TRANSIT 4B (00202)

COSPAR: 1961-031A | Alt Name: Transit IV-B

Image

Additional Sources

Launch Details

Launch Date

November 15, 1961

Launch Site

Cape Canaveral Space Force Station

Launch Pad

LC-17B

Launch Vehicle

Thor DM-21 Ablestar

Orbital Elements

NORAD ID

00202

International Designator

1961-031A

Epoch

Sat, 04 Jul 2026 05:33:54 GMT

Apogee

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Perigee

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Inclination

32.44°

Right Ascension

276.92°

Eccentricity

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Argument of Perigee

344.19°

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

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   26185.23188491  .00000075  00000-0  63929-4 0  9998

2 00202  32.4377 276.9248 0101226 344.1935  15.5539 13.63794939223325

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

Launch Mass

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

This tool will help you track the satellite's position and predict its upcoming passes over your location. Simply input the coordinates or click the geolocation button to get started.

Latitude

Longitude

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Azimuth Elevation Time (Local)

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Max Elevation

Stop Azimuth

Time Until

Pass Duration

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