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: 3 hours ago
TLE from 3 hours ago
0 COSMOS 2125
1 21100U 91009A 26155.22163288 -.00000017 00000-0 -67051-5 0 9998
2 21100 74.0307 337.6657 0010158 219.1352 256.1134 12.49966652611114Epoch: 2026-06-04T05:19Z
TLE epoch observation values (Epoch: 2026-06-04T05:19:09.080Z)
Latitude
60.59721°
Longitude
154.85667°
Altitude
1,476.507 km
Speed
7.13 km/s
True Right ascension
08h 29m 15s
True Declination
60° 27' 48"
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
17:45:12
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,470.434 km
Perigee altitude
1,454.505 km
Semi-major axis
7,840.606 km
Eccentricity
0.00102
Inclination
74.0307°
RAAN
337.6657°
Arg. of periapsis
219.1352°
True anomaly
256.00043°
Mean anomaly
256.1134°
Eccentric anomaly
256.05691°
Mean motion
3.12621 °/min
Orbital period
115.16 mins
BSTAR
-0.0000067051
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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 12:28:34.419Z | 163.684° S | 2026-06-04 12:35:34.419Z | 102.883° ESE | 34.307° | 2026-06-04 12:43:34.419Z | 32.338° NE |
| 14 mins | 2026-06-04 14:26:34.419Z | 233.15° WSW | 2026-06-04 14:33:34.419Z | 301.977° NW | 34.273° | 2026-06-04 14:40:34.419Z | 5.038° NNE |
| 14 mins | 2026-06-04 22:35:34.419Z | 355.632° N | 2026-06-04 22:42:34.419Z | 66.533° ENE | 35.531° | 2026-06-04 22:49:34.419Z | 131.128° SE |
| 14 mins | 2026-06-05 00:33:34.419Z | 321.422° NNW | 2026-06-05 00:39:34.419Z | 265.213° W | 32.735° | 2026-06-05 00:47:34.419Z | 197.109° SSW |
Co-orbital & Co-planar RSOs
Thresholds — Semi-major Axis: ±100 km, RAAN: ±3°, Inclination: ±5°
TCA is derived from TLE conjunctions
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CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
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