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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.
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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.
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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.
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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.
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