We choose to go to the Moon a week after Kennedy's assassination. The idea of a joint Moon mission was abandoned after Kennedy's death, but the Apollo Project became a memorial to him. His goal was fulfilled in July 1969, with the successful Apollo 11 Moon landing. This accomplishment remains an enduring legacy of Kennedy's speech, but his deadline demanded a necessarily narrow focus, and there was no indication of what should be done next once it was achieved. Apollo did not usher in an era of lunar exploration, and no further missions were sent to the Moon after Apollo 17 in 1972. Subsequent planned Apollo missions
Callisto (moon) facilitate remote exploration of Europa, or be an ideal location for a Jovian system waystation servicing spacecraft heading farther into the outer Solar System, using a gravity assist from a close flyby of Jupiter after departing Callisto. In December 2003, NASA reported that a manned mission to Callisto might be possible in the 2040s. Callisto (moon) </math>.</ref> Callisto (Jupiter IV) is the second-largest moon of Jupiter, after Ganymede. It is the third-largest moon in the Solar System after Ganymede and Saturn's largest moon Titan, and the largest object in the Solar System not to be properly differentiated. Callisto was discovered