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ESIAFI 1 (COMSTAR 4) (12309)
COSPAR: 1981-018A | Alt Name: Comstar 204
Image
Additional Sources
Launch Details
Launch Date
February 21, 1981
Launch Site
Launch Pad
LC36A
Launch Vehicle
Atlas SLV-3D Centaur
Orbital Elements
NORAD ID
12309
International Designator
1981-018A
Epoch
Fri, 03 Jul 2026 21:19:35 GMT
Apogee
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Perigee
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Inclination
8.67°
Right Ascension
311.12°
Eccentricity
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Argument of Perigee
92.84°
Period
1436.06 min
Mean Motion
1.00 rev/day
Latitude
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Longitude
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Altitude
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Velocity
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Polar Plot
3D Visualization
Basic Satellite Info
Name
ESIAFI 1 (COMSTAR 4)
Alternative Name
Comstar 204
Type
Payload
Status
Non-operational
Owner
COM
Country
United States
Constellation
N/A
Related Satellites
Major Events
N/A
Latest TLEs
1 12309U 81018A 26184.88861081 -.00000031 00000-0 00000-0 0 9999
2 12309 8.6703 311.1191 0003096 92.8439 267.3146 1.00274260167613
Source: Celestrak
Summary
ESIAFI 1 (COMSTAR 4), also known as Comstar 204, is a communication satellite launched on February 21, 1981, from the AFETR launch site using LC36A and an Atlas SLV-3D Centaur launch vehicle. Manufactured by HSES, it has dimensions of 3.5 meters in length, 2.4 meters in diameter, and a span of 6.3 meters. The satellite weighs 748 kilograms at launch and has a dry mass of 590 kilograms. It is equipped with 24 C-band transponders for communication purposes and uses solar cells mounted on its body along with batteries for power supply. ESIAFI 1 operates in a cylindrical shape augmented by antennas, with a radar cross-section (RCS) of 22.06 square meters. The satellite's mission duration was planned for seven years.
Physical Characteristics
Length
3.5
Diameter
2.4
Span
6.3
Dry Mass
590
Launch Mass
748
Shape
Cyl + Ant
Radar Cross Section
22.06
Visual Magnitude
Unknown
Color
Unknown
Material Composition
Unknown
Technical Details
Payload
Comstar D-4
Purpose
Communication
Mission
Communication
Manufacturer
HSES
Life Expectancy
7 years
Bus
HS-351
Configuration
HS-351
Motor
SVM-4A
Equipment
24 C-band transponders
Power System
Solar cells (body mounted), batteries
ADCS
Unknown
Transmitter Frequency
Unknown
Map
Next Pass
Azimuth Elevation Time (Local)
Start Azimuth
Max Elevation
Stop Azimuth
Time Until
Pass Duration
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