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
Unknown
Radar Cross Section
Small (<0.1 m²)
Expand to show TLE details & historyLast TLE update: 8 hours ago
TLE from 8 hours ago
0 CALSPHERE 4(A)
1 01520U 65065H 26133.92415014 .00000101 00000-0 17647-3 0 9991
2 01520 89.8964 122.8282 0068949 198.6205 194.2181 13.36271718958137Epoch: 2026-05-13T22:10Z
TLE epoch observation values (Epoch: 2026-05-13T22:10:46.572Z)
Latitude
32.70266°
Longitude
-81.47687°
Altitude
1,177.637 km
Speed
7.243 km/s
True Right ascension
08h 11m 34s
True Declination
32° 33' 19"
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
14:34:19
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,171.97 km
Perigee altitude
1,068.569 km
Semi-major axis
7,498.406 km
Eccentricity
0.00689
Inclination
89.8964°
RAAN
122.8282°
Arg. of periapsis
198.6205°
True anomaly
194.02565°
Mean anomaly
194.2181°
Eccentric anomaly
194.12172°
Mean motion
3.34264 °/min
Orbital period
107.7 mins
BSTAR
0.00017647
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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 | 2026-05-14 11:11:47.424Z | 10.536° NNE | 2026-05-14 11:17:47.424Z | 84.542° E | 40.887° | 2026-05-14 11:23:47.424Z | 167.106° S |
| 7 mins | 2026-05-14 13:01:47.424Z | 320.71° NNW | 2026-05-14 13:04:47.424Z | 287.954° WNW | 20.511° | 2026-05-14 13:08:47.424Z | 246.197° WSW |
| 13 mins | 2026-05-14 23:15:47.424Z | 164.409° S | 2026-05-14 23:22:47.424Z | 76.083° E | 42.771° | 2026-05-14 23:28:47.424Z | 4.47° NNE |
| 9 mins | 2026-05-15 01:06:47.424Z | 242.849° WSW | 2026-05-15 01:10:47.424Z | 281.821° WNW | 19.493° | 2026-05-15 01:15:47.424Z | 327.474° 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 descending order |
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CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
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