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NAVSTAR 23 (USA 71), 21552

Orbit data source: Space-Track

NAVSTAR 23 (USA 71), 21552 is a payload satellite owned by USAF SSD (US) in MEO that was launched on Thu, 04 Jul 1991 UTC via a DELTA 7925 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 src="https://www.satcat.com/sats-embedded/21552?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/21552?theme=dark&initialShowStats=false

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ISO8601 Format

Identifier

21552, 1991-047A

Orbit

MEO

Country

Related business

United States Air Force (US)

Manufacturer

Rockwell/SB

Mission

Non-operational Defense Navigation

Bus & Motor

GPS IIA, STAR 37XFP

Mass

~1,881 kg wet, 860 kg dry

Launch date (UTC)

1991-07-04 (35 years ago)

Launch vehicle

DELTA 7925

Launch site

Air Force Eastern Test Range (AFETR)

Object type

Payload

Rocket body

Debris

Shape & HBR

Box + 2 Pan, 2.6 m

Radar Cross Section

7.641 m², Large (>1 m²)

Expand to show TLE details & history
Last TLE update: 21 hours ago

TLE from 21 hours ago

0 NAVSTAR 23 (USA 71)
1 21552U 91047A   26091.50891883 -.00000113  00000-0  00000-0 0  9992
2 21552  56.5171 355.2820 0032556 132.9802  85.3502  1.91858418249916

Epoch: 2026-04-01T12:12Z

TLE epoch observation values (Epoch: 2026-04-01T12:12:50.586Z)

Latitude

-31.49204°

Longitude

-173.94017°

Altitude

20,982.376 km

Speed

3.818 km/s

True Right ascension

13h 16m 33s

True Declination

-31° 27' 08"

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

15:15:06

Azimuth

Unknown

Elevation

Unknown

Doppler factor

Unknown

Orbital elements

Apogee altitude

21,068.682 km

Perigee altitude

20,890.55 km

Semi-major axis

27,357.753 km

Eccentricity

0.00326

Inclination

56.5171°

RAAN

355.282°

Arg. of periapsis

132.9802°

True anomaly

85.72216°

Mean anomaly

85.3502°

Eccentric anomaly

85.53617°

Mean motion

0.47965 °/min

Orbital period

750.55 mins

BSTAR

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Other satellites on launch #47 in the year 1991 (1991-07-04 UTC)

DELTA 2 DEB, 26793 (Decayed)

LOSAT X, 21553 (Decayed)

DELTA 2 R/B(1), 21554 (Decayed)

DELTA 2 R/B(2) (PAM-D), 21555 (Decayed)

DELTA 2 DEB, 23563 (Decayed)

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NAVSTAR 23 (USA 71) 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.
374 mins	2026-04-02 17:02:35.636Z	185.306° SSW	2026-04-02 19:51:35.636Z	111.627° ESE	44.94°	2026-04-02 23:16:35.636Z	74.181° E

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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 NAVSTAR 23 (USA 71), 21552 on other resources

View NAVSTAR 23 (USA 71), 21552 on NASA - NSSDCA Website

View NAVSTAR 23 (USA 71), 21552 on Heavens-Above

View NAVSTAR 23 (USA 71), 21552 on Keep Track

View NAVSTAR 23 (USA 71), 21552 on Celestrak

View NAVSTAR 23 (USA 71), 21552 on Gunter's Space Page

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

NAVSTAR 23 (USA 71), 21552

Orbit data source: Space-Track

Expand to show TLE details & historyLast TLE update: 21 hours ago

TLE from 21 hours ago

TLE epoch observation values (Epoch: 2026-04-01T12:12:50.586Z)

Visualization orbit readout

Visualization observer readout

Orbital elements

Other satellites on launch #47 in the year 1991 (1991-07-04 UTC)

NAVSTAR 23 (USA 71) Visibility forecast

Co-orbital & Co-planar RSOs

Check out NAVSTAR 23 (USA 71), 21552 on other resources

Documentation

Expand to show TLE details & history
Last TLE update: 21 hours ago