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: 11 hours ago
TLE from 11 hours ago
0 CALSPHERE 4(A)
1 1520U 65065H 26304.97310303 .00000077 00000-0 12833-3 0 9995
2 1520 89.8844 121.0643 0071467 77.7997 85.1884 13.36298086980972Epoch: 2026-10-31T23:21Z
TLE epoch observation values (Epoch: 2026-10-31T23:21:16.101Z)
Latitude
16.17574°
Longitude
-89.5573°
Altitude
1,121.268 km
Speed
7.295 km/s
True Right ascension
20h 04m 07s
True Declination
16° 05' 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
06:03:09
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,173.759 km
Perigee altitude
1,066.582 km
Semi-major axis
7,498.308 km
Eccentricity
0.00715
Inclination
89.8844°
RAAN
121.0643°
Arg. of periapsis
77.7997°
True anomaly
86.00505°
Mean anomaly
85.1884°
Eccentric anomaly
85.59667°
Mean motion
3.34271 °/min
Orbital period
107.7 mins
BSTAR
0.00012833
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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 | 2026-11-01 11:14:44.701Z | 132.378° SE | 2026-11-01 11:19:44.701Z | 77.616° E | 30.976° | 2026-11-01 11:24:44.701Z | 21.823° NNE |
| 10 mins | 2026-11-01 13:02:44.701Z | 213.411° SW | 2026-11-01 13:06:44.701Z | 265.391° W | 41.138° | 2026-11-01 13:12:44.701Z | 341.273° N |
| 5 mins | 2026-11-01 22:33:44.701Z | 60.273° ENE | 2026-11-01 22:35:44.701Z | 79.907° E | 14.751° | 2026-11-01 22:38:44.701Z | 106.985° ESE |
| 11 mins | 2026-11-02 00:18:44.701Z | 0.024° NNE | 2026-11-02 00:23:44.701Z | 269.431° W | 83.982° | 2026-11-02 00:29:44.701Z | 187.118° SSW |
| 4 mins | 2026-11-02 02:08:44.701Z | 305.143° NW | 2026-11-02 02:09:44.701Z | 295.989° NW | 12.573° | 2026-11-02 02:12:44.701Z | 269.072° W |
Co-orbital & Co-planar RSOs
Thresholds — Semi-major Axis: ±100 km, RAAN: ±3°, Inclination: ±5°
TCA is derived from TLE conjunctions
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CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
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