Space Brief 22 Aug 2025
SpaceX's X-37B spaceplane launch, featuring advanced tech, highlights today’s space events. The launch of the first reprogrammable navigation satellite by the US Space Force is another significant milestone.
Vanguard 2 (00011)
COSPAR: 1959-001A | Alt Name: Vanguard II
Image
Additional Sources
Launch Details
Launch Date
February 17, 1959
Launch Site
Launch Pad
LC-18A
Launch Vehicle
Vanguard SLV-4
Orbital Elements
NORAD ID
00011
International Designator
1959-001A
Epoch
Sat, 04 Jul 2026 06:04:05 GMT
Apogee
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Perigee
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Inclination
32.87°
Right Ascension
20.55°
Eccentricity
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Argument of Perigee
154.06°
Period
120.95 min
Mean Motion
11.91 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
Vanguard 2
Alternative Name
Vanguard II
Type
Payload
Status
Unknown
Country
United States
Constellation
N/A
Related Satellites
Major Events
First weather satellite launched; provided data on Earth's cloud cover and atmospheric density.
Latest TLEs
1 00011U 59001A 26185.25284651 .00001694 00000-0 88490-3 0 9994
2 00011 32.8684 20.5518 1444956 154.0557 214.0298 11.90559699537506
Source: Celestrak
Summary
Vanguard 2 was a weather satellite launched on February 17, 1959, from Cape Canaveral Air Force Station in Florida. The satellite measured cloud-cover distribution and provided information on atmospheric density over its 19-day operational period. It had two optical telescopes with photocells for measuring sunlight reflected from Earth's surface.
The Vanguard 2 was a small sphere, 10.75 kg (23.6 lbs) in mass and 0.508 meters (1.66 feet) in diameter. Its power source consisted of mercury batteries, and it was equipped with an optical scanner to collect cloud cover data and instruments for measuring atmospheric density. The satellite's spin axis orientation proved unsatisfactory, resulting in poor data quality.
The Vanguard 2 mission marked the first launch of a weather satellite into space, providing valuable insights into Earth's cloud cover and atmospheric conditions during its operational period.
Physical Characteristics
Length
0.508
Diameter
0.508
Span
0.508
Dry Mass
10.75
Launch Mass
10.75
Shape
Spherical
Radar Cross Section
0.3823
Visual Magnitude
10.2
Color
Externally covered with an aluminum deposit coated with silicon oxide
Material Composition
Magnesium sphere internally gold-plated and externally covered with an aluminum deposit coated with silicon oxide.
Technical Details
Payload
Optical scanner for cloud cover data and instruments to measure atmospheric density.
Purpose
Science
Mission
Designed to measure cloud-cover distribution over the daylight portion of its orbit and to provide information on the density of the atmosphere.
Manufacturer
Naval Research Laboratory
Life Expectancy
The satellite's optical scanner experiment was designed to operate for 19 days; however, due to an unsatisfactory orientation of the spin axis, the data obtained was poor.
Bus
Vanguard
Configuration
Vanguard 2E
Motor
None
Equipment
Two optical telescopes with photocells for measuring sunlight reflected from Earth's surface and cloud cover.
Power System
Mercury batteries
ADCS
Spin-stabilized at approximately 50 rpm
Transmitter Frequency
108.00 MHz, 108.03 MHz
Map
Next Pass
Azimuth Elevation Time (Local)
Start Azimuth
Max Elevation
Stop Azimuth
Time Until
Pass Duration
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