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: 20 hours ago
TLE from 20 hours ago
0 GREB
1 00731U 64001E 25296.66770815 .00000072 00000-0 91183-4 0 9991
2 00731 69.9069 55.2273 0015583 322.7237 37.2785 13.96260872144560Epoch: 2025-10-23T16:01Z
TLE epoch observation values (Epoch: 2025-10-23T16:01:29.984Z)
Latitude
-0.00004°
Longitude
142.52868°
Altitude
900.051 km
Speed
7.407 km/s
True Right ascension
03h 40m 54s
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
07:09:46
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
916.173 km
Perigee altitude
893.475 km
Semi-major axis
7,282.961 km
Eccentricity
0.00156
Inclination
69.9069°
RAAN
55.2273°
Arg. of periapsis
322.7237°
True anomaly
37.38682°
Mean anomaly
37.2785°
Eccentric anomaly
37.33265°
Mean motion
3.49206 °/min
Orbital period
103.09 mins
BSTAR
0.000091183
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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 | 2025-10-24 18:21:40.176Z | 347.778° N | 2025-10-24 18:26:40.176Z | 47.027° ENE | 35.256° | 2025-10-24 18:32:40.176Z | 131.566° SE |
| 8 mins | 2025-10-24 20:08:40.176Z | 304.304° NW | 2025-10-24 20:12:40.176Z | 252.702° W | 24.417° | 2025-10-24 20:16:40.176Z | 205.601° SW |
| 4 mins | 2025-10-25 07:43:40.176Z | 112.817° SE | 2025-10-25 07:44:40.176Z | 101.845° ESE | 13.8° | 2025-10-25 07:47:40.176Z | 70.43° E |
| 10 mins | 2025-10-25 09:25:40.176Z | 210.032° SW | 2025-10-25 09:29:40.176Z | 277.923° WNW | 44.397° | 2025-10-25 09:35:40.176Z | 22.264° NNE |
| 4 mins | 2025-10-25 11:14:40.176Z | 296.303° NW | 2025-10-25 11:16:40.176Z | 318.054° NNW | 13.753° | 2025-10-25 11:18:40.176Z | 339.128° 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 ascending order |
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CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
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