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OPS 3674 (VELA 4), 837

Orbit data source: Space-Track

OPS 3674 (VELA 4), 837 is a payload satellite owned by USAF SSD (US) in HEO that was launched on Fri, 17 Jul 1964 UTC via an ATLAS AGENA D 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 URL

https://www.satcat.com/sats-embedded/837?theme=dark&initialShowStats=false

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ISO8601 Format

Identifier

837, 1964-040B

Orbit

HEO

Country

Related business

United States Space Force (US)

Manufacturer

TRW

Mission

Spacecraft

Bus & Motor

VELA, BE-3

Mass

~217 kg wet, 125 kg dry

Launch date (UTC)

1964-07-17 (61 years ago)

Launch vehicle

ATLAS AGENA D

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: 3 months ago

TLE from 3 months ago

0 OPS 3674 (VELA 4)
1   837U 64040B   25267.08260992  .00000086  00000-0  00000+0 0  9993
2   837  48.8014 128.4628 5006560 257.7278   0.4454  0.23999503 54080

Epoch: 2025-09-24T01:58Z

TLE epoch observation values (Epoch: 2025-09-24T01:58:57.497Z)

Latitude

-47.27128°

Longitude

-12.96938°

Altitude

47,688.75 km

Speed

3.332 km/s

True Right ascension

01h 19m 44s

True Declination

-47° 14' 55"

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

07:37:12

Azimuth

Unknown

Elevation

Unknown

Doppler factor

Unknown

Orbital elements

Apogee altitude

157,762.254 km

Perigee altitude

48,239.656 km

Semi-major axis

109,379.092 km

Eccentricity

0.50066

Inclination

48.8014°

RAAN

128.4628°

Arg. of periapsis

257.7278°

True anomaly

1.54617°

Mean anomaly

0.4454°

Eccentric anomaly

0.89193°

Mean motion

0.06 °/min

Orbital period

6,000.13 mins

BSTAR

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Other satellites on launch #40 in the year 1964 (1964-07-17 UTC)

ERS 13, 838 (Decayed)

OPS 3662 (VELA 3), 836

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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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OPS 3674 (VELA 4) 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.
923 mins	2025-12-18 08:48:46.688Z	54.885° ENE	2025-12-18 14:50:46.688Z	0.12° NNE	44.673°	2025-12-19 00:11:46.688Z	324.515° NNW

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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 OPS 3674 (VELA 4), 837 on other resources

View OPS 3674 (VELA 4), 837 on NASA - NSSDCA Website

View OPS 3674 (VELA 4), 837 on Heavens-Above

View OPS 3674 (VELA 4), 837 on Keep Track

View OPS 3674 (VELA 4), 837 on Celestrak

View OPS 3674 (VELA 4), 837 on Gunter's Space Page

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

OPS 3674 (VELA 4), 837

Orbit data source: Space-Track

Expand to show TLE details & historyLast TLE update: 3 months ago

TLE from 3 months ago

TLE epoch observation values (Epoch: 2025-09-24T01:58:57.497Z)

Visualization orbit readout

Visualization observer readout

Orbital elements

Other satellites on launch #40 in the year 1964 (1964-07-17 UTC)

OPS 3674 (VELA 4) Visibility forecast

Co-orbital & Co-planar RSOs

Check out OPS 3674 (VELA 4), 837 on other resources

Documentation

Expand to show TLE details & history
Last TLE update: 3 months ago