Deimos contains a space station that runs an Urenbeck Catapult. It is nominally independently run, but its strategic value causes it to be the scene of the power struggles between BAHRAM and the UNSF.
In 2167, the Deimos Incident takes place; the UNSF's attempt to take control of the Orbital Frame Idolo by holding its researchers hostage ends in disaster when one hostage, Dolores Hayes, is killed, while the other, Rachel Links, escaped to be rescued by BAHRAM. The UNSF suffers heavy casualties, and Idolo's parts would later be salvaged by BAHRAM to make other Orbital Frames.
In 2172, Deimos is occupied by the UNSF as they continue their inspections on Mars for traces of Orbital Frame technological development. However, a group of BAHRAM soldiers led by Radium Lavans and Abu Simbel attack the Urenbeck Catapult, and subsequently use it to launch on a trajectory towards Earth in their ill-fated mission to topple the Earth Orbital Elevator. The Links family attempt to stop him by catching up via the Ender.
By 2174, the Urenbeck Catapult is controlled by BAHRAM, who had installed many unmanned defenses. However, lapses in defenses had somehow allowed the UNSF pilot Taper to inflitrate the station, and with a runaway Jehuty's assistance, escape with intelligence on the Vector Cannon.