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: 13 hours ago
TLE from 13 hours ago
0 EXPLORER 31 (ISIS-X)
1 01806U 65098B 25356.83193562 .00000499 00000-0 16645-3 0 9998
2 01806 79.7787 135.2635 1423351 120.2005 254.7716 12.08188179627390Epoch: 2025-12-22T19:57Z
TLE epoch observation values (Epoch: 2025-12-22T19:57:59.237Z)
Latitude
-0.00007°
Longitude
104.14229°
Altitude
2,088.759 km
Speed
6.671 km/s
True Right ascension
09h 01m 03s
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
07:59:35
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
2,783.375 km
Perigee altitude
500.324 km
Semi-major axis
8,019.987 km
Eccentricity
0.14234
Inclination
79.7787°
RAAN
135.2635°
Arg. of periapsis
120.2005°
True anomaly
239.90511°
Mean anomaly
254.7716°
Eccentric anomaly
247.25082°
Mean motion
3.02192 °/min
Orbital period
119.13 mins
BSTAR
0.00016645
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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. |
|---|---|---|---|---|---|---|---|
| 15 mins | 2025-12-23 09:56:26.795Z | 179.118° S | 2025-12-23 10:06:26.795Z | 83.77° E | 42.896° | 2025-12-23 10:11:26.795Z | 19.101° NNE |
| 8 mins | 2025-12-23 12:02:26.795Z | 254.352° W | 2025-12-23 12:06:26.795Z | 286.584° WNW | 17.719° | 2025-12-23 12:10:26.795Z | 327.63° NNW |
| 4 mins | 2025-12-23 20:26:26.795Z | 39.643° NE | 2025-12-23 20:27:26.795Z | 63.61° ENE | 22.882° | 2025-12-23 20:30:26.795Z | 124.491° SE |
Co-orbital & Co-planar RSOs
Thresholds — Semi-major Axis: ±100 km, RAAN: ±3°, Inclination: ±5°
TCA is derived from TLE conjunctions
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CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
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