Showing default

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.

Loading next visibility...

Iframe embed code

<iframe src="https://www.satcat.com/sats-embedded/731?theme=dark&initialShowStats=false" width="600" height="400" frameborder="0" title="Kayhan Space Satcat Satellite Viewer"></iframe>

Iframe URL

https://www.satcat.com/sats-embedded/731?theme=dark&initialShowStats=false

Optional Secondary NORAD IDs

Max 10 NORAD IDs; Separated by commas

Initial load time (optional)

ISO8601 Format

TLE date request (optional)

ISO8601 Format

Identifier

731, 1964-001E

Orbit

LEO

Country

Related business

National Reconnaissance Office (US)

Manufacturer

NRL

Mission

Defense Sigint

Bus & Motor

NRL 20", Unknown motor

Mass

29 kg wet, 29 kg dry

Launch date (UTC)

1964-01-11 (62 years ago)

Launch vehicle

THOR SLV-2A AGENA D

Launch site

Air Force Western Test Range (AFWTR)

Object type

Payload

Rocket body

Debris

Shape & HBR

Sphere, 0.3 m

Radar Cross Section

0.196 m², Medium (>0.1 m² and < 1m²)

Expand to show TLE details & history
Last TLE update: 21 hours ago

TLE from 21 hours ago

0 GREB
1 00731U 64001E   25242.15081703  .00000093  00000-0  10678-3 0  9999
2 00731  69.9064 172.3505 0012264  31.7034 328.4808 13.96247104136957

Epoch: 2025-08-30T03:37Z

TLE epoch observation values (Epoch: 2025-08-30T03:37:10.591Z)

Latitude

0.00006°

Longitude

139.46716°

Altitude

901.512 km

Speed

7.405 km/s

True Right ascension

11h 29m 24s

True Declination

0° 00' 00"

Sunlit

Object was in daylight at epoch

Visualization orbit readout

Latitude

Unknown

Longitude

Unknown

Altitude

Unknown

Speed

Unknown

Apparent Right ascension

Unknown

Apparent Declination

Unknown

Sunlit

N/A

Visualization observer readout

Local Sidereal Time

16:00:01

Azimuth

Unknown

Elevation

Unknown

Doppler factor

Unknown

Orbital elements

Apogee altitude

913.804 km

Perigee altitude

895.94 km

Semi-major axis

7,283.009 km

Eccentricity

0.00123

Inclination

69.9064°

RAAN

172.3505°

Arg. of periapsis

31.7034°

True anomaly

328.40723°

Mean anomaly

328.4808°

Eccentric anomaly

328.44403°

Mean motion

3.49202 °/min

Orbital period

103.09 mins

BSTAR

0.00010678

Loading maneuver chart data...

Computing Atmospheric mass density...

Loading historical data...

Other satellites on launch #1 in the year 1964 (1964-01-11 UTC)

THOR AGENA D R/B, 727

GGSE 1 (GGRS), 728

SECOR 1B, 729

SOLRAD 7A, 730

GREB Visibility forecast

Observer location: undefined°, undefined°
Set Observer location

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	2025-08-31 05:58:43.572Z	348.035° N	2025-08-31 06:02:43.572Z	48.185° ENE	39.53°	2025-08-31 06:08:43.572Z	139.529° SSE
6 mins	2025-08-31 07:45:43.572Z	289.594° WNW	2025-08-31 07:47:43.572Z	264.902° W	19.78°	2025-08-31 07:51:43.572Z	217.493° SW
5 mins	2025-08-31 19:18:43.572Z	125.251° SE	2025-08-31 19:20:43.572Z	101.006° ESE	17.504°	2025-08-31 19:23:43.572Z	66.586° ENE
9 mins	2025-08-31 21:01:43.572Z	220.517° SW	2025-08-31 21:05:43.572Z	293.553° NW	41.743°	2025-08-31 21:10:43.572Z	16.583° NNE