COSMOS 1639, 15621
Orbit data source: Space-Track
COSMOS 1639, 15621 is a payload satellite owned by GUKOS (CIS) in LEO that was launched on Thu, 21 Mar 1985 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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15621 intel report (Beta)
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Edit Public Description
Identifier
Orbit
Country
CISRelated business
Manufacturer
NPO PM
Mission
Spacecraft
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
Unknown
Radar Cross Section
Medium (>0.1 m² and <1 m²)
Expand to show TLE details & historyLast TLE update: 15 hours ago
TLE from 15 hours ago
0 COSMOS 1639
1 15621U 85023E 25348.98874054 -.00000001 00000-0 97046-4 0 9992
2 15621 74.0534 212.3790 0025154 352.2918 73.5708 12.51055078860470Epoch: 2025-12-14T23:43Z
TLE epoch observation values (Epoch: 2025-12-14T23:43:47.182Z)
Latitude
61.65745°
Longitude
164.35016°
Altitude
1,464.732 km
Speed
7.139 km/s
True Right ascension
16h 16m 45s
True Declination
61° 31' 35"
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
13:24:34
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,477.628 km
Perigee altitude
1,438.206 km
Semi-major axis
7,836.054 km
Eccentricity
0.00252
Inclination
74.0534°
RAAN
212.379°
Arg. of periapsis
352.2918°
True anomaly
73.84752°
Mean anomaly
73.5708°
Eccentric anomaly
73.70914°
Mean motion
3.12894 °/min
Orbital period
115.05 mins
BSTAR
0.000097046
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Other satellites on launch #23 in the year 1985 (1985-03-21 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 1639 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. |
|---|---|---|---|---|---|---|---|
| 12 mins | 2025-12-15 14:50:00.200Z | 144.15° SSE | 2025-12-15 14:56:00.200Z | 95.662° ESE | 24.638° | 2025-12-15 15:02:00.200Z | 45.269° ENE |
| 15 mins | 2025-12-15 16:46:00.200Z | 214.907° SW | 2025-12-15 16:53:00.200Z | 294.663° NW | 41.707° | 2025-12-15 17:01:00.200Z | 12.826° NNE |
| 6 mins | 2025-12-15 18:50:00.200Z | 298.368° NW | 2025-12-15 18:52:00.200Z | 313.229° NW | 13.803° | 2025-12-15 18:56:00.200Z | 342.409° N |
| 13 mins | 2025-12-16 00:55:00.200Z | 2.135° NNE | 2025-12-16 01:01:00.200Z | 52.81° ENE | 27.261° | 2025-12-16 01:08:00.200Z | 112.865° SE |
| 15 mins | 2025-12-16 02:52:00.200Z | 332.769° NNW | 2025-12-16 02:59:00.200Z | 267.391° W | 41.357° | 2025-12-16 03:07:00.200Z | 180.932° 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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