CERTIFICATE OF RE-ENTRYOrbital Register™ · by Orbital Radar™
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Entry no.
2025-1172

COSMOS 1666

COSMOS 1666 (NORAD 15889) re-entered Earth’s atmosphere on 15 June 2025 over the North Pacific Ocean, after 39 years, 11 months in orbit.

Official date
NORAD number
15889
International designator
1985-058A
Object type
Spacecraft
Country
USSR
Launched
8 Jul 1985Plesetsk Cosmodrome
Re-entered (UTC)
15 Jun 2025Recorded time 12:01 UTC
Time in orbit
39 years, 11 months14,587 days
How it ended
Re-entered (natural decay)
Latitude range
82.4°N to 82.4°SFinal inclination 82.4°
Mass
1,750 kg
Operator
GRU
Built by
Southern SDB
Bus
Tselina-D
Programme
Tselina-D

Where it came down

Recorded position

Recorded position 46.0°N, 140.0°W at 12:01 UTC. Its final orbit, inclined at 82.4°, allowed a re-entry anywhere between 82.4°N and 82.4°S.

Life in orbit

39 years, 11 months

COSMOS 1666’s lowest and highest points above Earth, week by week, from its tracking history.

Also ended on 15 Jun 2025

5 entries
2025-1174STARLINK-14122025-1175STARLINK-20102025-1176STARLINK-22842025-1177STARLINK-112082025-1173SL-24 DEB
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Entered in the Orbital Register™, founding volume, September 2026.
Record version 1 · No corrections · orbitalradar.com/register/2025-1172
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