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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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
SPHERE, 1.1 m
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 00731U 64001E 26274.80559588 -.00000014 00000-0 28583-4 0 9997
2 00731 69.9073 37.9960 0016542 254.9215 105.0060 13.96322222192463Epoch: 2026-10-01T19:20Z
TLE epoch observation values (Epoch: 2026-10-01T19:20:03.484Z)
Latitude
-0°
Longitude
97.44486°
Altitude
912.004 km
Speed
7.395 km/s
True Right ascension
02h 31m 59s
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
23:30:48
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
916.658 km
Perigee altitude
892.564 km
Semi-major axis
7,282.748 km
Eccentricity
0.00165
Inclination
69.9073°
RAAN
37.996°
Arg. of periapsis
254.9215°
True anomaly
105.18899°
Mean anomaly
105.006°
Eccentric anomaly
105.09751°
Mean motion
3.49221 °/min
Orbital period
103.09 mins
BSTAR
0.000028583
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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. |
|---|---|---|---|---|---|---|---|
| 11 mins | 2026-10-02 09:11:25.356Z | 178.407° S | 2026-10-02 09:16:25.356Z | 121.285° SE | 45.604° | 2026-10-02 09:22:25.356Z | 37.015° NE |
| 8 mins | 2026-10-02 10:59:25.356Z | 260.584° W | 2026-10-02 11:02:25.356Z | 301.367° NW | 28.605° | 2026-10-02 11:07:25.356Z | 2.311° NNE |
| 9 mins | 2026-10-02 18:14:25.356Z | 1.978° NNE | 2026-10-02 18:18:25.356Z | 52.945° ENE | 28.913° | 2026-10-02 18:23:25.356Z | 112.088° ESE |
| 9 mins | 2026-10-02 20:00:25.356Z | 315.449° NNW | 2026-10-02 20:04:25.356Z | 248.222° W | 45.635° | 2026-10-02 20:09:25.356Z | 183.152° SSW |
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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