Meditation spheres were spherical attack craft ten meters in diameter. They resembled giant, floating eyeballs with batlike wings.
At the heart of the meditation sphere used by Naga Sadow was the Sith Lord's meditation chamber. The chamber had jagged walls that sloped inwards and at the center the Sith Lord would crouch and focus his dark side powers that allowed him to amplify his intentions and send them out over great distances to control his armies and ensure victory for his forces. Thanks to the Sphere, the Dark Lord could create Illusions and make them real enough to cause damage, giving him an edge in battle.
In his chamber he was able to see the whole galaxy laid out and monitor the progress of his minions. A giant holoscreen on the wall displayed more detailed tactical information.
Over time, the spheres seemed to have been replaced in use by meditation chambers, some retaining the spherical shape, aboard larger Sith vessels such as Lord Kaan's Nightfall.
Ben Skywalker activated and piloted another Sith Meditation Sphere to escape Ziost during the Second Galactic Civil War. The ship was self-aware and guided Ben with voices over the course of many days. The ship had formerly been piloted by a female of the original Sith species. The ship was armed with a ventral laser cannon and a dorsal magnetic accelerator. Ben also stated that the Meditation Sphere seems to have whatever weapons you wanted.
Once Ben had returned to the Anakin Solo with the Meditation Sphere, Jacen Solo gave the ship to Lumiya. Ben once again spoke with the ship, which was intensely curious as to where all the Sith had gone. After Lumiya's death at the hands of a grief-stricken Luke Skywalker the ship was taken by Alema Rar.
Alema Rar used the sphere to take her to Lumiya's habitat, where she found a chip with the coordinates of Korriban. She used the data on the chip to track down the Sith order hiding on Korriban. She then traveled to Kashyyyk and helped the Anakin Solo escape following their attack on that world.
When Jaina Solo, Zekk, and Jagged Fel tracked Alema Rar to Lumiya's former hideout, Zekk was able to call on the dark side of the Force to convince the sphere to leave Alema's service. The sphere left to find a truly worthy master. Soon after, it was sighted near Ziost by the crew of the Poison Moon, a One Sith frigate under the command of Dician.
Dician spoke with the sphere and ordered it to come with her to Korriban and serve the One Sith. The ship rejected the philosophy of the new Sith order and departed for Kesh to make contact with the Sith there and help build a force to invade the galaxy and strike at the New Jedi Order. Upon the emergence of Abeloth, Ship was forced to do her will, and was hunted by the Jedi in hopes of finding and defeating Abeloth once and for all.