Telstar design and construction and early results of the scientific space experiments

The Telstar satellite is a spherical spin-stabilized satellite which is a microwave repeater for intercontinental communications. It is an efficient non-demodulating repeater with an intermediate frequency centered at 90 mc (megacycles). Telemetry data from the communications circuits and from the radiation experiment are transmitted to the ground station, while vhf (very-High-frequency) signals from the ground actuate switches to reduce battery drain between passes. The spherical shape of Telstar provides an isotropic solar cell array and permits a nearly isotropic microwave antenna pattern. The electronics, which are packaged inside a hermetically sealed container, are isolated thermally with respect to conductive heat transfer and vibrationally from the satellite frame. A thermally activated bellows mechanism controls the temperature of the electronics chassis.