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Radio Beacon

NSSDCA ID: 1958-002B-01

Mission Name: Vanguard 1


A 10-mW mercury-battery-powered telemetry transmitter on the 108-MHz band used for IGY scientific satellites, and a 5-mW, 108.03-MHz Minitrack transmitter powered by six solar cells were used as part of a radio phase-comparison angle-tracking system. The system transmitted signals through the satellite's six spring-loaded aluminum alloy aerials. Satellite tracking was achieved using these transmitters and Minitrack ground stations situated around the globe. The tracking data were used to show that the Earth was pear-shaped with the stem at the North Pole. These radio signals were also used to determine the total electron content between the satellite and selected ground-receiving stations. The battery-powered transmitter provided internal package temperature for about 16 days and sent tracking signals for 20 days. The solar-cell-powered transmitter operated for more than 6 years. Signals gradually weakened and were last received at the Minitrack station in Quito, Ecuador, in May 1964.

Alternate Names

  • Vanguard1/RadioBeacon

Facts in Brief

Mass: 1 kg
Power (avg): 1 W


  • Space Physics: Ionospheric Studies

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams



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