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: 10 hours ago
TLE from 10 hours ago
0 GREB
1 731U 64001E 25343.16065002 .00000090 00000-0 10457-3 0 9998
2 731 69.9062 315.3426 0017038 272.0032 87.9122 13.96273879151050Epoch: 2025-12-09T03:51Z
TLE epoch observation values (Epoch: 2025-12-09T03:51:20.161Z)
Latitude
-0.00003°
Longitude
179.35927°
Altitude
908.602 km
Speed
7.398 km/s
True Right ascension
21h 01m 22s
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
12:08:45
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
917.188 km
Perigee altitude
892.371 km
Semi-major axis
7,282.916 km
Eccentricity
0.0017
Inclination
69.9062°
RAAN
315.3426°
Arg. of periapsis
272.0032°
True anomaly
88.10733°
Mean anomaly
87.9122°
Eccentric anomaly
88.00976°
Mean motion
3.49209 °/min
Orbital period
103.09 mins
BSTAR
0.00010457
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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. |
|---|---|---|---|---|---|---|---|
| 9 mins | 2025-12-09 22:52:58.659Z | 163.794° S | 2025-12-09 22:56:58.659Z | 114.663° SE | 29.224° | 2025-12-09 23:01:58.659Z | 46.397° ENE |
| 9 mins | 2025-12-10 00:38:58.659Z | 244.796° WSW | 2025-12-10 00:42:58.659Z | 303.17° NW | 30.85° | 2025-12-10 00:47:58.659Z | 7.133° NNE |
| 7 mins | 2025-12-10 07:55:58.659Z | 15.919° NNE | 2025-12-10 07:58:58.659Z | 54.963° ENE | 21.145° | 2025-12-10 08:02:58.659Z | 99.516° ESE |
| 10 mins | 2025-12-10 09:39:58.659Z | 326.104° NNW | 2025-12-10 09:44:58.659Z | 239.904° WSW | 41.13° | 2025-12-10 09:49:58.659Z | 172.564° 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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