 The Europa Jupiter System Mission ( EJSM ) was a joint NASA / ESA proposal for exploration of Jupiter and its moons . In February 2009 it was announced that both space agencies had given this mission priority ahead of the Titan Saturn System Mission . The proposal included a launch date of around 2020 and consists of the NASA @-@ led Jupiter Europa Orbiter , and the ESA @-@ led Jupiter Ganymede Orbiter . ESA 's contribution had encountered funding competition from other ESA projects . However , the Jupiter Europa Orbiter ( JEO ) , NASA 's contribution , was considered by the Planetary Decadal Survey to be too expensive . The survey supported a cheaper alternative to JEO . 
 The Europa Jupiter System Mission ( EJSM ) was a joint NASA / ESA proposal for exploration of Jupiter and its moons . In February 2009 it was announced that both space agencies <a href='been_done' title='1'><mark>had</mark></a> given this mission priority ahead of the Titan Saturn System Mission . The proposal included a launch date of around 2020 and <a href='uninflect' title='2'><mark>consists</mark></a> of the NASA @-@ led Jupiter Europa Orbiter , and the ESA @-@ led Jupiter Ganymede Orbiter . ESA <a href='null_genetive' title='3'><mark>'s</mark></a>contribution <a href='been_done' title='4'><mark>had</mark></a> encountered funding competition from other ESA projects . However , the Jupiter Europa Orbiter ( JEO ) , NASA <a href='null_genetive' title='5'><mark>'s</mark></a>contribution , was considered by the Planetary Decadal Survey to be too expensive . The survey supported a cheaper alternative to JEO . 
Da Europa Jupiter System Mission ( EJSM ) was a joint NASA / ESA proposal for exploration of Jupiter and its moons . In February 2009 it was announced dat both space agencies done given this mission priority ahead of tdaTitan Saturn System Mission . The proposal included a launch date of around 2020 and consist of the NASA @-@ led Jupiter Europa Orbiter , and the ESA @-@ led Jupiter Ganymede Orbiter . ESA  contribution done encountered funding competition from other ESA projects . However , thdaupiter Europa Orbiter ( JEO ) , NASA  contribution , was considered by the Planetary Decadal Survey to be too expensive . Thedarvey supported a cheaper alternative to JEO .