There were a few problems reported with particles being in the light path of instruments at the Cassegrain focus. The area above the main mirror was checked, and the mirror covers, the sky baffle lid, and the top half meter inside the baffle were cleaned. The inside of the baffle was found to be very dusty. Also, some of seals were found to be flaky, and loose pieces were removed.
A more thorough check, refurbishment and cleaning of the baffle is planned when we aluminise the mirrors coming summer.