- Spacecraft Brief Description -
ISIS 1 was an ionospheric observatory instrumented with sweep- and
fixed-frequency ionosondes, a VLF receiver, energetic and soft particle
detectors, an ion mass ... spectrometer, an electrostatic probe, an electrostatic
analyzer, a beacon transmitter, and a cosmic noise experiment. The sounder used
two dipole antennas (73 and 18.7 m long). The satellite was spin-stabilized at
about 2.9 rpm after antenna deployment. Some control was exercised over the
spin rate and attitude by using magnetically induced torques to change the spin
rate and to precess the spin axis. A tape recorder with 1-h capacity was
included on the satellite. The satellite could be programmed to take recorded
observations for four different time periods for each full recording period.
The recorder data were dumped only at Ottawa. For non-tape-recorded
observations, data for the satellite and subsatellite regions could be acquired
and telemetered when the spacecraft was in the line of sight of telemetry
stations. The selected telemetry stations were in areas that provided primary
data coverage near the 80-deg-W meridian and in areas near Hawaii, Singapore,
Australia, England, 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 1 operations were terminated in Canada on
March 9, 1984. The Radio Research Laboratories (Tokyo, Japan) then requested
and received permission to reactivate ISIS 1. Regular ISIS 1 operations were
started from Kashima, Japan, in early August 1984. ISIS 1 was deactivated
effective January 24, 1990.
- Auxiliary Information -
Launch Date and Time : 1969-01-30 06:43:00
Epoch Date and Time : 1969-02-04
Apogee (km or AU): 3526.
Perigee (km or AU): 578.
Inclination (degree) : 88.42
Orbit Type : Geocentric
Information last updated on 1992-03-09