Left – temperature of LFI focal plane sensors TSL1 to TSL6 (see Fig. 31) in the period from 125 to 389 days after launch. Until intentional changes in the TSA setpoint started around day 350, the temperature shows only the slow drift correlated with distance from the Sun. See also Fig. 35. Right – temperature of the LFI backend sensors (left backend block sensors) in the period from 125 to 389 days after launch. Until day 259, the transponder was on only during downlinks. This approximately diurnal variation drove a large periodic variation in temperature. After day 259, the transponder was left on continuously, and the daily temperature variations became much smaller.