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: 6 hours ago
TLE from 6 hours ago
0 CALSPHERE 4(A)
1 01520U 65065H 26030.21607005 .00000113 00000-0 19726-3 0 9995
2 01520 89.9100 123.8206 0071469 132.4757 260.9687 13.36251814944284Epoch: 2026-01-30T05:11Z
TLE epoch observation values (Epoch: 2026-01-30T05:11:08.452Z)
Latitude
32.69376°
Longitude
-83.36475°
Altitude
1,136.332 km
Speed
7.283 km/s
True Right ascension
08h 15m 30s
True Declination
32° 32' 44"
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
12:19:45
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,173.935 km
Perigee altitude
1,066.753 km
Semi-major axis
7,498.481 km
Eccentricity
0.00715
Inclination
89.91°
RAAN
123.8206°
Arg. of periapsis
132.4757°
True anomaly
260.16104°
Mean anomaly
260.9687°
Eccentric anomaly
260.56475°
Mean motion
3.34259 °/min
Orbital period
107.7 mins
BSTAR
0.00019726
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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 | 2026-01-30 18:11:29.367Z | 7.623° NNE | 2026-01-30 18:17:29.367Z | 69.671° E | 42.43° | 2026-01-30 18:23:29.367Z | 171.414° S |
| 7 mins | 2026-01-30 20:01:29.367Z | 321.347° NNW | 2026-01-30 20:04:29.367Z | 290.764° WNW | 17.872° | 2026-01-30 20:08:29.367Z | 250.466° W |
| 12 mins | 2026-01-31 06:17:29.367Z | 167.846° S | 2026-01-31 06:22:29.367Z | 121.109° SE | 43.692° | 2026-01-31 06:29:29.367Z | 1.539° NNE |
| 6 mins | 2026-01-31 08:08:29.367Z | 255.974° W | 2026-01-31 08:11:29.367Z | 285.793° WNW | 16.417° | 2026-01-31 08:14:29.367Z | 314.509° NW |
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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