COSMOS 2125, 21100
Orbit data source: Space-Track
COSMOS 2125, 21100 is a payload satellite owned by UNKS RF (CIS) in LEO that was launched on Tue, 12 Feb 1991 UTC via a KOSMOS 11K65M launch vehicle from the Plesetsk Missile And Space Complex (PKMTR). Payload-class satellites include a variety of spacecraft equipped with specific instruments for various scientific and technological missions. These include communications satellites like Starlink; space stations such as the ISS; scientific satellites like the Hubble; Earth observation satellites from companies like Planet Labs, Umbra, and HawkEye 360; GPS; miniature CubeSats for education and research; and military/defense satellites.
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21100 intel report (Beta)
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Identifier
Orbit
Country
CISRelated business
Manufacturer
NPO PM
Mission
Defense Communications
Bus & Motor
STRELA-1 11F625, Unknown motor
Mass
60 kg wet, 60 kg dry
Launch date (UTC)
Launch vehicle
Launch site
Object type
Shape & HBR
Sphere, 0.4 m
Radar Cross Section
0.588 m², Medium (>0.1 m² and < 1m²)
Expand to show TLE details & historyLast TLE update: 15 hours ago
TLE from 15 hours ago
0 COSMOS 2125
1 21100U 91009A 26154.65145402 -.00000016 00000-0 -61687-6 0 9991
2 21100 74.0307 338.4235 0010159 219.9892 210.3800 12.49966672611049Epoch: 2026-06-03T15:38Z
TLE epoch observation values (Epoch: 2026-06-03T15:38:05.627Z)
Latitude
64.94018°
Longitude
-110.68857°
Altitude
1,482.351 km
Speed
7.125 km/s
True Right ascension
01h 03m 46s
True Declination
64° 49' 13"
Sunlit
Visualization orbit readout
Latitude
Unknown
Longitude
Unknown
Altitude
Unknown
Speed
Unknown
Apparent Right ascension
Unknown
Apparent Declination
Unknown
Sunlit
Visualization observer readout
Local Sidereal Time
16:32:03
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,470.435 km
Perigee altitude
1,454.504 km
Semi-major axis
7,840.606 km
Eccentricity
0.00102
Inclination
74.0307°
RAAN
338.4235°
Arg. of periapsis
219.9892°
True anomaly
210.32119°
Mean anomaly
210.38°
Eccentric anomaly
210.35059°
Mean motion
3.12621 °/min
Orbital period
115.16 mins
BSTAR
-6.1687e-7
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Other satellites on launch #9 in the year 1991 (1991-02-12 UTC)
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You can import UDL-sourced sensor .json files into the Sandbox to generate a visibility chart that accounts for multi-vendor sensor geometry.COSMOS 2125 Visibility forecast
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Span | Click to sort rows by Start time (UTC) header in descending order | Start Az. | Max El. time (UTC) | Max El. Az. | Max El. | End time (UTC) | End Az. |
|---|---|---|---|---|---|---|---|
| 15 mins | 2026-06-04 12:28:37.530Z | 163.519° S | 2026-06-04 12:35:37.530Z | 102.018° ESE | 34.324° | 2026-06-04 12:43:37.530Z | 32.198° NE |
| 14 mins | 2026-06-04 14:26:37.530Z | 233.347° WSW | 2026-06-04 14:33:37.530Z | 302.839° NW | 34.256° | 2026-06-04 14:40:37.530Z | 5.22° NNE |
| 14 mins | 2026-06-04 22:35:37.530Z | 355.823° N | 2026-06-04 22:42:37.530Z | 67.47° ENE | 35.513° | 2026-06-04 22:49:37.530Z | 131.295° SE |
| 13 mins | 2026-06-05 00:33:37.530Z | 321.209° NNW | 2026-06-05 00:39:37.530Z | 264.413° W | 32.747° | 2026-06-05 00:46:37.530Z | 200.208° SSW |
Co-orbital & Co-planar RSOs
Thresholds — Semi-major Axis: ±100 km, RAAN: ±3°, Inclination: ±5°
TCA is derived from TLE conjunctions
Click to sort rows by RSO header in ascending order | Click to sort rows by Country header in ascending order | Click to sort rows by Type header in ascending order | Click to sort rows by Inclination Δ header in ascending order | Click to sort rows by RAAN Δ header in ascending order | Click to sort rows by Coplanar Angle header in ascending order | Click to sort rows by SMA Δ header in ascending order | Click to sort rows by Orbital period header in ascending order | Click to sort rows by <5km Md TCA header in descending order |
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CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
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