Magion 2 was manufactured as the subsatellite of the ACTIVE
(Intercosmos 24) spacecraft and as the first subsatellite of a series of international
scientific projects ACTIVE, APEX,
INTERBALL. As opposed to Magion 1 this spacecraft series with
weight up to 65 kg had the form of a simmetrical polyhedron, had a set of folding booms
for sensors, has digital system of data collection and had a gasjet propulsion engine. The
scientific goal of the subsatellite of the ACTIVE project
was to investigate space structure of physical phenomena which accompany plasma injection
and to investigate powerful ULF emission into the magnetosphere as in a near (up to 10 km)
zone, as well as in middle and far zones of the main spacecraft on which active injecting
devices were mounted.
The Magion 3 spacecraft was manufactured as the subsatellite of the APEX (Intercosmos 25) spacecraft. The APEX project had the following primary objectives:
Simulation and initiation of aurora and radio frequency radiation in the auroral area;
study of the dinamics of modulated beams and plasmoids in the near - earth plasma; study
of the nature of electrodinamic relationship of electromagnetic waves in magnetosphere and
ionosphere; determination of radio emission characteristics of modulated beams of charged
particles and plasmoids; search for non-linear wave structures of the electromagnetic
soliton type in disturbed environment. The Magion 3 scientific payload was almost the same
as for Magion 2.
The Interball Project is a multi-national effort that consists of four spacecraft: two
main spacecraft of the Prognoz series (Interbol 1, 2), made
in Russia, each with a small subsatellite made in Czechoslovakia. The main objective is to
study the physical mechanisms responsible for the transmission of solar wind energy to the
magnetosphere, its storage there, and subsequent dissipation in the tail and auroral
regions of the magnetosphere, ionosphere, and atmosphere during magnetospheric substorms.
A ground-based support group will provide coordinated and simultaneous ground-based data
of many types, including observations from auroral and polar cap regions. Interball is an
IACG-related mission. Key physical parameters will be generated, and will be available for
exchange with other projects. Campaigns for intercomparison with the Wind
and Geotail spacecraft are expected. One pair of spacecraft,
Tail Probe and its subsatellite Magion 4 or S2-X (X for the first letter of the Russian word for
``Tail''), was launched into the magnetospheric tail. The second pair, Auroral Probe
and Magion 5 or S2-A (A for ``Auroral''), will have an orbit that crosses the auroral oval to observe
the acceleration of auroral particles and the flow of electric currents that connect the
magnetospheric tail with the conducting ionosphere. To study the equilibrium tail
structure, during about half of each year the Tail Probe pair will cross the main parts of
the magnetotail every four days. The Tail Probe, with approximately 30 earth radii apogee,
will cross the noon-midnight plane on December 1, so the measurements in the magnetotail
will cover the period from October 1995 to February 1996. The Auroral Probe pair will
support the Tail Probe pair with auroral region measurements.
The subsatellites are small, each with about ten scientific instruments. The spin axis
will be directed within 10 degrees of the sun, with a spin period of ~120 s, as with the
main spacecraft. The subsatellites also carry gas-jet thrusters for limited control of the
orbit. Separation distance will range from hundreds of kilometers to several tens of
thousands of kilometers for the Tail Probe pair. Separation distance will range from
hundreds of meters to hundreds of kilometers for the Auroral Probe pair. The Tail Probe
has two telemetry systems, at up to 32 Kbps in real-time, with a memory mode capacity of
30 Mb in the RTK telemetry system and 120 Mb in the SSNI system. The Auroral Probe has
similar capability plus the additional real-time-only STO system, capable of 40 Kbps. Each
subsatellite has only the STO real-time telemetry system. For S2-X the rate can be varied
from 2-40 kbps.