RE: Kosmos 2542/2543 vs USA 245?

From: Tim Collins via Seesat-l <>
Date: Thu, 26 Dec 2019 15:18:31 -0000

The cat-and-mouse activities and orbital change would appear to be an unlikely coincidence.  Maybe the Kosmos is on a mission to get close to the NRO satellite and take photographs to demonstrate its non-Earth reconnaissance capabilities.  It would be illogical for the Kosmos to catch a friendly, ie another Kosmos, as (a) the resulting demonstration photographs if released could compromise Russian capabilities, and (b) if they hit there is a risk of losing two Russian assets.  Alternatively, maybe the chase is just a test of collision avoidance technologies.

Clear skies and good luck with re-acquisition of 245.

Tim C

-----Original Message-----
From: Seesat-l [] On Behalf Of Nico Janssen via Seesat-l
Sent: 26 December 2019 14:56
Subject: Kosmos 2542/2543 vs USA 245?

Kosmos 2542 was launched on 2019-11-25 into a 368x857 km orbit.
Interestingly, its orbit plane is almost exactly the same as USA 245's
orbit plane. The difference is less than 1 degree.

On 2019-12-06 the inspector satellite Kosmos 2543 was deployed from
Kosmos 2542. After some initial maneuvers near its 'mother' satellite
Kosmos 2543 started raising its orbit.

On 2019-12-09 or 2019-12-10 USA 245 changed its orbit. Before its
maneuver it was in a 272x985 km orbit. This is the last TLE set that I
could determine before the maneuver:
USA 245
1 39232U 13043A   19342.41935900  .00010000  00000-0  10147-3 0 00
2 39232  97.8900  42.9218 0508960 301.2530 203.1441 14.80147872 09

I lost track of USA 245 after its orbit maneuver. I suspect it is now in a
much higher orbit.

Kosmos 2542 is still in its original orbit. But meanwhile Kosmos 2543 has
climbed to a 590x859 km orbit, still in the same orbit plane as USA 245.

So what is going on? Is Kosmos 2543 chasing USA 245? And is USA 245
trying to escape by changing its orbit? Or is all this just a coincidence?

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Received on Thu Dec 26 2019 - 09:19:12 UTC

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