Alouette 1 [CSA]
The Canadian satellites Alouette 1 and 2 were small ionospheric observatories built as a joint project between Canada's Defence and Research Telecommunications Establishment (DRTE) and NASA. Alouette 1 was also the first Canadian satellite.
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 deg.) 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 deg W meridian and in areas near Hawaii, Singapore, Australia, Europe, and Central Africa. Initially, data were recorded for about 6 h per day. In September 1972, spacecraft operations were terminated.
Alouette 2 was a small ionospheric observatory instrumented with a sweep-frequency ionospheric sounder, a VLF receiver, an energetic particle experiment, a cosmic noise experiment, and an electrostatic probe. The spacecraft used two long dipole antennas (73 m and 22.8 m, respectively) for the sounder, VLF, and cosmic noise experiments. The satellite was spin-stabilized at about 2.25 rpm after antenna deployment. End plates on the 73 m antenna corrected the rapid despin that had occurred on Alouette 1, and which was believed to result from thermal distortion of the antenna and from radiation pressure. There was no tape recorder, so that data were available only when the spacecraft was in line of sight of telemetry stations. Telemetry stations were located so that primary data coverage was near the 80 deg W meridan plus areas near Hawaii, Singapore, Australia, the UK, India, Norway, and Central Africa. Initially data were recorded about 8 h per day. degradation of the power supply system had, by June 1975, reduced the operating time to about 1/2 h per day. Routine operations were terminated in July 1975. The spacecraft was successfully reactivated on November 28 and 29, 1975, in order to obtain data on its 10th anniversary.
|Type / Application:||Science, ionosphere|
|Power:||Solar cells, batteries|
|Mass:||145 kg (#1), 146 kg (#2)|
|Orbit:||996 km × 1032 km, 80.5° (#1); 505 km × 2987 km, 79.8°|
|Alouette 1||1962 βα 1||29.09.1962||Va 75-1-1||Thor-DM21 Agena-B||with TAVE|
|Alouette 2||1965-098A||29.11.1965||Va 75-1-1||Thor-DM21 Agena-B||with Explorer 31|