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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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
SPHERE, 1.1 m
Radar Cross Section
Medium (>0.1 m² and <1 m²)
Expand to show TLE details & historyLast TLE update: 20 hours ago
TLE from 20 hours ago
0 CALSPHERE 4(A)
1 01520U 65065H 26312.23849131 .00000117 00000-0 20523-3 0 9999
2 01520 89.8843 120.9828 0071198 57.7374 116.1655 13.36299445981941Epoch: 2026-11-08T05:43Z
TLE epoch observation values (Epoch: 2026-11-08T05:43:25.649Z)
Latitude
5.28492°
Longitude
167.68302°
Altitude
1,149.361 km
Speed
7.267 km/s
True Right ascension
20h 03m 53s
True Declination
5° 15' 18"
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
21:49:23
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,173.552 km
Perigee altitude
1,066.779 km
Semi-major axis
7,498.303 km
Eccentricity
0.00712
Inclination
89.8843°
RAAN
120.9828°
Arg. of periapsis
57.7374°
True anomaly
116.89488°
Mean anomaly
116.1655°
Eccentric anomaly
116.53048°
Mean motion
3.34271 °/min
Orbital period
107.7 mins
BSTAR
0.00020523
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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. |
|---|---|---|---|---|---|---|---|
| 13 mins | 2026-11-09 11:29:51.895Z | 167.371° S | 2026-11-09 11:36:51.895Z | 53.318° ENE | 69.363° | 2026-11-09 11:42:51.895Z | 2.398° NNE |
| 6 mins | 2026-11-09 13:21:51.895Z | 254.56° W | 2026-11-09 13:24:51.895Z | 285.391° WNW | 17.148° | 2026-11-09 13:27:51.895Z | 314.989° NW |
| 11 mins | 2026-11-09 22:47:51.895Z | 24.253° NE | 2026-11-09 22:52:51.895Z | 82.775° E | 36.371° | 2026-11-09 22:58:51.895Z | 148.242° SSE |
| 10 mins | 2026-11-10 00:35:51.895Z | 338.34° N | 2026-11-10 00:40:51.895Z | 273.903° WNW | 36.818° | 2026-11-10 00:45:51.895Z | 220.831° SW |
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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