| Activity | Date |
| Call for proposals for Cosmic Vision missions | March 2007 |
| Selection of L-class candidate missions for assessment studies | October 2007 |
| ESA internal assessment phase, focused on identification of key technology areas | November 2007 - February 2009 |
| Down selection of the two outer Solar System missions | February 2009 |
| Industrial assessment phase and definition of technology development plan | September 2009 - September 2010 |
End of joint Europe-US mission studies Start of European-led reformulation studies | March 2011 |
| Recommendation on mission selection to SPC | April 2012 |
| Selection of first Large mission (L1) | May 2012 |
| Mission launch (L1) | Early 2020's |