Space Brief 8 Dec 2024
Explore today's key space events including a SpaceX Starlink launch, Neuraspace's new telescope for space traffic monitoring, and Globalstar's defense-focused satellite service debut.
TRANSIT 4B (00202)
COSPAR: 1961-031A | Alt Name: Transit IV-B
Image
Additional Sources
Launch Details
Launch Date
November 15, 1961
Launch Site
Launch Pad
LC-17B
Launch Vehicle
Thor DM-21 Ablestar
Orbital Elements
NORAD ID
00202
International Designator
1961-031A
Epoch
Mon, 20 Jul 2026 09:53:09 GMT
Apogee
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Perigee
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Inclination
32.44°
Right Ascension
195.88°
Eccentricity
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Argument of Perigee
107.26°
Period
105.59 min
Mean Motion
13.64 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
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Basic Satellite Info
Name
TRANSIT 4B
Alternative Name
Transit IV-B
Type
Payload
Status
Unknown
Owner
U.S. Navy
Country
United States
Constellation
Transit
Related Satellites
Major Events
Ceased operation in 1964 due to radiation damage from the Starfish Prime nuclear test in 1962.
Latest TLEs
1 00202U 61031A 26201.41191169 .00000029 00000+0 95587-5 0 9997
2 00202 32.4351 195.8778 0100890 107.2623 253.9067 13.63795415225531
Source: Celestrak
Summary
The Transit 4B satellite was a cylindrical spacecraft built by the Johns Hopkins University Applied Physics Laboratory for the US Navy. It measured 0.8 meters in length and 1.1 meters in diameter, with a dry mass of approximately 89 kilograms. The satellite was equipped with a SNAP-3 Radioisotope Thermoelectric Generator (RTG) to provide power, as well as radio transmitters operating at 150 MHz and 400 MHz frequencies.
The primary mission of Transit 4B was to provide navigation data for the US Navy, which it achieved by transmitting precise location information. The satellite also tested the use of a nuclear power source in space, a pioneering achievement at the time. Unfortunately, its operation was cut short due to radiation damage from the Starfish Prime nuclear test in 1962.
Transit 4B ceased operation in 1964 and remained active for approximately three years.
Physical Characteristics
Length
0.8
Diameter
1.1
Span
1.1
Dry Mass
89
Launch Mass
89
Shape
Cylindrical
Radar Cross Section
1.9757
Visual Magnitude
5.5
Color
Silver
Material Composition
Aluminum alloy structure with solar cells.
Technical Details
Payload
Navigation instrumentation and SNAP-3 RTG.
Purpose
Unknown
Mission
To provide navigation data for the U.S. Navy and to test the use of a nuclear power source in space.
Manufacturer
Johns Hopkins University Applied Physics Laboratory (JHU/APL)
Life Expectancy
Operated until 1964, with transmissions ceasing due to radiation damage from the Starfish Prime nuclear test.
Bus
Transit 4
Configuration
Cylindrical
Motor
Unknown
Equipment
SNAP-3 RTG (Radioisotope Thermoelectric Generator), radio transmitters operating at 150 MHz and 400 MHz frequencies.
Power System
Primary power from solar cells; secondary power from the SNAP-3 RTG.
ADCS
Spin-stabilized
Transmitter Frequency
150 MHz, 400 MHz
Map
Next Pass
Azimuth Elevation Time (Local)
Start Azimuth
Max Elevation
Stop Azimuth
Time Until
Pass Duration
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