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: 9 hours ago
TLE from 9 hours ago
0 CALSPHERE 4(A)
1 1520U 65065H 26090.12562444 .00000137 00000-0 24727-3 0 9991
2 1520 89.8990 123.2654 0068301 325.3277 95.5536 13.36263328952289Epoch: 2026-03-31T03:00Z
TLE epoch observation values (Epoch: 2026-03-31T03:00:53.951Z)
Latitude
61.74618°
Longitude
-110.27971°
Altitude
1,139.186 km
Speed
7.286 km/s
True Right ascension
08h 13m 48s
True Declination
61° 36' 35"
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
17:24:14
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
1,171.516 km
Perigee altitude
1,069.086 km
Semi-major axis
7,498.438 km
Eccentricity
0.00683
Inclination
89.899°
RAAN
123.2654°
Arg. of periapsis
325.3277°
True anomaly
96.33193°
Mean anomaly
95.5536°
Eccentric anomaly
95.94283°
Mean motion
3.34262 °/min
Orbital period
107.7 mins
BSTAR
0.00024727
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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 | 2026-03-31 14:05:14.317Z | 10.633° NNE | 2026-03-31 14:11:14.317Z | 75.709° E | 40.825° | 2026-03-31 14:18:14.317Z | 167.891° S |
| 9 mins | 2026-03-31 15:54:14.317Z | 329.843° NNW | 2026-03-31 15:58:14.317Z | 290.746° WNW | 22.043° | 2026-03-31 16:03:14.317Z | 241.163° WSW |
| 11 mins | 2026-04-01 02:11:14.317Z | 160.634° S | 2026-04-01 02:16:14.317Z | 83.196° E | 42.341° | 2026-04-01 02:22:14.317Z | 4.986° NNE |
| 7 mins | 2026-04-01 04:01:14.317Z | 248.959° W | 2026-04-01 04:04:14.317Z | 280.329° WNW | 18.918° | 2026-04-01 04:08:14.317Z | 320.388° 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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