Author Topic: Rokot/Briz-KM with 3 Rodnik + Kosmos 2491 - December 25, 2013 (0031UTC)  (Read 14143 times)

Offline input~2

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Offline input~2

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One object now cataloged - 2013-076A in a 1469 x 1508 km x 82.50 deg orbit.
So, at least roughly the right orbit - tentative mission success (perigee is a touch low but not completely out of family)
Corresponding to epoch 0159UTC that could have been the upper unit before separation at 0216UTC

2 new objects have now been catalogued:
39484/2013-076B in 1148 x 1503 km x 82.47 at epoch 0351UTC could be Briz-KM
39485/2013-076C in 1482 x 1511 km x 82.48 at epoch 0355UTC could be one of the 3 Rodnik

Addendum#1:
39483/2013-076A in 1478 x 1509 km x 82.48 at epoch 0355UTC could be a 2nd Rodnik

Addendum#2
and finally the 3rd Rodnik
39486/2013-076D in 1480 x 1511 km x 82.49 at epoch 0747UTC
« Last Edit: 12/25/2013 10:21 AM by input~2 »

Offline owais.usmani

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« Last Edit: 12/25/2013 07:47 AM by input~2 »

Offline input~2

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Offline jcm

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One object now cataloged - 2013-076A in a 1469 x 1508 km x 82.50 deg orbit.
So, at least roughly the right orbit - tentative mission success (perigee is a touch low but not completely out of family)
Corresponding to epoch 0159UTC that could have been the upper unit before separation at 0216UTC
 

Yes although be careful:  the "epoch" of a TLE set doesn't mean that is the instant of observation - JSPOC's
orbit determination code generates a TLE set at the epoch of equator crossing on the orbit of interest, even if
the observations were later. So sometimes for GTO objects the epoch is even before launch.  You can't conclude
from an epoch of 0159 UTC that the object existed/had separated prior to 0216 UTC - they may have spotted it
any time on that orbit.
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Jonathan McDowell
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Offline input~2

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One object now cataloged - 2013-076A in a 1469 x 1508 km x 82.50 deg orbit.
So, at least roughly the right orbit - tentative mission success (perigee is a touch low but not completely out of family)
Corresponding to epoch 0159UTC that could have been the upper unit before separation at 0216UTC
 

Yes although be careful:  the "epoch" of a TLE set doesn't mean that is the instant of observation - JSPOC's
orbit determination code generates a TLE set at the epoch of equator crossing on the orbit of interest, even if
the observations were later. So sometimes for GTO objects the epoch is even before launch.  You can't conclude
from an epoch of 0159 UTC that the object existed/had separated prior to 0216 UTC - they may have spotted it
any time on that orbit.

Thanks for that!
Let's try to verify that Object A was in the equatorial plane at the epoch of its first TLE:
Then at that time, its true anomaly (T) plus the argument of perigee (P) of its orbit should have been a multiple of 180.
From the 1st TLE, argument of  perigee was 298.57 and mean anomaly (M) was 61.26.
As the orbit was nearly circular, the Object's mean anomaly was close to its true anomaly (T) and
P +T ~ P + M = 359.83 close enough to 360 QED ;)

Offline jcm

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One object now cataloged - 2013-076A in a 1469 x 1508 km x 82.50 deg orbit.
So, at least roughly the right orbit - tentative mission success (perigee is a touch low but not completely out of family)
Corresponding to epoch 0159UTC that could have been the upper unit before separation at 0216UTC
 

Yes although be careful:  the "epoch" of a TLE set doesn't mean that is the instant of observation - JSPOC's
orbit determination code generates a TLE set at the epoch of equator crossing on the orbit of interest, even if
the observations were later. So sometimes for GTO objects the epoch is even before launch.  You can't conclude
from an epoch of 0159 UTC that the object existed/had separated prior to 0216 UTC - they may have spotted it
any time on that orbit.

Thanks for that!
Let's try to verify that Object A was in the equatorial plane at the epoch of its first TLE:
Then at that time, its true anomaly (T) plus the argument of perigee (P) of its orbit should have been a multiple of 180.
From the 1st TLE, argument of  perigee was 298.57 and mean anomaly (M) was 61.26.
As the orbit was nearly circular, the Object's mean anomaly was close to its true anomaly (T) and
P +T ~ P + M = 359.83 close enough to 360 QED ;)

So it's been pointed out to me that nowadays not all TLEs satisfy this rule. It was true for the Rodniks
but not for the Soyuz-2-1V launch.  So I'll revise
my statement to say: IF you check the TLE and its epoch corresponds to an equator crossing,
THEN the TLE was made using software that enforces this and doesn't necessarily correspond to epoch
of observation.

Edit by input~2: We can reveal that I was the one who pointed out these "non equatorial" TLEs ;)
« Last Edit: 12/29/2013 10:56 AM by input~2 »
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Jonathan McDowell
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Offline input~2

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It is now confirmed that there were 4 satellites launched by this Rockot
source: http://www.oosa.unvienna.org/pdf/reports/regdocs/ser709E.pdf

Offline Stan Black

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Online Alter Sachse

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Cosmos 2519 has engine K50-10.5 from OKB Fakel.

http://www.fakel-russia.com/images/content/o_kompanii/letnaya_istoriya/KA_s_oborudovaniem.pdf

K50-10.6 for Kosmos-2499 and Kosmos-2504.
There is a confused entry for Kosmos-2491?

http://www.fakel-russia.com/images/content/products/fakel_tkd_en_print.pdf
24.03.2014 (Moscow time) was Kosmos 2492 Glonass M54

Online Alter Sachse

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Kosmos 2491 possibly without engine
(or are maneuvers known?)

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