USA 81, 21949
Orbit data source: Space-Track
USA 81, 21949 is a payload satellite owned by NRO (US) in LEO that was launched on Sat, 25 Apr 1992 UTC via a TITAN II SLV 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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21949 intel report (Beta)
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Identifier
Orbit
Country
USRelated business
Manufacturer
LMSC/MOTO
Mission
Defense Sigint
Bus & Motor
NRO-T2, Unknown motor
Mass
~1,450 kg wet, ~1,200 kg dry
Launch date (UTC)
Launch vehicle
Launch site
Object type
Shape & HBR
Cyl + 1 Ant, 5.0 m
Radar Cross Section
1.422 m², Large (>1 m²)
Expand to show TLE details & historyLast TLE update: 7 hours ago
TLE from 7 hours ago
0 USA 81
1 21949U 92023A 26169.74183113 .00000145 00000-0 46218-4 0 9998
2 21949 85.0074 73.1103 0002753 83.3128 276.8378 14.32398597109257Epoch: 2026-06-18T17:48Z
TLE epoch observation values (Epoch: 2026-06-18T17:48:14.209Z)
Latitude
-0.00002°
Longitude
-100.92971°
Altitude
786.516 km
Speed
7.461 km/s
True Right ascension
04h 52m 26s
True Declination
0° 00' 00"
Sunlit
Visualization orbit readout
Latitude
Unknown
Longitude
Unknown
Altitude
Unknown
Speed
Unknown
Apparent Right ascension
Unknown
Apparent Declination
Unknown
Sunlit
Visualization observer readout
Local Sidereal Time
12:05:47
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
782.696 km
Perigee altitude
778.754 km
Semi-major axis
7,158.862 km
Eccentricity
0.00028
Inclination
85.0074°
RAAN
73.1103°
Arg. of periapsis
83.3128°
True anomaly
276.80648°
Mean anomaly
276.8378°
Eccentric anomaly
276.82214°
Mean motion
3.58325 °/min
Orbital period
100.47 mins
BSTAR
0.000046218
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Other satellites on launch #23 in the year 1992 (1992-04-25 UTC)
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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.USA 81 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. |
|---|---|---|---|---|---|---|---|
| 6 mins | 2026-06-19 04:27:06.601Z | 35.634° NE | 2026-06-19 04:30:06.601Z | 73.432° E | 17.224° | 2026-06-19 04:33:06.601Z | 111.608° ESE |
| 8 mins | 2026-06-19 06:08:06.601Z | 337.686° N | 2026-06-19 06:11:06.601Z | 284.757° WNW | 37.129° | 2026-06-19 06:16:06.601Z | 197.918° SSW |
| 7 mins | 2026-06-19 17:25:06.601Z | 131.399° SE | 2026-06-19 17:28:06.601Z | 77.197° E | 27.16° | 2026-06-19 17:32:06.601Z | 25.999° NE |
| 7 mins | 2026-06-19 19:06:06.601Z | 239.284° WSW | 2026-06-19 19:09:06.601Z | 290.649° WNW | 25.039° | 2026-06-19 19:13:06.601Z | 340.931° N |
Co-orbital & Co-planar RSOs
Thresholds — Semi-major Axis: ±100 km, RAAN: ±3°, Inclination: ±5°
TCA is derived from TLE conjunctions
Click to sort rows by RSO header in ascending order | Click to sort rows by Country header in ascending order | Click to sort rows by Type header in ascending order | Click to sort rows by Inclination Δ header in ascending order | Click to sort rows by RAAN Δ header in ascending order | Click to sort rows by Coplanar Angle header in ascending order | Click to sort rows by SMA Δ header in ascending order | Click to sort rows by Orbital period header in ascending order | Click to sort rows by <5km Md TCA header in descending order |
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CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
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