spase://SMWG/Observatory/Alouette1

Alouette 1 was a small ionospheric observatory instrumented with an ionospheric sounder, a VLF receiver,
an energetic particle detector, and a cosmic noise experiment. Extended from the satellite shell were two dipole
antennas (45.7 m and 22.8 m long, respectively) which were shared by three of the experiments on the spacecraft.
The satellite was spin-stabilized at about 1.4 rpm after antenna extension. After about 500 days, the spin slowed more
than had been expected, to about 0.6 rpm when satellite spin-stabilization failed. It is believed that the satellite
gradually progressed toward a gravity gradient stabilization with the longer antenna pointing earthward. Attitude
information was deduced only from a single magnetometer and temperature measurements on the upper and lower heat shields.
Attitude determination could have been in error by as much as 10 degrees. There was no tape recorder, so data were available
only from the vicinity of telemetry stations. Telemetry stations were located to provide primary data coverage near the 80
degree W meridian and in areas near Hawaii, Singapore, Australia, Europe, and Central Africa. Initially, data were recorded
for about six hours per day. In September 1972, spacecraft operations were terminated. A data restoration effort began in the
late nineties and successfully saved a considerable portion of the high-resolution data before the telemetry tapes were
discarded.