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: 12 hours ago
TLE from 12 hours ago
0 CALSPHERE 4(A)
1 01520U 65065H 25304.26708032 .00000156 00000-0 28208-3 0 9997
2 01520 89.9082 124.6154 0070551 30.8993 152.4037 13.36227488932133Epoch: 2025-10-31T06:24Z
TLE epoch observation values (Epoch: 2025-10-31T06:24:35.739Z)
Latitude
-3.81047°
Longitude
168.6586°
Altitude
1,173.866 km
Speed
7.243 km/s
True Right ascension
20h 18m 29s
True Declination
-3° 47' 20"
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
14:25:50
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,173.338 km
Perigee altitude
1,067.532 km
Semi-major axis
7,498.572 km
Eccentricity
0.00706
Inclination
89.9082°
RAAN
124.6154°
Arg. of periapsis
30.8993°
True anomaly
152.7753°
Mean anomaly
152.4037°
Eccentric anomaly
152.58979°
Mean motion
3.34253 °/min
Orbital period
107.7 mins
BSTAR
0.00028208
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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 | 2025-11-01 00:03:01.530Z | 9.935° NNE | 2025-11-01 00:10:01.530Z | 99.241° ESE | 40.449° | 2025-11-01 00:16:01.530Z | 166.557° S |
| 9 mins | 2025-11-01 01:53:01.530Z | 325.932° NNW | 2025-11-01 01:57:01.530Z | 283.032° WNW | 21.839° | 2025-11-01 02:02:01.530Z | 236.869° WSW |
| 11 mins | 2025-11-01 12:10:01.530Z | 159.813° S | 2025-11-01 12:15:01.530Z | 71.985° E | 41.935° | 2025-11-01 12:21:01.530Z | 4.696° NNE |
| 7 mins | 2025-11-01 14:00:01.530Z | 250.564° W | 2025-11-01 14:03:01.530Z | 282.998° WNW | 18.378° | 2025-11-01 14:07:01.530Z | 322.571° 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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