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: 7 hours ago
TLE from 7 hours ago
0 EXPLORER 31 (ISIS-X)
1 1806U 65098B 25327.01758071 .00000411 00000-0 13969-3 0 9998
2 1806 79.7724 159.8417 1423963 178.6041 181.9730 12.08106845623794Epoch: 2025-11-23T00:25Z
TLE epoch observation values (Epoch: 2025-11-23T00:25:18.973Z)
Latitude
-0.00007°
Longitude
91.27469°
Altitude
2,789.504 km
Speed
6.108 km/s
True Right ascension
10h 39m 22s
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
05:02:33
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
2,784.278 km
Perigee altitude
500.142 km
Semi-major axis
8,020.347 km
Eccentricity
0.1424
Inclination
79.7724°
RAAN
159.8417°
Arg. of periapsis
178.6041°
True anomaly
181.49645°
Mean anomaly
181.973°
Eccentric anomaly
181.7271°
Mean motion
3.02171 °/min
Orbital period
119.14 mins
BSTAR
0.00013969
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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. |
|---|---|---|---|---|---|---|---|
| 22 mins | 2025-11-23 12:24:51.640Z | 148.913° SSE | 2025-11-23 12:37:51.640Z | 85.302° E | 32.955° | 2025-11-23 12:46:51.640Z | 29.458° NE |
| 25 mins | 2025-11-23 14:23:51.640Z | 203.358° SW | 2025-11-23 14:37:51.640Z | 283.382° WNW | 42.4° | 2025-11-23 14:48:51.640Z | 5.337° NNE |
| 13 mins | 2025-11-23 16:33:51.640Z | 271.176° WNW | 2025-11-23 16:39:51.640Z | 299.262° NW | 16.89° | 2025-11-23 16:46:51.640Z | 338.288° N |
| 7 mins | 2025-11-24 01:01:51.640Z | 338.577° N | 2025-11-24 01:04:51.640Z | 295.355° NW | 39.673° | 2025-11-24 01:08:51.640Z | 185.316° SSW |
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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