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: 15 hours ago
TLE from 15 hours ago
0 CALSPHERE 4(A)
1 01520U 65065H 25303.29160913 .00000147 00000-0 26355-3 0 9990
2 01520 89.9082 124.6240 0070624 33.6165 140.0154 13.36227228932003Epoch: 2025-10-30T06:59Z
TLE epoch observation values (Epoch: 2025-10-30T06:59:55.028Z)
Latitude
5.77176°
Longitude
160.78299°
Altitude
1,166.492 km
Speed
7.251 km/s
True Right ascension
20h 18m 27s
True Declination
5° 44' 22"
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
18:00:33
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,173.394 km
Perigee altitude
1,067.478 km
Semi-major axis
7,498.573 km
Eccentricity
0.00706
Inclination
89.9082°
RAAN
124.624°
Arg. of periapsis
33.6165°
True anomaly
140.53193°
Mean anomaly
140.0154°
Eccentric anomaly
140.27402°
Mean motion
3.34253 °/min
Orbital period
107.7 mins
BSTAR
0.00026355
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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. |
|---|---|---|---|---|---|---|---|
| 7 mins | 2025-10-30 22:56:05.809Z | 44.279° NE | 2025-10-30 23:00:05.809Z | 81.812° E | 15.653° | 2025-10-30 23:03:05.809Z | 108.981° ESE |
| 12 mins | 2025-10-31 00:42:05.809Z | 359.199° N | 2025-10-31 00:48:05.809Z | 250.5° W | 44.522° | 2025-10-31 00:54:05.809Z | 189.143° SSW |
| 7 mins | 2025-10-31 11:03:05.809Z | 101.831° ESE | 2025-10-31 11:06:05.809Z | 71.339° E | 16.883° | 2025-10-31 11:10:05.809Z | 33.221° NE |
| 11 mins | 2025-10-31 12:48:05.809Z | 187.554° SSW | 2025-10-31 12:53:05.809Z | 283.324° WNW | 43.446° | 2025-10-31 12:59:05.809Z | 353.269° 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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