GREB, 731
Orbit data source: Space-Track
GREB, 731 is an American payload satellite in LEO that was launched on Sat, 11 Jan 1964 UTC via a THOR SLV-2A AGENA D 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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731 intel report (Beta)
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Edit Public Description
Identifier
Orbit
Country
USRelated business
Manufacturer
NRL
Mission
Spacecraft
Bus & Motor
NRL 20", Unknown motor
Mass
29 kg wet, 29 kg dry
Launch date (UTC)
Launch vehicle
Launch site
Object type
Shape & HBR
Unknown
Radar Cross Section
Medium (>0.1 m² and <1 m²)
Expand to show TLE details & historyLast TLE update: 5 hours ago
TLE from 5 hours ago
0 GREB
1 00731U 64001E 25342.58755001 .00000128 00000-0 13191-3 0 9998
2 00731 69.9062 316.5739 0017036 272.6260 87.2895 13.96273886150975Epoch: 2025-12-08T14:06Z
TLE epoch observation values (Epoch: 2025-12-08T14:06:04.320Z)
Latitude
-0.00004°
Longitude
27.47145°
Altitude
908.467 km
Speed
7.398 km/s
True Right ascension
21h 06m 17s
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
17:39:37
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
917.186 km
Perigee altitude
892.372 km
Semi-major axis
7,282.916 km
Eccentricity
0.0017
Inclination
69.9062°
RAAN
316.5739°
Arg. of periapsis
272.626°
True anomaly
87.48452°
Mean anomaly
87.2895°
Eccentric anomaly
87.38701°
Mean motion
3.49209 °/min
Orbital period
103.09 mins
BSTAR
0.00013191
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Other satellites on launch #1 in the year 1964 (1964-01-11 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.GREB 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. |
|---|---|---|---|---|---|---|---|
| 8 mins | 2025-12-08 22:48:52.678Z | 151.37° SSE | 2025-12-08 22:52:52.678Z | 104.43° ESE | 22.991° | 2025-12-08 22:56:52.678Z | 55.699° ENE |
| 10 mins | 2025-12-09 00:33:52.678Z | 230.848° WSW | 2025-12-09 00:37:52.678Z | 287.992° WNW | 36.648° | 2025-12-09 00:43:52.678Z | 13.893° NNE |
| 5 mins | 2025-12-09 07:51:52.678Z | 24.479° NE | 2025-12-09 07:53:52.678Z | 48.044° ENE | 16.869° | 2025-12-09 07:56:52.678Z | 81.346° E |
| 10 mins | 2025-12-09 09:35:52.678Z | 333.048° NNW | 2025-12-09 09:39:52.678Z | 299.807° NW | 44.422° | 2025-12-09 09:45:52.678Z | 160.479° S |
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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