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EXPLORER 20, 870

Orbit data source: Space-Track

EXPLORER 20, 870 is a payload satellite owned by GSFC (US) in LEO that was launched on Tue, 25 Aug 1964 UTC via an SCOUT X-4 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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Iframe embed code

<iframe src="https://www.satcat.com/sats-embedded/870?theme=dark&initialShowStats=false" width="600" height="400" frameborder="0" title="Kayhan Space Satcat Satellite Viewer"></iframe>

Iframe URL

https://www.satcat.com/sats-embedded/870?theme=dark&initialShowStats=false

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ISO8601 Format

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ISO8601 Format

Identifier

870, 1964-051A

Orbit

LEO

Last TLE update

18 hours ago

Origin

National Aeronautics and Space Administration (NASA) (US)

Manufacturer

Cutler-Hammer/AIL

Mission

Civil Science

Bus & Motor

S-48, Unknown motor

Mass

44 kg wet, 44 kg dry

Launch date (UTC)

1964-08-25 (61 years ago)

Launch vehicle

SCOUT X-4

Launch site

Air Force Western Test Range (AFWTR)

Object type

Payload

Rocket body

Debris

Shape & HBR

Double Cone + 6 Rod, 37 m

Radar Cross Section

0.292 m², Medium (>0.1 m² and < 1m²)

Expand to show TLE details & history

TLE from 18 hours ago

0 EXPLORER 20
1 00870U 64051A   25183.78475611  .00000101  00000-0  69938-4 0  9990
2 00870  79.8990 298.9541 0097888 121.9748 239.0969 13.91694790 84839

Epoch: 2025-07-02T18:50Z

TLE epoch observation values (Epoch: 2025-07-02T18:50:02.927Z)

Latitude

-0.00014°

Longitude

95.381°

Altitude

962.749 km

Speed

7.352 km/s

True Right ascension

19h 55m 48s

True Declination

0° 00' 00"

Sunlit

Object was in full shadow at epoch

Visualization orbit readout

Latitude

29.53277°

Longitude

-91.19489°

Altitude

864.217 km

Speed

7.455 km/s

Apparent Right ascension

09h 39m 34s

Apparent Declination

-3° 21' 27"

Sunlit

Object is in daylight

Visualization observer readout

Local Sidereal Time

00:34:41

Azimuth

58.846° ENE

Elevation

-36.184°

Doppler factor

Orbital elements

Apogee altitude

991.404 km

Perigee altitude

848.525 km

Semi-major axis

7,298.102 km

Eccentricity

0.00979

Inclination

79.899°

RAAN

298.9541°

Arg. of periapsis

121.9748°

True anomaly

Unknown

Mean anomaly

239.0969°

Eccentric anomaly

Unknown

Mean motion

3.48119 °/min

Orbital period

103.41 mins

BSTAR

0.000069938

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Other satellites on launch #51 in the year 1964 (1964-08-25 UTC)

SCOUT X-4 R/B, 871

SCOUT X-4 DEB, 873 (Decayed)

SCOUT X-4 DEB, 874 (Decayed)

SCOUT X-4 DEB, 875 (Decayed)

SCOUT X-4 DEB, 40592 (Decayed)

EXPLORER 20 Visibility forecast

Observer location: undefined°, undefined°

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.
4 mins	2025-07-03 17:51:58.221Z	41.61° NE	2025-07-03 17:53:58.221Z	64.5° ENE	13.66°	2025-07-03 17:55:58.221Z	87.03° E
9 mins	2025-07-03 19:34:58.221Z	343.66° N	2025-07-03 19:38:58.221Z	278.998° WNW	43.861°	2025-07-03 19:43:58.221Z	178.196° S
6 mins	2025-07-04 07:12:58.221Z	118.297° SE	2025-07-04 07:14:58.221Z	94.59° ESE	18.354°	2025-07-04 07:18:58.221Z	48.118° ENE
10 mins	2025-07-04 08:54:58.221Z	210.437° SW	2025-07-04 08:59:58.221Z	298.417° NW	38.874°	2025-07-04 09:04:58.221Z	1.066° NNE

Authenticating...

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Check out EXPLORER 20, 870 on other resources

View EXPLORER 20, 870 on NASA - NSSDCA Website

View EXPLORER 20, 870 on Heavens-Above

View EXPLORER 20, 870 on Keep Track

View EXPLORER 20, 870 on Celestrak

View EXPLORER 20, 870 on Gunter's Space Page

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