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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 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

Identifier

870, 1964-051A

Orbit

LEO

Last TLE update

14 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 14 hours ago

0 EXPLORER 20
1 00870U 64051A   25186.37289953  .00000096  00000-0  65966-4 0  9990
2 00870  79.8990 296.1383 0097924 115.2298 245.9048 13.91695298 85198

Epoch: 2025-07-05T08:56Z

TLE epoch observation values (Epoch: 2025-07-05T08:56:58.519Z)

Latitude

-0.00005°

Longitude

-121.71742°

Altitude

955.298 km

Speed

7.359 km/s

True Right ascension

19h 44m 33s

True Declination

0° 00' 00"

Sunlit

Object was in full shadow at epoch

Visualization orbit readout

Latitude

-27.70699°

Longitude

-127.67715°

Altitude

988.761 km

Speed

7.328 km/s

Apparent Right ascension

20h 42m 24s

Apparent Declination

-35° 34' 52"

Sunlit

Object is in full shadow

Visualization observer readout

Local Sidereal Time

10:33:14

Azimuth

87.614° E

Elevation

-67.762°

Doppler factor

Orbital elements

Apogee altitude

991.429 km

Perigee altitude

848.497 km

Semi-major axis

7,298.1 km

Eccentricity

0.00979

Inclination

79.899°

RAAN

296.1383°

Arg. of periapsis

115.2298°

True anomaly

Unknown

Mean anomaly

245.9048°

Eccentric anomaly

Unknown

Mean motion

3.4812 °/min

Orbital period

103.41 mins

BSTAR

0.000065966

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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.
10 mins	2025-07-06 07:29:01.107Z	159.119° S	2025-07-06 07:34:01.107Z	97.886° ESE	32.138°	2025-07-06 07:39:01.107Z	29.096° NE
8 mins	2025-07-06 09:15:01.107Z	239.737° WSW	2025-07-06 09:19:01.107Z	292.373° WNW	24.907°	2025-07-06 09:23:01.107Z	343.206° N
9 mins	2025-07-06 18:19:01.107Z	10.622° NNE	2025-07-06 18:23:01.107Z	73.165° E	32.376°	2025-07-06 18:28:01.107Z	140.586° SSE
7 mins	2025-07-06 20:04:01.107Z	314.709° NW	2025-07-06 20:07:01.107Z	275.91° WNW	22.804°	2025-07-06 20:11:01.107Z	222.805° SW

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.