The BB-series astromech droid, also known as a 33 series astromech and frequently called a BB unit or rollie, represented a model of astromech droid produced by Industrial Automaton and operational during the Cold War period. Its design featured a spherical body, enabling omnidirectional rolling movement, and a head typically positioned atop the body, though not permanently affixed to allow for uninhibited rolling. Similar to earlier astromechs, the BB unit was designed to fit within the droid socket of a starfighter. A well-known example of a BB unit is BB-8, who belonged to the pilot Poe Dameron.
The astromech droid known as the BB-series was powered by a selenium drive. These droids incorporated an internal orbiculate motor, facilitating the spherical body's movement across diverse terrains while maintaining the domed head's position through magnetic casters. Instead of a single tether point, wireless telemetry enabled communication between the droid's two sections. The internal gyroscopic propulsion system featured self-correction capabilities, and surface sensors on the spherical body allowed for navigation across uneven surfaces like deserts. This design offered the advantage of a shell sealed against dust contamination. For challenging terrains, BB units were equipped with compressed liquid-cable launchers for tethering and retrieving the droid from difficult-to-reach areas. Given the droid's body's constant omnidirectional orientation, it primarily required acceleration rather than turning. The dense shell of the BB unit incorporated six interchangeable circular tool-bay disks, compatible with various equipment such as a magnetic-tipped bolt-spinner.
The droid's domed head consisted of a lightweight cranial frame with a prominent, circular primary photoreceptor and a smaller, articulated holoprojector array. The droid's sensors incorporated advanced calibrated synthetic optics. Transmitter and receiver antennae extended from the head's top, and data ports were located above a stainless inoxium band encircling the dome's bottom. Significant force could dislodge the head, but the magnetic casters allowed for rapid reattachment.
BB units were characterized by a dedicated and goal-oriented personality, along with self-preservation protocols. However, certain experienced droids developed strong loyalty subprograms, leading them to engage in risky situations to aid their masters and owners. These droids communicated using droidspeak variants of the most common astromech language. Additionally, BB units possessed a thermal hyperscan vindicator.
The BB-series, manufactured by Industrial Automaton, represented an advancement from ball-shaped droids utilized towards the end of the Galactic Civil War. Examples include prototype therapy droids such as QT-9, which assisted New Republic veterans on Hosnian Prime after the Battle of Endor. This knee-high droid moved on a blue-and-gold body with a square head balanced on top.
The BB-series was in service during the later years of the New Republic, with some units employed by General Leia Organa's Resistance. It was considered a new-model astromech at the time of the attack on Tuanul in 34 ABY. Like its larger, older astromech predecessors, the BB unit was compatible with the astromech socket of starfighters such as the T-70 X-wing starfighter, and was capable of managing on-board flight and power distribution systems. BB-8 served as the trusted companion of Resistance pilot Poe Dameron, who held his droid companion in high regard and ensured the upkeep of BB-8's systems and components. Despite the droid's self-preservation protocols making him somewhat timid and easily startled, his experiences fostered a strong loyalty subprogram, leading BB-8 to accompany Dameron into numerous perilous situations.