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: 20 hours ago
TLE from 20 hours ago
0 CALSPHERE 4(A)
1 01520U 65065H 25348.42323071 .00000153 00000-0 27782-3 0 9992
2 01520 89.9098 124.2260 0068246 264.7195 164.5298 13.36240173938038Epoch: 2025-12-14T10:09Z
TLE epoch observation values (Epoch: 2025-12-14T10:09:27.133Z)
Latitude
69.52623°
Longitude
-111.23305°
Altitude
1,184.804 km
Speed
7.243 km/s
True Right ascension
08h 17m 51s
True Declination
69° 25' 11"
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
04:35:43
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,171.562 km
Perigee altitude
1,069.213 km
Semi-major axis
7,498.524 km
Eccentricity
0.00682
Inclination
89.9098°
RAAN
124.226°
Arg. of periapsis
264.7195°
True anomaly
164.7367°
Mean anomaly
164.5298°
Eccentric anomaly
164.63342°
Mean motion
3.34256 °/min
Orbital period
107.7 mins
BSTAR
0.00027782
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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. |
|---|---|---|---|---|---|---|---|
| 12 mins | 2025-12-15 09:16:35.672Z | 163.189° S | 2025-12-15 09:22:35.672Z | 71.449° E | 42.794° | 2025-12-15 09:28:35.672Z | 4.175° NNE |
| 8 mins | 2025-12-15 11:06:35.672Z | 243.521° WSW | 2025-12-15 11:10:35.672Z | 282.74° WNW | 19.223° | 2025-12-15 11:14:35.672Z | 321.17° NNW |
| 11 mins | 2025-12-15 20:34:35.672Z | 26.667° NE | 2025-12-15 20:39:35.672Z | 85.065° E | 29.579° | 2025-12-15 20:45:35.672Z | 146.642° SSE |
| 10 mins | 2025-12-15 22:22:35.672Z | 338.861° N | 2025-12-15 22:26:35.672Z | 290.899° WNW | 32.644° | 2025-12-15 22:32:35.672Z | 218.137° 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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