Telstar 1

Description

Telstar 1, primarily a communications satellite, carried an experiment designed to measure the energetic proton and electron distribution in the Van Allen belts. The spacecraft spin rate varied according to r=(178.2)exp(-t/333) rpm, where t was in days from launch. The spin axis original orientation was right ascension 81.96 deg and declination -65.57 deg. It varied slowly over the lifetime of the spacecraft. For example, on November 9, 1962, the right ascension was 94.05 deg, and the declination was -51.91 deg. Scientific information was transmitted by the spacecraft beacon, which was one of two onboard transmitters, via a PCM/FM/AM encoder. The telemetry sequence required about 1 min. The spacecraft operated normally from launch until November 1962, when the command channel began to behave erratically. The satellite was turned on continuously to circumvent this problem. On November 23, 1962, the command channel ceased to respond. On December 20, the satellite was successfully reactivated, and intermittent data were obtained until February 21, 1963, when the transmitter failed.