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VANGUARD 3, 20

Orbit data source: Space-Track

VANGUARD 3, 20 is a payload satellite owned by GSFC (US) in LEO that was launched on Fri, 18 Sep 1959 UTC via a VANGUARD launch vehicle from the Air Force Eastern Test Range (AFETR). 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 URL

https://www.satcat.com/sats-embedded/20?theme=dark&initialShowStats=false

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Identifier

20, 1959-007A

Orbit

LEO

Country

Related business

National Aeronautics and Space Administration (NASA) (US)

Manufacturer

NRL

Mission

Spacecraft

Bus & Motor

NRL 20", Unknown motor

Mass

47 kg wet, 23 kg dry

Launch date (UTC)

1959-09-18 (67 years ago)

Launch vehicle

VANGUARD

Launch site

Air Force Eastern Test Range (AFETR)

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: 7 hours ago

TLE from 7 hours ago

0 VANGUARD 3
1    20U 59007A   26122.19367441  .00000533  00000-0  20806-3 0  9991
2    20  33.3429  72.5242 1637487 167.0282 197.8248 11.61937713479268

Epoch: 2026-05-02T04:38Z

TLE epoch observation values (Epoch: 2026-05-02T04:38:53.469Z)

Latitude

-0.00002°

Longitude

142.6863°

Altitude

3,154.863 km

Speed

5.937 km/s

True Right ascension

04h 50m 05s

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

19:33:54

Azimuth

Unknown

Elevation

Unknown

Doppler factor

Unknown

Orbital elements

Apogee altitude

3,207.775 km

Perigee altitude

510.147 km

Semi-major axis

8,237.098 km

Eccentricity

0.16375

Inclination

33.3429°

RAAN

72.5242°

Arg. of periapsis

167.0282°

True anomaly

193.02752°

Mean anomaly

197.8248°

Eccentric anomaly

195.34242°

Mean motion

2.90323 °/min

Orbital period

124 mins

BSTAR

0.00020806

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Other satellites on launch #7 in the year 1959 (1959-09-18 UTC)

VANGUARD 3 DEB, 31405 (Decayed)

VANGUARD 3 DEB, 29005 (Decayed)

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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.

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VANGUARD 3 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.
20 mins	2026-05-02 21:09:44.307Z	181.684° SSW	2026-05-02 21:20:44.307Z	145.327° SSE	18.854°	2026-05-02 21:29:44.307Z	107.672° ESE
24 mins	2026-05-02 23:20:44.307Z	217.459° SW	2026-05-02 23:34:44.307Z	157.807° S	33.378°	2026-05-02 23:44:44.307Z	93.725° ESE
19 mins	2026-05-03 01:35:44.307Z	246.151° WSW	2026-05-03 01:47:44.307Z	176.23° S	40.169°	2026-05-03 01:54:44.307Z	101.286° ESE
13 mins	2026-05-03 03:51:44.307Z	262.348° W	2026-05-03 03:59:44.307Z	192.919° SSW	36.919°	2026-05-03 04:04:44.307Z	124.726° SE
6 mins	2026-05-03 06:06:44.307Z	247.765° W	2026-05-03 06:09:44.307Z	216.514° SW	16.103°	2026-05-03 06:12:44.307Z	178.293° S

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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 VANGUARD 3, 20 on other resources

View VANGUARD 3, 20 on NASA - NSSDCA Website

View VANGUARD 3, 20 on Heavens-Above

View VANGUARD 3, 20 on Keep Track

View VANGUARD 3, 20 on Celestrak

View VANGUARD 3, 20 on Gunter's Space Page

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

VANGUARD 3, 20

Orbit data source: Space-Track

Expand to show TLE details & historyLast TLE update: 7 hours ago

TLE from 7 hours ago

TLE epoch observation values (Epoch: 2026-05-02T04:38:53.469Z)

Visualization orbit readout

Visualization observer readout

Orbital elements

Other satellites on launch #7 in the year 1959 (1959-09-18 UTC)

VANGUARD 3 Visibility forecast

Co-orbital & Co-planar RSOs

Check out VANGUARD 3, 20 on other resources

Documentation

Expand to show TLE details & history
Last TLE update: 7 hours ago