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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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: 2 days ago
TLE from 2 days ago
0 RELAY 2
1 737U 64003A 26048.54058477 -.00000010 00000-0 00000+0 0 9991
2 737 46.4627 120.3412 2600288 247.1393 83.5385 7.39537338677242Epoch: 2026-02-17T12:58Z
TLE epoch observation values (Epoch: 2026-02-17T12:58:26.524Z)
Latitude
-0.00001°
Longitude
138.21157°
Altitude
5,166.83 km
Speed
5.766 km/s
True Right ascension
08h 01m 21s
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
18:21:32
Azimuth
Unknown
Elevation
Unknown
Doppler factor
Unknown
Orbital elements
Apogee altitude
7,645.01 km
Perigee altitude
1,857.171 km
Semi-major axis
11,129.228 km
Eccentricity
0.26003
Inclination
46.4627°
RAAN
120.3412°
Arg. of periapsis
247.1393°
True anomaly
112.9222°
Mean anomaly
83.5385°
Eccentric anomaly
98.28169°
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
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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. |
|---|---|---|---|---|---|---|---|
| 19 mins | 2026-02-19 15:23:39.575Z | 222.912° SW | 2026-02-19 15:23:39.575Z | 222.912° SW | 41.326° | 2026-02-19 15:42:39.575Z | 157.116° SSE |
| 35 mins | 2026-02-20 02:43:39.575Z | 120.508° SE | 2026-02-20 02:58:39.575Z | 95° ESE | 14.979° | 2026-02-20 03:18:39.575Z | 68.867° E |
| 82 mins | 2026-02-20 05:50:39.575Z | 203.648° SW | 2026-02-20 06:23:39.575Z | 129.099° SE | 42.53° | 2026-02-20 07:12:39.575Z | 59.084° ENE |
| 89 mins | 2026-02-20 09:22:39.575Z | 258.711° W | 2026-02-20 10:10:39.575Z | 352.217° N | 44.435° | 2026-02-20 10:51:39.575Z | 84.559° E |
| 73 mins | 2026-02-20 13:09:39.575Z | 295.549° NW | 2026-02-20 13:57:39.575Z | 226.659° WSW | 44.691° | 2026-02-20 14:22:39.575Z | 134.231° SE |
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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