Historical Photo of the Month - February 2007

Helical Beam Antennas in 1951
Photograph Number 331-629B

Is this a scene from a corny science fiction movie of the 1950s? It's actually one of the early steps in the evolution of the Deep Space Network.

In 1951, JPL was working on missile development for the U.S. Army. In order to receive data signals from missiles in flight, JPL also developed telemetering ground equipment. The system included these helical antennas as well as receivers, recording equipment, gas-powered generators and batteries for power, and telephones for communication between primary and secondary telemetering sites. All the equipment, including a control room, was installed in trucks so it could be easily transported and set up in the field.

The directional antennas were mounted on top of 35-foot telephone poles. During testing, each antenna was steered using a small wheel, like a ship's wheel, near the bottom of the pole, attached to the antenna by rope.

Next month's Historical Photo will show JPL's progress up to 1956 in the development of tracking antennas.

For more detailed information about the history of JPL, and about the evolution of communication technology, contact the JPL Archives for assistance. [Archival sources: Photo albums and indexes, History Collection documents 3-40 and 3-124.]