STARLINK-35631, 66121
Orbit data source: Space-Track
STARLINK-35631, 66121 is a payload satellite owned by SpaceX/Seattle (US) in LEO that was launched on Wed, 22 Oct 2025 UTC via an FALCON 9 launch vehicle from the Air Force Western Test Range (AFWTR). 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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66121 intel report (Beta)
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Edit Public Description
Identifier
Orbit
Country
USRelated business
Manufacturer
SpaceX/Seattle
Mission
Operational spacecraft
Bus & Motor
STARLINK V2MO, Unknown motor
Mass
575 kg wet, ~530 kg dry
Launch date (UTC)
Launch vehicle
Launch site
Object type
Shape & HBR
Unknown shape, 17.7 m
Radar Cross Section
RCS unknown
Expand to show TLE details & historyLast TLE update: 7 hours ago
TLE from 7 hours ago
0 STARLINK-35631
1 66121U 25237H 25312.16668980 -.01835778 00000-0 -16945-1 0 9999
2 66121 53.1596 251.4217 0001030 101.7094 184.1437 15.70303139 3929Epoch: 2025-11-08T04:00Z
TLE epoch observation values (Epoch: 2025-11-08T04:00:01.998Z)
Latitude
-50.51312°
Longitude
79.10003°
Altitude
376.158 km
Speed
7.683 km/s
True Right ascension
12h 26m 50s
True Declination
-50° 20' 05"
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
06:46:26
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
358.985 km
Perigee altitude
357.597 km
Semi-major axis
6,736.428 km
Eccentricity
0.0001
Inclination
53.1596°
RAAN
251.4217°
Arg. of periapsis
101.7094°
True anomaly
184.14285°
Mean anomaly
184.1437°
Eccentric anomaly
184.14327°
Mean motion
3.92553 °/min
Orbital period
91.71 mins
BSTAR
-0.016945
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Other satellites on launch #237 in the year 2025 (2025-10-22 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.STARLINK-35631 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. |
|---|---|---|---|---|---|---|---|
| 5 mins | 2025-11-08 22:51:25.445Z | 230.77° WSW | 2025-11-08 22:53:25.445Z | 289.095° WNW | 44.936° | 2025-11-08 22:56:25.445Z | 49.372° ENE |
| 4 mins | 2025-11-09 05:17:25.445Z | 326.436° NNW | 2025-11-09 05:19:25.445Z | 80.076° E | 36.932° | 2025-11-09 05:21:25.445Z | 116.099° SE |
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 ascending order |
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CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
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Click to sort rows by Secondary header in ascending order | Click to sort rows by Secondary name header in ascending order | Click to sort rows by Country header in ascending order | Click to sort rows by Owner header in ascending order | Click to sort rows by Obj. Type header in ascending order | Click to sort rows by Miss dist. header in ascending order | Click to sort rows by Rel. speed header in ascending order | Click to sort rows by Apr. angle header in ascending order | Click to sort rows by TCA header in ascending order |
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