DELTA 1 DEB, 21551

Orbit data source: Space-Track

DELTA 1 DEB, 21551 is space debris in SSO originally from a launch on Thu, 12 Jun 1975 UTC launched from the Air Force Western Test Range (AFWTR). Debris objects in space refer to the collection of defunct objects orbiting the Earth. Examples of debris include non-operational satellites, rocket bodies, and fragments generated from explosions, collisions, or faulty payload assembly.

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Iframe URL

https://www.satcat.com/sats-embedded/21551?theme=dark&initialShowStats=false

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ISO8601 Format

Identifier

21551, 1975-052HF

Orbit

SSO

Country

Related business

National Aeronautics and Space Administration (NASA) (US)

Manufacturer

Unknown

Mission

Spacecraft

Bus & Motor

Unknown

Mass

Unknown

Launch date (UTC)

1975-06-12 (51 years ago)

Launch vehicle

Unknown

Launch site

Air Force Western Test Range (AFWTR)

Object type

Payload

Rocket body

Debris

Shape & HBR

Unknown shape, 0.1 m

Radar Cross Section

Small (<0.1 m²)

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Last TLE update: 6 hours ago

TLE from 6 hours ago

0 DELTA 1 DEB
1 21551U 75052HF  26127.19736191  .00000138  00000-0  40140-3 0  9992
2 21551  99.7875  24.3390 0106957  49.4832 101.7951 13.24613444689199

Epoch: 2026-05-07T04:44Z

TLE epoch observation values (Epoch: 2026-05-07T04:44:12.069Z)

Latitude

27.12944°

Longitude

-86.71317°

Altitude

1,187.646 km

Speed

7.254 km/s

True Right ascension

13h 57m 32s

True Declination

26° 59' 53"

Sunlit

Object was in full shadow 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

18:15:19

Azimuth

Unknown

Elevation

Unknown

Doppler factor

Unknown

Orbital elements

Apogee altitude

1,245.163 km

Perigee altitude

1,083.815 km

Semi-major axis

7,542.626 km

Eccentricity

0.0107

Inclination

99.7875°

RAAN

24.339°

Arg. of periapsis

49.4832°

True anomaly

102.9915°

Mean anomaly

101.7951°

Eccentric anomaly

102.39364°

Mean motion

3.31329 °/min

Orbital period

108.65 mins

BSTAR

0.0004014

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Other satellites on launch #52 in the year 1975 (1975-06-12 UTC)

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DELTA 1 DEB 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.
4 mins	2026-05-07 15:04:41.920Z	69.246° E	2026-05-07 15:06:41.920Z	50.295° ENE	12.445°	2026-05-07 15:08:41.920Z	31.977° NE
11 mins	2026-05-07 16:47:41.920Z	153.713° SSE	2026-05-07 16:52:41.920Z	45.733° ENE	43.742°	2026-05-07 16:58:41.920Z	348.956° N
6 mins	2026-05-07 18:37:41.920Z	243.893° WSW	2026-05-07 18:39:41.920Z	264.313° W	16.165°	2026-05-07 18:43:41.920Z	303.897° NW
4 mins	2026-05-08 04:13:41.920Z	76.35° E	2026-05-08 04:14:41.920Z	85.159° E	12.015°	2026-05-08 04:17:41.920Z	110.854° ESE
12 mins	2026-05-08 05:57:41.920Z	18.17° NNE	2026-05-08 06:02:41.920Z	64.105° ENE	44.383°	2026-05-08 06:09:41.920Z	192.267° SSW
7 mins	2026-05-08 07:46:41.920Z	330.111° NNW	2026-05-08 07:49:41.920Z	298.935° NW	18.361°	2026-05-08 07:53:41.920Z	262.418° W

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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 DELTA 1 DEB, 21551 on other resources

View DELTA 1 DEB, 21551 on Heavens-Above

View DELTA 1 DEB, 21551 on Keep Track

View DELTA 1 DEB, 21551 on Celestrak

View DELTA 1 DEB, 21551 on Gunter's Space Page

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

DELTA 1 DEB, 21551

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: 2026-05-07T04:44:12.069Z)

Visualization orbit readout

Visualization observer readout

Orbital elements

Other satellites on launch #52 in the year 1975 (1975-06-12 UTC)

DELTA 1 DEB Visibility forecast

Co-orbital & Co-planar RSOs

Check out DELTA 1 DEB, 21551 on other resources

Documentation

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