NASA is planning the final stages in Cassini's grand trip around Saturn and its many moons, saving the oddest toward the end.

According to Discovery News, Cassini will cap off its mission by flying in close to the small, strangely shaped moon known as Hyperion. The flyby is scheduled to take place Sunday, May 31 at 9:36 a.m. ET.

Hyperion is known for the "spongy" appearance of its composition, but also for its oblong shape. William Cranch Bond, George Phillips Bond and William Lassell discovered Hyperion in 1848 and determined it was the first moon ever spotted that was not round.

Of Saturn's 62 moons, Hyperion is one of only 13 to have diameters greater than 50 kilometers, at 270km. NASA has only obtained photos of one side of Hyperion, so the space agency hopes to capture the opposite to better learn its composition.

"Mission scientists have hopes of seeing different terrain on Hyperion than the mission has previously explored in detail during the encounter, but this is not guaranteed," NASA's Jet Propulsion Laboratory said in a statement. "Hyperion rotates chaotically, essentially tumbling unpredictably through space as it orbits Saturn. Because of this, it's challenging to target a specific region of the moon's surface, and most of Cassini's previous close approaches have encountered more or less the same familiar side of the craggy moon."

Cassini previously flew by Hyperion on Sept. 26, 2005. The spacecraft will flyby Enceladus in Oct. before heading into the final year of its mission.