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: 18 hours ago
TLE from 18 hours ago
0 EXPLORER 31 (ISIS-X)
1 01806U 65098B 25309.62482856 -.00000180 00000-0 -63927-4 0 9995
2 01806 79.7812 174.1829 1423587 212.6705 137.7997 12.08105867621691Epoch: 2025-11-05T14:59Z
TLE epoch observation values (Epoch: 2025-11-05T14:59:45.187Z)
Latitude
0.00002°
Longitude
-95.85019°
Altitude
2,556.468 km
Speed
6.291 km/s
True Right ascension
11h 36m 43s
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
05:04:59
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
2,783.981 km
Perigee altitude
500.447 km
Semi-major axis
8,020.351 km
Eccentricity
0.14236
Inclination
79.7812°
RAAN
174.1829°
Arg. of periapsis
212.6705°
True anomaly
147.43185°
Mean anomaly
137.7997°
Eccentric anomaly
142.73815°
Mean motion
3.02171 °/min
Orbital period
119.14 mins
BSTAR
-0.000063927
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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. |
|---|---|---|---|---|---|---|---|
| 12 mins | 2025-11-06 13:04:07.566Z | 94.824° ESE | 2025-11-06 13:10:07.566Z | 71.496° E | 13.792° | 2025-11-06 13:16:07.566Z | 47.229° ENE |
| 26 mins | 2025-11-06 14:55:07.566Z | 160.011° S | 2025-11-06 15:08:07.566Z | 89.118° E | 40.003° | 2025-11-06 15:21:07.566Z | 19.512° NNE |
| 27 mins | 2025-11-06 16:55:07.566Z | 216.613° SW | 2025-11-06 17:09:07.566Z | 290.706° WNW | 38.812° | 2025-11-06 17:22:07.566Z | 3.125° NNE |
| 13 mins | 2025-11-06 19:07:07.566Z | 285.869° WNW | 2025-11-06 19:13:07.566Z | 310.452° NW | 15.336° | 2025-11-06 19:20:07.566Z | 341.644° N |
| 11 mins | 2025-11-07 01:33:07.566Z | 6.21° NNE | 2025-11-07 01:39:07.566Z | 54.488° ENE | 27.052° | 2025-11-07 01:44:07.566Z | 115.951° SE |
| 11 mins | 2025-11-07 03:34:07.566Z | 334.151° NNW | 2025-11-07 03:40:07.566Z | 280.047° WNW | 32.478° | 2025-11-07 03:45:07.566Z | 208.689° 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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