Left – frequency spectrum of the temperature of the bolometer plate, measured in flight (red) and on the ground (blue). Right – spectrum of the flight measurements over a wider frequency range. The shoulder on the low frequency side is due to the temperature fluctuations described in Fig. 30. The bump in the 10^-2 to 10^-3 Hz range seen, also seen in the left panel but only in the flight curve, is probably associated with the effect of cosmic rays in the bolometer structures.