A final close flyby of the moon Titan on April 22 used the moon's gravity to reshape Cassini's trajectory so that the spacecraft leapt over the planet's icy rings to pass between the rings and Saturn. During 22 such passes over about five months, the spacecraft's altitude above Saturn's clouds varied from about 1,000 to 2,500 miles (1,600 to 4,000 kilometers), thanks to occasional distant passes by Titan that shifted the closest approach distance. At times, Cassini skirted the very inner edge of the rings; at other times, it skimmed the outer edges of the atmosphere. During its final five orbits, its orbit passed through Saturn's uppermost atmosphere, before finally plunging directly into the planet on Sept. 15.
