Marie Dominique is the LYRA-keeper at the STCE. She keeps an eye on the telescope and especially how it ages because of the hostile space environment. PROBA2, the satellite with LYRA onboard, orbits Earth at a height of around 750 km. So, it is protected by the Earth magnetic field but still, it has to pass through places with particles bombarding the spacecraft and the telescope. On top of this, part of the solar light imposes extra stress on the telescope.
A risky job, there out in space.
Update on our understanding of the degradation of LYRA
LYRA has been operating onboard PROBA2 since end 2009 and has covered the full solar cycle 24. During those 11 years, the instrument has experienced aging, which affects its performances. Since its launch, regular calibration campaigns have allowed to track the evolution of the instrument dark current and of the response to on-board calibration sources. The main source of degradation has long been identified as the deposit of a contaminant layer on the filter surface. Comparing the way this contaminant layer modifies the response of each of the four LYRA channels allows us to get information about the type of contaminant and the thickness of the layer. However, it seems that some channels do not fit the overall picture. I will present an update of what we've learnt about the aging processes affecting the LYRA instrument.
If you want to join for the seminar, please contact petra.vanlommel at oma.be
