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
Unknown
Radar Cross Section
Medium (>0.1 m² and <1 m²)
Expand to show TLE details & historyLast TLE update: 5 days ago
TLE from 5 days ago
0 GREB
1 00731U 64001E 26154.81641040 .00000042 00000-0 69503-4 0 9997
2 00731 69.9064 295.8006 0012091 36.7801 323.4131 13.96308172175713Epoch: 2026-06-03T19:35Z
TLE epoch observation values (Epoch: 2026-06-03T19:35:37.858Z)
Latitude
-0.00006°
Longitude
109.62324°
Altitude
901.844 km
Speed
7.405 km/s
True Right ascension
19h 43m 12s
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
23:51:28
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
913.465 km
Perigee altitude
895.854 km
Semi-major axis
7,282.797 km
Eccentricity
0.00121
Inclination
69.9064°
RAAN
295.8006°
Arg. of periapsis
36.7801°
True anomaly
323.33042°
Mean anomaly
323.4131°
Eccentric anomaly
323.37177°
Mean motion
3.49217 °/min
Orbital period
103.09 mins
BSTAR
0.000069503
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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. |
|---|---|---|---|---|---|---|---|
| 10 mins | 2026-06-08 18:46:07.190Z | 351.657° N | 2026-06-08 18:51:07.190Z | 55.86° ENE | 31.933° | 2026-06-08 18:56:07.190Z | 122.906° SE |
| 8 mins | 2026-06-08 20:33:07.190Z | 305.82° NW | 2026-06-08 20:37:07.190Z | 246.5° WSW | 27.81° | 2026-06-08 20:41:07.190Z | 198.364° SSW |
| 10 mins | 2026-06-09 09:49:07.190Z | 201.826° SSW | 2026-06-09 09:54:07.190Z | 57.32° ENE | 44.933° | 2026-06-09 09:59:07.190Z | 25.213° NE |
| 5 mins | 2026-06-09 11:38:07.190Z | 286.974° WNW | 2026-06-09 11:40:07.190Z | 309.456° NW | 15.648° | 2026-06-09 11:43:07.190Z | 343.057° 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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