NASA’s Cassini spacecraft flew by Saturn’s spongelike moon Hyperion on Sunday, its last visit before taking a closer look at several other moons as its operational life begins to wind down.

The Cassini spacecraft flew to a distance of about 21,000 mile, which isn’t its closest ever visit but is still quite close, according to a Christian Science Monitor report.

Hyperion is hte largest of the irregularly shaped moons in Saturn’s orbit, and it reaches 255 miles at its widest point. Scientists believe that Hyperion was a chunk of a larger body that was blown off in an impact.

The space rock, which actually has a spongelike appearance, flies in an eccentric orbit around Saturn at about 920,000 miles away, about four times the distance of our moon from the Earth, according to the report.

Scientists expect to get images from that flyby either today or tomorrow.

Hyperion is the eighth largest moon in Saturn’s orbit despite its relatively small size and the fact that it has a porous texture with a very low density — just 50 percent of water, in fact.

Cassini once came within an extremely close distance to Hyperion back in 2005, when it was a mere 310 miles from the space rock.