024 blogpost here. Based on statements that a kind of prototype of the satellite in question was in Low Earth Orbit 'in a region not used by any other spacecraft', Kosmos 2553 was identified as the likely suspect.

More recently, in April 2025, various news sources (e.g. here and here) reported that as of late 2024, Kosmos 2553 had started to tumble, indicating a possible loss of attitude control.

I imaged Kosmos 2553 on May 20, 2025, and it indeed shows a brightness variation that was not present when I imaged it a year earlier. The image above is a 530-frame (21.2 second) stack, and the brightness variation can be clearly seen in it. Below is a sequence of the actual video footage:

 

We can compare this to video footage from a year earlier (20 May 2024) when the object was steady:

 

I extracted almost 9 minutes of photometric information from the 20 May 2025 video. This shows a prominent flash cycle of (peak-to-peak) 2.22 seconds, with a regular pattern consisting of a brighter flash followed by a fainter flash, ad infinitum. 

Below is a diagram of the full 9-minute photometry series, and a detail of a part of the curve which shows the pattern of the brightness variation: the red line is a fitted multi-sinusoid who's main period is 2.22 seconds. Gaps in the data are moments the camera was repositioned, or the object was closely passing a star.

Click diagram to enlarge

 

 

Click diagram to enlarge

The datapoints in the diagrams are 5-frame running averages. The data in the two diagrams above have been corrected for range and phase angle variation, i.e. to absolute magnitude (normalisation to 1000 km range and 90 degree phase angle). 

The apparent observed magnitude varied between magnitude +5.7 and +9.4. Below are these apparent photometric measurements uncorrected for phase angle and range (note that a calibration of the data to the Visual band has been done to correct for instrument spectral sensitivity):

 

Click diagram to enlarge

The imagery was made from my home in Leiden, the Netherlands, with a WATEC 902H2 Supreme camera and Samyang 1.4/85 mm lens, filming at 25 frames/second. 

The photometry clearly supports reports that Kosmos 2553 has started a tumble or spin. Whether this means it is no longer operational, is another question that is less easily answered. Given the regularity of the flash period, the flashing could be due to spin stabilization. On the other hand: why did this only become apparent some 2 years into the mission?

In orbital data for Kosmos 2553, a sudden subtle change in orbital altitude can be seen starting around 15-16 November 2024 (see diagram below). Perhaps this is when the tumbling or spin started.

Click diagram to enlarge

Multiple analysts, including myself, believe Kosmos 2553 to be a (Radar) imaging satellite (possibly 'Neitron'). It has a ground track that after four days closely repeats itself, which would fit an imaging satellite. It is not clear why some in US Government circles believe that Kosmos 2553 is connected to a 'nuclear space weapon' program (presumably Ekipazh). That suspicion must be based on undisclosed HUMINT.

Russia itself has stated that Kosmos 2553 is a "technological spacecraft […] equipped with newly developed onboard instruments and systems for testing them under the influence of radiation and heavy charged particles". That explanation does not sit entirely well with several analysts: yes, at 2000 km altitude the radiation regime is different and more severe compared to a more typical Low Earth Orbit: but not thát much different and severe, really.

Kosmos 482 Descent Craft reentry forecasts [PERIODICALLY UPDATED]

Click diagram to enlarge

Last update: 11 May 2025 10:15 UTC 

 

(this post is being periodically updated with new reentry forecasts/postcasts)

 

* The last Tudat nominal forecast is reentry on 10 May 2025, 6:39 UTC ± 1.5 hr *

* The Tudat nominal aftercast is reentry on 10 May 2025, 6:40 UTC ± 1.5 hr *

 

 

 

In the second week of May 2025, an unusual object reentered. It concerns the Kosmos 482 Descent Craft (1972-023E, cat. nr. 6073).

This object is the lander module from a 1972 failed Soviet Venera mission to Venus. Because of a failure of the upper stage of the rocket that launched it, it got stuck in a very elliptical orbit around Earth in 1972, instead of going to Venus. 

 

I published an extensive discussion and analysis of this object and its history three years ago in The Space Review. The identification of this object as the lander module was initially suggested by Jonathan McDowell (see his brief interesting history here).

Recently declassified Russian historic documents unearthed by Anatoly Zak point out that after failure to get to a heliocentric orbit, the lander was deliberately separated from the main bus by the spacecraft operators. My analysis published in 2022 suggests that this happened in June 1972. The lander is encased in a semi-spherical shaped Titanium protective shell, a kind of rounded metal bucket so you will (see image below).

As this is a lander that was designed to survive passage through the Venus atmosphere, it is possible that it will survive reentry through the Earth atmosphere intact, and impact intact. It likely will be a hard impact: I doubt the parachute deployment system will still work after 53 years and with dead batteries. There are many uncertain factors in whether the lander will survive reentry though, including that this will be a long shallow reentry trajectory, and the age of the object.

 

 

Venera 7 lander mock-up. The Kosmos 482 Descent Craft is probably similar. Photo: NASA

 

The risks involved are not particularly high, but not zero: with a mass of just under 500 kg and 1-meter size, risks are somewhat similar to that of a meteorite impact. A Tudat reentry analysis to ground level suggests an impact speed (after atmospheric deceleration) of about  65-70 meter per second (~242 km/h), assuming the reentering lander did not break up or extensively ablate during reentry (see the diagram below: note the logarithmic scale of the x-axis). The kinetic energy at impact is similar to that of a 40-55 cm large (after ablation) meteorite fragment. As it will likely reach earth surface as only one single object, the risks involved are lower than for example those created by a Falcon 9 upper stage reentry, which showers multiple meter-sized objects over a large area (as we saw recently with the impact of Falcon 9 remains in Poland).

 

Click diagram to enlarge

 

The diagrams below shows the change in altitude of apogee and perigee over the past 1.5 years and the past 4 months: notably apogee has been coming down steadily, but in the past few months, perigee has started to come down too. Early May 10 around 00:35 UTC, the object was in a 166 x 120 km orbit, with apogee coming down by 70 km/day and perigee by 25 km/day (and these values increasing each day, see diagram below).

 

Click diagram to enlarge

 

Click diagrams to enlarge

 

The reentry is an uncontrolled reentry. Even close to reeentry, we cannot say with any degree of certainty when and where the Kosmos 482 Descent Craft exactly will reenter.

With an orbital inclination of 51.95 degrees [note: I initially erroneously stated 51.7 here], the reentry can occur  between latitude 52 N and 52 S.

Over the past months, together with my colleague Dominic Dirkx,  we have been developing a reentry model for this object in Tudat.

 

Tudat, the TU Delft Astrodynamics Toolbox is open source, multi-platform Astrodynamics software developed and maintained at the Aerospace faculty of Delft University of Technology (TU Delft) in the Netherlands (where I work). The Tudat script we use for our analysis is here, while the Tudat software itself is available here.

 

The Kosmos 482 Descent Craft is probably similar to the descent craft of Venera 8 (which was launched only a few days earlier in 1972). Literature values suggest that the object is about 1 meter in size and semi-spherical, with a mass of ~495 kg. 

 

Using our Tudat model and a 1-meter diameter, and the NRLMSISE00 model atmosphere with historic space weather data, we find that the orbital evolution of  the object from mid-1972 to early 2025 is actually best matched when we use a mass of 480 kg, 15 kg less than the literature value. All our forecast predictions are therefore done using a mass of 480 kg. 

 

For our forecasts we employ the NRLMSISE00 model atmosphere, and historic spaceweather data plus estimated future space weather (solar flux). Orbit updates for each run are sourced from the US Military tracking network CSpOC (so as a note: our forecasts are not based on our own tracking data. They are based on our own custom reentry model developed at Delft University of Technology, with external tracking data from CSpOC as input).

 

Click diagram to enlarge

The diagrams in top of this post and below (which I will periodically update) give the evolution of our reentry predictions, based on orbits issued for the object since November 2024. Over the past half year, the model has consistently pointed to reentry within a few days of 9-10 May 2025. 

 

The latest nominal forecasts currently center on early May 10, but are still fluctuating with each orbital update. Early May, there was a short-lived tendency in the model runs of a shift towards a later time of reentry (i.e. May 11 rather than May 10), as can be seen in the below diagrams and the table near the end of this post. But lately, the new forecast runs have been returning to nominally May 10. 

 

 

Click diagram to enlarge

 

Click diagram to enlarge

 

The brief shift towards a later date in the early May model runs was due to space weather forecasts underestimating future solar activity at that time. I had started to note this (when comparing earlier forecast solar flux values to actual solar flux values for the last days of April  and the first days of May) and already expected the nominal forecasts to return to May 10, as they now indeed have done.

 

This highlights the influence of uncertainties in estimated future solar activity on the forecasts. Future solar activity is not well predictable. Even the best reentry models will be off in their forecast if actual solar activity in the window between the moment of forecast and the moment of reentry develops differently than the predictions. Solar flux variations are an important driving factor of short-term variations in density and extent of the upper atmosphere. The latter determine how many drag the object experiences over its orbit, and with that how quick the orbit decays. Stronger solar activity will mean an earlier reentry, lower solar activity a later reentry.

 

Of course, at this point the uncertainty in the forecast is still +/- 1.5 hours. Yet, the uncertainty window has now decreased to the point that we can rule out certain parts of the world: Africa is safe. So is Japan, East Asia, and the USA.

 

The map below gives the trajectory of the object over the current uncertainty window of the Tudat reentry forecast (red dots are cities with over 1 million inhabitants, between latitude 52 N and 52 S). In our model the spacecraft could have reentered anywhere along the blue line:

 

Click map to enlarge

 

 

CSpOC, the US military tracking network, has started to provide TIP (Time of Impact Prediction) messages for the object since May 6. They are depicted as red circles in the diagram earlier in this post.

 

The last orbit update published by CSpOC has epoch 10 May 2025, 00:36 UTC, i.e. dates from about 6 hours before the time we think it actually reentered. There are later radar detections from Europe, per ESA, dating to as late as 6:04 UTC, but no orbit based on that has been published.

A roundup of current reentry forecasts from various sources (each running their own reentry model) compiled 10 May 15:30 UTC:

 

Tudat forecast:              10 May   06:39 ± 91  min UTC

Tudat postcast:              10 May   06:40 ± 91  min UTC

Aerospace Corp forecast:     10 May   06:29 ± 120 min UTC

RosCosmos postcast:          10 May   06:24 ± ?   min UTC

ESA postcast:                10 May   06:16 ± 22  min UTC

EU-SST forecast:             10 May   06:04 ± 20  min UTC

CSpOC TIP postcast:          10 May   05:32 ± 12  min UTC *

 

* this cannot be correct given that a positive radar detection from Germany at 6:04 UTC was reported by ESA.

 

note: forecast = issued before the reentry; postcast = issued after the reentry after re-analysis.

 

ESA reports that they had a positive radar detection of the spacecraft, still on-orbit, at 6:04 UTC while it was passing over Germany (presumably with the TIRA radar); and a negative detection one orbital revolution later, at 7:32 UTC. This implies reentry during the window 6:04 - 7:32 UTC. Five of the forecasts fall in that window: our Tudat forecast, and those by RosCosmos, ESA, the Aerospace Corporation, and also EU-SST when taking the error margins on the latter into account.

 

Roscosmos, the Russian Space Agency, on Telegram states reentry at "6:24 UTC" over the Indian Ocean. That is not too far (15 minutes) from our latest TUDAT model results. Three remarks: (1) this is not a reentry detection but likely another model result (just as the others), based on an earlier groundbased detection during a pass over presumably southern Russia. (2) It does not come with a stated uncertainty window: is that 10 minutes, 30 minutes, an hour? (3) It remains a question how serious one should take Russian State statements these days as sometimes pragmatic considerations (such as deliberate denial of responsibility or risk) are leading. 

 

While many news media seem to treat the RosCosmos announcement as 'authoritive' and the 'most accurate' or 'final' say on the matter, there is in reality no clear reason to do so. It is not clear at all whether the RosCosmos position is more accurate than the other model estimates, and how meaningful the stated positions and time are given the lack of error margin information.

A final accurate TIP from CSpOC has not yet appeared (and might not appear if they have no space-based detections of the reentry fireball). CSpOC sometimes, several hours to a day after a reentry, publishes a very accurate (with quoted +- 1 minute uncertainty) final TIP which Jonathan McDowell and I believe is not based on a reentry model, but on space-based (SBIRS satellite) detections of the reentry fireball, hence the accuracy. They have not issued such a TIP so far for this reentry, unfortunately. Note that their last issued TIP cannot be correct, given the reported positive radar detection of the spacecraft passing over Germany at 6:04 UTC.

 

This is how the nominal reentry points have been placed by various organisations, each based on their own modelling:

 

Click map to enlarge

 

It is clear that the assessments spread. Ignoring the clearly incorrect CSpOC TIP, the other models all suggest reentry over either southwest Asia or the Indian Ocean. My verdict is that the latter area is the most likely place.

 

Below is the evolution of the reentry forecast from our TU Delft Tudat model in tabular form, latest forecast at the bottom. Please take note of the uncertainty values listed in the last column!

 

The 'postcast' value is a re-run of the model after-the-fact based on the last published orbit and the actual rather than estimated space weather of May 10.

 

--------------------------------------------------------------------
TUDAT REENTRY FORECAST EVOLUTION for KOSMOS 482 Descent Craft
M. Langbroek & D. Dirkx, Delft University of Technology

Date/times in UTC

REFERENCE ORBIT    ORBIT EPOCH      REENTRY FORECAST   +/-   
----------------------------------------------------------------
15-11-2024 05:43   24320.23870400   05-05-2025 23:33   42.9 days   
01-12-2024 05:32   24336.23116452   08-05-2025 09:09   39.5 days   
15-12-2024 18:58   24350.79080401   07-05-2025 11:51   35.7 days   
01-01-2025 11:20   25001.47260254   09-05-2025 07:20   32.0 days   
15-01-2025 03:23   25015.14140884   10-05-2025 20:40   28.9 days   
02-02-2025 08:54   25033.37115746   13-05-2025 17:52   25.1 days   
15-02-2025 03:20   25046.13941015   11-05-2025 09:52   21.3 days   
01-03-2025 00:07   25060.00535989   10-05-2025 17:51   17.7 days   
15-03-2025 05:56   25074.24770046   10-05-2025 07:57   14.0 days   
30-03-2025 12:05   25089.50360681   09-05-2025 21:11   10.1 days   
13-04-2025 21:32   25103.89775709   09-05-2025 22:01    6.5 days   
20-04-2025 01:39   25110.06916305   09-05-2025 11:31    4.9 days   
22-04-2025 21:24   25112.89204293   09-05-2025 12:48    4.2 days   
23-04-2025 22:57   25113.95657237   09-05-2025 19:43    4.0 days   
27-04-2025 00:27   25117.01893077   10-05-2025 04:52    3.3 days   
28-04-2025 00:24   25118.01685903   10-05-2025 06:33    3.1 days   
28-04-2025 22:50   25118.95143786   10-05-2025 06:01    2.8 days   
01-05-2025 20:57   25121.87323063   10-05-2025 14:30    2.2 days   
02-05-2025 09:12   25122.38386703   11-05-2025 02:36    2.2 days   
02-05-2025 12:16   25122.51167762   11-05-2025 03:41    2.2 days   
02-05-2025 17:52   25122.74476620   11-05-2025 06:50    2.1 days   
03-05-2025 18:07   25123.75533175   10-05-2025 20:48    1.8 days   
03-05-2025 21:05   25123.87876286   10-05-2025 23:06    1.8 days   
04-05-2025 20:47   25124.86648285   10-05-2025 19:05    1.5 days   
05-05-2025 20:29   25125.85361170   10-05-2025 07:26    1.1 days   
06-05-2025 09:39   25126.40254557   10-05-2025 08:37    1.0 day
06-05-2025 21:26   25126.89335737   10-05-2025 07:51   20.6 hr
07-05-2025 21:00   25127.87559184   10-05-2025 07:34   14.6 hr
08-05-2025 11:31   25128.48053679   10-05-2025 07:24   11.0 hr
08-05-2025 13:13   25128.55136979   10-05-2025 07:34   10.6 hr
08-05-2025 19:13   25128.80083450   10-05-2025 07:54    9.2 hr
09-05-2025 12:37   25129.52575525   10-05-2025 06:23    4.4 hr
09-05-2025 14:12   25129.59226104   10-05-2025 06:30    4.1 hr
09-05-2025 15:43   25129.65543839   10-05-2025 06:35    3.7 hr
09-05-2025 19:55   25129.82989846   10-05-2025 06:34    2.7 hr
10-05-2025 00:35   25130.02495443   10-05-2025 06:39    1.5 hr

                               nominal location 35.7 S 126.5 E

POSTCAST:

10-05-2025 00:35   25130.02495443   10-05-2025 06:40    1.5 hr

                               nominal location 38.0 S 129.8 E

 

I will periodically update this table with new forecasts, more frequently so when the reentry dates comes nearer.

Here is footage I shot of the Kosmos 482 Descent Craft with my tracking camera in Leiden, in 2020:

An added note: about that parachute....

To muddy the waters further, a story is spreading that the parachute of the landing craft might already have deployed in space. This is based on telescopic imagery purportedly showing this.

I have strong doubts that the imagery in question shows any meaningful detail. The imagery has the same origin, and the same problems attached, as the imagery I discussed in 2022 in my Space Review article. I think the "detail" is the result of camera/telescope shake and atmospheric distortion.

 

UPDATE 28 May 2025:
With my colleague Dominic Dirkx, I wrote a 'post mortem' on the reentry for The Space Review that can be read here.

This post has been updated with new forecasts and additional background information several times

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 SIGINT satellite LUCH (OLYMP-K) 2 has moved again

LUCH (OLYMP) 2 position change. Click image to enlarge

 

Luch (OLYMP) 2 (2023-031A), the second Russian OLYMP-K/LUCH 5X SIGINT satellite in geosynchronous orbit, has changed position several times since its launch in 2023. Each time, it was placed near a commercial communications satellite. I have written about it before on this blog (e.g. here), and two (here and here) 2023 Space Review article by Bart Hendrickx provides more background on the OLYMP-K program.

And now LUCH (OLYMP) 2 has moved again. From its previous position stalking THOR 7 (2015-022A) at longitude 0.54 W, where it arrived on July 1 2024, it has now made a small hop to the other side of the THOR + INTELSAT grouplet, to 0.92 W, taking a position inbetween THOR 6 (2009-058B) and INTELSAT 1002 (2004-022A).  

The move started on 16 September 2024 near 22 UTC and was completed on September 18.

LUCH 2 positions over time. Click diagram to enlarge

 

detail of the lastest move (top). Click diagram to enlarge

The photographs in top of this blogpost shows the change in position by LUCH (OLYMP) 2 over the past week: basically moving from one end of the grouplet to the other.

(as soon as the moon is less of a nuisance, I will attempt to get a better picture of LUCH (OLYMP) 2 at its new position, with a larger phase angle).

This is not the first "small hop" of LUCH (OLYMP) 2 to the other side of a visited satellite grouplet. In December 2023, it also made a small hop, from 3.2 E to 2.6 E, moving from EUTELSAT 3B to EUTELSAT KONNECT VHTS.

Meanwhile, it is not the first time either that a LUCH (OLYMP-K) satellite is checking out INTELSAT 1002. The latter has been visited by an earlier LUCH (OLYMP) satellite, LUCH (OLYMP) 1 (2014-058A) twice before.

The relocations of LUCH (OLYMP) 2 so far come at intervals of roughly 3 months.

It is still a bit mysterious why exactly these LUCH (OLYMP) satellites are stalking commercial satellites. The roles of their victims are somewhat diverse, although most of the stalking targets in one way or another have to do with data transmissions and TV broadcasts (but there appear to be no relations to recent Russian satellite TV hacks). They could perhaps be mapping contact networks, tapping data streams, analysing frequency hopping patterns, or even analyse weak energy field transmissions within their target satellites. Or they are just there to feed paranoia and provoke counterspace methods.

The Russian SIGINT satellite LUCH (OLYMP) 2 has arrived at its new destination, next to THOR 7

LUCH (OLYMP) 2 imaged at its new location on July 6. Click image to enlarge

 

In a previous blogpost I signalled that the Russian military SIGINT satellite LUCH (OLYMP) 2 (2023-031A), also known as LUCH-5X, a satellite that stalks other satellites, started another relocation move on July 22, leaving its position near ASTRA 4A at longitude 4.8 E and drifting west at 0.9 degrees per day. 

On July 1, the drift stopped as it arrived at its new target destination at longitude 0.54 W. As expected, it has been placed close to yet another western commercial geosynchronous satellite: the Norwegian satellite THOR 7 (2015-022A).

The image above shows both satellites - plus a couple of other neighbouring ones - as imaged by me from Leiden in the night of July 6/7, when I finally had clear skies again, albeit briefly. The image is a 10-second exposure taken with a ZWO ASI 6200 MM PRO + 1.2/85 mm lens. 

At the moment the image was taken, LUCH (OLYMP) 2 and THOR 7 were some 84 km apart. That distance might diminish further: the Russian satellite is still slowly drifting closer to THOR 7.

This is the sixth relocation of LUCH (OLYMP) 2, and the fifth satellite it visits (see diagram above). I expect that it will stay close to THOR 7 for a few weeks and then move on again, possibly to one of the neighbouring satellites (THOR 5 or 6, or INTELSAT 1002), or to a new location altogether.

I also imaged LUCH (OLYMP) 1 (2014-058A), the predecessor of LUCH (OLYMP) 2 (see image below). It has been parked close to INTELSAT 37E (2017-059A) at longitude 18.1 W since September 2022, following an earlier life of frequent relocations (some 30 relocations between 2014 and 2022):

 

LUCH (OLYMP) 1 near INTELSAT 37E on July 6. Click image to enlarge

More on both LUCH (OLYMP) 1 and 2 and their program backgrounds can be found in this article from 2023 by Bart Hendrickx in The Space Review.

As I wrote in a previous blogpost, what LUCH (OLYMP) 2 and its predecesssor LUCH (OLYMP) 1 are doing so close to commercial satellites is an interesting issue. To name a few possibilities: they might be gathering information to map contact networks; geolocating targets that use the satellites; eavesdropping on data communications; prepare for or actually do jamming or spoofing activities; or checking these satellites for vulnerabilities that might provide a means to disable them, might need come.

LUCH (OLYMP) 2 is on the move again [UPDATED]

Image from June 27, 2024. Click to enlarge

 [ UPDATED on 5 July 2024 ]

The Russian military geosynchronous SIGINT satellite LUCH (OLYMP) 2 (2023-031A) is on the move again. It has left its position at longitude 4.7 E with a manoeuver initiated on 22 June 2024, likely around 11:40 UTC. It is now drifting westwards with a drift rate of approximately 0.9 degrees per day. 

The change in several orbital elements after mid June 22 is well visible in the TLE data:

It will be interesting to see what LUCH (OLYMP) 2's next stalking victim will be.

LUCH (OLYMP) 2, which was launched on 12 March 2023, is building a history of frequent relocations, like its predecessor LUCH (OLYMP) 1 (2014-048A) did. With each relocation, it is placed close to a commercial satellite. Below shows the position it had between April 1 and June 22 close (daily varying between 20-75 km) to ASTRA 4A at 4.7 E, where it arrived on April 2, 2024 (see this earlier blogpost) until it left there on June 22. 

 

 

So far LUCH (OLYMP) 2 has stalked at least four commercial satellites:

ARRIVED      LEFT         LON      NEXT TO
22-05-2023   25-09-2023   9.0 E    EUTELSAT (KA SAT) 9A/EUTELSAT 9B
04-10-2023   04-12-2023   3.2 E    EUTELSAT 3B
05-12-2023   26-03-2024   2.6 E    EUTELSAT KONNECT VHTS
01-04-2024   22-06-2024   4.7 E    ASTRA 4A

Below, the movements since launch in diagram form, showing the longitude of placement The first two placements at 78 E and 58 E were probably check-out placements.

click diagram to enlarge

What LUCH (OLYMP) 2 (and its predecesssor LUCH (OLYMP) 1) is doing so close to commercial satellites is an interesting issue. To name a few possibilities: it might be gathering information to map contact networks; geolocating targets that use the satellites; eavesdropping on data communications; prepare for or actually do jamming or spoofing activities; or checking these satellites for vulnerabilities that might provide a means to disable them, might need come.

 

UPDATES 5 and 7 July 2024

The westward drift of LUCH (OLYMP) 2 stopped on July 1, at longitude 0.54 W, where it has now stabilized its position. LUCH (OLYM) 2 is now close to the Norwegian commercial geosat THOR 7 (2015-022A). Due to bad weather, I have not been able to image it there yet. I imaged it at its new position on July 6/7, see this new blogpost.

A Russian Optical Reconnaissance satellite launch from Plesetsk upcoming [UPDATED TWICE]

click map to enlarge

 

(two updates at bottom of post)

Navigational Warnings have appeared that point to a Russian launch from Plesetsk between May 16-26. The direction of launch as indicated by the hazard zones from the Navigational Warnings (see maps above and below), points to launch into a ~97.75 degree inclined Sun-synchronous orbit. This, in turn, points to an IMINT mission, i.e. an optical reconnaissance satellite.

There are two options: another BARS M satellite (BARS M6), or something new. There are indications of the latter. Compared to previous BARS M launches, in addition to hazard zones near the Kola peninsula and Svalbard, there is an extra deorbit zone, in the NE Pacific some 1100 km out of the coast of California. As Bart Hendrickx pointed out, this might indicate the addition of a Fregat upper stage to a Soyuz 2 rocket, something not seen before for launches into SSO from Plesetsk.

Bart Hendrickx thinks it might perhaps concern a launch of three small Razbeg optical reconnaissance satellites.

click map to enlarge

 

Launch window as indicated by the Navigational Warnings is May 16-26, 20:00-23:00 UTC daily. These are the relevant Navigational Warnings (which are plotted in the maps above):

 

NAVAREA XX 062/24
BARENTS SEA.
CHART RUS 10100.
1. ROCKET LAUNCHING 2000 TO 2300 UTC
DAILY 16 TO 26 MAY NAVIGATION
PROHIBITED IN TERRITORIAL WATERS
DANGEROUS OUTSIDE IN AREA BOUNDED BY:
70-56-00N 032-04-58E, 70-10-00N 033-40-00E,
69-54-00N 032-40-00E, 70-08-00N 032-04-58E,
70-15-00N 031-50-00E, 70-30-07N 031-50-00E,
70-36-22N 031-43-18E.


111952Z MAY 24
HYDROARC 75/24(42,43).
BARENTS SEA.
SVALBARD.
DNC 22.
1. HAZARDOUS OPERATIONS, SPACE DEBRIS
   2000Z TO 2300Z DAILY 16 THRU 26 MAY
   IN AREA BOUND BY
   76-30.00N 022-00.00E, 75-20.00N 024-40.00E,
   74-50.00N 021-40.00E, 75-50.00N 018-40.00E.
2. CANCEL THIS MSG 270001Z MAY 24.


120900Z MAY 24
NAVAREA XII 330/24(18).
EASTERN NORTH PACIFIC.
1. HAZARDOUS OPERATIONS, SPACE DEBRIS
   2000Z TO 2300Z DAILY 16 THRU 26 MAY
   IN AREA BOUND BY
   29-21.00N 126-46.00W, 29-50.00N 128-52.00W,
   24-22.00N 130-24.00W, 23-53.00N 128-15.00W.
2. CANCEL THIS MSG 270001Z MAY 24.

Assuming an orbital altitude at ~500 km, this is an approximate orbit guess for launch at the start of the window (the orbital inclination could be off by a few tenths of a degree, and orbital altitude is a guess only):

Russian IMINT                  for launch on 16 May 2024 20:00:00 UTC
1 70000U 24999A   24137.83333333  .00000000  00000-0  00000-0 0    09
2 70000 097.7500 232.3966 0010908 075.7763 325.4205 15.22766913    04

 

UPDATE 1, 17 May 2024:

The launch was at 21:21 UTC (May 16). One single payload (59773, 2024-092A) has so far been catalogued, in a 97.25 degree inclined, 451 x 436 km sun-synchronous orbit. So my pre-launch orbit estimate above was off by 0.5 degrees in inclination and ~50 km in orbital altitude [but: see second update below].

The payload will likely get the designation Kosmos 2576. The orbital altitude is some 53.5 km lower than the typical orbit of a BARS M satellite, indeed suggesting this might be something new. The orbit also doesn't fit well into the existing BARS M constellation

KOSMOS 2576 (yellow) compared to BARS M constellation (white)

UPDATE 2, 19 May 2024:

8 additional objects have now been catalogued (59774 to 59781), making a total of 9. They fall in three/four groups:

GROUP     ORBIT       INC     PERIOD   OBJECTS
I         451 x 435   97.25   93.45    A
II        796 x 780   98.59   100.62   G,H,J
IIIa      552 x 532   97.59   95.52    D,E,F
IIIb      548 x 531   97.59   95.45    B,C

More in a follow-up post, as there might be something more to these orbits....

click to enlarge