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: 8 hours ago
TLE from 8 hours ago
0 GREB
1 731U 64001E 26069.13963890 .00000034 00000-0 63583-4 0 9990
2 731 69.9049 119.8822 0013025 167.9225 192.2195 13.96294187163755Epoch: 2026-03-10T03:21Z
TLE epoch observation values (Epoch: 2026-03-10T03:21:04.800Z)
Latitude
-0.00005°
Longitude
-98.21033°
Altitude
918.238 km
Speed
7.388 km/s
True Right ascension
07h 59m 31s
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
15:33:15
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
914.195 km
Perigee altitude
895.223 km
Semi-major axis
7,282.846 km
Eccentricity
0.0013
Inclination
69.9049°
RAAN
119.8822°
Arg. of periapsis
167.9225°
True anomaly
192.18796°
Mean anomaly
192.2195°
Eccentric anomaly
192.20372°
Mean motion
3.49214 °/min
Orbital period
103.09 mins
BSTAR
0.000063583
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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. |
|---|---|---|---|---|---|---|---|
| 4 mins | 2026-03-10 12:30:07.114Z | 21.787° NNE | 2026-03-10 12:32:07.114Z | 42.494° NE | 12.696° | 2026-03-10 12:34:07.114Z | 63.497° ENE |
| 10 mins | 2026-03-10 14:14:07.114Z | 340.71° N | 2026-03-10 14:19:07.114Z | 80.111° E | 43.561° | 2026-03-10 14:24:07.114Z | 148.068° SSE |
| 5 mins | 2026-03-10 16:02:07.114Z | 280.294° WNW | 2026-03-10 16:04:07.114Z | 257.375° W | 15.044° | 2026-03-10 16:07:07.114Z | 226.381° WSW |
| 7 mins | 2026-03-11 03:33:07.114Z | 144.396° SSE | 2026-03-11 03:36:07.114Z | 106.96° ESE | 22.615° | 2026-03-11 03:40:07.114Z | 57.186° ENE |
| 10 mins | 2026-03-11 05:17:07.114Z | 229.544° WSW | 2026-03-11 05:22:07.114Z | 314.908° NW | 36.705° | 2026-03-11 05:27:07.114Z | 13.621° NNE |
Co-orbital & Co-planar RSOs
Thresholds — Semi-major Axis: ±100 km, RAAN: ±3°, Inclination: ±5°
TCA is derived from TLE conjunctions
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CAUTION: Conjunctions in this section are generated from low-fidelity TLE screenings
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