ESA has recently issued an announcement of opportunity for new science ideas in the Science Programme. The ESA Director of Science solicits from the broad scientific community proposals for the competitive selection of new "Science Ideas", to be investigated in terms of feasibility and needed technology developments. Full details can be found here. The deadline for submission of letters of intent is 9 May 2016 12:00 CEST.
Since last year, ESO and ESA have agreed closer co-ordination (see the ESO public announcement).
ESA Announcement of Opportunity for New Science Ideas
Published: 15 Feb 2016
Composite image of the galaxy cluster Abell 2744: in X-rays with ESA/XMM-Newton showing the hot gas (red); in optical with WFI on the MPG/ESO 2.2m telescope (white); and dark matter from NASA/ESA & CFHT observations (blue).
ESA image ID 350883. Copyright: ESA, NASA & CFHT.