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SKYNET 4A (20401)
COSPAR: 1990-001A | Alt Name: Skynet 4A
Image
Additional Sources
Launch Details
Launch Date
January 1, 1990
Launch Site
Launch Pad
LC40
Launch Vehicle
Commercial Titan 3
Orbital Elements
NORAD ID
20401
International Designator
1990-001A
Epoch
Sat, 04 Jul 2026 05:10:13 GMT
Apogee
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Perigee
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Inclination
12.49°
Right Ascension
349.55°
Eccentricity
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Argument of Perigee
314.30°
Period
1454.55 min
Mean Motion
0.99 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
SKYNET 4A
Alternative Name
Skynet 4A
Type
Payload
Status
Non-operational
Owner
MOD
Country
United Kingdom
Constellation
N/A
Related Satellites
Major Events
N/A
Latest TLEs
1 20401U 90001A 26185.21543620 -.00000229 00000-0 00000-0 0 9996
2 20401 12.4940 349.5484 0013283 314.2966 11.8635 0.98999801 46933
Source: Celestrak
Summary
SKYNET 4A, also known as Skynet 4A, is a military communication satellite launched by the UK on January 1, 1990, from Cape Canaveral Air Force Station using a Commercial Titan 3 launch vehicle from LC40. With dimensions of 2.1 meters in length and 1.9 meters in diameter, it has a span of 16 meters due to its deployable solar arrays and batteries for power supply. The satellite weighs 763 kilograms at launch and 615 kilograms dry. It is equipped with various transponders including 4 SHF, 2 UHF, and 2 C-band transponders, designed for military communication purposes. SKYNET 4A was manufactured by BAES (BAE Systems) using the ECS-Bus configuration and had a planned lifetime of 6 years. The satellite’s shape is described as Box + 2 Pan with a radar cross section (RCS) of 8.1093, owned and operated by MOD (Ministry of Defence).
Physical Characteristics
Length
2.1
Diameter
1.9
Span
16
Dry Mass
615
Launch Mass
763
Shape
Box + 2 Pan
Radar Cross Section
8.1093
Visual Magnitude
Unknown
Color
Unknown
Material Composition
Unknown
Technical Details
Payload
Skynet 4A
Purpose
Military communication
Mission
Military communication
Manufacturer
BAES
Life Expectancy
6 years
Bus
ECS
Configuration
ECS-Bus
Motor
TE-M-700-19
Equipment
4 SHF transponders (all), 2 UHF transponders (all), 2 C-band transponders (#D-F)
Power System
2 deployable solar arrays, 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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