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: 8 hours ago
TLE from 8 hours ago
0 CALSPHERE 4(A)
1 01520U 65065H 26313.86982260 .00000101 00000-0 17593-3 0 9996
2 01520 89.8844 120.9645 0071107 53.2277 43.8815 13.36299772982164Epoch: 2026-11-09T20:52Z
TLE epoch observation values (Epoch: 2026-11-09T20:52:32.672Z)
Latitude
82.35111°
Longitude
-62.06821°
Altitude
1,098.469 km
Speed
7.329 km/s
True Right ascension
20h 00m 25s
True Declination
82° 18' 28"
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
01:22:46
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,173.482 km
Perigee altitude
1,066.846 km
Semi-major axis
7,498.301 km
Eccentricity
0.00711
Inclination
89.8844°
RAAN
120.9645°
Arg. of periapsis
53.2277°
True anomaly
44.44994°
Mean anomaly
43.8815°
Eccentric anomaly
44.16536°
Mean motion
3.34271 °/min
Orbital period
107.7 mins
BSTAR
0.00017593
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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
Loading observer location...
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. |
|---|---|---|---|---|---|---|---|
| 11 mins | 2026-11-10 10:52:44.165Z | 143.738° SSE | 2026-11-10 10:58:44.165Z | 71.164° E | 39.217° | 2026-11-10 11:03:44.165Z | 15.794° NNE |
| 10 mins | 2026-11-10 12:41:44.165Z | 224.216° SW | 2026-11-10 12:45:44.165Z | 272.87° WNW | 31.922° | 2026-11-10 12:51:44.165Z | 338.172° N |
| 8 mins | 2026-11-10 22:10:44.165Z | 41.996° NE | 2026-11-10 22:14:44.165Z | 82.953° E | 20.017° | 2026-11-10 22:18:44.165Z | 120.654° SE |
| 12 mins | 2026-11-10 23:56:44.165Z | 354.723° N | 2026-11-11 00:02:44.165Z | 262.054° W | 65.882° | 2026-11-11 00:08:44.165Z | 196.604° SSW |
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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