Deimos

Deimos /ˈdaɪmɒs/ (systematic designation: Mars II) is the smaller and outermost of the two natural satellites of Mars, the other being Phobos. Deimos has a mean radius of 6.2 km (3.9 mi) and takes 30.3 hours to orbit Mars. Deimos is 23,460 km (14,580 mi) from Mars, much farther than Mars's other moon, Phobos. It is named after Deimos, the Ancient Greek god and personification of dread and terror, and who is also a son of Ares and Aphrodite and the twin brother of Phobos.
In 2219, the United Space Command set up a military outpost on Deimos for planetary defense. Sometime after the Martian Rebellions in 2380, and Mars' independence from the UNF, Deimos' military base fell under the jurisdiction of the Martian Defense Ministery. However, USC forces are still allowed to station personnel on within the base as long as they abide by Martian military doctrine.