Isis 2

Canada

International Sat. n°:

Canadian satellite n°: 4

Launch data

Designation05104 / 71024A
Launch date 01 Apr 1971 - 02:57:07 UT
Launch site:Va, SLC-2E
Launch vehicle Delta-E1 (#491/D84)
MissionScientific: ionosphere study
Earth orbit on:
Perigee/Apogee 1353/1423 km
Inclination 88.5°
Period 113.5 min

Spacecraft data:

Prime manufactor CA Victor Co., Montreal
Platform 
Operator CSA
Mass at launch  262 kg
Dry Mass  kg
Basic shape  
Dimension (m) 
Equipment 
Solar array 
Stabilization  
Propulsion 
DC power  
Design lifetime  

Description:

ISIS 2 was an ionospheric observatory instrumented with a sweep- and a fixed-frequency ionosonde, a VLF receiver, energetic and soft particle detectors, an ion mass spectrometer, an electrostatic probe, a retarding potential analyzer, a beacon transmitter, a cosmic noise experiment, and two photometers. Two long crossed-dipole antennas (73 and 18.7 m) were used for the sounding, VLF, and cosmic noise experiments. The spacecraft was spin-stabilized to about 2 rpm after antenna deployment. There were two basic orientation modes for the spacecraft, cartwheel and orbit-aligned. The spacecraft operated approximately the same length of time in each mode, remaining in one mode typically 3 to 5 months. The cartwheel mode with the axis perpendicular to the orbit plane was made available to provide ram and wake data for some experiments for each spin period, rather than for each orbit period. Attitude and spin information was obtained from a three-axis magnetometer and a sun sensor. Control of attitude and spin was possible by means of magnetic torquing. The experiment package also included a programmable tape recorder with a 1-h capacity. For nonrecorded observations, data from satellite and subsatellite regions were telemetered when the spacecraft was in the line of sight of a telemetry station. Telemetry stations were located so that primary data coverage was near the 80-deg-W meridian and near Hawaii, Singapore, Australia, England, France, Norway, India, Japan, Antarctica, New Zealand, and Central Africa. NASA support of the ISIS project was terminated on October 1, 1979. A significant amount of experimental data, however, was acquired after this date by the Canadian project team. ISIS 2 operations were terminated in Canada on March 9, 1984. The Radio Research Laboratories (Tokyo, Japan) then requested and received permission to reactivate ISIS 2. Regular ISIS 2 operations were started from Kashima, Japan, in early August 1984. ISIS 2 was deactivated effective 24, 1990.
Ref: #7, #14 - update: 19.09.11