EXPLORER 31 (ISIS-X), 1806
Orbit data source: Space-Track
EXPLORER 31 (ISIS-X), 1806 is a payload satellite owned by GSFC (US) in LEO that was launched on Mon, 29 Nov 1965 UTC via a THOR SLV-2 AGENA B 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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1806 intel report (Beta)
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Edit Public Description
Identifier
Orbit
Country
USRelated business
Manufacturer
APL
Mission
Spacecraft
Bus & Motor
DME, Unknown motor
Mass
98 kg wet, 98 kg dry
Launch date (UTC)
Launch vehicle
Launch site
Object type
Shape & HBR
Unknown
Radar Cross Section
Medium (>0.1 m² and <1 m²)
Expand to show TLE details & historyLast TLE update: 14 hours ago
TLE from 14 hours ago
0 EXPLORER 31 (ISIS-X)
1 1806U 65098B 25312.60639426 -.00000222 00000-0 -78820-4 0 9999
2 1806 79.7795 171.7252 1423670 206.8230 145.1827 12.08105542622051Epoch: 2025-11-08T14:33Z
TLE epoch observation values (Epoch: 2025-11-08T14:33:12.464Z)
Latitude
0°
Longitude
-94.61032°
Altitude
2,630.044 km
Speed
6.232 km/s
True Right ascension
11h 26m 54s
True Declination
0° 00' 00"
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
01:03:12
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
2,784.049 km
Perigee altitude
500.382 km
Semi-major axis
8,020.353 km
Eccentricity
0.14237
Inclination
79.7795°
RAAN
171.7252°
Arg. of periapsis
206.823°
True anomaly
153.27878°
Mean anomaly
145.1827°
Eccentric anomaly
149.34206°
Mean motion
3.02171 °/min
Orbital period
119.14 mins
BSTAR
-0.00007882
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Other satellites on launch #98 in the year 1965 (1965-11-29 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.EXPLORER 31 (ISIS-X) 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. |
|---|---|---|---|---|---|---|---|
| 9 mins | 2025-11-09 12:39:11.709Z | 88.605° E | 2025-11-09 12:43:11.709Z | 73.058° E | 12.444° | 2025-11-09 12:48:11.709Z | 52.717° ENE |
| 26 mins | 2025-11-09 14:28:11.709Z | 158.501° S | 2025-11-09 14:41:11.709Z | 93.81° ESE | 39.062° | 2025-11-09 14:54:11.709Z | 20.553° NNE |
| 27 mins | 2025-11-09 16:28:11.709Z | 213.932° SW | 2025-11-09 16:42:11.709Z | 286.077° WNW | 39.534° | 2025-11-09 16:55:11.709Z | 3.39° NNE |
| 14 mins | 2025-11-09 18:39:11.709Z | 280.095° WNW | 2025-11-09 18:46:11.709Z | 308.844° NW | 15.713° | 2025-11-09 18:53:11.709Z | 341.091° N |
| 10 mins | 2025-11-10 01:06:11.709Z | 8.212° NNE | 2025-11-10 01:12:11.709Z | 60.416° ENE | 23.926° | 2025-11-10 01:16:11.709Z | 109.16° ESE |
| 10 mins | 2025-11-10 03:07:11.709Z | 334.932° NNW | 2025-11-10 03:13:11.709Z | 271.898° WNW | 33.512° | 2025-11-10 03:17:11.709Z | 207.968° SW |
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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