  We present the lessons learned about the degradation observed in several
space solar missions, based on contributions at the Workshop about On-Orbit
Degradation of Solar and Space Weather Instruments that took place at the Solar
Terrestrial Centre of Excellence (Royal Observatory of Belgium) in Brussels on
3 May 2012. The aim of this workshop was to open discussions related to the
degradation observed in Sun-observing instruments exposed to the effects of the
space environment. This article summarizes the various lessons learned and
offers recommendations to reduce or correct expected degradation with the goal
of increasing the useful lifespan of future and ongoing space missions.
