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: 10 hours ago
TLE from 10 hours ago
0 CALSPHERE 4(A)
1 1520U 65065H 25317.49431700 .00000199 00000-0 36481-3 0 9990
2 1520 89.9079 124.4980 0069441 353.7101 60.8943 13.36231288933905Epoch: 2025-11-13T11:51Z
TLE epoch observation values (Epoch: 2025-11-13T11:51:48.988Z)
Latitude
55.39586°
Longitude
-106.17467°
Altitude
1,107.548 km
Speed
7.316 km/s
True Right ascension
08h 18m 31s
True Declination
55° 14' 33"
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
17:56:31
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,172.491 km
Perigee altitude
1,068.35 km
Semi-major axis
7,498.558 km
Eccentricity
0.00694
Inclination
89.9079°
RAAN
124.498°
Arg. of periapsis
353.7101°
True anomaly
61.59248°
Mean anomaly
60.8943°
Eccentric anomaly
61.2431°
Mean motion
3.34254 °/min
Orbital period
107.7 mins
BSTAR
0.00036481
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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 | 2025-11-13 22:58:01.857Z | 15.475° NNE | 2025-11-13 23:04:01.857Z | 81.034° E | 36.132° | 2025-11-13 23:11:01.857Z | 159.278° S |
| 10 mins | 2025-11-14 00:47:01.857Z | 333.746° NNW | 2025-11-14 00:51:01.857Z | 291.242° WNW | 26.669° | 2025-11-14 00:57:01.857Z | 228.526° WSW |
| 11 mins | 2025-11-14 11:04:01.857Z | 150.765° SSE | 2025-11-14 11:09:01.857Z | 86.785° E | 37.632° | 2025-11-14 11:15:01.857Z | 10.153° NNE |
| 9 mins | 2025-11-14 12:53:01.857Z | 233.742° WSW | 2025-11-14 12:57:01.857Z | 278.526° WNW | 23.281° | 2025-11-14 13:02:01.857Z | 330.465° NNW |
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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