Launch Date
October 13, 1959
Launch Site
Launch Pad
LC-5
Launch Vehicle
Juno II
NORAD ID
00022
International Designator
1959-009A
Epoch
Sat, 04 Jul 2026 00:06:42 GMT
Apogee
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Perigee
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Inclination
50.24°
Right Ascension
16.94°
Eccentricity
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Argument of Perigee
192.92°
Period
94.17 min
Mean Motion
15.29 rev/day
Latitude
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Longitude
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Altitude
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Velocity
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Name
Explorer 7
Alternative Name
NASA S-1A
Type
Status
Owner
NASA
Country
United States
Constellation
N/A
Related Satellites
Major Events
Explorer 7 was launched on October 13, 1959, and provided significant geophysical information on radiation and magnetic storms. It was the first satellite to measure Earth's radiation balance.
1 00022U 59009A 26185.00465619 .00016402 00000-0 53139-3 0 9997
2 00022 50.2430 16.9373 0077808 192.9187 166.9781 15.29192616802927
Source: Celestrak
Length
0.76
Diameter
0.76
Span
7
Dry Mass
41.5
Launch Mass
41.5
Shape
Two truncated conical fiberglass shells joined by a cylindrical aluminum center section.
Radar Cross Section
0.506
Visual Magnitude
8.2
Color
Silver
Material Composition
Fiberglass shells and aluminum center section.
Payload
Scientific instruments for measuring solar radiation, cosmic rays, and micrometeoroids.
Purpose
Science
Mission
Explorer 7 was designed to measure solar X-ray and Lyman-alpha flux, trapped energetic particles, and heavy primary cosmic rays. Secondary objectives included collecting data on micrometeoroid penetration and studying the Earth's radiation balance.
Manufacturer
Jet Propulsion Laboratory
Life Expectancy
The satellite transmitted useful data from launch until February 1961 and intermittently until August 24, 1961.
Bus
S-1A
Configuration
Science Explorer
Motor
None
Equipment
The satellite was equipped with instruments to measure solar X-ray and Lyman-alpha flux, trapped energetic particles, heavy primary cosmic rays, micrometeoroid penetration, and thermal radiation.
Power System
Approximately 3,000 solar cells mounted on the satellite's exterior, supplemented by 15 nickel-cadmium batteries.
ADCS
Spin-stabilized
Transmitter Frequency
20 MHz, 108 MHz
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