Master Thesis - OUFTI-1

In our case, because of the limited available power and the fact that the payloads do
not require a precise attitude control, it was decided to use a passive control system. This
system comprises one permanent magnet, with dimensions of 20 × 4 × 4 mm, made of
AlNiCo 5 (an Aluminum-Nickel-Cobalt alloy) and four hysteretic bars, with dimensions
of 80 × 1 × 1 mm, made of P ermenorm 5000 H2. The principle is the following one: the
permanent magnet tends to align its magnetization axis with the local Earth's magnetic
eld (as shown in Figure 2.10). The hysteretic bars allow to limit, by hysteretic damping,
the rotation rate of the satellite to an acceptable value (which will have to be determined
by tests).
Figure 2.10: Principle of the OUFTI-1 ADCS subsystem [25]
Last year, a solution with only two hysteretic bars was implemented (the conguration
is available in Figure 2.11).
Figure 2.11: Last year's conguration of the ADCS
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