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.
Focus sentinelFocus sentinel
Request partner network tasking
Focus sentinelFocus sentinel
Embed this page
Focus sentinelFocus sentinel
1806 intel report (Beta)
Focus sentinelFocus sentinel
Edit Public Description
Focus sentinelFocus sentinel
Edit Sat Name
Focus sentinelFocus sentinel
Create New Watchlist
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: 10 hours ago
TLE from 10 hours ago
0 EXPLORER 31 (ISIS-X)
1 01806U 65098B 26188.39844646 .00000125 00000-0 35209-4 0 9993
2 01806 79.7803 333.1453 1422798 94.9840 281.4633 12.08371044651133Epoch: 2026-07-07T09:33Z
TLE epoch observation values (Epoch: 2026-07-07T09:33:45.774Z)
Latitude
0.00003°
Longitude
-95.66506°
Altitude
1,580.044 km
Speed
7.108 km/s
True Right ascension
22h 12m 34s
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
07:59:48
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
2,782.007 km
Perigee altitude
500.073 km
Semi-major axis
8,019.177 km
Eccentricity
0.14228
Inclination
79.7803°
RAAN
333.1453°
Arg. of periapsis
94.984°
True anomaly
265.12503°
Mean anomaly
281.4633°
Eccentric anomaly
273.32499°
Mean motion
3.02238 °/min
Orbital period
119.11 mins
BSTAR
0.000035209
Loading maneuver chart data...
Computing Atmospheric mass density...
Loading historical data...
Loading historical data...
Loading historical data...
Loading historical data...
Loading historical data...
Loading historical data...
Loading historical data...
Other satellites on launch #98 in the year 1965 (1965-11-29 UTC)
Did you know?
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
Loading observer location...
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. |
|---|---|---|---|---|---|---|---|
| 8 mins | 2026-07-07 22:04:05.766Z | 319.59° NNW | 2026-07-07 22:07:05.766Z | 244° WSW | 33.789° | 2026-07-07 22:12:05.766Z | 192.193° SSW |
| 7 mins | 2026-07-08 09:32:05.766Z | 140.972° SSE | 2026-07-08 09:36:05.766Z | 91.398° ESE | 23.309° | 2026-07-08 09:39:05.766Z | 47.694° ENE |
| 7 mins | 2026-07-08 11:32:05.766Z | 232.959° WSW | 2026-07-08 11:36:05.766Z | 282.645° WNW | 25.031° | 2026-07-08 11:39:05.766Z | 333.639° 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 |
|---|
CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
Authenticating...
Click to sort rows by Secondary header in ascending order | Click to sort rows by Secondary name header in ascending order | Click to sort rows by Country header in ascending order | Click to sort rows by Owner header in ascending order | Click to sort rows by Obj. Type header in ascending order | Click to sort rows by Miss dist. header in ascending order | Click to sort rows by Rel. speed header in ascending order | Click to sort rows by Apr. angle header in ascending order | Click to sort rows by TCA header in descending order |
|---|