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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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https://www.satcat.com/sats-embedded/1806?theme=dark&initialShowStats=false

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Identifier

1806, 1965-098B

Orbit

LEO

Country

Related business

National Aeronautics and Space Administration (NASA) (US)

Manufacturer

APL

Mission

Spacecraft

Bus & Motor

DME, Unknown motor

Mass

98 kg wet, 98 kg dry

Launch date (UTC)

1965-11-29 (60 years ago)

Launch vehicle

THOR SLV-2 AGENA B

Launch site

Air Force Western Test Range (AFWTR)

Object type

Payload

Rocket body

Debris

Shape & HBR

Unknown

Radar Cross Section

Medium (>0.1 m² and <1 m²)

Expand to show TLE details & history
Last TLE update: 6 hours ago

TLE from 6 hours ago

0 EXPLORER 31 (ISIS-X)
1  1806U 65098B   26052.44134019  .00000516  00000-0  17756-3 0  9995
2  1806  79.7752  85.3000 1423234   1.4677 358.9935 12.08248070634719

Epoch: 2026-02-21T10:35Z

TLE epoch observation values (Epoch: 2026-02-21T10:35:31.792Z)

Latitude

0.00003°

Longitude

135.05366°

Altitude

505.071 km

Speed

8.135 km/s

True Right ascension

05h 41m 12s

True Declination

0° 00' 00"

Sunlit

Object was in daylight at epoch

Visualization orbit readout

Latitude

Unknown

Longitude

Unknown

Altitude

Unknown

Speed

Unknown

Apparent Right ascension

Unknown

Apparent Declination

Unknown

Sunlit

N/A

Visualization observer readout

Local Sidereal Time

19:32:21

Azimuth

Unknown

Elevation

Unknown

Doppler factor

Unknown

Orbital elements

Apogee altitude

2,782.979 km

Perigee altitude

500.191 km

Semi-major axis

8,019.722 km

Eccentricity

0.14232

Inclination

79.7752°

RAAN

85.3°

Arg. of periapsis

1.4677°

True anomaly

358.64571°

Mean anomaly

358.9935°

Eccentric anomaly

358.82649°

Mean motion

3.02207 °/min

Orbital period

119.12 mins

BSTAR

0.00017756

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Other satellites on launch #98 in the year 1965 (1965-11-29 UTC)

THOR AGENA B DEB, 2153

ALOUETTE 2, 1804

ALOUETTE 2 DEB, 25058 (Decayed)

THOR AGENA B DEB, 1951

THOR AGENA B DEB, 1948

THOR AGENA B R/B, 1807

THOR AGENA B DEB, 2092

THOR AGENA B DEB, 1808 (Decayed)

THOR AGENA B DEB, 1944 (Decayed)

ALOUETTE 2 DEB, 20833 (Decayed)

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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.
8 mins	2026-02-22 02:36:25.303Z	161.783° S	2026-02-22 02:39:25.303Z	90.74° ESE	36.462°	2026-02-22 02:44:25.303Z	21.439° NNE
12 mins	2026-02-22 10:59:25.303Z	29.709° NE	2026-02-22 11:04:25.303Z	56.582° ENE	15.401°	2026-02-22 11:11:25.303Z	87.718° E
24 mins	2026-02-22 12:57:25.303Z	359.299° N	2026-02-22 13:07:25.303Z	80.466° E	41.026°	2026-02-22 13:21:25.303Z	152.683° SSE
23 mins	2026-02-22 14:58:25.303Z	331.265° NNW	2026-02-22 15:07:25.303Z	272.147° WNW	35.446°	2026-02-22 15:21:25.303Z	205.457° SW

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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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Check out EXPLORER 31 (ISIS-X), 1806 on other resources

View EXPLORER 31 (ISIS-X), 1806 on NASA - NSSDCA Website

View EXPLORER 31 (ISIS-X), 1806 on Heavens-Above

View EXPLORER 31 (ISIS-X), 1806 on Keep Track

View EXPLORER 31 (ISIS-X), 1806 on Celestrak

View EXPLORER 31 (ISIS-X), 1806 on Gunter's Space Page

Satcat and Kayhan Space are not affiliated with NASA, Celestrak, Heavens-Above, Keep Track, or Gunter's Space Page.

EXPLORER 31 (ISIS-X), 1806

Orbit data source: Space-Track

Expand to show TLE details & historyLast TLE update: 6 hours ago

TLE from 6 hours ago

TLE epoch observation values (Epoch: 2026-02-21T10:35:31.792Z)

Visualization orbit readout

Visualization observer readout

Orbital elements

Other satellites on launch #98 in the year 1965 (1965-11-29 UTC)

EXPLORER 31 (ISIS-X) Visibility forecast

Co-orbital & Co-planar RSOs

Check out EXPLORER 31 (ISIS-X), 1806 on other resources

Documentation

Expand to show TLE details & history
Last TLE update: 6 hours ago