CALSPHERE 4(A), 1520
Orbit data source: Space-Track
CALSPHERE 4(A), 1520 is a payload satellite owned by NRL (US) in LEO that was launched on Fri, 13 Aug 1965 UTC via a THOR ABLESTAR 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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1520 intel report (Beta)
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Edit Public Description
Identifier
Orbit
Country
USRelated business
Manufacturer
NRL
Mission
Operational spacecraft
Bus & Motor
NRL 14", Unknown motor
Mass
4 kg wet, 4 kg dry
Launch date (UTC)
Launch vehicle
Launch site
Object type
Shape & HBR
Unknown
Radar Cross Section
Small (<0.1 m²)
Expand to show TLE details & historyLast TLE update: 14 hours ago
TLE from 14 hours ago
0 CALSPHERE 4(A)
1 01520U 65065H 25318.24292463 .00000191 00000-0 35060-3 0 9999
2 01520 89.9079 124.4913 0069375 351.5898 62.0291 13.36231551934001Epoch: 2025-11-14T05:49Z
TLE epoch observation values (Epoch: 2025-11-14T05:49:48.688Z)
Latitude
54.41753°
Longitude
-16.42272°
Altitude
1,108.259 km
Speed
7.315 km/s
True Right ascension
08h 18m 28s
True Declination
54° 15' 44"
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
16:15:02
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,172.441 km
Perigee altitude
1,068.398 km
Semi-major axis
7,498.557 km
Eccentricity
0.00694
Inclination
89.9079°
RAAN
124.4913°
Arg. of periapsis
351.5898°
True anomaly
62.73406°
Mean anomaly
62.0291°
Eccentric anomaly
62.3813°
Mean motion
3.34254 °/min
Orbital period
107.7 mins
BSTAR
0.0003506
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Other satellites on launch #65 in the year 1965 (1965-08-13 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.CALSPHERE 4(A) 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. |
|---|---|---|---|---|---|---|---|
| 10 mins | 2025-11-14 22:20:53.338Z | 30.639° NE | 2025-11-14 22:25:53.338Z | 81.776° E | 24.094° | 2025-11-14 22:30:53.338Z | 131.892° SE |
| 11 mins | 2025-11-15 00:08:53.338Z | 346.579° N | 2025-11-15 00:13:53.338Z | 272.46° WNW | 38.734° | 2025-11-15 00:19:53.338Z | 205.733° SW |
| 9 mins | 2025-11-15 10:27:53.338Z | 118.213° SE | 2025-11-15 10:31:53.338Z | 68.062° E | 25.05° | 2025-11-15 10:36:53.338Z | 20.309° NNE |
| 11 mins | 2025-11-15 12:13:53.338Z | 207.215° SW | 2025-11-15 12:18:53.338Z | 280.203° WNW | 35.806° | 2025-11-15 12:24:53.338Z | 345.44° N |
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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