In February 2008, ESA and NASA initiated joint studies of two alternatives for a highly capable scientific mission to the outer planets: one to the Jupiter system focused on the moons Europa and Ganymede and the other to the Saturn system focused on Titan. Joint Science Definition Teams (JSDTs) were formed with U.S. and European membership to guide the study activities that were conducted collaboratively by engineering teams working on both sides of the Atlantic.

The agencies reached a joint decision on the destination for the first mission and announced this decision on February 18, 2009.They prioritized the targets with Jupiter-Europa-Ganymede to come first and Titan-Saturn to come next. NASA and ESA are now working together on the Europa Jupiter System Mission concept with a nominal 2020 launch date. NASA is continuing to develop the technologies for a Titan mission with Titan risk reduction and focused studies targeted at a later launch date.

The Jet Propulsion Laboratory, in partnership with the Applied Physics Laboratory of Johns Hopkins University, is leading the studies.

This portal is intended to provide information on the status and results of the studies and to alert the community at large to important workshops and other events which are supporting the program.