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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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<iframe src="https://www.satcat.com/sats-embedded/737?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/737?theme=dark&initialShowStats=false

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ISO8601 Format

Identifier

737, 1964-003A

Orbit

Active

Last TLE update

12 hours ago

Origin

National Aeronautics and Space Administration (NASA) (US)

Manufacturer

RCA/East Windsor

Mission

Civil Communications

Bus & Motor

RELAY, Unknown motor

Mass

83 kg wet, 83 kg dry

Launch date (UTC)

1964-01-21 (61 years ago)

Launch vehicle

THOR DELTA B

Launch site

Air Force Eastern Test Range (AFETR)

Object type

Payload

Rocket body

Debris

Shape & HBR

Oct Cyl, 0.4 m

Radar Cross Section

0.652 m², Medium (>0.1 m² and < 1m²)

Expand to show TLE details & history

TLE from 12 hours ago

0 RELAY 2
1 00737U 64003A   25199.45429767 -.00000019  00000-0  00000-0 0  9991
2 00737  46.4704   1.3732 2597208   6.9958 356.0611  7.39536474661407

Epoch: 2025-07-18T10:54Z

TLE epoch observation values (Epoch: 2025-07-18T10:54:11.318Z)

Latitude

0.00001°

Longitude

-98.67947°

Altitude

1,872.496 km

Speed

7.799 km/s

True Right ascension

00h 05m 29s

True Declination

0° 00' 00"

Sunlit

Object was in daylight at epoch

Visualization orbit readout

Latitude

-46.57293°

Longitude

170.02033°

Altitude

4,407.844 km

Speed

6.177 km/s

Apparent Right ascension

20h 15m 41s

Apparent Declination

-53° 29' 55"

Sunlit

Object is in full shadow

Visualization observer readout

Local Sidereal Time

12:05:55

Azimuth

129.361° SE

Elevation

-49.511°

Doppler factor

Orbital elements

Apogee altitude

7,641.592 km

Perigee altitude

1,860.604 km

Semi-major axis

11,129.235 km

Eccentricity

0.25972

Inclination

46.4704°

RAAN

1.3732°

Arg. of periapsis

6.9958°

True anomaly

353.06604°

Mean anomaly

356.0611°

Eccentric anomaly

354.68185°

Mean motion

1.84861 °/min

Orbital period

194.74 mins

BSTAR

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Other satellites on launch #3 in the year 1964 (1964-01-21 UTC)

DELTA 1 R/B, 738

RELAY 2 Visibility forecast

Observer location: undefined°, undefined°

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.
46 mins	2025-07-19 00:47:20.374Z	281.907° WNW	2025-07-19 01:07:20.374Z	249.584° W	17.468°	2025-07-19 01:33:20.374Z	216.594° SW
24 mins	2025-07-19 12:58:20.374Z	205.475° SW	2025-07-19 13:06:20.374Z	139.912° SSE	39.318°	2025-07-19 13:22:20.374Z	61.727° ENE
42 mins	2025-07-19 16:22:20.374Z	271.592° WNW	2025-07-19 16:34:20.374Z	347.504° N	43.564°	2025-07-19 17:04:20.374Z	83.235° E
66 mins	2025-07-19 19:49:20.374Z	296.652° NW	2025-07-19 20:09:20.374Z	221.309° SW	44.818°	2025-07-19 20:55:20.374Z	133.891° 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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Authenticating...

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Check out RELAY 2, 737 on other resources

View RELAY 2, 737 on NASA - NSSDCA Website

View RELAY 2, 737 on Heavens-Above

View RELAY 2, 737 on Keep Track

View RELAY 2, 737 on Celestrak

View RELAY 2, 737 on Gunter's Space Page

Satcat and Kayhan Space are not affiliated with NASA, Celestrak, Heavens-Above, Keep Track, or Gunter's Space Page.