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, 0.2 m
Radar Cross Section
Medium (>0.1 m² and <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 26236.65719081 .00000072 00000-0 12195-3 0 9996
2 01520 89.8944 121.8068 0067906 270.8518 120.7091 13.36288320971853Epoch: 2026-08-24T15:46Z
TLE epoch observation values (Epoch: 2026-08-24T15:46:21.285Z)
Latitude
32.2823°
Longitude
-87.65126°
Altitude
1,153.603 km
Speed
7.266 km/s
True Right ascension
08h 07m 29s
True Declination
32° 08' 07"
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
18:55:59
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,171.125 km
Perigee altitude
1,069.289 km
Semi-major axis
7,498.344 km
Eccentricity
0.00679
Inclination
89.8944°
RAAN
121.8068°
Arg. of periapsis
270.8518°
True anomaly
121.37522°
Mean anomaly
120.7091°
Eccentric anomaly
121.04245°
Mean motion
3.34268 °/min
Orbital period
107.7 mins
BSTAR
0.00012195
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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. |
|---|---|---|---|---|---|---|---|
| 14 mins | 2026-08-25 04:46:45.325Z | 1.765° NNE | 2026-08-25 04:53:45.325Z | 340.757° N | 44.993° | 2026-08-25 05:00:45.325Z | 184.348° SSW |
| 6 mins | 2026-08-25 06:37:45.325Z | 314.427° NW | 2026-08-25 06:40:45.325Z | 287.046° WNW | 14.28° | 2026-08-25 06:43:45.325Z | 261.127° W |
| 6 mins | 2026-08-25 15:08:45.325Z | 96.623° ESE | 2026-08-25 15:11:45.325Z | 68.188° E | 16.111° | 2026-08-25 15:14:45.325Z | 40.581° NE |
| 12 mins | 2026-08-25 16:52:45.325Z | 180.596° SSW | 2026-08-25 16:57:45.325Z | 215.543° SW | 44.339° | 2026-08-25 17:04:45.325Z | 356.044° 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 descending order |
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CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
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