18 September 1959: At 05:16:00 UTC, a three-stage Vanguard Satellite Launch Vehicle lifted of from Launch Complex 18A at the Cape Canaveral Air Force Station, Florida. The rocket placed a 50 pound (22.7 kilogram) scientific satellite into Earth orbit.

Contained inside the satellite’s 20 inch (50.8 centimeter) diameter magnesium outer shell were sensors and transmitters. The satellite collected data on the Earth’s magnetic field, the Van Allen Radiation Belt, micrometeorite impacts on the satellite and measured drag acting to slow the satellite in its orbit.

Vanguard 3 transmitted data for 84 days before it stopped functioning. It is estimated that it will remain in orbit around the Earth for 300 years.

© 2015, Bryan R. Swopes