MAGION 5

MAGION-5 satellite was launched five years ago, on August 29, 1996, as a part of the INTERBALL Mission with the main goal to study the inner magnetosphere. The planed lifetime of MAGION-5 (68.5 kg) was 18 months but regular sessions with the spacecraft continued till the end of June 2001. The total amount of telemetry data recorded till June 30, 2001 is 41 GB of digital data and over 1500 hours of analog broadband VLF-wave data. The data acquisition continues now in a limited amount only. What happened? MAGION-5 is constructed as a Sun-oriented and spin stabilized s/c. Attitude correction has to be done about twice a week using the onboard cold-gas engine. Since June 29, 2001 the attitude control maneuvers have to be stopped as the compressed gas used as fuell for the jet-engine ran out. The satellite attitude to the Sun is now uncotrolled providing limited and highly variable illumination of the solar array. The Panska Ves control and telemetry station is keeping short sessions with the satellite depending on the current power situation. The telemetry information shows that the onboard systems remain in good condition. Since August 2001 an extended mission part started with housekeeping, technological and reduced scientific data collection.

Launched on August 29,1996 MAGION5 has survived four years in the space and continues in scientific exploration of the auroral regions of the magnetosphere. Regulary everyday sessions with the satellite have been kept from ground telemetry station Panska Ves. Once or two times in a week the attitude correction is done using the onboard gas-jet engine. The predicted gas supply is sufficient for next 12 months.

This month MAGION5 satellite celebrated two years period after its reactivation on May 7, 1998. We continue in data collection of information from scientific instruments and housekeeping systems. As the Sun activity rises, many interested effects were recorded. About twice a week a cold gas-jet engine is used to correct the satellite attitude and to redirect the spin axis towards the Sun. The satellite rotation was risen too and the period was changed from 52 to 30 sec. Despite the high solar activity in last time, the satellite remains in good condition and no significant degradation of solar panels was detected.

At the end of the year 1999 MAGION5 successfully reached its 5000 orbit. As the mother spacecraft INTERBALL 2 is already out of operation, MAGION5 became the main object of the INTERBALL- AURORAL Mission. Since December 22, 1999 MAGION5 have been entering into the Earth”s shadow. Necessary measures were made to avoid freezing of the spacecraft”s systems. More than 19GB of raw telemetry data and more than 1500 hours of analog VLF telemetry were recorded during the year 1999. Now beginning year 2000 MAGION5 is still in good condition, no Y2K problems were encountered and satellite successfully continues its extended operation.

Launched on August 29, 1996, MAGION 5 is now three years in space. The housekeeping and scientific systems remain in good condition and regular data acquisition continues at the TC/TM Station Panska Ves. Just one day before the 3-rd launch anniversary, on 28 August, 1999, the last one of the four booms was successfully deployed together with the last (yet undeployed) solar panel. The first attitude maneuver under this improved configuration was done on 31 August, 1999 at about 06 UT during the orbit No 4550.

One year after reactivation all housekeeping and scientific systems of MAGION 5 satellite are in good condition. Solar panels show some degradation, but it don`t cause energy shortage yet. The satellite is fulfiling scientific program and telemetry station Panska Ves is in regulary contact with it.

MAGION 5, the INTERBALL-Auroral Probe Subsatellite was successfully reactivated on May 7, 1998 after 20 months in space. It was launched on August 29, 1996, together with the INTERBALL 2 spacecraft, the AURORAL PROBE, into an eliptic orbit with apogee 20000km and inclination of 65° as the last one of the four INTERBALL-Project satellites. After only one day of operation, on 30 August, 1996, Magion 5 went out of control and ceased to transmit telemetry data for a critical deficit of power. After analyzing the telemetry data and after spare subsystems laboratory tests it was concluded that the failure was caused by a short circuit in the solar array and it was decided to continue periodically in attempts to reactivate the spacecraft. The first telecommand response from MAGION 5 was achieved at the Panska Ves TC/TM station of the Institute of Atmospheric Physics (Czech Academy of Sci.) on 6 May and on 7 May, 1998, all the principal subsystems of MAGION 5 were successfully activated. The following 10 days were devoted mainly to tests of the power-subsystems, attitude control and housekeeping measurements. Regular data acquisition including housekeeping as well as scientific information was started at Panska Ves on 17 May, 1998. The orbit of MAGION 5 is essentially the same as the orbit of the AURORAL PROBE and the distance between two s/c has been estimated to be about 15 minutes and 20 seconds.