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RELAY 1 (A-15), 503

Orbit data source: Space-Track

RELAY 1 (A-15), 503 is a payload satellite owned by GSFC (US) that was launched on Thu, 13 Dec 1962 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/503?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/503?theme=dark&initialShowStats=false

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ISO8601 Format

Identifier

503, 1962-068A

Orbit

Active

Country

Related business

National Aeronautics and Space Administration (NASA) (US)

Manufacturer

RCA/East Windsor

Mission

Spacecraft

Bus & Motor

RELAY, Unknown motor

Mass

78 kg wet, 78 kg dry

Launch date (UTC)

1962-12-13 (63 years ago)

Launch vehicle

THOR DELTA B

Launch site

Air Force Eastern Test Range (AFETR)

Object type

Payload

Rocket body

Debris

Shape & HBR

Unknown

Radar Cross Section

Medium (>0.1 m² and <1 m²)

Expand to show TLE details & history
Last TLE update: 14 hours ago

TLE from 14 hours ago

0 RELAY 1 (A-15)
1   503U 62068A   26100.91969735 -.00000029  00000-0  00000+0 0  9999
2   503  47.4910 151.3012 2838285 136.8997  19.8627  7.78167411800246

Epoch: 2026-04-10T22:04Z

TLE epoch observation values (Epoch: 2026-04-10T22:04:21.851Z)

Latitude

5.16031°

Longitude

156.33907°

Altitude

1,665.805 km

Speed

7.879 km/s

True Right ascension

21h 46m 18s

True Declination

5° 07' 59"

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

17:57:25

Azimuth

Unknown

Elevation

Unknown

Doppler factor

Unknown

Orbital elements

Apogee altitude

7,432.968 km

Perigee altitude

1,326.256 km

Semi-major axis

10,757.749 km

Eccentricity

0.28383

Inclination

47.491°

RAAN

151.3012°

Arg. of periapsis

136.8997°

True anomaly

36.06032°

Mean anomaly

19.8627°

Eccentric anomaly

27.32854°

Mean motion

1.94519 °/min

Orbital period

185.07 mins

BSTAR

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Other satellites on launch #68 in the year 1962 (1962-12-13 UTC)

DELTA 1 R/B, 515

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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.

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RELAY 1 (A-15) 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.
15 mins	2026-04-11 13:09:04.500Z	295.933° NW	2026-04-11 13:17:04.500Z	206.532° SW	40.93°	2026-04-11 13:24:04.500Z	140.617° SSE
46 mins	2026-04-12 03:37:04.500Z	190.78° SSW	2026-04-12 04:08:04.500Z	131.362° SE	34.214°	2026-04-12 04:23:04.500Z	68.505° E
35 mins	2026-04-12 07:02:04.500Z	243.093° WSW	2026-04-12 07:27:04.500Z	334.916° NNW	44.683°	2026-04-12 07:37:04.500Z	61.981° ENE
19 mins	2026-04-12 10:33:04.500Z	290.78° WNW	2026-04-12 10:45:04.500Z	22.844° NE	41.249°	2026-04-12 10:52:04.500Z	91.46° ESE

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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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Check out RELAY 1 (A-15), 503 on other resources

View RELAY 1 (A-15), 503 on NASA - NSSDCA Website

View RELAY 1 (A-15), 503 on Heavens-Above

View RELAY 1 (A-15), 503 on Keep Track

View RELAY 1 (A-15), 503 on Celestrak

View RELAY 1 (A-15), 503 on Gunter's Space Page

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

RELAY 1 (A-15), 503

Orbit data source: Space-Track

Expand to show TLE details & historyLast TLE update: 14 hours ago

TLE from 14 hours ago

TLE epoch observation values (Epoch: 2026-04-10T22:04:21.851Z)

Visualization orbit readout

Visualization observer readout

Orbital elements

Other satellites on launch #68 in the year 1962 (1962-12-13 UTC)

RELAY 1 (A-15) Visibility forecast

Co-orbital & Co-planar RSOs

Check out RELAY 1 (A-15), 503 on other resources

Documentation

Expand to show TLE details & history
Last TLE update: 14 hours ago