RELAY 2, 737
Orbit data source: Space-Track
RELAY 2, 737 is a payload satellite owned by GSFC (US) that was launched on Tue, 21 Jan 1964 UTC via a THOR DELTA B launch vehicle from the Air Force Eastern Test Range (AFETR). 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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Edit Public Description
Identifier
Orbit
Country
USRelated business
Manufacturer
RCA/East Windsor
Mission
Spacecraft
Bus & Motor
RELAY, Unknown motor
Mass
83 kg wet, 83 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: 1 day ago
TLE from 1 day ago
0 RELAY 2
1 00737U 64003A 25352.99880575 -.00000017 00000-0 00000-0 0 9997
2 00737 46.4415 188.4879 2595075 179.2096 181.3871 7.39535814672767Epoch: 2025-12-18T23:58Z
TLE epoch observation values (Epoch: 2025-12-18T23:58:16.816Z)
Latitude
-0.00005°
Longitude
101.07152°
Altitude
7,637.494 km
Speed
4.59 km/s
True Right ascension
12h 33m 57s
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
06:17:21
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
7,639.231 km
Perigee altitude
1,862.985 km
Semi-major axis
11,129.245 km
Eccentricity
0.25951
Inclination
46.4415°
RAAN
188.4879°
Arg. of periapsis
179.2096°
True anomaly
180.84446°
Mean anomaly
181.3871°
Eccentric anomaly
181.10132°
Mean motion
1.84861 °/min
Orbital period
194.74 mins
BSTAR
0
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Other satellites on launch #3 in the year 1964 (1964-01-21 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.RELAY 2 Visibility forecast
Loading 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. |
|---|---|---|---|---|---|---|---|
| 56 mins | 2025-12-20 11:28:16.949Z | 151.702° SSE | 2025-12-20 12:00:16.949Z | 110.763° ESE | 21.671° | 2025-12-20 12:24:16.949Z | 72.028° E |
| 74 mins | 2025-12-20 14:45:16.949Z | 212.553° SW | 2025-12-20 15:33:16.949Z | 140.165° SSE | 43.587° | 2025-12-20 15:59:16.949Z | 61.697° ENE |
| 54 mins | 2025-12-20 18:33:16.949Z | 264.809° W | 2025-12-20 19:11:16.949Z | 357.859° N | 43.852° | 2025-12-20 19:27:16.949Z | 80.208° E |
| 31 mins | 2025-12-20 22:22:16.949Z | 297.621° NW | 2025-12-20 22:42:16.949Z | 223.335° SW | 44.049° | 2025-12-20 22:53:16.949Z | 134.464° SE |
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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