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NAVSTAR 21 (USA 64) (20830)
COSPAR: 1990-088A | Alt Name: GPS II-9
Image
Additional Sources
Launch Details
Launch Date
October 1, 1990
Launch Site
Launch Pad
LC17A
Launch Vehicle
Delta 6925
Orbital Elements
NORAD ID
20830
International Designator
1990-088A
Epoch
Fri, 03 Jul 2026 23:00:09 GMT
Apogee
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Perigee
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Inclination
56.48°
Right Ascension
9.34°
Eccentricity
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Argument of Perigee
291.17°
Period
766.96 min
Mean Motion
1.88 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
NAVSTAR 21 (USA 64)
Alternative Name
GPS II-9
Type
Payload
Status
Non-operational
Owner
AFSSD2
Country
United States
Constellation
N/A
Related Satellites
Major Events
N/A
Latest TLEs
1 20830U 90088A 26184.95844109 -.00000073 00000-0 00000-0 0 9990
2 20830 56.4757 9.3377 0022044 291.1734 70.1016 1.87753247253129
Source: Celestrak
Summary
NAVSTAR 21 (USA 64), also known as GPS II-9, is a satellite part of the GPS constellation operated by AFSSD2 for navigation purposes. It was launched on October 1, 1990, from Launch Pad LC17A at AFETR using a Delta 6925 launch vehicle. The spacecraft features a box shape with two panels and measures 2.4 meters in length, 1.8 meters in diameter, and spans 5.3 meters when its solar arrays are deployed. It has a dry mass of 776 kg, the same as its launch mass. Equipped with deployable solar arrays for power generation and batteries, NAVSTAR 21 is designed to operate on a three-axis stabilized platform. Its mission lifetime was projected at 7.5 years. The satellite's payload is GPS SVN 15, and it carries an unspecified equipment load. Manufactured by RWISB, the spacecraft also includes a Star 37F motor for propulsion. NAVSTAR 21 contributes to providing navigation services as part of the US global positioning system constellation.
Physical Characteristics
Length
2.4
Diameter
1.8
Span
5.3
Dry Mass
776
Launch Mass
776
Shape
Box + 2 Pan
Radar Cross Section
2.0801
Visual Magnitude
Unknown
Color
Unknown
Material Composition
Unknown
Technical Details
Payload
GPS SVN 15
Purpose
Navigation
Mission
Navigation
Manufacturer
RWISB
Life Expectancy
7.5 years
Bus
GPS II
Configuration
3-Axis stabilized
Motor
Star 37F
Equipment
?
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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