STARLINK-2121, 47399
Orbit data source: Space-Track
STARLINK-2121, 47399 is a payload satellite owned by SpaceX/Seattle (US) in LEO that was launched on Wed, 20 Jan 2021 UTC via an FALCON 9 launch vehicle from the Air Force Eastern Test Range (AFETR). 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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47399 intel report (Beta)
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Identifier
Orbit
Country
USRelated business
Manufacturer
SpaceX/Seattle
Mission
Operational Commercial Communications
Bus & Motor
STARLINK, Unknown motor
Mass
260 kg wet, ~248 kg dry
Launch date (UTC)
Launch vehicle
Launch site
Object type
Shape & HBR
Box + 1 Pan, 10.1 m
Radar Cross Section
13.562 m², Large (>1 m²)
Expand to show TLE details & historyLast TLE update: 3 days ago
TLE from 3 days ago
0 STARLINK-2121
1 47399U 21005BC 26170.58146744 .00001160 00000-0 49130-4 0 9994
2 47399 53.1595 282.6792 0001068 71.3258 288.7859 15.31703597299007Epoch: 2026-06-19T13:57Z
TLE epoch observation values (Epoch: 2026-06-19T13:57:18.786Z)
Latitude
-0.00006°
Longitude
165.54249°
Altitude
471.394 km
Speed
7.632 km/s
True Right ascension
18h 50m 42s
True Declination
0° 00' 00"
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
21:32:00
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
471.717 km
Perigee altitude
470.254 km
Semi-major axis
6,849.123 km
Eccentricity
0.00011
Inclination
53.1595°
RAAN
282.6792°
Arg. of periapsis
71.3258°
True anomaly
288.77431°
Mean anomaly
288.7859°
Eccentric anomaly
288.78011°
Mean motion
3.82905 °/min
Orbital period
94.02 mins
BSTAR
0.00004913
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Other satellites on launch #5 in the year 2021 (2021-01-20 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-2121 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. |
|---|---|---|---|---|---|---|---|
| 4 mins | 2026-06-22 11:07:59.208Z | 303.999° NW | 2026-06-22 11:09:59.208Z | 343.925° N | 17.172° | 2026-06-22 11:11:59.208Z | 19.521° NNE |
| 4 mins | 2026-06-22 14:25:59.208Z | 346.661° N | 2026-06-22 14:27:59.208Z | 24.1° NE | 15.903° | 2026-06-22 14:29:59.208Z | 59.068° ENE |
| 5 mins | 2026-06-22 16:03:59.208Z | 316.443° NNW | 2026-06-22 16:05:59.208Z | 12.935° NNE | 43.677° | 2026-06-22 16:08:59.208Z | 123.545° SE |
| 6 mins | 2026-06-23 08:57:59.208Z | 221.361° SW | 2026-06-23 09:00:59.208Z | 80.196° E | 41.745° | 2026-06-23 09:03:59.208Z | 53.257° ENE |
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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